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Sample records for body size variation

  1. Body weight in relation to variation in body size of Oystercatchers Haematopus ostralegus

    NARCIS (Netherlands)

    Zwarts, L; Hulscher, JB; Koopman, K; Zegers, PM

    1996-01-01

    This paper analyses the relationships between body weight in the Oystercatcher and two measures of its body size, bill length and wing length. The weight variation between individuals due to differences in body size is nearly as large as the seasonal variation in body weight within individuals. Wing

  2. Spatial and temporal variation of body size among early Homo.

    Science.gov (United States)

    Will, Manuel; Stock, Jay T

    2015-05-01

    The estimation of body size among the earliest members of the genus Homo (2.4-1.5Myr [millions of years ago]) is central to interpretations of their biology. It is widely accepted that Homo ergaster possessed increased body size compared with Homo habilis and Homo rudolfensis, and that this may have been a factor involved with the dispersal of Homo out of Africa. The study of taxonomic differences in body size, however, is problematic. Postcranial remains are rarely associated with craniodental fossils, and taxonomic attributions frequently rest upon the size of skeletal elements. Previous body size estimates have been based upon well-preserved specimens with a more reliable species assessment. Since these samples are small (n Koobi Fora after 1.7Myr, indicating regional size variation. The significant body size differences between specimens from Koobi Fora and Olduvai support the cranial evidence for at least two co-existing morphotypes in the Early Pleistocene of eastern Africa. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Variation of Body Size in Rice Water Weevil (Coleoptera: Curculionidae) and Its Associations with Population Biology

    OpenAIRE

    Huang, Yunshan; Ao, Yan; Jiang, Mingxing; Way, Michael O

    2018-01-01

    Abstract Life history characteristics help us to determine the ability of invasive species to establish and thrive in an exotic environment. However, so far, there have been very few reports concerning geographic variation in the body size of invasive insects and the associations between body size variation and population biology. In this study, we surveyed the geographic variation in body size of an invasive agricultural pest, the rice water weevil Lissorhoptrus oryzophilus Kuschel (Coleopte...

  4. Geographical variation in body size and sexual size dimorphism in an Australian lizard, Boulenger's Skink (Morethia boulengeri).

    Science.gov (United States)

    Michael, Damian R; Banks, Sam C; Piggott, Maxine P; Cunningham, Ross B; Crane, Mason; MacGregor, Christopher; McBurney, Lachlan; Lindenmayer, David B

    2014-01-01

    Ecogeographical rules help explain spatial and temporal patterns in intraspecific body size. However, many of these rules, when applied to ectothermic organisms such as reptiles, are controversial and require further investigation. To explore factors that influence body size in reptiles, we performed a heuristic study to examine body size variation in an Australian lizard, Boulenger's Skink Morethia boulengeri from agricultural landscapes in southern New South Wales, south-eastern Australia. We collected tissue and morphological data on 337 adult lizards across a broad elevation and climate gradient. We used a model-selection procedure to determine if environmental or ecological variables best explained body size variation. We explored the relationship between morphology and phylogenetic structure before modeling candidate variables from four broad domains: (1) geography (latitude, longitude and elevation), (2) climate (temperature and rainfall), (3) habitat (vegetation type, number of logs and ground cover attributes), and (4) management (land use and grazing history). Broad phylogenetic structure was evident, but on a scale larger than our study area. Lizards were sexually dimorphic, whereby females had longer snout-vent length than males, providing support for the fecundity selection hypothesis. Body size variation in M. boulengeri was correlated with temperature and rainfall, a pattern consistent with larger individuals occupying cooler and more productive parts of the landscape. Climate change forecasts, which predict warmer temperature and increased aridity, may result in reduced lizard biomass and decoupling of trophic interactions with potential implications for community organization and ecosystem function.

  5. Life course variations in the heritability of body size

    DEFF Research Database (Denmark)

    Zhao, J.; Luan, J.A.; Sharp, S.J.

    aim was to use this approach to investigate the life course variations in heritability of body size. Methods: We analysed height, weight and body mass index variables at 11 time-points in 2,452 individuals (1,225 men, 1,227 women) born in 1946 and enrolled in the MRC National Survey of Health...... and Development (NSHD), with genotypes at 147,949 single nucleotide polymorphisms (SNPs) on Metabochips which were subsequently imputed to 506,255 according to the 1000Genomes project. We obtained genome-wide kinship matrices using genotypes at SNPs on Metabochips and genotypes at all SNPs, which were used.......11(0-0.20), 0.10(0-0.22) for height, weight and body mass index, respectively. Variation in estimates was also seen between alternative procedures. Conclusion: This work supports the utility of large-scale genotype data in heritability estimation and highlights the age-related variability in genetic...

  6. Body Size Adaptations to Altitudinal Climatic Variation in Neotropical Grasshoppers of the Genus Sphenarium (Orthoptera: Pyrgomorphidae)

    Science.gov (United States)

    2015-01-01

    Altitudinal clines in body size can result from the effects of natural and sexual selection on growth rates and developing times in seasonal environments. Short growing and reproductive seasons constrain the body size that adults can attain and their reproductive success. Little is known about the effects of altitudinal climatic variation on the diversification of Neotropical insects. In central Mexico, in addition to altitude, highly heterogeneous topography generates diverse climates that can occur even at the same latitude. Altitudinal variation and heterogeneous topography open an opportunity to test the relative impact of climatic variation on body size adaptations. In this study, we investigated the relationship between altitudinal climatic variation and body size, and the divergence rates of sexual size dimorphism (SSD) in Neotropical grasshoppers of the genus Sphenarium using a phylogenetic comparative approach. In order to distinguish the relative impact of natural and sexual selection on the diversification of the group, we also tracked the altitudinal distribution of the species and trends of both body size and SSD on the phylogeny of Sphenarium. The correlative evidence suggests no relationship between altitude and body size. However, larger species were associated with places having a warmer winter season in which the temporal window for development and reproduction can be longer. Nonetheless, the largest species were also associated with highly seasonal environments. Moreover, large body size and high levels of SSD have evolved independently several times throughout the history of the group and male body size has experienced a greater evolutionary divergence than females. These lines of evidence suggest that natural selection, associated with seasonality and sexual selection, on maturation time and body size could have enhanced the diversification of this insect group. PMID:26684616

  7. Population-based resequencing of experimentally evolved populations reveals the genetic basis of body size variation in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Thomas L Turner

    2011-03-01

    Full Text Available Body size is a classic quantitative trait with evolutionarily significant variation within many species. Locating the alleles responsible for this variation would help understand the maintenance of variation in body size in particular, as well as quantitative traits in general. However, successful genome-wide association of genotype and phenotype may require very large sample sizes if alleles have low population frequencies or modest effects. As a complementary approach, we propose that population-based resequencing of experimentally evolved populations allows for considerable power to map functional variation. Here, we use this technique to investigate the genetic basis of natural variation in body size in Drosophila melanogaster. Significant differentiation of hundreds of loci in replicate selection populations supports the hypothesis that the genetic basis of body size variation is very polygenic in D. melanogaster. Significantly differentiated variants are limited to single genes at some loci, allowing precise hypotheses to be formed regarding causal polymorphisms, while other significant regions are large and contain many genes. By using significantly associated polymorphisms as a priori candidates in follow-up studies, these data are expected to provide considerable power to determine the genetic basis of natural variation in body size.

  8. Microgeographic body size variation in a high elevation Andean anole (Anolis mariarum; Squamata, Polychrotidae

    Directory of Open Access Journals (Sweden)

    Brian C Bock

    2009-12-01

    Full Text Available Intra-specific body size variation is common and often is assumed to be adaptive. Studies of body size variation among sites should include or consider environmental and ecological variables in their designs. Additionally, reciprocal transplant or common garden studies will support which variables are really contributing to the observed body size variation. This study analyzed the microgeographic body size variation in Anolis mariarum, a small lizard endemic to Antioquia, Colombia. Parameters such as body size, shape, and lepidosis variation were quantified in 217 adult A. mariarum, belonging to six populations separated by less than 80km. Results showed that significant body size variation was not related to differences among sites in mean annual temperature, but covaried with mean annual precipitation, with the largest individuals occurring in dryer sites. Mark-recapture data obtained from 115 individuals from both the wettest and dryest sites from October 2004 to April 2005 showed that growth rates were higher at the latter. Eight males from each site were captured at the end of the mark- recapture study and reared for two months under identical conditions in a common garden study. Individuals from both sites grew faster when reared in the laboratory with food provided ad libitum. Although growth rates of males from the two populations did not differ significantly in the laboratory, males from the dryest site still maintained a significantly larger asymptotic body size in their growth trajectories. Multivariate analyses also demonstrated that both males and females from the six populations differed in terms of body shape and lepidosis. However, only female body size was found to covary significantly with an environmental gradient (precipitation. A. mariarum does not conform to Bergmann’s rule, but the relationship found between mean body size and asympotic growth with mean annual precipitation at these sites needs further analysis

  9. The genetic basis of natural variation in mushroom body size in Drosophila melanogaster.

    Science.gov (United States)

    Zwarts, Liesbeth; Vanden Broeck, Lies; Cappuyns, Elisa; Ayroles, Julien F; Magwire, Michael M; Vulsteke, Veerle; Clements, Jason; Mackay, Trudy F C; Callaerts, Patrick

    2015-12-11

    Genetic variation in brain size may provide the basis for the evolution of the brain and complex behaviours. The genetic substrate and the selective pressures acting on brain size are poorly understood. Here we use the Drosophila Genetic Reference Panel to map polymorphic variants affecting natural variation in mushroom body morphology. We identify 139 genes and 39 transcription factors and confirm effects on development and adult plasticity. We show correlations between morphology and aggression, sleep and lifespan. We propose that natural variation in adult brain size is controlled by interaction of the environment with gene networks controlling development and plasticity.

  10. Geographic variation in body size and its relationship with environmental gradients in the Oriental Garden Lizard, Calotes versicolor.

    Science.gov (United States)

    Wei, Xiaomei; Yan, Linmiao; Zhao, Chengjian; Zhang, Yueyun; Xu, Yongli; Cai, Bo; Jiang, Ni; Huang, Yong

    2018-05-01

    Patterns of geographic variation in body size are predicted to evolve as adaptations to local environmental gradients. However, many of these clinal patterns in body size, such as Bergmann's rule, are controversial and require further investigation into ectotherms such as reptiles on a regional scale. To examine the environmental variables (temperature, precipitation, topography and primary productivity) that shaped patterns of geographic variation in body size in the reptile Calotes versicolor , we sampled 180 adult specimens (91 males and 89 females) at 40 locations across the species range in China. The MANOVA results suggest significant sexual size dimorphism in C. versicolor ( F 23,124  = 11.32, p  body size of C. versicolor differed for males and females, but mechanisms related to heat balance and water availability hypotheses were involved in both sexes. Temperature seasonality, precipitation of the driest month, precipitation seasonality, and precipitation of the driest quarter were the most important predictors of variation in body size in males, whereas mean precipitation of the warmest quarter, mean temperature of the wettest quarter, precipitation seasonality, and precipitation of the wettest month were most important for body size variation in females. The discrepancy between patterns of association between the sexes suggested that different selection pressures may be acting in males and females.

  11. Comparison of organ doses in human phantoms: variations due to body size and posture

    International Nuclear Information System (INIS)

    Feng, Xu; Xiang-Hong, Jia; Xue-Jun, Yu; Zhan-Chun, Pan; Qian, Liu; Chun-Xin, Yang

    2017-01-01

    Organ dose calculations performed using human phantoms can provide estimates of astronauts' health risks due to cosmic radiation. However, the characteristics of such phantoms strongly affect the estimation precision. To investigate organ dose variations with body size and posture in human phantoms, a non-uniform rational B-spline boundary surfaces model was constructed based on cryo-section images. This model was used to establish four phantoms with different body size and posture parameters, whose organs parameters were changed simultaneously and which were voxelised with 4x4x4 mm"3 resolution. Then, using Monte Carlo transport code, the organ doses caused by ≤500 MeV isotropic incident protons were calculated. The dose variations due to body size differences within a certain range were negligible, and the doses received in crouching and standing-up postures were similar. Therefore, a standard Chinese phantom could be established, and posture changes cannot effectively protect astronauts during solar particle events. (authors)

  12. Intraspecific Variation in Maximum Ingested Food Size and Body Mass in Varecia rubra and Propithecus coquereli

    Directory of Open Access Journals (Sweden)

    Adam Hartstone-Rose

    2011-01-01

    Full Text Available In a recent study, we quantified the scaling of ingested food size (Vb—the maximum size at which an animal consistently ingests food whole—and found that Vb scaled isometrically between species of captive strepsirrhines. The current study examines the relationship between Vb and body size within species with a focus on the frugivorous Varecia rubra and the folivorous Propithecus coquereli. We found no overlap in Vb between the species (all V. rubra ingested larger pieces of food relative to those eaten by P. coquereli, and least-squares regression of Vb and three different measures of body mass showed no scaling relationship within each species. We believe that this lack of relationship results from the relatively narrow intraspecific body size variation and seemingly patternless individual variation in Vb within species and take this study as further evidence that general scaling questions are best examined interspecifically rather than intraspecifically.

  13. Variations in otolith patterns, sizes and body morphometrics of jack mackerel Trachurus japonicus juveniles.

    Science.gov (United States)

    Kanaji, Y; Kishida, M; Watanabe, Y; Kawamura, T; Xie, S; Yamashita, Y; Sassa, C; Tsukamoto, Y

    2010-10-01

    Variations in otolith patterns, sizes and body morphometrics of jack mackerel Trachurus japonicus juveniles were investigated. Under transmitted light, translucent (W(t)) and opaque otoliths (W(o)) were detected in juveniles collected from Wakasa Bay between July 2005 and April 2006, whereas only opaque otoliths (G(o)) were detected in Goto-nada Sea individuals between May and June 2006. Three groups of juveniles were distinguished based on differences in hatch season, otolith size and growth history, and body morphometrics. As T. japonicus has different spawning seasons according to spawning grounds, each group was estimated to hatch in different waters. Juveniles with W(t) otoliths were considered to have stayed in coastal habitat longer, as the hatch area was estimated to be near Wakasa Bay. Juveniles with W(o) and G(o) otoliths appear to recruit to coastal waters at larger size, since their hatch areas were estimated to be far from each collection area. Larger otoliths of W(t) were attributed to otolith accretion after the second growth flexion, which was observed only for W(t) . Standard length of W(t) fish at the second otolith growth flexion was estimated to correspond to recruitment size to coastal rocky reefs in Wakasa Bay. Body morphometrics were correlated with otolith size after removing body size effect, suggesting that morphological variations of T. japonicus juveniles were also associated with the timing of recruitment to coastal habitat. © 2010 The Authors. Journal compilation © 2010 The Fisheries Society of the British Isles.

  14. Body size and allometric shape variation in the molly Poecilia vivipara along a gradient of salinity and predation.

    Science.gov (United States)

    Araújo, Márcio S; Perez, S Ivan; Magazoni, Maria Julia C; Petry, Ana C

    2014-12-04

    Phenotypic diversity among populations may result from divergent natural selection acting directly on traits or via correlated responses to changes in other traits. One of the most frequent patterns of correlated response is the proportional change in the dimensions of anatomical traits associated with changes in growth or absolute size, known as allometry. Livebearing fishes subject to predation gradients have been shown to repeatedly evolve larger caudal peduncles and smaller cranial regions under high predation regimes. Poecilia vivipara is a livebearing fish commonly found in coastal lagoons in the north of the state of Rio de Janeiro, Brazil. Similar to what is observed in other predation gradients, lagoons inhabited by P. vivipara vary in the presence of piscivorous fishes; contrary to other poeciliid systems, populations of P. vivipara vary greatly in body size, which opens the possibility of strong allometric effects on shape variation. Here we investigated body shape diversification among six populations of P. vivipara along a predation gradient and its relationship with allometric trajectories within and among populations. We found substantial body size variation and correlated shape changes among populations. Multivariate regression analysis showed that size variation among populations accounted for 66% of shape variation in females and 38% in males, suggesting that size is the most important dimension underlying shape variation among populations of P. vivipara in this system. Changes in the relative sizes of the caudal peduncle and cranial regions were only partly in line with predictions from divergent natural selection associated with predation regime. Our results suggest the possibility that adaptive shape variation among populations has been partly constrained by allometry in P. vivipara. Processes governing body size changes are therefore important in the diversification of this species. We conclude that in species characterized by substantial

  15. Beyond body size: muscle biochemistry and body shape explain ontogenetic variation of anti-predatory behaviour in the lizard Salvator merianae.

    Science.gov (United States)

    de Barros, Fábio Cury; de Carvalho, José Eduardo; Abe, Augusto Shinya; Kohlsdorf, Tiana

    2016-06-01

    Anti-predatory behaviour evolves under the strong action of natural selection because the success of individuals avoiding predation essentially defines their fitness. Choice of anti-predatory strategies is defined by prey characteristics as well as environmental temperature. An additional dimension often relegated in this multilevel equation is the ontogenetic component. In the tegu Salvator merianae, adults run away from predators at high temperatures but prefer fighting when it is cold, whereas juveniles exhibit the same flight strategy within a wide thermal range. Here, we integrate physiology and morphology to understand ontogenetic variation in the temperature-dependent shift of anti-predatory behaviour in these lizards. We compiled data for body shape and size, and quantified enzyme activity in hindlimb and head muscles, testing the hypothesis that morphophysiological models explain ontogenetic variation in behavioural associations. Our prediction is that juveniles exhibit body shape and muscle biochemistry that enhance flight strategies. We identified biochemical differences between muscles mainly in the LDH:CS ratio, whereby hindlimb muscles were more glycolytic than the jaw musculature. Juveniles, which often use evasive strategies to avoid predation, have more glycolytic hindlimb muscles and are much smaller when compared with adults 1-2 years old. Ontogenetic differences in body shape were identified but marginally contributed to behavioural variation between juvenile and adult tegus, and variation in anti-predatory behaviour in these lizards resides mainly in associations between body size and muscle biochemistry. Our results are discussed in the ecological context of predator avoidance by individuals differing in body size living at temperature-variable environments, where restrictions imposed by the cold could be compensated by specific phenotypes. © 2016. Published by The Company of Biologists Ltd.

  16. Rule reversal: Ecogeographical patterns of body size variation in the common treeshrew (Mammalia, Scandentia)

    Science.gov (United States)

    Sargis, Eric J.; Millien, Virginie; Woodman, Neal; Olson, Link E.

    2018-01-01

    There are a number of ecogeographical “rules” that describe patterns of geographical variation among organisms. The island rule predicts that populations of larger mammals on islands evolve smaller mean body size than their mainland counterparts, whereas smaller‐bodied mammals evolve larger size. Bergmann's rule predicts that populations of a species in colder climates (generally at higher latitudes) have larger mean body sizes than conspecifics in warmer climates (at lower latitudes). These two rules are rarely tested together and neither has been rigorously tested in treeshrews, a clade of small‐bodied mammals in their own order (Scandentia) broadly distributed in mainland Southeast Asia and on islands throughout much of the Sunda Shelf. The common treeshrew, Tupaia glis, is an excellent candidate for study and was used to test these two rules simultaneously for the first time in treeshrews. This species is distributed on the Malay Peninsula and several offshore islands east, west, and south of the mainland. Using craniodental dimensions as a proxy for body size, we investigated how island size, distance from the mainland, and maximum sea depth between the mainland and the islands relate to body size of 13 insular T. glis populations while also controlling for latitude and correlation among variables. We found a strong negative effect of latitude on body size in the common treeshrew, indicating the inverse of Bergmann's rule. We did not detect any overall difference in body size between the island and mainland populations. However, there was an effect of island area and maximum sea depth on body size among island populations. Although there is a strong latitudinal effect on body size, neither Bergmann's rule nor the island rule applies to the common treeshrew. The results of our analyses demonstrate the necessity of assessing multiple variables simultaneously in studies of ecogeographical rules.

  17. Variation in male body size and reproductive allocation in the leafcutter ant Atta colombica

    DEFF Research Database (Denmark)

    Stürup, M.; den Boer, S. P. A.; Nash, David Richard

    2011-01-01

    species. In 2008 and 2009, we revisited a Panamanian population of Atta colombica leafcutter ants to partially repeat and complement a study of more than 15 years ago. We compared within- and between-colony variation in male body size (mass and width of head, mesosoma and gaster) and sperm characteristics...

  18. Body size and allometric variation in facial shape in children.

    Science.gov (United States)

    Larson, Jacinda R; Manyama, Mange F; Cole, Joanne B; Gonzalez, Paula N; Percival, Christopher J; Liberton, Denise K; Ferrara, Tracey M; Riccardi, Sheri L; Kimwaga, Emmanuel A; Mathayo, Joshua; Spitzmacher, Jared A; Rolian, Campbell; Jamniczky, Heather A; Weinberg, Seth M; Roseman, Charles C; Klein, Ophir; Lukowiak, Ken; Spritz, Richard A; Hallgrimsson, Benedikt

    2018-02-01

    Morphological integration, or the tendency for covariation, is commonly seen in complex traits such as the human face. The effects of growth on shape, or allometry, represent a ubiquitous but poorly understood axis of integration. We address the question of to what extent age and measures of size converge on a single pattern of allometry for human facial shape. Our study is based on two large cross-sectional cohorts of children, one from Tanzania and the other from the United States (N = 7,173). We employ 3D facial imaging and geometric morphometrics to relate facial shape to age and anthropometric measures. The two populations differ significantly in facial shape, but the magnitude of this difference is small relative to the variation within each group. Allometric variation for facial shape is similar in both populations, representing a small but significant proportion of total variation in facial shape. Different measures of size are associated with overlapping but statistically distinct aspects of shape variation. Only half of the size-related variation in facial shape can be explained by the first principal component of four size measures and age while the remainder associates distinctly with individual measures. Allometric variation in the human face is complex and should not be regarded as a singular effect. This finding has important implications for how size is treated in studies of human facial shape and for the developmental basis for allometric variation more generally. © 2017 Wiley Periodicals, Inc.

  19. Additive genetic variation in the craniofacial skeleton of baboons (genus Papio) and its relationship to body and cranial size.

    Science.gov (United States)

    Joganic, Jessica L; Willmore, Katherine E; Richtsmeier, Joan T; Weiss, Kenneth M; Mahaney, Michael C; Rogers, Jeffrey; Cheverud, James M

    2018-02-01

    Determining the genetic architecture of quantitative traits and genetic correlations among them is important for understanding morphological evolution patterns. We address two questions regarding papionin evolution: (1) what effect do body and cranial size, age, and sex have on phenotypic (V P ) and additive genetic (V A ) variation in baboon crania, and (2) how might additive genetic correlations between craniofacial traits and body mass affect morphological evolution? We use a large captive pedigreed baboon sample to estimate quantitative genetic parameters for craniofacial dimensions (EIDs). Our models include nested combinations of the covariates listed above. We also simulate the correlated response of a given EID due to selection on body mass alone. Covariates account for 1.2-91% of craniofacial V P . EID V A decreases across models as more covariates are included. The median genetic correlation estimate between each EID and body mass is 0.33. Analysis of the multivariate response to selection reveals that observed patterns of craniofacial variation in extant baboons cannot be attributed solely to correlated response to selection on body mass, particularly in males. Because a relatively large proportion of EID V A is shared with body mass variation, different methods of correcting for allometry by statistically controlling for size can alter residual V P patterns. This may conflate direct selection effects on craniofacial variation with those resulting from a correlated response to body mass selection. This shared genetic variation may partially explain how selection for increased body mass in two different papionin lineages produced remarkably similar craniofacial phenotypes. © 2017 Wiley Periodicals, Inc.

  20. Size Matters: Individual Variation in Ectotherm Growth and Asymptotic Size

    Science.gov (United States)

    King, Richard B.

    2016-01-01

    Body size, and, by extension, growth has impacts on physiology, survival, attainment of sexual maturity, fecundity, generation time, and population dynamics, especially in ectotherm animals that often exhibit extensive growth following attainment of sexual maturity. Frequently, growth is analyzed at the population level, providing useful population mean growth parameters but ignoring individual variation that is also of ecological and evolutionary significance. Our long-term study of Lake Erie Watersnakes, Nerodia sipedon insularum, provides data sufficient for a detailed analysis of population and individual growth. We describe population mean growth separately for males and females based on size of known age individuals (847 captures of 769 males, 748 captures of 684 females) and annual growth increments of individuals of unknown age (1,152 males, 730 females). We characterize individual variation in asymptotic size based on repeated measurements of 69 males and 71 females that were each captured in five to nine different years. The most striking result of our analyses is that asymptotic size varies dramatically among individuals, ranging from 631–820 mm snout-vent length in males and from 835–1125 mm in females. Because female fecundity increases with increasing body size, we explore the impact of individual variation in asymptotic size on lifetime reproductive success using a range of realistic estimates of annual survival. When all females commence reproduction at the same age, lifetime reproductive success is greatest for females with greater asymptotic size regardless of annual survival. But when reproduction is delayed in females with greater asymptotic size, lifetime reproductive success is greatest for females with lower asymptotic size when annual survival is low. Possible causes of individual variation in asymptotic size, including individual- and cohort-specific variation in size at birth and early growth, warrant further investigation. PMID

  1. Size Matters: Individual Variation in Ectotherm Growth and Asymptotic Size.

    Directory of Open Access Journals (Sweden)

    Richard B King

    Full Text Available Body size, and, by extension, growth has impacts on physiology, survival, attainment of sexual maturity, fecundity, generation time, and population dynamics, especially in ectotherm animals that often exhibit extensive growth following attainment of sexual maturity. Frequently, growth is analyzed at the population level, providing useful population mean growth parameters but ignoring individual variation that is also of ecological and evolutionary significance. Our long-term study of Lake Erie Watersnakes, Nerodia sipedon insularum, provides data sufficient for a detailed analysis of population and individual growth. We describe population mean growth separately for males and females based on size of known age individuals (847 captures of 769 males, 748 captures of 684 females and annual growth increments of individuals of unknown age (1,152 males, 730 females. We characterize individual variation in asymptotic size based on repeated measurements of 69 males and 71 females that were each captured in five to nine different years. The most striking result of our analyses is that asymptotic size varies dramatically among individuals, ranging from 631-820 mm snout-vent length in males and from 835-1125 mm in females. Because female fecundity increases with increasing body size, we explore the impact of individual variation in asymptotic size on lifetime reproductive success using a range of realistic estimates of annual survival. When all females commence reproduction at the same age, lifetime reproductive success is greatest for females with greater asymptotic size regardless of annual survival. But when reproduction is delayed in females with greater asymptotic size, lifetime reproductive success is greatest for females with lower asymptotic size when annual survival is low. Possible causes of individual variation in asymptotic size, including individual- and cohort-specific variation in size at birth and early growth, warrant further

  2. Latitudinal clines in Drosophila melanogaster: body size, allozyme ...

    Indian Academy of Sciences (India)

    Unknown

    logy, in explaining such natural genetic variation in D. melanogaster body size and development time. It is argued .... high latitudes were found to use limited food more effi- ciently, so ..... always associate fast development with small body size.

  3. Sauropod dinosaurs evolved moderately sized genomes unrelated to body size.

    Science.gov (United States)

    Organ, Chris L; Brusatte, Stephen L; Stein, Koen

    2009-12-22

    Sauropodomorph dinosaurs include the largest land animals to have ever lived, some reaching up to 10 times the mass of an African elephant. Despite their status defining the upper range for body size in land animals, it remains unknown whether sauropodomorphs evolved larger-sized genomes than non-avian theropods, their sister taxon, or whether a relationship exists between genome size and body size in dinosaurs, two questions critical for understanding broad patterns of genome evolution in dinosaurs. Here we report inferences of genome size for 10 sauropodomorph taxa. The estimates are derived from a Bayesian phylogenetic generalized least squares approach that generates posterior distributions of regression models relating genome size to osteocyte lacunae volume in extant tetrapods. We estimate that the average genome size of sauropodomorphs was 2.02 pg (range of species means: 1.77-2.21 pg), a value in the upper range of extant birds (mean = 1.42 pg, range: 0.97-2.16 pg) and near the average for extant non-avian reptiles (mean = 2.24 pg, range: 1.05-5.44 pg). The results suggest that the variation in size and architecture of genomes in extinct dinosaurs was lower than the variation found in mammals. A substantial difference in genome size separates the two major clades within dinosaurs, Ornithischia (large genomes) and Saurischia (moderate to small genomes). We find no relationship between body size and estimated genome size in extinct dinosaurs, which suggests that neutral forces did not dominate the evolution of genome size in this group.

  4. The evolution of body size and shape in the human career

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    Grabowski, Mark; Hatala, Kevin G.; Richmond, Brian G.

    2016-01-01

    Body size is a fundamental biological property of organisms, and documenting body size variation in hominin evolution is an important goal of palaeoanthropology. Estimating body mass appears deceptively simple but is laden with theoretical and pragmatic assumptions about best predictors and the most appropriate reference samples. Modern human training samples with known masses are arguably the ‘best’ for estimating size in early bipedal hominins such as the australopiths and all members of the genus Homo, but it is not clear if they are the most appropriate priors for reconstructing the size of the earliest putative hominins such as Orrorin and Ardipithecus. The trajectory of body size evolution in the early part of the human career is reviewed here and found to be complex and nonlinear. Australopith body size varies enormously across both space and time. The pre-erectus early Homo fossil record from Africa is poor and dominated by relatively small-bodied individuals, implying that the emergence of the genus Homo is probably not linked to an increase in body size or unprecedented increases in size variation. Body size differences alone cannot explain the observed variation in hominin body shape, especially when examined in the context of small fossil hominins and pygmy modern humans. This article is part of the themed issue ‘Major transitions in human evolution’. PMID:27298459

  5. Size variation in Middle Pleistocene humans.

    Science.gov (United States)

    Arsuaga, J L; Carretero, J M; Lorenzo, C; Gracia, A; Martínez, I; Bermúdez de Castro, J M; Carbonell, E

    1997-08-22

    It has been suggested that European Middle Pleistocene humans, Neandertals, and prehistoric modern humans had a greater sexual dimorphism than modern humans. Analysis of body size variation and cranial capacity variation in the large sample from the Sima de los Huesos site in Spain showed instead that the sexual dimorphism is comparable in Middle Pleistocene and modern populations.

  6. Geographic body size and shape variation in a mainland anolis (Squamata: Dactyloidae) from northwestern South America (Colombia)

    International Nuclear Information System (INIS)

    Calderon Espinosa, Martha L; Barragan Contreras, Leidy Alejandra

    2014-01-01

    Anolis auratus is a widely distributed species, from Costa Rica in Central America, through northern South America, including Colombia, Venezuela, northern Brazil, Surinam and the Guyanas. In Colombia, its widespread distribution across different life zones suggests that these lizards occupy different environments and exhibit different microhabitat use in different geographic areas. On the other hand, some observations suggest that this species prefers open areas, selecting grasslands over brushy areas, and thus, an alternative hypothesis is that microhabitat use is similar among different populations. In Anolis, body variables related to locomotion (body size and shape) defines structural microhabitat use, so two distinct patterns could be expected in this species: Conservative or highly variable body size and shape throughout the species distribution. To test these predictions, we characterized geographic variation in morphometric traits of this species in Colombia. Females and males were similar in body size, but exhibited differences in some variables related to body shape. These characteristics also varied among males and females from different regions, suggesting heterogeneous use of structural microhabitat, between sexes and among populations. As an alternative, phylogenetic divergence among populations could also account for the observed differences. Absence of ecological and phylogenetic data limits our ability to identify the underlying causes of this pattern. However, we provide a general framework to explore hypotheses about evolution of body size and shape in this species.

  7. Body size and geographic range do not explain long term variation in fish populations: a Bayesian phylogenetic approach to testing assembly processes in stream fish assemblages.

    Directory of Open Access Journals (Sweden)

    Stephen J Jacquemin

    Full Text Available We combine evolutionary biology and community ecology to test whether two species traits, body size and geographic range, explain long term variation in local scale freshwater stream fish assemblages. Body size and geographic range are expected to influence several aspects of fish ecology, via relationships with niche breadth, dispersal, and abundance. These traits are expected to scale inversely with niche breadth or current abundance, and to scale directly with dispersal potential. However, their utility to explain long term temporal patterns in local scale abundance is not known. Comparative methods employing an existing molecular phylogeny were used to incorporate evolutionary relatedness in a test for covariation of body size and geographic range with long term (1983 - 2010 local scale population variation of fishes in West Fork White River (Indiana, USA. The Bayesian model incorporating phylogenetic uncertainty and correlated predictors indicated that neither body size nor geographic range explained significant variation in population fluctuations over a 28 year period. Phylogenetic signal data indicated that body size and geographic range were less similar among taxa than expected if trait evolution followed a purely random walk. We interpret this as evidence that local scale population variation may be influenced less by species-level traits such as body size or geographic range, and instead may be influenced more strongly by a taxon's local scale habitat and biotic assemblages.

  8. INTRASPECIFIC VARIATION IN ACOUSTIC TRAITS AND BODY SIZE, AND NEW DISTRIBUTIONAL RECORDS FOR PSEUDOPALUDICOLA GIARETTAI CARVALHO, 2012 (ANURA, LEPTODACTYLIDAE, LEIUPERINAE: IMPLICATIONS FOR ITS CONGENERIC DIAGNOSIS

    Directory of Open Access Journals (Sweden)

    THIAGO RIBEIRO DE CARVALHO

    2015-01-01

    Full Text Available In this paper, we provide an updated diagnosis for Pseudopaludicola giarettai based on the morphometric and acoustic variation observed with the assessment of new populations, plus an expansion of its distribution range. Our results support that all acoustic variation observed might be attributed to intraspecific variation. The variation in body size and dorsal stripe patterns observed for Pseudopaludicola giarettai reinforces that the distinctive whistling advertisement call pattern is the most reliable evidence line to diagnose it from its congeners, whereas morphological (robust body, glandular dorsum and morphometric (body size features vary considerably within and among populations so that they should no longer be employed as diagnostic features of Pseudopaludicola giarettai.

  9. Effect of body size and body mass on δ 13 C and δ 15 N in coastal fishes and cephalopods

    Science.gov (United States)

    Vinagre, C.; Máguas, C.; Cabral, H. N.; Costa, M. J.

    2011-11-01

    Carbon and nitrogen isotopes have been widely used in the investigation of trophic relations, energy pathways, trophic levels and migrations, under the assumption that δ 13C is independent of body size and that variation in δ 15N occurs exclusively due to ontogenetic changes in diet and not body size increase per se. However, several studies have shown that these assumptions are uncertain. Data from food-webs containing an important number of species lack theoretical support on these assumptions because very few species have been tested for δ 13C and δ 15N variation in captivity. However, if sampling comprises a wide range of body sizes from various species, the variation of δ 13C and δ 15N with body size can be investigated. While correlation between body size and δ 13C and δ 15N can be due to ontogenetic diet shifts, stability in such values throughout the size spectrum can be considered an indication that δ 13C and δ 15N in muscle tissues of such species is independent of body size within that size range, and thus the basic assumptions can be applied in the interpretation of such food webs. The present study investigated the variation in muscle δ 13C and δ 15N with body size and body mass of coastal fishes and cephalopods. It was concluded that muscle δ 13C and δ 15N did not vary with body size or mass for all bony fishes with only one exception, the dragonet Callionymus lyra. Muscle δ 13C and δ 15N also did not vary with body size or mass in cartilaginous fishes and cephalopods, meaning that body size/mass per se have no effect on δ 13C or δ 15N, for most species analysed and within the size ranges sampled. The assumption that δ 13C is independent of body size and that variation in δ 15N is not affected by body size increase per se was upheld for most organisms and can be applied to the coastal food web studied taking into account that C. lyra is an exception.

  10. Body size evolution in insular speckled rattlesnakes (Viperidae: Crotalus mitchellii.

    Directory of Open Access Journals (Sweden)

    Jesse M Meik

    2010-03-01

    Full Text Available Speckled rattlesnakes (Crotalus mitchellii inhabit multiple islands off the coast of Baja California, Mexico. Two of the 14 known insular populations have been recognized as subspecies based primarily on body size divergence from putative mainland ancestral populations; however, a survey of body size variation from other islands occupied by these snakes has not been previously reported. We examined body size variation between island and mainland speckled rattlesnakes, and the relationship between body size and various island physical variables among 12 island populations. We also examined relative head size among giant, dwarfed, and mainland speckled rattlesnakes to determine whether allometric differences conformed to predictions of gape size (and indirectly body size evolving in response to shifts in prey size.Insular speckled rattlesnakes show considerable variation in body size when compared to mainland source subspecies. In addition to previously known instances of gigantism on Angel de la Guarda and dwarfism on El Muerto, various degrees of body size decrease have occurred frequently in this taxon, with dwarfed rattlesnakes occurring mostly on small, recently isolated, land-bridge islands. Regression models using the Akaike information criterion (AIC showed that mean SVL of insular populations was most strongly correlated with island area, suggesting the influence of selection for different body size optima for islands of different size. Allometric differences in head size of giant and dwarf rattlesnakes revealed patterns consistent with shifts to larger and smaller prey, respectively.Our data provide the first example of a clear relationship between body size and island area in a squamate reptile species; among vertebrates this pattern has been previously documented in few insular mammals. This finding suggests that selection for body size is influenced by changes in community dynamics that are related to graded differences in area over

  11. Body Size Shifts in Philippine Reef Fishes: Interfamilial Variation in Responses to Protection

    Directory of Open Access Journals (Sweden)

    Robert Y. Fidler

    2014-03-01

    Full Text Available As a consequence of intense fishing pressure, fished populations experience reduced population sizes and shifts in body size toward the predominance of smaller and early maturing individuals. Small, early-maturing fish exhibit significantly reduced reproductive output and, ultimately, reduced fitness. As part of resource management and biodiversity conservation programs worldwide, no-take marine protected areas (MPAs are expected to ameliorate the adverse effects of fishing pressure. In an attempt to advance our understanding of how coral reef MPAs meet their long-term goals, this study used visual census data from 23 MPAs and fished reefs in the Philippines to address three questions: (1 Do MPAs promote shifts in fish body size frequency distribution towards larger body sizes when compared to fished reefs? (2 Do MPA size and (3 age contribute to the efficacy of MPAs in promoting such shifts? This study revealed that across all MPAs surveyed, the distribution of fishes between MPAs and fished reefs were similar; however, large-bodied fish were more abundant within MPAs, along with small, young-of-the-year individuals. Additionally, there was a significant shift in body size frequency distribution towards larger body sizes in 12 of 23 individual reef sites surveyed. Of 22 fish families, eleven demonstrated significantly different body size frequency distributions between MPAs and fished reefs, indicating that shifts in the size spectrum of fishes in response to protection are family-specific. Family-level shifts demonstrated a significant, positive correlation with MPA age, indicating that MPAs become more effective at increasing the density of large-bodied fish within their boundaries over time.

  12. Molecular Characterization of Bovine SMO Gene and Effects of Its Genetic Variations on Body Size Traits in Qinchuan Cattle (Bos taurus)

    Science.gov (United States)

    Zhang, Ya-Ran; Gui, Lin-Sheng; Li, Yao-Kun; Jiang, Bi-Jie; Wang, Hong-Cheng; Zhang, Ying-Ying; Zan, Lin-Sen

    2015-01-01

    Smoothened (Smo)-mediated Hedgehog (Hh) signaling pathway governs the patterning, morphogenesis and growth of many different regions within animal body plans. This study evaluated the effects of genetic variations of the bovine SMO gene on economically important body size traits in Chinese Qinchuan cattle. Altogether, eight single nucleotide polymorphisms (SNPs: 1–8) were identified and genotyped via direct sequencing covering most of the coding region and 3ʹUTR of the bovine SMO gene. Both the p.698Ser.>Ser. synonymous mutation resulted from SNP1 and the p.700Ser.>Pro. non-synonymous mutation caused by SNP2 mapped to the intracellular C-terminal tail of bovine Smo protein; the other six SNPs were non-coding variants located in the 3ʹUTR. The linkage disequilibrium was analyzed, and five haplotypes were discovered in 520 Qinchuan cattle. Association analyses showed that SNP2, SNP3/5, SNP4 and SNP6/7 were significantly associated with some body size traits (p 0.05). Meanwhile, cattle with wild-type combined haplotype Hap1/Hap1 had significantly (p < 0.05) greater body length than those with Hap2/Hap2. Our results indicate that variations in the SMO gene could affect body size traits of Qinchuan cattle, and the wild-type haplotype Hap1 together with the wild-type alleles of these detected SNPs in the SMO gene could be used to breed cattle with superior body size traits. Therefore, our results could be helpful for marker-assisted selection in beef cattle breeding programs. PMID:26225956

  13. Craniomandibular form and body size variation of first generation mouse hybrids: A model for hominin hybridization.

    Science.gov (United States)

    Warren, Kerryn A; Ritzman, Terrence B; Humphreys, Robyn A; Percival, Christopher J; Hallgrímsson, Benedikt; Ackermann, Rebecca Rogers

    2018-03-01

    Hybridization occurs in a number of mammalian lineages, including among primate taxa. Analyses of ancient genomes have shown that hybridization between our lineage and other archaic hominins in Eurasia occurred numerous times in the past. However, we still have limited empirical data on what a hybrid skeleton looks like, or how to spot patterns of hybridization among fossils for which there are no genetic data. Here we use experimental mouse models to supplement previous studies of primates. We characterize size and shape variation in the cranium and mandible of three wild-derived inbred mouse strains and their first generation (F 1 ) hybrids. The three parent taxa in our analysis represent lineages that diverged over approximately the same period as the human/Neanderthal/Denisovan lineages and their hybrids are variably successful in the wild. Comparisons of body size, as quantified by long bone measurements, are also presented to determine whether the identified phenotypic effects of hybridization are localized to the cranium or represent overall body size changes. The results indicate that hybrid cranial and mandibular sizes, as well as limb length, exceed that of the parent taxa in all cases. All three F 1 hybrid crosses display similar patterns of size and form variation. These results are generally consistent with earlier studies on primates and other mammals, suggesting that the effects of hybridization may be similar across very different scenarios of hybridization, including different levels of hybrid fitness. This paper serves to supplement previous studies aimed at identifying F 1 hybrids in the fossil record and to introduce further research that will explore hybrid morphologies using mice as a proxy for better understanding hybridization in the hominin fossil record. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Maintenance of phenotypic variation: repeatibility, heritability, and size-dependent processes in a wild brook trout population

    Science.gov (United States)

    Benjamin H. Letcher; Jason A Coombs; Keith H. Nislow

    2011-01-01

    Phenotypic variation in body size can result from within-cohort variation in birth dates, among-individual growth variation and size-selective processes. We explore the relative effects of these processes on the maintenance of wide observed body size variation in stream-dwelling brook trout (Salvelinus fontinalis). Based on the analyses of multiple...

  15. Decreases in beetle body size linked to climate change and warming temperatures.

    Science.gov (United States)

    Tseng, Michelle; Kaur, Katrina M; Soleimani Pari, Sina; Sarai, Karnjit; Chan, Denessa; Yao, Christine H; Porto, Paula; Toor, Anmol; Toor, Harpawantaj S; Fograscher, Katrina

    2018-05-01

    Body size is a fundamental ecological trait and is correlated with population dynamics, community structure and function, and ecosystem fluxes. Laboratory data from broad taxonomic groups suggest that a widespread response to a warming world may be an overall decrease in organism body size. However, given the myriad of biotic and abiotic factors that can also influence organism body size in the wild, it is unclear whether results from these laboratory assays hold in nature. Here we use datasets spanning 30 to 100 years to examine whether the body size of wild-caught beetles has changed over time, whether body size changes are correlated with increased temperatures, and we frame these results using predictions derived from a quantitative review of laboratory responses of 22 beetle species to temperature. We found that 95% of laboratory-reared beetles decreased in size with increased rearing temperature, with larger-bodied species shrinking disproportionately more than smaller-bodied beetles. In addition, the museum datasets revealed that larger-bodied beetle species have decreased in size over time, that mean beetle body size explains much of the interspecific variation in beetle responses to temperature, and that long-term beetle size changes are explained by increases in autumn temperature and decreases in spring temperature in this region. Our data demonstrate that the relationship between body size and temperature of wild-caught beetles matches relatively well with results from laboratory studies, and that variation in this relationship is largely explained by interspecific variation in mean beetle body size. This long-term beetle dataset is one of the most comprehensive arthropod body size datasets compiled to date, it improves predictions regarding the shrinking of organisms with global climate change, and together with the meta-analysis data, call for new hypotheses to explain why larger-bodied organisms may be more sensitive to temperature. © 2018 The

  16. Reference man and woman more fully characterized: Variations on the basis of body size, age, sex, and race

    International Nuclear Information System (INIS)

    Ellis, K.J.

    1990-01-01

    Total body neutron activation analysis, prompt-gamma neutron activation analysis, and whole body counting have been used to determine the elemental composition of the human body. The total body elements measured were potassium, nitrogen, calcium, sodium, chlorine, and phosphorus. Total body water was also determined by the dilution principle using tritiated water. Observations were made in an adult US population that totaled 1374 and ranged in age from 20 to 90 yr. The dataset for the white population consisted of 175 males and 1134 females observations; for the black population, it consisted of 30 male and 35 female observations. The variation in the elemental composition of both males and females in any 5-yr age group was large and ranged up to 20% (SD). Age-, race-, sex-, and size-specific differences were evident. When equations were developed that predicted the elemental composition of the adult on the basis of age, weight, and height, the variation in the age groups was reduced approximately in half. Age-specific mean values for the 20- to 29-yr-old white population were also compared with values for the International Commission on Radiological Protection (ICRP)-23 Reference Man. The open-quotes averageclose quotes young adult male was larger than Reference Man; the in vivo data also indicated a larger skeletal mass, more lean tissues and body water, but lower body sodium. When in vivo prediction equations were used to adjust for size differences, good agreement was found between the expected values and those for Reference Man. The ICRP-23 does not contain elemental data for Reference Woman; therefore, the in vivo data in the present study provide the first estimates of body composition for Reference Woman

  17. Effects of Abiotic Factors on the Geographic Distribution of Body Size Variation and Chromosomal Polymorphisms in Two Neotropical Grasshopper Species (Dichroplus: Melanoplinae: Acrididae

    Directory of Open Access Journals (Sweden)

    Claudio J. Bidau

    2012-01-01

    Full Text Available We review the effects of abiotic factors on body size in two grasshopper species with large geographical distributions: Dichroplus pratensis and D. vittatus, inhabiting Argentina in diverse natural habitats. Geographical spans for both species provide an opportunity to study the effects of changes in abiotic factors on body size. The analyses of body size distribution in both species revealed a converse Bergmannian pattern: body size is positively correlated with latitude, altitude, and seasonality that influences time available for development and growth. Allen’s rule is also inverted. Morphological variability increases towards the ends of the Bergmannian clines and, in D. pratensis, is related with a central-marginal distribution of chromosomal variants that influence recombination. The converse Bergmannian patterns influence sexual size dimorphism in both species but in different fashions. Body size variation at a microspatial scale in D. pratensis is extremely sensitive to microclimatic clines. We finally compare our results with those for other Orthopteran species.

  18. Body size and lean mass of brown bears across and within four diverse ecosystems

    Science.gov (United States)

    Hilderbrand, Grant V.; Gustine, David; Mangipane, Buck A.; Joly, Kyle; Leacock, William; Mangipane, Lindsey S.; Erlenbach, Joy; Sorum, Mathew; Cameron, Matthew; Belant, Jerrold L.; Cambier, Troy

    2018-01-01

    Variation in body size across populations of brown bears (Ursus arctos) is largely a function of the availability and quality of nutritional resources while plasticity within populations reflects utilized niche width with implications for population resiliency. We assessed skull size, body length, and lean mass of adult female and male brown bears in four Alaskan study areas that differed in climate, primary food resources, population density, and harvest regime. Full body-frame size, as evidenced by asymptotic skull size and body length, was achieved by 8 to 14 years of age across populations and sexes. Lean body mass of both sexes continued to increase throughout their life. Differences between populations existed for all morphological measures in both sexes, bears in ecosystems with abundant salmon were generally larger. Within all populations, broad variation was seen in body size measures of adults with females displaying roughly a 2-fold difference in lean mass and males showing a 3- to 4-fold difference. The high level of intraspecific variation seen across and within populations suggests the presence of multiple life-history strategies and niche variation relative to resource partitioning, risk tolerance or aversion, and competition. Further, this level of variation indicates broad potential to adapt to changes within a given ecosystem and across the species’ range.

  19. Heritability of body size in the polar bears of Western Hudson Bay.

    Science.gov (United States)

    Malenfant, René M; Davis, Corey S; Richardson, Evan S; Lunn, Nicholas J; Coltman, David W

    2018-04-18

    Among polar bears (Ursus maritimus), fitness is dependent on body size through males' abilities to win mates, females' abilities to provide for their young and all bears' abilities to survive increasingly longer fasting periods caused by climate change. In the Western Hudson Bay subpopulation (near Churchill, Manitoba, Canada), polar bears have declined in body size and condition, but nothing is known about the genetic underpinnings of body size variation, which may be subject to natural selection. Here, we combine a 4449-individual pedigree and an array of 5,433 single nucleotide polymorphisms (SNPs) to provide the first quantitative genetic study of polar bears. We used animal models to estimate heritability (h 2 ) among polar bears handled between 1966 and 2011, obtaining h 2 estimates of 0.34-0.48 for strictly skeletal traits and 0.18 for axillary girth (which is also dependent on fatness). We genotyped 859 individuals with the SNP array to test for marker-trait association and combined p-values over genetic pathways using gene-set analysis. Variation in all traits appeared to be polygenic, but we detected one region of moderately large effect size in body length near a putative noncoding RNA in an unannotated region of the genome. Gene-set analysis suggested that variation in body length was associated with genes in the regulatory cascade of cyclin expression, which has previously been associated with body size in mice. A greater understanding of the genetic architecture of body size variation will be valuable in understanding the potential for adaptation in polar bear populations challenged by climate change. © 2018 John Wiley & Sons Ltd.

  20. Spatial variation in egg size of a top predator: Interplay of body size and environmental factors?

    Science.gov (United States)

    Louzao, Maite; Igual, José M.; Genovart, Meritxell; Forero, Manuela G.; Hobson, Keith A.; Oro, Daniel

    2008-09-01

    It is expected that nearby populations are constrained by the same ecological features shaping in turn similarity in their ecological traits. Here, we studied the spatio-temporal variability in egg size among local populations of the critically endangered Balearic shearwater Puffinus mauretanicus, a top marine predator endemic to the western Mediterranean region. Specifically we assessed whether this trait was influenced by maternal body size, as an indicator of a genetic component, and feeding ecology (through stable-carbon and nitrogen-isotope measurements), as an indicator of environmental factors. We found that egg size varied among local populations, an unexpected result at such a small spatial scale. Body size differences at the local population level only partially explained such differences. Blood isotope measurements also differed among local populations. Values of δ 15N suggested inter-population differences in trophic level, showing a similar general pattern with egg size, and suggesting a nutritional link between them whereby egg size was affected by differences in feeding resources and/or behaviour. Values of δ 13C suggested that local populations did not differ in foraging habits with respect to benthic- vs. pelagic-based food-webs. Egg size did not vary among years as did breeding performance, suggesting that a differential temporal window could affect both breeding parameters in relation to food availability. The absence of a relationship between breeding performance and egg size suggested that larger eggs might only confer an advantage during harsh conditions. Alternatively parental quality could greatly affect breeding performance. We showed that inter-population differences in egg size could be influenced by both body size and environmental factors.

  1. Intrapopulational body size variation and cranial capacity variation in Middle Pleistocene humans: the Sima de los Huesos sample (Sierra de Atapuerca, Spain).

    Science.gov (United States)

    Lorenzo, C; Carretero, J M; Arsuaga, J L; Gracia, A; Martínez, I

    1998-05-01

    A sexual dimorphism more marked than in living humans has been claimed for European Middle Pleistocene humans, Neandertals and prehistoric modern humans. In this paper, body size and cranial capacity variation are studied in the Sima de los Huesos Middle Pleistocene sample. This is the largest sample of non-modern humans found to date from one single site, and with all skeletal elements represented. Since the techniques available to estimate the degree of sexual dimorphism in small palaeontological samples are all unsatisfactory, we have used the bootstraping method to asses the magnitude of the variation in the Sima de los Huesos sample compared to modern human intrapopulational variation. We analyze size variation without attempting to sex the specimens a priori. Anatomical regions investigated are scapular glenoid fossa; acetabulum; humeral proximal and distal epiphyses; ulnar proximal epiphysis; radial neck; proximal femur; humeral, femoral, ulnar and tibial shaft; lumbosacral joint; patella; calcaneum; and talar trochlea. In the Sima de los Huesos sample only the humeral midshaft perimeter shows an unusual high variation (only when it is expressed by the maximum ratio, not by the coefficient of variation). In spite of that the cranial capacity range at Sima de los Huesos almost spans the rest of the European and African Middle Pleistocene range. The maximum ratio is in the central part of the distribution of modern human samples. Thus, the hypothesis of a greater sexual dimorphism in Middle Pleistocene populations than in modern populations is not supported by either cranial or postcranial evidence from Sima de los Huesos.

  2. AN AGENT-BASED APPROACH TO MODELING MAMMALIAN EVOLUTION: HOW RESOURCE DISTRIBUTION AND PREDATION AFFECT BODY SIZE

    OpenAIRE

    ANNE KANDLER; JEROEN B. SMAERS

    2012-01-01

    Macro-evolutionary investigations into cross-scale patterns of body size variation have put many of the pieces of the evolutionary body size puzzle in place. To further tackle micro- and meso-scale process-based reasons underlying changes in body size, researchers compare natural populations across different habitat structures, assessing which habitat structures correspond to which changes in body size variation. The complex multi-scale dynamics underlying the effect of the external environme...

  3. Body size and the timing of egg production in parasitoid wasps.

    NARCIS (Netherlands)

    Ellers, J.; Jervis, M.

    2003-01-01

    In insects several key fitness-related variables are positively correlated with intraspecific variation in body size, but little is known about size-related variation in the timing of egg production within species. Female insects are known to vary in the degree to which they concentrate egg

  4. Ecological and evolutionary influences on body size and shape in the Galápagos marine iguana (Amblyrhynchus cristatus).

    Science.gov (United States)

    Chiari, Ylenia; Glaberman, Scott; Tarroso, Pedro; Caccone, Adalgisa; Claude, Julien

    2016-07-01

    Oceanic islands are often inhabited by endemic species that have undergone substantial morphological evolutionary change due to processes of multiple colonizations from various source populations, dispersal, and local adaptation. Galápagos marine iguanas are an example of an island endemic exhibiting high morphological diversity, including substantial body size variation among populations and sexes, but the causes and magnitude of this variation are not well understood. We obtained morphological measurements from marine iguanas throughout their distribution range. These data were combined with genetic and local environmental data from each population to investigate the effects of evolutionary history and environmental conditions on body size and shape variation and sexual dimorphism. Our results indicate that body size and shape are highly variable among populations. Sea surface temperature and island perimeter, but not evolutionary history as depicted by phylogeographic patterns in this species, explain variation in body size among populations. Conversely, evolutionary history, but not environmental parameters or island size, was found to influence variation in body shape among populations. Finally, in all populations except one, we found strong sexual dimorphism in body size and shape in which males are larger, with higher heads than females, while females have longer heads than males. Differences among populations suggest that plasticity and/or genetic adaptation may shape body size and shape variation in marine iguanas. This study will help target future investigations to address the contribution of plasticity versus genetic adaptation on size and shape variation in marine iguanas.

  5. Tradeoffs in the evolution of caste and body size in the hyperdiverse ant genus Pheidole.

    Directory of Open Access Journals (Sweden)

    Terrence P McGlynn

    Full Text Available The efficient investment of resources is often the route to ecological success, and the adaptability of resource investment may play a critical role in promoting biodiversity. The ants of the "hyperdiverse" genus Pheidole produce two discrete sterile castes, soldiers and minor workers. Within Pheidole, there is tremendous interspecific variation in proportion of soldiers. The causes and correlates of caste ratio variation among species of Pheidole remain enigmatic. Here we test whether a body size threshold model accounts for interspecific variation in caste ratio in Pheidole, such that species with larger body sizes produce relatively fewer soldiers within their colonies. We evaluated the caste ratio of 26 species of Pheidole and found that the body size of workers accounts for interspecific variation in the production of soldiers as we predicted. Twelve species sampled from one forest in Costa Rica yielded the same relationship as found in previously published data from many localities. We conclude that production of soldiers in the most species-rich group of ants is regulated by a body size threshold mechanism, and that the great variation in body size and caste ratio in Pheidole plays a role in niche divergence in this rapidly evolving taxon.

  6. Body size estimation of self and others in females varying in BMI.

    Directory of Open Access Journals (Sweden)

    Anne Thaler

    Full Text Available Previous literature suggests that a disturbed ability to accurately identify own body size may contribute to overweight. Here, we investigated the influence of personal body size, indexed by body mass index (BMI, on body size estimation in a non-clinical population of females varying in BMI. We attempted to disentangle general biases in body size estimates and attitudinal influences by manipulating whether participants believed the body stimuli (personalized avatars with realistic weight variations represented their own body or that of another person. Our results show that the accuracy of own body size estimation is predicted by personal BMI, such that participants with lower BMI underestimated their body size and participants with higher BMI overestimated their body size. Further, participants with higher BMI were less likely to notice the same percentage of weight gain than participants with lower BMI. Importantly, these results were only apparent when participants were judging a virtual body that was their own identity (Experiment 1, but not when they estimated the size of a body with another identity and the same underlying body shape (Experiment 2a. The different influences of BMI on accuracy of body size estimation and sensitivity to weight change for self and other identity suggests that effects of BMI on visual body size estimation are self-specific and not generalizable to other bodies.

  7. Body size estimation of self and others in females varying in BMI.

    Science.gov (United States)

    Thaler, Anne; Geuss, Michael N; Mölbert, Simone C; Giel, Katrin E; Streuber, Stephan; Romero, Javier; Black, Michael J; Mohler, Betty J

    2018-01-01

    Previous literature suggests that a disturbed ability to accurately identify own body size may contribute to overweight. Here, we investigated the influence of personal body size, indexed by body mass index (BMI), on body size estimation in a non-clinical population of females varying in BMI. We attempted to disentangle general biases in body size estimates and attitudinal influences by manipulating whether participants believed the body stimuli (personalized avatars with realistic weight variations) represented their own body or that of another person. Our results show that the accuracy of own body size estimation is predicted by personal BMI, such that participants with lower BMI underestimated their body size and participants with higher BMI overestimated their body size. Further, participants with higher BMI were less likely to notice the same percentage of weight gain than participants with lower BMI. Importantly, these results were only apparent when participants were judging a virtual body that was their own identity (Experiment 1), but not when they estimated the size of a body with another identity and the same underlying body shape (Experiment 2a). The different influences of BMI on accuracy of body size estimation and sensitivity to weight change for self and other identity suggests that effects of BMI on visual body size estimation are self-specific and not generalizable to other bodies.

  8. How acoustic signals scale with individual body size: common trends across diverse taxa

    OpenAIRE

    Rafael L. Rodríguez; Marcelo Araya-Salas; David A. Gray; Michael S. Reichert; Laurel B. Symes; Matthew R. Wilkins; Rebecca J. Safran; Gerlinde Höbel

    2015-01-01

    We use allometric analysis to explore how acoustic signals scale on individual body size and to test hypotheses about the factors shaping relationships between signals and body size. Across case studies spanning birds, crickets, tree crickets, and tree frogs, we find that most signal traits had low coefficients of variation, shallow allometric scalings, and little dispersion around the allometric function. We relate variation in these measures to the shape of mate preferences and the level of...

  9. Variation in age and size in Fennoscandian three-spined sticklebacks (Gasterosteus aculeatus).

    Science.gov (United States)

    DeFaveri, Jacquelin; Merilä, Juha

    2013-01-01

    Average age and maximum life span of breeding adult three-spined sticklebacks (Gasterosteus aculeatus) were determined in eight Fennoscandian localities with the aid of skeletochronology. The average age varied from 1.8 to 3.6 years, and maximum life span from three to six years depending on the locality. On average, fish from marine populations were significantly older than those from freshwater populations, but variation within habitat types was large. We also found significant differences in mean body size among different habitat types and populations, but only the population differences remained significant after accounting for variation due to age effects. These results show that generation length and longevity in three-spined sticklebacks can vary significantly from one locality to another, and that population differences in mean body size cannot be explained as a simple consequence of differences in population age structure. We also describe a nanistic population from northern Finland exhibiting long life span and small body size.

  10. Variation in age and size in Fennoscandian three-spined sticklebacks (Gasterosteus aculeatus.

    Directory of Open Access Journals (Sweden)

    Jacquelin DeFaveri

    Full Text Available Average age and maximum life span of breeding adult three-spined sticklebacks (Gasterosteus aculeatus were determined in eight Fennoscandian localities with the aid of skeletochronology. The average age varied from 1.8 to 3.6 years, and maximum life span from three to six years depending on the locality. On average, fish from marine populations were significantly older than those from freshwater populations, but variation within habitat types was large. We also found significant differences in mean body size among different habitat types and populations, but only the population differences remained significant after accounting for variation due to age effects. These results show that generation length and longevity in three-spined sticklebacks can vary significantly from one locality to another, and that population differences in mean body size cannot be explained as a simple consequence of differences in population age structure. We also describe a nanistic population from northern Finland exhibiting long life span and small body size.

  11. Dinosaurs, dragons, and dwarfs: The evolution of maximal body size

    Science.gov (United States)

    Burness, Gary P.; Diamond, Jared; Flannery, Timothy

    2001-01-01

    Among local faunas, the maximum body size and taxonomic affiliation of the top terrestrial vertebrate vary greatly. Does this variation reflect how food requirements differ between trophic levels (herbivores vs. carnivores) and with taxonomic affiliation (mammals and birds vs. reptiles)? We gathered data on the body size and food requirements of the top terrestrial herbivores and carnivores, over the past 65,000 years, from oceanic islands and continents. The body mass of the top species was found to increase with increasing land area, with a slope similar to that of the relation between body mass and home range area, suggesting that maximum body size is determined by the number of home ranges that can fit into a given land area. For a given land area, the body size of the top species decreased in the sequence: ectothermic herbivore > endothermic herbivore > ectothermic carnivore > endothermic carnivore. When we converted body mass to food requirements, the food consumption of a top herbivore was about 8 times that of a top carnivore, in accord with the factor expected from the trophic pyramid. Although top ectotherms were heavier than top endotherms at a given trophic level, lower metabolic rates per gram of body mass in ectotherms resulted in endotherms and ectotherms having the same food consumption. These patterns explain the size of the largest-ever extinct mammal, but the size of the largest dinosaurs exceeds that predicted from land areas and remains unexplained. PMID:11724953

  12. Four loci explain 83% of size variation in the horse.

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    Shokouh Makvandi-Nejad

    Full Text Available Horse body size varies greatly due to intense selection within each breed. American Miniatures are less than one meter tall at the withers while Shires and Percherons can exceed two meters. The genetic basis for this variation is not known. We hypothesize that the breed population structure of the horse should simplify efforts to identify genes controlling size. In support of this, here we show with genome-wide association scans (GWAS that genetic variation at just four loci can explain the great majority of horse size variation. Unlike humans, which are naturally reproducing and possess many genetic variants with weak effects on size, we show that horses, like other domestic mammals, carry just a small number of size loci with alleles of large effect. Furthermore, three of our horse size loci contain the LCORL, HMGA2 and ZFAT genes that have previously been found to control human height. The LCORL/NCAPG locus is also implicated in cattle growth and HMGA2 is associated with dog size. Extreme size diversification is a hallmark of domestication. Our results in the horse, complemented by the prior work in cattle and dog, serve to pinpoint those very few genes that have played major roles in the rapid evolution of size during domestication.

  13. Molecular Characterization of Bovine SMO Gene and Effects of Its Genetic Variations on Body Size Traits in Qinchuan Cattle (Bos taurus).

    Science.gov (United States)

    Zhang, Ya-Ran; Gui, Lin-Sheng; Li, Yao-Kun; Jiang, Bi-Jie; Wang, Hong-Cheng; Zhang, Ying-Ying; Zan, Lin-Sen

    2015-07-27

    Smoothened (Smo)-mediated Hedgehog (Hh) signaling pathway governs the patterning, morphogenesis and growth of many different regions within animal body plans. This study evaluated the effects of genetic variations of the bovine SMO gene on economically important body size traits in Chinese Qinchuan cattle. Altogether, eight single nucleotide polymorphisms (SNPs: 1-8) were identified and genotyped via direct sequencing covering most of the coding region and 3'UTR of the bovine SMO gene. Both the p.698Ser.>Ser. synonymous mutation resulted from SNP1 and the p.700Ser.>Pro. non-synonymous mutation caused by SNP2 mapped to the intracellular C-terminal tail of bovine Smo protein; the other six SNPs were non-coding variants located in the 3'UTR. The linkage disequilibrium was analyzed, and five haplotypes were discovered in 520 Qinchuan cattle. Association analyses showed that SNP2, SNP3/5, SNP4 and SNP6/7 were significantly associated with some body size traits (p 0.05). Meanwhile, cattle with wild-type combined haplotype Hap1/Hap1 had significantly (p cattle, and the wild-type haplotype Hap1 together with the wild-type alleles of these detected SNPs in the SMO gene could be used to breed cattle with superior body size traits. Therefore, our results could be helpful for marker-assisted selection in beef cattle breeding programs.

  14. Flight biomechanics of developmentally-induced size variation in the solitary bee Osmia lignaria

    Science.gov (United States)

    Body size covaries with morphology, functional performance, and fitness. For insects, variation in adult phenotypies are derived from developmental variation in larval growth and metamorphosis. In this study, we asked how larval growth impacted adult morphology in Osmia lignaria—especially traits th...

  15. Intraspecific variation in body size and shape in an Andean highland anole species, Anolis ventrimaculatus (Squamata: Dactyloidae

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    Martha L. Calderón-Espinosa

    2013-03-01

    Full Text Available Variation in body characteristics related to lizard locomotion has been poorly studied at the intraspecific level in Anolis species. Local adaptation due to habitat heterogeneity has been reported in some island species. However, studies of mainland species are particularly scarce and suggest different patterns: high variability among highland lizards and poorly differentiated populations in one Amazonian species. We characterized inter population variation of body size and shape in the highland Andean Anolis ventrimaculatus, an endemic species from Western Colombia. A total of 15 morphometric variables were measured in specimens from the reptile collection of the Instituto de Ciencias Naturales, Universidad Nacional, Colombia. The study included individuals from seven different highland localities. We found size and shape sexual dimorphism, both of which varied among localities. Patterns of variation in body proportions among populations were different in both males and females, suggesting that either sexual or natural selective factors are different in each locality and between sexes. Since this species exhibits a fragmented distribution in highlands, genetic divergence may also be a causal factor of the observed variation. Ecological, behavioral, additional morphological as well as phylogenetic data, may help to understand the evolutionary processes behind the geographic patterns found in this species.La diversificación fenotípica al interior de una especie en características de dimensiones corporales relacionadas con la locomoción de los lagartos, se ha estudiado poco en especies de Anolis. Los datos de algunas especies de isla revelan patrones distintos de variación geográfica y sugieren que la adaptación local, debida a la heterogeneidad del hábitat, ocurre a este nivel. Los estudios de especies de continente son particularmente escasos y sugieren patrones distintos: un lagarto altoandino altamente variable y poblaciones poco

  16. The rate-size trade-off structures intraspecific variation in Daphnia ambigua life history parameters.

    Science.gov (United States)

    DeLong, John P; Hanley, Torrance C

    2013-01-01

    The identification of trade-offs is necessary for understanding the evolution and maintenance of diversity. Here we employ the supply-demand (SD) body size optimization model to predict a trade-off between asymptotic body size and growth rate. We use the SD model to quantitatively predict the slope of the relationship between asymptotic body size and growth rate under high and low food regimes and then test the predictions against observations for Daphnia ambigua. Close quantitative agreement between observed and predicted slopes at both food levels lends support to the model and confirms that a 'rate-size' trade-off structures life history variation in this population. In contrast to classic life history expectations, growth and reproduction were positively correlated after controlling for the rate-size trade-off. We included 12 Daphnia clones in our study, but clone identity explained only some of the variation in life history traits. We also tested the hypothesis that growth rate would be positively related to intergenic spacer length (i.e. the growth rate hypothesis) across clones, but we found that clones with intermediate intergenic spacer lengths had larger asymptotic sizes and slower growth rates. Our results strongly support a resource-based optimization of body size following the SD model. Furthermore, because some resource allocation decisions necessarily precede others, understanding interdependent life history traits may require a more nested approach.

  17. The rate-size trade-off structures intraspecific variation in Daphnia ambigua life history parameters.

    Directory of Open Access Journals (Sweden)

    John P DeLong

    Full Text Available The identification of trade-offs is necessary for understanding the evolution and maintenance of diversity. Here we employ the supply-demand (SD body size optimization model to predict a trade-off between asymptotic body size and growth rate. We use the SD model to quantitatively predict the slope of the relationship between asymptotic body size and growth rate under high and low food regimes and then test the predictions against observations for Daphnia ambigua. Close quantitative agreement between observed and predicted slopes at both food levels lends support to the model and confirms that a 'rate-size' trade-off structures life history variation in this population. In contrast to classic life history expectations, growth and reproduction were positively correlated after controlling for the rate-size trade-off. We included 12 Daphnia clones in our study, but clone identity explained only some of the variation in life history traits. We also tested the hypothesis that growth rate would be positively related to intergenic spacer length (i.e. the growth rate hypothesis across clones, but we found that clones with intermediate intergenic spacer lengths had larger asymptotic sizes and slower growth rates. Our results strongly support a resource-based optimization of body size following the SD model. Furthermore, because some resource allocation decisions necessarily precede others, understanding interdependent life history traits may require a more nested approach.

  18. Insights into bioassessment of marine pollution using body-size distinctness of planktonic ciliates based on a modified trait hierarchy.

    Science.gov (United States)

    Xu, Henglong; Jiang, Yong; Xu, Guangjian

    2016-06-15

    Based on a modified trait hierarchy of body-size units, the feasibility for bioassessment of water pollution using body-size distinctness of planktonic ciliates was studied in a semi-enclosed bay, northern China. An annual dataset was collected at five sampling stations within a gradient of heavy metal contaminants. Results showed that: (1) in terms of probability density, the body-size spectra of the ciliates represented significant differences among the five stations; (2) bootstrap average analysis demonstrated a spatial variation in body-size rank patterns in response to pollution stress due to heavy metals; and (3) the average body-size distinctness (Δz(+)) and variation in body-size distinctness (Λz(+)), based on the modified trait hierarchy, revealed a clear departure pattern from the expected body-size spectra in areas with pollutants. These results suggest that the body-size diversity measures based on the modified trait hierarchy of the ciliates may be used as a potential indicator of marine pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Variations in leopard cat (Prionailurus bengalensis skull morphology and body size: sexual and geographic influences

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    Fernando L. Sicuro

    2015-10-01

    Full Text Available The leopard cat, Prionailurus bengalensis (Kerr, 1792, is one of the most widespread Asian cats, occurring in continental eastern and southeastern Asia. Since 1929, several studies have focused on the morphology, ecology, and taxonomy of leopard cats. Nevertheless, hitherto there has been no agreement on basic aspects of leopard cat biology, such as the presence or absence of sexual dimorphism, morphological skull and body differences between the eleven recognized subspecies, and the biogeography of the different morphotypes. Twenty measurements on 25 adult leopard cat skulls from different Asian localities were analyzed through univariate and multivariate statistical approaches. Skull and external body measurements from studies over the last 77 years were assembled and organized in two categories: full data and summary data. Most of this database comprises small samples, which have never been statistically tested and compared with each other. Full data sets were tested with univariate and multivariate statistical analyses; summary data sets (i.e., means, SDs, and ranges were analyzed through suitable univariate approaches. The independent analyses of the data from these works confirmed our original results and improved the overview of sexual dimorphism and geographical morphological variation among subspecies. Continental leopard cats have larger skulls and body dimensions. Skulls of Indochinese morphotypes have broader and higher features than those of continental morphotypes, while individuals from the Sunda Islands have skulls with comparatively narrow and low profiles. Cranial sexual dimorphism is present in different degrees among subspecies. Most display subtle sex-related variations in a few skull features. However, in some cases, sexual dimorphism in skull morphology is absent, such as in P. b. sumatranus and P. b. borneoensis. External body measurement comparisons also indicate the low degree of sexual dimorphism. Apart from the gonads

  20. Geographic body size variation in the periodical cicadas Magicicada: implications for life cycle divergence and local adaptation.

    Science.gov (United States)

    Koyama, T; Ito, H; Kakishima, S; Yoshimura, J; Cooley, J R; Simon, C; Sota, T

    2015-06-01

    Seven species in three species groups (Decim, Cassini and Decula) of periodical cicadas (Magicicada) occupy a wide latitudinal range in the eastern United States. To clarify how adult body size, a key trait affecting fitness, varies geographically with climate conditions and life cycle, we analysed the relationships of population mean head width to geographic variables (latitude, longitude, altitude), habitat annual mean temperature (AMT), life cycle and species differences. Within species, body size was larger in females than males and decreased with increasing latitude (and decreasing habitat AMT), following the converse Bergmann's rule. For the pair of recently diverged 13- and 17-year species in each group, 13-year cicadas were equal in size or slightly smaller on average than their 17-year counterparts despite their shorter developmental time. This fact suggests that, under the same climatic conditions, 17-year cicadas have lowered growth rates compared to their 13-years counterparts, allowing 13-year cicadas with faster growth rates to achieve body sizes equivalent to those of their 17-year counterparts at the same locations. However, in the Decim group, which includes two 13-year species, the more southerly, anciently diverged 13-year species (Magicicada tredecim) was characterized by a larger body size than the other, more northerly 13- and 17-year species, suggesting that local adaptation in warmer habitats may ultimately lead to evolution of larger body sizes. Our results demonstrate how geographic clines in body size may be maintained in sister species possessing different life cycles. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  1. Intrapopulation genome size variation in D. melanogaster reflects life history variation and plasticity.

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    Lisa L Ellis

    2014-07-01

    Full Text Available We determined female genome sizes using flow cytometry for 211 Drosophila melanogaster sequenced inbred strains from the Drosophila Genetic Reference Panel, and found significant conspecific and intrapopulation variation in genome size. We also compared several life history traits for 25 lines with large and 25 lines with small genomes in three thermal environments, and found that genome size as well as genome size by temperature interactions significantly correlated with survival to pupation and adulthood, time to pupation, female pupal mass, and female eclosion rates. Genome size accounted for up to 23% of the variation in developmental phenotypes, but the contribution of genome size to variation in life history traits was plastic and varied according to the thermal environment. Expression data implicate differences in metabolism that correspond to genome size variation. These results indicate that significant genome size variation exists within D. melanogaster and this variation may impact the evolutionary ecology of the species. Genome size variation accounts for a significant portion of life history variation in an environmentally dependent manner, suggesting that potential fitness effects associated with genome size variation also depend on environmental conditions.

  2. Intrapopulation Genome Size Variation in D. melanogaster Reflects Life History Variation and Plasticity

    Science.gov (United States)

    Ellis, Lisa L.; Huang, Wen; Quinn, Andrew M.; Ahuja, Astha; Alfrejd, Ben; Gomez, Francisco E.; Hjelmen, Carl E.; Moore, Kristi L.; Mackay, Trudy F. C.; Johnston, J. Spencer; Tarone, Aaron M.

    2014-01-01

    We determined female genome sizes using flow cytometry for 211 Drosophila melanogaster sequenced inbred strains from the Drosophila Genetic Reference Panel, and found significant conspecific and intrapopulation variation in genome size. We also compared several life history traits for 25 lines with large and 25 lines with small genomes in three thermal environments, and found that genome size as well as genome size by temperature interactions significantly correlated with survival to pupation and adulthood, time to pupation, female pupal mass, and female eclosion rates. Genome size accounted for up to 23% of the variation in developmental phenotypes, but the contribution of genome size to variation in life history traits was plastic and varied according to the thermal environment. Expression data implicate differences in metabolism that correspond to genome size variation. These results indicate that significant genome size variation exists within D. melanogaster and this variation may impact the evolutionary ecology of the species. Genome size variation accounts for a significant portion of life history variation in an environmentally dependent manner, suggesting that potential fitness effects associated with genome size variation also depend on environmental conditions. PMID:25057905

  3. Association between different phases of menstrual cycle and body image measures of perceived size, ideal size, and body dissatisfaction.

    Science.gov (United States)

    Teixeira, André Luiz S; Dias, Marcelo Ricardo C; Damasceno, Vinícius O; Lamounier, Joel A; Gardner, Rick M

    2013-12-01

    The association between phases of the menstrual cycle and body image was investigated. 44 university women (M age = 23.3 yr., SD = 4.7) judged their perceived and ideal body size, and body dissatisfaction was calculated at each phase of the menstrual cycle, including premenstrual, menstrual, and intermenstrual. Participants selected one of nine figural drawings ranging from very thin to obese that represented their perceived size and ideal size. Body dissatisfaction was measured as the absolute difference between scores on perceived and ideal figural drawings. During each menstrual phase, anthropometric measures of weight, height, body mass index, circumference of waist and abdomen, and body composition were taken. There were no significant differences in any anthropometric measures between the three menstrual cycle phases. Perceived body size and body dissatisfaction were significantly different between menstrual phases, with the largest perceived body size and highest body dissatisfaction occurring during the menstrual phase. Ideal body size did not differ between menstrual phases, although participants desired a significantly smaller ideal size as compared to the perceived size.

  4. Intraspecific variation in egg size and egg composition in birds: effects on offspring fitness.

    Science.gov (United States)

    Williams, T D

    1994-02-01

    1. There is little unequivocal evidence to date in support of a positive relationship between egg size and offspring fitness in birds. Although 40 studies (of 34 species) have considered the effect of variation in egg size on chick growth and/or survival up to fledgling only 12 studies have controlled for other characters potentially correlated both with egg size and offspring fitness. Of these only two have reported a significant residual effect of egg size on chick growth (in the roseate tern and European blackbird) and three a residual effect on chick survival (all in seabirds: common tern, lesser black-backed gull and kittiwake). 2. More consistent evidence exists, though from fewer studies, for a positive relationship between egg size and offspring fitness early in the chick-rearing period; chick growth and chick survival being dependent on egg size in 8 of 10 studies and 4 of 5 studies respectively. It is suggested that the most important effect of variation in egg size might be in determining the probability of offspring survival in the first few days after hatching. 3. Egg size explains on average 66% of the variation in chick mass at hatching (n = 35 studies) but only 30% of the variation in chick body size (n = 18). When effects of hatching body size are controlled for chick mass remains significantly correlated with egg size, though the reverse is not true. This supports the hypothesis that large eggs give rise to heavier chicks at hatching, i.e., chicks with more nutrient (yolk) reserves, rather than structurally larger chicks. 4. Egg composition increased isometrically with increasing egg size in about half the studies so far reported (n equals approximately 20). However, in seabirds, and some passerines, larger eggs contain disproportionately more albumen, whilst in some waterfowl percentage yolk content increases with increasing egg size. Changes in albumen content largely reflect variation in the water content of eggs, but changes in yolk content

  5. The relations between forest fragmentation and bird community body size and biodiversity and bird community body size.

    OpenAIRE

    Hopman, F.

    2017-01-01

    Bachelor thesis Future Planet Studies, major biologie ABSTRACT Animal species with a larger body-size tend to have larger home ranges than small-bodied animals. Therefore it is likely that they are more affected by habitat fragmentation than small-bodied species. Body size of birds also seems to have a negative relation with species richness. This research has therefore looked into whether birds with a larger body-size are more sensitive to habitat fragmentation caused by forest...

  6. Glenoid version and size: does gender, ethnicity, or body size play a role?

    Science.gov (United States)

    Piponov, Hristo Ivanov; Savin, David; Shah, Neal; Esposito, Domenic; Schwartz, Brian; Moretti, Vincent; Goldberg, Benjamin

    2016-11-01

    Variations in glenoid morphology among patients of different gender, body habitus, and ethnicity have been of interest for surgeons. Understanding these anatomical variations is a critical step in restoring normal glenohumeral structure during shoulder reconstruction surgery. Retrospective review of 108 patient shoulder CT scans was performed and glenoid version, AP diameter and height were measured. Statistical multiple regression models were used to investigate the ability of gender and ethnicity to predict glenoid AP diameter, height, and version independently of patient weight and height. The mean glenoid AP diameter was 24.7 ± 3.5, the mean glenoid height was 31.7 ± 3.7, and the mean glenoid version was 0.05 ± 9.05. According to our regression models, males would be expected to exhibit 8.4° more glenoid retroversion than females (p = 0.003) and have 2.9 mm larger glenoid height compared to females (p = 0.002). The predicted male glenoid AP diameter was 3.4 mm higher than that in females (p variations in glenoid size and version are observed among ethnicities, larger sample size ethnic groups will be necessary to explore the precise relations. Surgeons should consider gender and ethnic variations in the pre-operative planning and surgical restoration of the native glenohumeral relationship. Anatomic Study.

  7. Explaining body size beliefs in anorexia.

    Science.gov (United States)

    Gadsby, Stephen

    2017-11-01

    Cognitive neuropsychiatry has had much success in providing theoretical models for the causal origins of many delusional beliefs. Recently, it has been suggested that some anorexia nervosa patients' beliefs about their own body size should be considered delusions. As such, it seems high time the methods of cognitive neuropsychiatry were turned to modelling the false body size beliefs of anorexics. In this paper, I adopt an empiricist approach to modelling the causal origins of false body size beliefs in anorexia. Within the background of cognitive neuropsychiatry, empiricist models claim that abnormal beliefs are grounded by abnormal experiences bearing similar content. I discuss the kinds of abnormal experiences of body size anorexics suffer from which could ground their false beliefs about body size. These oversized experiences come in three varieties: false self-other body comparisons, spontaneous mental imagery of a fat body and distorted perception of affordances. Further theoretical and empirical research into the oversized experiences which anorexics suffer from presents a promising avenue for understanding and treating the disorder.

  8. Evolution of body size in Galapagos marine iguanas.

    Science.gov (United States)

    Wikelski, Martin

    2005-10-07

    Body size is one of the most important traits of organisms and allows predictions of an individual's morphology, physiology, behaviour and life history. However, explaining the evolution of complex traits such as body size is difficult because a plethora of other traits influence body size. Here I review what we know about the evolution of body size in a group of island reptiles and try to generalize about the mechanisms that shape body size. Galapagos marine iguanas occupy all 13 larger islands in this Pacific archipelago and have maximum island body weights between 900 and 12 000g. The distribution of body sizes does not match mitochondrial clades, indicating that body size evolves independently of genetic relatedness. Marine iguanas lack intra- and inter-specific food competition and predators are not size-specific, discounting these factors as selective agents influencing body size. Instead I hypothesize that body size reflects the trade-offs between sexual and natural selection. We found that sexual selection continuously favours larger body sizes. Large males establish display territories and some gain over-proportional reproductive success in the iguanas' mating aggregations. Females select males based on size and activity and are thus responsible for the observed mating skew. However, large individuals are strongly selected against during El Niño-related famines when dietary algae disappear from the intertidal foraging areas. We showed that differences in algae sward ('pasture') heights and thermal constraints on large size are causally responsible for differences in maximum body size among populations. I hypothesize that body size in many animal species reflects a trade-off between foraging constraints and sexual selection and suggest that future research could focus on physiological and genetic mechanisms determining body size in wild animals. Furthermore, evolutionary stable body size distributions within populations should be analysed to better

  9. Body size of commom opossum Didelphis aurita Wied-Neuwied 1826 (Didelphimorphia: Didelphidae on southern brazilian islands

    Directory of Open Access Journals (Sweden)

    CH. Salvador

    Full Text Available The body size of vertebrates isolated on islands can undergo changes due to ecological features of these environments. This study aimed to compare the body size of the common opossum, Didelphis aurita, from different insular populations within the same archipelago in southern Brazil. The opossum populations showed corporal variation and different hypotheses were raised to understand the results. This study constitutes the most detailed body size comparison of a marsupial within different insular populations in the Neotropical zone and the data gathered represents an initial contribution for regional fauna biometric knowledge.

  10. Factors determining the average body size of geographically separated Arctodiaptomus salinus (Daday, 1885) populations.

    Science.gov (United States)

    Anufriieva, Elena V; Shadrin, Nickolai V

    2014-03-01

    Arctodiaptomus salinus inhabits water bodies across Eurasia and North Africa. Based on our own data and that from the literature, we analyzed the influences of several factors on the intra- and inter-population variability of this species. A strong negative linear correlation between temperature and average body size in the Crimean and African populations was found, in which the parameters might be influenced by salinity. Meanwhile, a significant negative correlation between female body size and the altitude of habitats was found by comparing body size in populations from different regions. Individuals from environments with highly varying abiotic parameters, e.g. temporary reservoirs, had a larger body size than individuals from permanent water bodies. The changes in average body mass in populations were at 11.4 times, whereas, those in individual metabolic activities were at 6.2 times. Moreover, two size groups of A. salinus in the Crimean and the Siberian lakes were observed. The ratio of female length to male length fluctuated between 1.02 and 1.30. The average size of A. salinus in populations and its variations were determined by both genetic and environmental factors. However, the parities of these factors were unequal in either spatial or temporal scales.

  11. Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators.

    Science.gov (United States)

    Pimiento, Catalina; Balk, Meghan A

    2015-06-01

    The extinct shark Carcharocles megalodon is one of the largest marine apex predators ever to exist. Nonetheless, little is known about its body-size variations through time and space. Here, we studied the body-size trends of C. megalodon through its temporal and geographic range to better understand its ecology and evolution. Given that this species was the last of the megatooth lineage, a group of species that shows a purported size increase through time, we hypothesized that C. megalodon also displayed this trend, increasing in size over time and reaching its largest size prior to extinction. We found that C. megalodon body-size distribution was left-skewed (suggesting a long-term selective pressure favoring larger individuals), and presented significant geographic variation (possibly as a result of the heterogeneous ecological constraints of this cosmopolitan species) over geologic time. Finally, we found that stasis was the general mode of size evolution of C. megalodon (i.e., no net changes over time), contrasting with the trends of the megatooth lineage and our hypothesis. Given that C. megalodon is a relatively long-lived species with a widely distributed fossil record, we further used this study system to provide a deep-time perspective to the understanding of the body-size trends of marine apex predators. For instance, our results suggest that (1) a selective pressure in predatory sharks for consuming a broader range of prey may favor larger individuals and produce left-skewed distributions on a geologic time scale; (2) body-size variations in cosmopolitan apex marine predators may depend on their interactions with geographically discrete communities; and (3) the inherent characteristics of shark species can produce stable sizes over geologic time, regardless of the size trends of their lineages.

  12. Intraspecific growth variation among rainbow trout and brook trout: Impact of initial body weight and feeding level

    DEFF Research Database (Denmark)

    Rasmussen, Richard Skøtt; Ostenfeld, T.

    2010-01-01

    larger body weight (BW) CVs compared to BT (0.257 vs. 0.206, P differences in weight gains enhance size variations in terms...... for species (RT: 3.71, BT: 2.32, P > 0.05). The magnitude of slopes decreased over time (weeks 0–3:4.27, weeks 3–6:3.02 and weeks 6–9:1.74, P differences in weight gains between experimental groups were reflected in differences in coefficients of variations (CVs) for body growth. RT had...... of higher CVs, and this may have implications for feeding tactics in aquaculture where large size variations in groups may be disadvantageous to fish farmers....

  13. Optimum body size of Holstein replacement heifers.

    Science.gov (United States)

    Hoffman, P C

    1997-03-01

    Criteria that define optimum body size of replacement heifers are required by commercial dairy producers to evaluate replacement heifer management programs. Historically recommended body size criteria have been based on live BW measurements. Numerous research studies have observed a positive relationship between BW at first calving and first lactation milk yield, which has served as the impetus for using live BW to define body size of replacement heifers. Live BW is, however, not the only available measurement to define body size. Skeletal measurements such as wither height, length, and pelvic area have been demonstrated to be related to first lactation performance and (or) dystocia. Live BW measurements also do not define differences in body composition. Differences in body composition of replacement heifers at first calving are also related to key performance variables. An updated research data base is available for the modern Holstein genotype to incorporate measures of skeletal growth and body composition with BW when defining body size. These research projects also lend insight into the relative importance of measurements that define body size of replacement heifers. Incorporation of these measurements from current research into present BW recommendations should aid commercial dairy producers to better define replacement heifer growth and management practices. This article proposes enhancements in defining optimum body size and growth characteristics of Holstein replacement heifers.

  14. Canalization of body size matters for lifetime reproductive success of male predatory mites (Acari: Phytoseiidae).

    Science.gov (United States)

    Walzer, Andreas; Schausberger, Peter

    2014-04-01

    The adaptive canalization hypothesis predicts that highly fitness-relevant traits are canalized via past selection, resulting in low phenotypic plasticity and high robustness to environmental stress. Accordingly, we hypothesized that the level of phenotypic plasticity of male body size of the predatory mites Phytoseiulus persimilis (low plasticity) and Neoseiulus californicus (high plasticity) reflects the effects of body size variation on fitness, especially male lifetime reproductive success (LRS). We first generated small and standard-sized males of P. persimilis and N. californicus by rearing them to adulthood under limited and ample prey supply, respectively. Then, adult small and standard-sized males were provided with surplus virgin females throughout life to assess their mating and reproductive traits. Small male body size did not affect male longevity or the number of fertilized females but reduced male LRS of P. persimilis but not N. californicus . Proximately, the lower LRS of small than standard-sized P. persimilis males correlated with shorter mating durations, probably decreasing the amount of transferred sperm. Ultimately, we suggest that male body size is more strongly canalized in P. persimilis than N. californicus because deviation from standard body size has larger detrimental fitness effects in P. persimilis than N. californicus .

  15. The impact of psychological stress on men's judgements of female body size.

    Science.gov (United States)

    Swami, Viren; Tovée, Martin J

    2012-01-01

    Previous work has suggested that the experience of psychological stress may influence physical attractiveness ideals, but most evidence in favour of this hypothesis remains archival. The objective of this study was to experimentally investigate the impact of stress on men's judgements of female body size. Men were randomly assigned to either an experimental group, in which they took part in a task that heightened stress (experimental group, n = 41) or in which they did not take part in such a task (control group, n = 40). Both groups rated the attractiveness of female bodies varying in size from emaciated to obese, completed a measure of appetite sensation, and had their body mass indices (BMIs) measured. Between-groups analyses showed that the experimental group was matched with the control group in terms of mean age, BMI, and appetite sensation. Further analyses showed that men in the experimental group rated a significantly heavier female body size as maximally attractive than the control group. Men in the experimental group also rated heavier female bodies as more attractive and idealised a wider range of female figures than did the control group. This study found that the experience of stress was associated with a preference among men for heavier female body sizes. These results indicate that human attractiveness judgements are sensitive to variations in local ecologies and reflect adaptive strategies for dealing with changing environmental conditions.

  16. Developmental origin of limb size variation in lizards.

    Science.gov (United States)

    Andrews, Robin M; Skewes, Sable A

    2017-05-01

    In many respects, reptile hatchlings are fully functional, albeit miniature, adults. This means that the adult morphology must emerge during embryonic development. This insight emphasizes the connection between the mechanisms that generate phenotypic variation during embryonic development and the action of selection on post-hatching individuals. To determine when species-specific differences in limb and tail lengths emerge during embryonic development, we compared allometric patterns of early limb growth of four distantly related species of lizards. The major questions addressed were whether early embryonic limb and tail growth is characterized by the gradual (continuous allometry) or by the abrupt emergence (transpositional allometry) of size differences among species. Our observations supported transpositional allometry of both limbs and tails. Species-specific differences in limb and tail length were exhibited when limb and tail buds first protruded from the body wall. Genes known to be associated with early limb development of tetrapods are obvious targets for studies on the genetic mechanisms that determine interspecific differences in relative limb length. Broadly comparative studies of gene regulation would facilitate understanding of the mechanisms underlying adaptive variation in limb size, including limb reduction and loss, of squamate reptiles. © 2017 Wiley Periodicals, Inc.

  17. Detecting size and shape of bodies capacitatively

    International Nuclear Information System (INIS)

    Walton, H.

    1980-01-01

    The size and shape of a body is determined by rolling it between the plates of capacitors and measuring the capacitance changes. A capacitor comprising two parallel, spaced wires inclined to the rolling direction and above and below the rolling body scans sections of the body along its longitudinal axis, another determines the body's lengths and a third comprising two non-parallel wires determines the position of the body. The capacitance changes are compared with those produced by a body of known size and shape so that the size and shape of the body can be determined. (author)

  18. The discrepancy between emotional vs. rational estimates of body size, actual size, and ideal body ratings: theoretical and clinical implications.

    Science.gov (United States)

    Thompson, J K; Dolce, J J

    1989-05-01

    Thirty-two asymptomatic college females were assessed on multiple aspects of body image. Subjects' estimation of the size of three body sites (waist, hips, thighs) was affected by instructional protocol. Emotional ratings, based on how they "felt" about their body, elicited ratings that were larger than actual and ideal size measures. Size ratings based on rational instructions were no different from actual sizes, but were larger than ideal ratings. There were no differences between actual and ideal sizes. The results are discussed with regard to methodological issues involved in body image research. In addition, a working hypothesis that differentiates affective/emotional from cognitive/rational aspects of body size estimation is offered to complement current theories of body image. Implications of the findings for the understanding of body image and its relationship to eating disorders are discussed.

  19. Caste-specific expression of genetic variation in the size of antibiotic-producing glands of leaf-cutting ants

    DEFF Research Database (Denmark)

    Hughes, W O H; Bot, A N M; Boomsma, J J

    2010-01-01

    are substantially larger than those of any workers, for their body size. The gland size of large workers varies significantly between patrilines in both Acromyrmex echinatior and Acromyrmex octospinosus. We also examined small workers and gynes in A. echinatior, again finding genetic variation in gland size...... in these castes. There were significant positive relationships between the gland sizes of patrilines in the different castes, indicating that the genetic mechanism underpinning the patriline variation has remained similar across phenotypes. The level of expressed genetic variation decreased from small workers......Social insect castes represent some of the most spectacular examples of phenotypic plasticity, with each caste being associated with different environmental conditions during their life. Here we examine the level of genetic variation in different castes of two polyandrous species of Acromyrmex leaf...

  20. Local climate determines intra- and interspecific variation in sexual size dimorphism in mountain grasshopper communities.

    Science.gov (United States)

    Laiolo, P; Illera, J C; Obeso, J R

    2013-10-01

    The climate is often evoked to explain broad-scale clines of body size, yet its involvement in the processes that generate size inequality in the two sexes (sexual size dimorphism) remains elusive. Here, we analyse climatic clines of sexual size dimorphism along a wide elevation gradient (i) among grasshopper species in a phylogenetically controlled scenario and (ii) within species differing in distribution and cold tolerance, to highlight patterns generated at different time scales, mainly evolutionary (among species or higher taxa) and ontogenetic or microevolutionary (within species). At the interspecific level, grasshoppers were slightly smaller and less dimorphic at high elevations. These clines were associated with gradients of precipitation and sun exposure, which are likely indicators of other factors that directly exert selective pressures, such as resource availability and conditions for effective thermoregulation. Within species, we found a positive effect of temperature and a negative effect of elevation on body size, especially on condition-dependent measures of body size (total body length rather than hind femur length) and in species inhabiting the highest elevations. In spite of a certain degree of species-specific variation, females tended to adjust their body size more often than males, suggesting that body size in females can evolve faster among species and can be more plastic or dependent on nutritional conditions within species living in adverse climates. Natural selection on female body size may therefore prevail over sexual selection on male body size in alpine environments, and abiotic factors may trigger consistent phenotypic patterns across taxonomic scales. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  1. Body size and predatory performance in wolves: is bigger better?

    Science.gov (United States)

    MacNulty, Daniel R; Smith, Douglas W; Mech, L David; Eberly, Lynn E

    2009-05-01

    1. Large body size hinders locomotor performance in ways that may lead to trade-offs in predator foraging ability that limit the net predatory benefit of larger size. For example, size-related improvements in handling prey may come at the expense of pursuing prey and thus negate any enhancement in overall predatory performance due to increasing size. 2. This hypothesis was tested with longitudinal data from repeated observations of 94 individually known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park, USA. Wolf size was estimated from an individually based sex-specific growth model derived from body mass measurements of 304 wolves. 3. Larger size granted individual wolves a net predatory advantage despite substantial variation in its effect on the performance of different predatory tasks; larger size improved performance of a strength-related task (grappling and subduing elk) but failed to improve performance of a locomotor-related task (selecting an elk from a group) for wolves > 39 kg. 4. Sexual dimorphism in wolf size also explained why males outperformed females in each of the three tasks considered (attacking, selecting, and killing). 5. These findings support the generalization that bigger predators are overall better hunters, but they also indicate that increasing size ultimately limits elements of predatory behaviour that require superior locomotor performance. We argue that this could potentially narrow the dietary niche of larger carnivores as well as limit the evolution of larger size if prey are substantially more difficult to pursue than to handle.

  2. Effects of exposure to bodies of different sizes on perception of and satisfaction with own body size: two randomized studies.

    Science.gov (United States)

    Bould, Helen; Carnegie, Rebecca; Allward, Heather; Bacon, Emily; Lambe, Emily; Sapseid, Megan; Button, Katherine S; Lewis, Glyn; Skinner, Andy; Broome, Matthew R; Park, Rebecca; Harmer, Catherine J; Penton-Voak, Ian S; Munafò, Marcus R

    2018-05-01

    Body dissatisfaction is prevalent among women and associated with subsequent obesity and eating disorders. Exposure to images of bodies of different sizes has been suggested to change the perception of 'normal' body size in others. We tested whether exposure to different-sized (otherwise identical) bodies changes perception of own and others' body size, satisfaction with body size and amount of chocolate consumed. In Study 1, 90 18-25-year-old women with normal BMI were randomized into one of three groups to complete a 15 min two-back task using photographs of women either of 'normal weight' (Body Mass Index (BMI) 22-23 kg m -2 ), or altered to appear either under- or over-weight. Study 2 was identical except the 96 participants had high baseline body dissatisfaction and were followed up after 24 h. We also conducted a mega-analysis combining both studies. Participants rated size of others' bodies, own size, and satisfaction with size pre- and post-task. Post-task ratings were compared between groups, adjusting for pre-task ratings. Participants exposed to over- or normal-weight images subsequently perceived others' bodies as smaller, in comparison to those shown underweight bodies ( p  < 0.001). They also perceived their own bodies as smaller (Study 1, p  = 0.073; Study 2, p  = 0.018; mega-analysis, p  = 0.001), and felt more satisfied with their size (Study 1, p  = 0.046; Study 2, p  = 0.004; mega-analysis, p  = 0.006). There were no differences in chocolate consumption. This study suggests that a move towards using images of women with a BMI in the healthy range in the media may help to reduce body dissatisfaction, and the associated risk of eating disorders.

  3. The impact of psychological stress on men's judgements of female body size.

    Directory of Open Access Journals (Sweden)

    Viren Swami

    Full Text Available BACKGROUND: Previous work has suggested that the experience of psychological stress may influence physical attractiveness ideals, but most evidence in favour of this hypothesis remains archival. The objective of this study was to experimentally investigate the impact of stress on men's judgements of female body size. METHODS: Men were randomly assigned to either an experimental group, in which they took part in a task that heightened stress (experimental group, n = 41 or in which they did not take part in such a task (control group, n = 40. Both groups rated the attractiveness of female bodies varying in size from emaciated to obese, completed a measure of appetite sensation, and had their body mass indices (BMIs measured. RESULTS: Between-groups analyses showed that the experimental group was matched with the control group in terms of mean age, BMI, and appetite sensation. Further analyses showed that men in the experimental group rated a significantly heavier female body size as maximally attractive than the control group. Men in the experimental group also rated heavier female bodies as more attractive and idealised a wider range of female figures than did the control group. CONCLUSION: This study found that the experience of stress was associated with a preference among men for heavier female body sizes. These results indicate that human attractiveness judgements are sensitive to variations in local ecologies and reflect adaptive strategies for dealing with changing environmental conditions.

  4. Body size distribution of the dinosaurs.

    Directory of Open Access Journals (Sweden)

    Eoin J O'Gorman

    Full Text Available The distribution of species body size is critically important for determining resource use within a group or clade. It is widely known that non-avian dinosaurs were the largest creatures to roam the Earth. There is, however, little understanding of how maximum species body size was distributed among the dinosaurs. Do they share a similar distribution to modern day vertebrate groups in spite of their large size, or did they exhibit fundamentally different distributions due to unique evolutionary pressures and adaptations? Here, we address this question by comparing the distribution of maximum species body size for dinosaurs to an extensive set of extant and extinct vertebrate groups. We also examine the body size distribution of dinosaurs by various sub-groups, time periods and formations. We find that dinosaurs exhibit a strong skew towards larger species, in direct contrast to modern day vertebrates. This pattern is not solely an artefact of bias in the fossil record, as demonstrated by contrasting distributions in two major extinct groups and supports the hypothesis that dinosaurs exhibited a fundamentally different life history strategy to other terrestrial vertebrates. A disparity in the size distribution of the herbivorous Ornithischia and Sauropodomorpha and the largely carnivorous Theropoda suggests that this pattern may have been a product of a divergence in evolutionary strategies: herbivorous dinosaurs rapidly evolved large size to escape predation by carnivores and maximise digestive efficiency; carnivores had sufficient resources among juvenile dinosaurs and non-dinosaurian prey to achieve optimal success at smaller body size.

  5. Body size distribution of the dinosaurs.

    Science.gov (United States)

    O'Gorman, Eoin J; Hone, David W E

    2012-01-01

    The distribution of species body size is critically important for determining resource use within a group or clade. It is widely known that non-avian dinosaurs were the largest creatures to roam the Earth. There is, however, little understanding of how maximum species body size was distributed among the dinosaurs. Do they share a similar distribution to modern day vertebrate groups in spite of their large size, or did they exhibit fundamentally different distributions due to unique evolutionary pressures and adaptations? Here, we address this question by comparing the distribution of maximum species body size for dinosaurs to an extensive set of extant and extinct vertebrate groups. We also examine the body size distribution of dinosaurs by various sub-groups, time periods and formations. We find that dinosaurs exhibit a strong skew towards larger species, in direct contrast to modern day vertebrates. This pattern is not solely an artefact of bias in the fossil record, as demonstrated by contrasting distributions in two major extinct groups and supports the hypothesis that dinosaurs exhibited a fundamentally different life history strategy to other terrestrial vertebrates. A disparity in the size distribution of the herbivorous Ornithischia and Sauropodomorpha and the largely carnivorous Theropoda suggests that this pattern may have been a product of a divergence in evolutionary strategies: herbivorous dinosaurs rapidly evolved large size to escape predation by carnivores and maximise digestive efficiency; carnivores had sufficient resources among juvenile dinosaurs and non-dinosaurian prey to achieve optimal success at smaller body size.

  6. Body Size Distribution of the Dinosaurs

    Science.gov (United States)

    O’Gorman, Eoin J.; Hone, David W. E.

    2012-01-01

    The distribution of species body size is critically important for determining resource use within a group or clade. It is widely known that non-avian dinosaurs were the largest creatures to roam the Earth. There is, however, little understanding of how maximum species body size was distributed among the dinosaurs. Do they share a similar distribution to modern day vertebrate groups in spite of their large size, or did they exhibit fundamentally different distributions due to unique evolutionary pressures and adaptations? Here, we address this question by comparing the distribution of maximum species body size for dinosaurs to an extensive set of extant and extinct vertebrate groups. We also examine the body size distribution of dinosaurs by various sub-groups, time periods and formations. We find that dinosaurs exhibit a strong skew towards larger species, in direct contrast to modern day vertebrates. This pattern is not solely an artefact of bias in the fossil record, as demonstrated by contrasting distributions in two major extinct groups and supports the hypothesis that dinosaurs exhibited a fundamentally different life history strategy to other terrestrial vertebrates. A disparity in the size distribution of the herbivorous Ornithischia and Sauropodomorpha and the largely carnivorous Theropoda suggests that this pattern may have been a product of a divergence in evolutionary strategies: herbivorous dinosaurs rapidly evolved large size to escape predation by carnivores and maximise digestive efficiency; carnivores had sufficient resources among juvenile dinosaurs and non-dinosaurian prey to achieve optimal success at smaller body size. PMID:23284818

  7. Artificial fish schools : Collective effects of school size, body size, and body form

    NARCIS (Netherlands)

    Kunz, H.; Hemelrijk, C.K.

    2003-01-01

    Individual-based models of schooling in fish have demonstrated that, via processes of self-organization. artificial fish may school in the absence of a leader or external stimuli, using local information only. We study for the first time how body size and body form of artificial fish affect school

  8. Size matters: relationships between body size and body mass of common coastal, aquatic invertebrates in the Baltic Sea

    Directory of Open Access Journals (Sweden)

    Johan Eklöf

    2017-01-01

    Full Text Available Background Organism biomass is one of the most important variables in ecological studies, making biomass estimations one of the most common laboratory tasks. Biomass of small macroinvertebrates is usually estimated as dry mass or ash-free dry mass (hereafter ‘DM’ vs. ‘AFDM’ per sample; a laborious and time consuming process, that often can be speeded up using easily measured and reliable proxy variables like body size or wet (fresh mass. Another common way of estimating AFDM (one of the most accurate but also time-consuming estimates of biologically active tissue mass is the use of AFDM/DM ratios as conversion factors. So far, however, these ratios typically ignore the possibility that the relative mass of biologically active vs. non-active support tissue (e.g., protective exoskeleton or shell—and therefore, also AFDM/DM ratios—may change with body size, as previously shown for taxa like spiders, vertebrates and trees. Methods We collected aquatic, epibenthic macroinvertebrates (>1 mm in 32 shallow bays along a 360 km stretch of the Swedish coast along the Baltic Sea; one of the largest brackish water bodies on Earth. We then estimated statistical relationships between the body size (length or height in mm, body dry mass and ash-free dry mass for 14 of the most common taxa; five gastropods, three bivalves, three crustaceans and three insect larvae. Finally, we statistically estimated the potential influence of body size on the AFDM/DM ratio per taxon. Results For most taxa, non-linear regression models describing the power relationship between body size and (i DM and (ii AFDM fit the data well (as indicated by low SE and high R2. Moreover, for more than half of the taxa studied (including the vast majority of the shelled molluscs, body size had a negative influence on organism AFDM/DM ratios. Discussion The good fit of the modelled power relationships suggests that the constants reported here can be used to quickly estimate

  9. Muzzle size, paranasal swelling size and body mass in Mandrillus leucophaeus.

    Science.gov (United States)

    Elton, Sarah; Morgan, Bethan J

    2006-04-01

    The drill (Mandrillus leucophaeus), a forest-living Old World monkey, is highly sexually dimorphic, with males exhibiting extreme secondary sexual characteristics, including growth of paranasal swellings on the muzzle. In this study, the size of the secondary bone that forms the paranasal swellings on the muzzles of drills was assessed in relation to body mass proxies. The relationship between the overall size of the muzzle and surrogate measures of body mass was also examined. In female drills, muzzle breadth was positively correlated with two proxies of overall body mass, greatest skull length and upper M1 area. However, there was no such correlation in males. Paranasal swellings in males also appeared to have no significant relationship to body mass proxies. This suggests that secondary bone growth on the muzzles of male drills is independent of overall body size. Furthermore, this secondary bone appears to be vermiculate, probably developing rapidly and in an irregular manner, with no correlation in the sizes of paranasal swelling height and breadth. However, various paranasal swelling dimensions were related to the size of the muzzle. It is suggested that the growth of the paranasal swellings and possibly the muzzle could be influenced by androgen production and reflect testes size and sperm motility. The size and appearance of the paranasal swellings may thus be an indicator of reproductive quality both to potential mates and male competitors. Further work is required to investigate the importance of the paranasal swellings as secondary sexual characteristics in Mandrillus and the relationship between body size and secondary sexual characteristics. Attention should also be paid to the mechanisms and trajectories of facial growth in Mandrillus.

  10. Body size and predatory performance in wolves: Is bigger better?

    Science.gov (United States)

    MacNulty, D.R.; Smith, D.W.; Mech, L.D.; Eberly, L.E.

    2009-01-01

    Large body size hinders locomotor performance in ways that may lead to trade-offs in predator foraging ability that limit the net predatory benefit of larger size. For example, size-related improvements in handling prey may come at the expense of pursuing prey and thus negate any enhancement in overall predatory performance due to increasing size. 2. This hypothesis was tested with longitudinal data from repeated observations of 94 individually known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park, USA. Wolf size was estimated from an individually based sex-specific growth model derived from body mass measurements of 304 wolves. 3. Larger size granted individual wolves a net predatory advantage despite substantial variation in its effect on the performance of different predatory tasks; larger size improved performance of a strength-related task (grappling and subduing elk) but failed to improve performance of a locomotor-related task (selecting an elk from a group) for wolves > 39 kg. 4. Sexual dimorphism in wolf size also explained why males outperformed females in each of the three tasks considered (attacking, selecting, and killing). 5. These findings support the generalization that bigger predators are overall better hunters, but they also indicate that increasing size ultimately limits elements of predatory behaviour that require superior locomotor performance. We argue that this could potentially narrow the dietary niche of larger carnivores as well as limit the evolution of larger size if prey are substantially more difficult to pursue than to handle. ?? 2009 British Ecological Society.

  11. Body composition variation following diaphragmatic breathing ...

    African Journals Online (AJOL)

    Body composition variation following diaphragmatic breathing. ... effect of commonly prescribed diaphragmatic breathing training on the body composition ... a non-exercising control (NE) group (n = 22) or diaphragmatic breathing (DB) group.

  12. Body Size Distribution of the Dinosaurs

    OpenAIRE

    O?Gorman, Eoin J.; Hone, David W. E.

    2012-01-01

    The distribution of species body size is critically important for determining resource use within a group or clade. It is widely known that non-avian dinosaurs were the largest creatures to roam the Earth. There is, however, little understanding of how maximum species body size was distributed among the dinosaurs. Do they share a similar distribution to modern day vertebrate groups in spite of their large size, or did they exhibit fundamentally different distributions due to unique evolutiona...

  13. Body size and premolar evolution in the early-middle eocene euprimates of Wyoming.

    Science.gov (United States)

    Jones, Katrina E; Rose, Kenneth D; Perry, Jonathan M G

    2014-01-01

    The earliest euprimates to arrive in North America were larger-bodied notharctids and smaller-bodied omomyids. Through the Eocene, notharctids generally continued to increase in body size, whereas omomyids generally radiated within small- and increasingly mid-sized niches in the middle Eocene. This study examines the influence of changing body size and diet on the evolution of the lower fourth premolar in Eocene euprimates. The P4 displays considerable morphological variability in these taxa. Despite the fact that most studies of primate dental morphology have focused on the molars, P4 can also provide important paleoecological insights. We analyzed the P4 from 177 euprimate specimens, representing 35 species (11 notharctids and 24 omomyids), in three time bins of approximately equal duration: early Wasatchian, late Wasatchian, and Bridgerian. Two-dimensional surface landmarks were collected from lingual photographs, capturing important variation in cusp position and tooth shape. Disparity metrics were calculated and compared for the three time bins. In the early Eocene, notharctids have a more molarized P4 than omomyids. During the Bridgerian, expanding body size range of omomyids was accompanied by a significant increase in P4 disparity and convergent evolution of the semimolariform condition in the largest omomyines. P4 morphology relates to diet in early euprimates, although patterns vary between families. Copyright © 2013 Wiley Periodicals, Inc.

  14. Nonplantigrade Foot Posture: A Constraint on Dinosaur Body Size.

    Directory of Open Access Journals (Sweden)

    Tai Kubo

    Full Text Available Dinosaurs had functionally digitigrade or sub-unguligrade foot postures. With their immediate ancestors, dinosaurs were the only terrestrial nonplantigrades during the Mesozoic. Extant terrestrial mammals have different optimal body sizes according to their foot posture (plantigrade, digitigrade, and unguligrade, yet the relationship of nonplantigrade foot posture with dinosaur body size has never been investigated, even though the body size of dinosaurs has been studied intensively. According to a large dataset presented in this study, the body sizes of all nonplantigrades (including nonvolant dinosaurs, nonvolant terrestrial birds, extant mammals, and extinct Nearctic mammals are above 500 g, except for macroscelid mammals (i.e., elephant shrew, a few alvarezsauroid dinosaurs, and nondinosaur ornithodirans (i.e., the immediate ancestors of dinosaurs. When nonplantigrade tetrapods evolved from plantigrade ancestors, lineages with nonplantigrade foot posture exhibited a steady increase in body size following Cope's rule. In contrast, contemporaneous plantigrade lineages exhibited no trend in body size evolution and were largely constrained to small body sizes. This evolutionary pattern of body size specific to foot posture occurred repeatedly during both the Mesozoic and the Cenozoic eras. Although disturbed by the end-Cretaceous extinction, species of mid to large body size have predominantly been nonplantigrade animals from the Jurassic until the present; conversely, species with small body size have been exclusively composed of plantigrades in the nonvolant terrestrial tetrapod fauna.

  15. Nonplantigrade Foot Posture: A Constraint on Dinosaur Body Size.

    Science.gov (United States)

    Kubo, Tai; Kubo, Mugino O

    2016-01-01

    Dinosaurs had functionally digitigrade or sub-unguligrade foot postures. With their immediate ancestors, dinosaurs were the only terrestrial nonplantigrades during the Mesozoic. Extant terrestrial mammals have different optimal body sizes according to their foot posture (plantigrade, digitigrade, and unguligrade), yet the relationship of nonplantigrade foot posture with dinosaur body size has never been investigated, even though the body size of dinosaurs has been studied intensively. According to a large dataset presented in this study, the body sizes of all nonplantigrades (including nonvolant dinosaurs, nonvolant terrestrial birds, extant mammals, and extinct Nearctic mammals) are above 500 g, except for macroscelid mammals (i.e., elephant shrew), a few alvarezsauroid dinosaurs, and nondinosaur ornithodirans (i.e., the immediate ancestors of dinosaurs). When nonplantigrade tetrapods evolved from plantigrade ancestors, lineages with nonplantigrade foot posture exhibited a steady increase in body size following Cope's rule. In contrast, contemporaneous plantigrade lineages exhibited no trend in body size evolution and were largely constrained to small body sizes. This evolutionary pattern of body size specific to foot posture occurred repeatedly during both the Mesozoic and the Cenozoic eras. Although disturbed by the end-Cretaceous extinction, species of mid to large body size have predominantly been nonplantigrade animals from the Jurassic until the present; conversely, species with small body size have been exclusively composed of plantigrades in the nonvolant terrestrial tetrapod fauna.

  16. Oocyte size, egg index, and body lipid content in relation to body size in the solitary bee Megachile rotundata.

    Science.gov (United States)

    O'Neill, Kevin M; Delphia, Casey M; O'Neill, Ruth P

    2014-01-01

    Females of solitary, nest-provisioning bees have relatively low fecundity, but produce large eggs as part of their overall strategy of investing substantially in each offspring. In intraspecific comparisons of several species of solitary, nest-provisioning bees and wasps, the size of the mature eggs produced increases with female body size. We further examined oocyte size-body size correlations in the solitary bee Megachile rotundata (F.), an important crop pollinator. We hypothesized that larger females carry larger basal oocytes (i.e., those next in line to be oviposited) but that body size-oocyte size correlations would be absent soon after emergence, before their first eggs fully matured. Because egg production is likely affected by the quantity of stored lipids carried over from the bees' immature stages, we also tested the hypothesis that female body size is correlated with the body lipid content at adult emergence, the time during which oocyte growth accelerates. We found significant correlations of body size with oocyte size variables chosen to reflect: (1) the magnitude of the investment in the next egg to be laid (i.e., the length and volume of the basal oocyte) and (2) the longer term potential to produce mature oocytes (i.e., the summed lengths and volumes of the three largest oocytes in each female). Positive correlations existed throughout the nesting season, even during the first week following adult emergence. The ability to produce and carry larger oocytes may be linked to larger females starting the nesting season with greater lipid stores (which we document here) or to greater space within the abdomen of larger females. Compared to other species of solitary bees, M. rotundata appears to have (1) smaller oocytes than solitary nest-provisioning bees in general, (2) comparable oocyte sizes relative to congeners, and (3) larger oocytes than related brood parasitic megachilids.

  17. Rates and modes of body size evolution in early carnivores and herbivores: a case study from Captorhinidae

    Directory of Open Access Journals (Sweden)

    Neil Brocklehurst

    2016-01-01

    Full Text Available Body size is an extremely important characteristic, impacting on a variety of ecological and life-history traits. It is therefore important to understand the factors which may affect its evolution, and diet has attracted much interest in this context. A recent study which examined the evolution of the earliest terrestrial herbivores in the Late Carboniferous and Early Permian concluded that in the four herbivorous clades examined there was a trend towards increased body size, and that this increase was more substantial than that observed in closely related carnivorous clades. However, this hypothesis was not based on quantitative examination, and phylogenetic comparative methods provide a more robust means of testing such hypotheses. Here, the evolution of body size within different dietary regimes is examined in Captorhinidae, the most diverse and longest lived of these earliest high fibre herbivores. Evolutionary models were fit to their phylogeny to test for variation in rate and mode of evolution between the carnivorous and herbivorous members of this clade, and an analysis of rate variation throughout the tree was carried out. Estimates of ancestral body sizes were calculated in order to compare the rates and direction of evolution of lineages with different dietary regimes. Support for the idea that the high fibre herbivores within captorhinids are being drawn to a higher adaptive peak in body size than the carnivorous members of this clade is weak. A shift in rates of body size evolution is identified, but this does not coincide with the evolution of high-fibre herbivory, instead occurring earlier in time and at a more basal node. Herbivorous lineages which show an increase in size are not found to evolve at a faster rate than those which show a decrease; in fact, it is those which experience a size decrease which evolve at higher rates. It is possible the shift in rates of evolution is related to the improved food processing ability of

  18. Sneaker Males Affect Fighter Male Body Size and Sexual Size Dimorphism in Salmon.

    Science.gov (United States)

    Weir, Laura K; Kindsvater, Holly K; Young, Kyle A; Reynolds, John D

    2016-08-01

    Large male body size is typically favored by directional sexual selection through competition for mates. However, alternative male life-history phenotypes, such as "sneakers," should decrease the strength of sexual selection acting on body size of large "fighter" males. We tested this prediction with salmon species; in southern populations, where sneakers are common, fighter males should be smaller than in northern populations, where sneakers are rare, leading to geographical clines in sexual size dimorphism (SSD). Consistent with our prediction, fighter male body size and SSD (fighter male∶female size) increase with latitude in species with sneaker males (Atlantic salmon Salmo salar and masu salmon Oncorhynchus masou) but not in species without sneakers (chum salmon Oncorhynchus keta and pink salmon Oncorhynchus gorbuscha). This is the first evidence that sneaker males affect SSD across populations and species, and it suggests that alternative male mating strategies may shape the evolution of body size.

  19. Joint evolution of predator body size and prey-size preference.

    NARCIS (Netherlands)

    Troost, T.A.; Kooi, B.W.; Dieckmann, U.

    2007-01-01

    We studied the joint evolution of predator body size and prey-size preference based on dynamic energy budget theory. The predators' demography and their functional response are based on general eco-physiological principles involving the size of both predator and prey. While our model can account for

  20. Joint evolution of predator body size and prey-size preference

    NARCIS (Netherlands)

    Troost, Tineke; Kooi, Bob; Dieckmann, Ulf

    2007-01-01

    We studied the joint evolution of predator body size and prey-size preference based on dynamic energy budget theory. The predators’ demography and their functional response are based on general eco-physiological principles involving the size of both predator and prey. While our model can account

  1. Oocyte size, egg index, and body lipid content in relation to body size in the solitary bee Megachile rotundata

    Directory of Open Access Journals (Sweden)

    Kevin M. O’Neill

    2014-03-01

    Full Text Available Females of solitary, nest-provisioning bees have relatively low fecundity, but produce large eggs as part of their overall strategy of investing substantially in each offspring. In intraspecific comparisons of several species of solitary, nest-provisioning bees and wasps, the size of the mature eggs produced increases with female body size. We further examined oocyte size–body size correlations in the solitary bee Megachile rotundata (F., an important crop pollinator. We hypothesized that larger females carry larger basal oocytes (i.e., those next in line to be oviposited but that body size–oocyte size correlations would be absent soon after emergence, before their first eggs fully matured. Because egg production is likely affected by the quantity of stored lipids carried over from the bees’ immature stages, we also tested the hypothesis that female body size is correlated with the body lipid content at adult emergence, the time during which oocyte growth accelerates. We found significant correlations of body size with oocyte size variables chosen to reflect: (1 the magnitude of the investment in the next egg to be laid (i.e., the length and volume of the basal oocyte and (2 the longer term potential to produce mature oocytes (i.e., the summed lengths and volumes of the three largest oocytes in each female. Positive correlations existed throughout the nesting season, even during the first week following adult emergence. The ability to produce and carry larger oocytes may be linked to larger females starting the nesting season with greater lipid stores (which we document here or to greater space within the abdomen of larger females. Compared to other species of solitary bees, M. rotundata appears to have (1 smaller oocytes than solitary nest-provisioning bees in general, (2 comparable oocyte sizes relative to congeners, and (3 larger oocytes than related brood parasitic megachilids.

  2. Song repertoire size correlates with measures of body size in Eurasian blackbirds

    DEFF Research Database (Denmark)

    Hesler, Nana; Mundry, Roger; Sacher, Thomas

    2012-01-01

    In most oscine bird species males possess a repertoire of different song patterns. The size of these repertoires is assumed to serve as an honest signal of male quality. The Eurasian blackbird’s (Turdus merula) song contains a large repertoire of different element types with a flexible song...... organisation. Here we investigated whether repertoire size in Eurasian blackbirds correlates with measures of body size, namely length of wing, 8th primary, beak and tarsus. So far, very few studies have investigated species with large repertoires and a flexible song organisation in this context. We found...... positive correlations, meaning that larger males had larger repertoires. Larger males may have better fighting abilities and, thus, advantages in territorial defence. Larger structural body size may also reflect better conditions during early development. Therefore, under the assumption that body size...

  3. Body Size, Fecundity, and Sexual Size Dimorphism in the Neotropical Cricket Macroanaxipha macilenta (Saussure) (Orthoptera: Gryllidae).

    Science.gov (United States)

    Cueva Del Castillo, R

    2015-04-01

    Body size is directly or indirectly correlated with fitness. Body size, which conveys maximal fitness, often differs between sexes. Sexual size dimorphism (SSD) evolves because body size tends to be related to reproductive success through different pathways in males and females. In general, female insects are larger than males, suggesting that natural selection for high female fecundity could be stronger than sexual selection in males. I assessed the role of body size and fecundity in SSD in the Neotropical cricket Macroanaxipha macilenta (Saussure). This species shows a SSD bias toward males. Females did not present a correlation between number of eggs and body size. Nonetheless, there were fluctuations in the number of eggs carried by females during the sampling period, and the size of females that were collected carrying eggs was larger than that of females collected with no eggs. Since mating induces vitellogenesis in some cricket species, differences in female body size might suggest male mate choice. Sexual selection in the body size of males of M. macilenta may possibly be stronger than the selection of female fecundity. Even so, no mating behavior was observed during the field observations, including audible male calling or courtship songs, yet males may produce ultrasonic calls due to their size. If female body size in M. macilenta is not directly related to fecundity, the lack of a correlated response to selection on female body size could represent an alternate evolutionary pathway in the evolution of body size and SSD in insects.

  4. Influence of body size on Cu bioaccumulation in zebra mussels Dreissena polymorpha exposed to different sources of particle-associated Cu

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Huan, E-mail: huanzhong1982@hotmail.com [Environmental and Resource Studies Program, Trent University, Peterborough, Ontario (Canada); Nanjing University, School of Environment, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province (China); Kraemer, Lisa; Evans, Douglas [Environmental and Resource Studies Program, Trent University, Peterborough, Ontario (Canada)

    2013-10-15

    Highlights: • Mussels exposed to algal/sediment-Cu have different size-related Cu accumulation. • Size-related Cu accumulation in mussels could be more dependant on algal-Cu uptake. • Importance of algal/sediment-Cu to Cu bioaccumulation varies with mussel body size. • Cu sources (algae and sediments) should be considered in “mussel watch” programs. • Cu stable isotope offers many advantages in Cu bioaccumulation studies. -- Abstract: Size of organisms is critical in controlling metal bioavailability and bioaccumulation, while mechanisms of size-related metal bioaccumulation are not fully understood. To investigate the influences of different sources of particle-associated Cu on body size-related Cu bioavailability and bioaccumulation, zebra mussels (Dreissena polymorpha) of different sizes were exposed to stable Cu isotope ({sup 65}Cu) spiked algae (Chlorella vulgaris) or sediments in the laboratory and the Cu tissue concentration-size relationships were compared with that in unexposed mussels. Copper tissue concentrations decreased with mussel size (tissue or shell dry weight) in both unexposed and algal-exposed mussels with similar decreasing patterns, but were independent of size in sediment-exposed mussels. Furthermore, the relative contribution of Cu uptake from algae (65–91%) to Cu bioaccumulation is always higher than that from sediments (9–35%), possibly due to the higher bioavailability of algal-Cu. Therefore, the size-related ingestion of algae could be more important in influencing the size-related variations in Cu bioaccumulation. However, the relative contribution of sediment-Cu to Cu bioaccumulation increased with body size and thus sediment ingestion may also affect the size-related Cu variations in larger mussels (tissue weight >7.5 mg). This study highlights the importance of considering exposure pathways in normalization of metal concentration variation when using bivalves as biomonitors.

  5. Influence of body size on Cu bioaccumulation in zebra mussels Dreissena polymorpha exposed to different sources of particle-associated Cu.

    Science.gov (United States)

    Zhong, Huan; Kraemer, Lisa; Evans, Douglas

    2013-10-15

    Size of organisms is critical in controlling metal bioavailability and bioaccumulation, while mechanisms of size-related metal bioaccumulation are not fully understood. To investigate the influences of different sources of particle-associated Cu on body size-related Cu bioavailability and bioaccumulation, zebra mussels (Dreissena polymorpha) of different sizes were exposed to stable Cu isotope ((65)Cu) spiked algae (Chlorella vulgaris) or sediments in the laboratory and the Cu tissue concentration-size relationships were compared with that in unexposed mussels. Copper tissue concentrations decreased with mussel size (tissue or shell dry weight) in both unexposed and algal-exposed mussels with similar decreasing patterns, but were independent of size in sediment-exposed mussels. Furthermore, the relative contribution of Cu uptake from algae (65-91%) to Cu bioaccumulation is always higher than that from sediments (9-35%), possibly due to the higher bioavailability of algal-Cu. Therefore, the size-related ingestion of algae could be more important in influencing the size-related variations in Cu bioaccumulation. However, the relative contribution of sediment-Cu to Cu bioaccumulation increased with body size and thus sediment ingestion may also affect the size-related Cu variations in larger mussels (tissue weight >7.5mg). This study highlights the importance of considering exposure pathways in normalization of metal concentration variation when using bivalves as biomonitors. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Rates of molecular evolution in tree ferns are associated with body size, environmental temperature, and biological productivity.

    Science.gov (United States)

    Barrera-Redondo, Josué; Ramírez-Barahona, Santiago; Eguiarte, Luis E

    2018-05-01

    Variation in rates of molecular evolution (heterotachy) is a common phenomenon among plants. Although multiple theoretical models have been proposed, fundamental questions remain regarding the combined effects of ecological and morphological traits on rate heterogeneity. Here, we used tree ferns to explore the correlation between rates of molecular evolution in chloroplast DNA sequences and several morphological and environmental factors within a Bayesian framework. We revealed direct and indirect effects of body size, biological productivity, and temperature on substitution rates, where smaller tree ferns living in warmer and less productive environments tend to have faster rates of molecular evolution. In addition, we found that variation in the ratio of nonsynonymous to synonymous substitution rates (dN/dS) in the chloroplast rbcL gene was significantly correlated with ecological and morphological variables. Heterotachy in tree ferns may be influenced by effective population size associated with variation in body size and productivity. Macroevolutionary hypotheses should go beyond explaining heterotachy in terms of mutation rates and instead, should integrate population-level factors to better understand the processes affecting the tempo of evolution at the molecular level. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

  7. Body size, energy use, and community structure of small mammals

    OpenAIRE

    Ernest, S.K. Morgan

    2005-01-01

    Body size has long been hypothesized to play a major role in community structure and dynamics. Two general hypotheses exist for how resources are distributed among body sizes: (1) resources are equally available and uniformly utilized across body sizes and (2) resources are differentially available to organisms of different body sizes, resulting in a nonuniform or modal distribution. It has also been predicted that the distri-bution of body sizes of species in a community should reflect the u...

  8. Genetic parameters for uniformity of harvest weight and body size traits in the GIFT strain of Nile tilapia.

    Science.gov (United States)

    Marjanovic, Jovana; Mulder, Han A; Khaw, Hooi L; Bijma, Piter

    2016-06-10

    Animal breeding programs have been very successful in improving the mean levels of traits through selection. However, in recent decades, reducing the variability of trait levels between individuals has become a highly desirable objective. Reaching this objective through genetic selection requires that there is genetic variation in the variability of trait levels, a phenomenon known as genetic heterogeneity of environmental (residual) variance. The aim of our study was to investigate the potential for genetic improvement of uniformity of harvest weight and body size traits (length, depth, and width) in the genetically improved farmed tilapia (GIFT) strain. In order to quantify the genetic variation in uniformity of traits and estimate the genetic correlations between level and variance of the traits, double hierarchical generalized linear models were applied to individual trait values. Our results showed substantial genetic variation in uniformity of all analyzed traits, with genetic coefficients of variation for residual variance ranging from 39 to 58 %. Genetic correlation between trait level and variance was strongly positive for harvest weight (0.60 ± 0.09), moderate and positive for body depth (0.37 ± 0.13), but not significantly different from 0 for body length and width. Our results on the genetic variation in uniformity of harvest weight and body size traits show good prospects for the genetic improvement of uniformity in the GIFT strain. A high and positive genetic correlation was estimated between level and variance of harvest weight, which suggests that selection for heavier fish will also result in more variation in harvest weight. Simultaneous improvement of harvest weight and its uniformity will thus require index selection.

  9. Body-size spectra of biofilm-dwelling protozoa and their seasonal shift in coastal ecosystems.

    Science.gov (United States)

    Zhao, Lu; Xu, Guangjian; Wang, Zheng; Xu, Henglong

    2016-10-01

    Community-based assessment of protozoa is usually performed at a taxon-dependent resolution. As an inherent 'taxon-free' trait, however, body-size spectrum has proved to be a highly informative indicator to summarize the functional structure of a community in both community research and monitoring programs in aquatic ecosystems. To demonstrate the relationships between the taxon-free resolution of protozoan communities and water conditions, the body-size spectra of biofilm-dwelling protozoa and their seasonal shift and environmental drivers were explored based on an annual dataset collected monthly from coastal waters of the Yellow Sea, northern China. Body sizes were calculated in equivalent spherical diameter (ESD). Among a total of 8 body-size ranks, S2 (19-27μm), S3 (28-36μm), S4 (37-50μm) and S5 (53-71μm) were the top four levels in frequency of occurrence, while rank S1 (13-17μm), S2 and S4 were the dominant levels in abundance. These dominants showed a clear seasonal succession: S2/S4 (spring)→S2/S4 (summer)→S4 (autumn)→S2 (winter) in frequency of occurrence; S1 (spring)→S4 (summer)→S2 (autumn)→S1 (winter) in abundance. Bootstrapped average analysis showed a clear seasonal shift in body-size spectra of the protozoa during a 1-year cycle, and the best-matching analysis demonstrated that the temporal variations in frequency of occurrence and abundance were significantly correlated with water temperature, pH, dissolved oxygen (DO), alone or in combination with chemical oxygen demand (COD) and nutrients. Thus, the body-size spectra of biofilm-dwelling protozoa were seasonally shaped and might be used as a time and cost efficient bioindicator of water quality in marine ecosystems. Copyright © 2016 Elsevier GmbH. All rights reserved.

  10. Association between inaccurate estimation of body size and obesity in schoolchildren

    Directory of Open Access Journals (Sweden)

    Larissa da Cunha Feio Costa

    2015-12-01

    Full Text Available Objectives: To investigate the prevalence of inaccurate estimation of own body size among Brazilian schoolchildren of both sexes aged 7-10 years, and to test whether overweight/obesity; excess body fat and central obesity are associated with inaccuracy. Methods: Accuracy of body size estimation was assessed using the Figure Rating Scale for Brazilian Children. Multinomial logistic regression was used to analyze associations. Results: The overall prevalence of inaccurate body size estimation was 76%, with 34% of the children underestimating their body size and 42% overestimating their body size. Obesity measured by body mass index was associated with underestimation of body size in both sexes, while central obesity was only associated with overestimation of body size among girls. Conclusions: The results of this study suggest there is a high prevalence of inaccurate body size estimation and that inaccurate estimation is associated with obesity. Accurate estimation of own body size is important among obese schoolchildren because it may be the first step towards adopting healthy lifestyle behaviors.

  11. Investigating Young Children's Perceptions of Body Size and Healthy Habits

    Science.gov (United States)

    Xu, Tingting; Nerren, Jannah S.

    2017-01-01

    Attitudes and biases toward body size perceived as fat and body size perceived as thin are present in young children (Cramer and Steinwert in "J Appl Dev Psychol" 19(3):429-451, 1998; Worobey and Worobey in "Body Image" 11:171-174, 2014). However, the information children have regarding body size and ways to modify body size…

  12. Body Size of Male Youth Soccer Players: 1978-2015.

    Science.gov (United States)

    Malina, Robert M; Figueiredo, António J; Coelho-E-Silva, Manuel J

    2017-10-01

    Studies of the body size and proportions of athletes have a long history. Comparisons of athletes within specific sports across time, though not extensive, indicate both positive and negative trends. To evaluate secular variation in heights and weights of male youth soccer players reported in studies between 1978 and 2015. Reported mean ages, heights, and weights of male soccer players 9-18 years of age were extracted from the literature and grouped into two intervals: 1978-99 and 2000-15. A third-order polynomial was fitted to the mean heights and weights across the age range for each interval, while the Preece-Baines model 1 was fitted to the grand means of mean heights and mean weights within each chronological year to estimate ages at peak height velocity and peak weight velocity for each time interval. Third-order polynomials applied to all data points and estimates based on the Preece-Baines model applied to grand means for each age group provided similar fits. Both indicated secular changes in body size between the two intervals. Secular increases in height and weight between 1978-99 and 2000-15 were especially apparent between 13 and 16 years of age, but estimated ages at peak height velocity (13.01 and 12.91 years) and peak weight velocity (13.86 and 13.77 years) did not differ between the time intervals. Although the body size of youth soccer players increased between 1978-99 and 2000-15, estimated ages at peak height velocity and peak weight velocity did not change. The increase in height and weight likely reflected improved health and nutritional conditions, in addition to the selectivity of soccer reflected in systematic selection and retention of players advanced in maturity status, and exclusion of late maturing players beginning at about 12-13 years of age. Enhanced training programs aimed at the development of strength and power are probably an additional factor contributing to secular increases in body weight.

  13. Size did not matter: An evolutionary account of the variation in penis size and size anxiety

    Directory of Open Access Journals (Sweden)

    Menelaos Apostolou

    2016-12-01

    Full Text Available The human penis exhibits considerable variation in size, while a substantial proportion of the adult male population experiences size anxiety. This paper employs an evolutionary framework in order to understand this variation, as well as the concern men exhibit about the adequacy of the size of their penis. It is argued that female choice has been one important sexual selection force, responsible for shaping the size of the penis. However, this force has been relatively weak, because women do not consider the size of their partners’ penis to be the most important determinant of their sexual satisfaction. Also, in ancestral human societies, sexual satisfaction was a secondary concern, while women had limited space to exercise mate choice. The mismatch between ancestral and modern conditions, with female choice being stronger in the present than in the past, causes anxiety in men about their ability to satisfy their partners, which is also manifested in their concerns about size.

  14. Queen Size Variation in the Ponerine Ant Ponera coarctata (Hymenoptera: Formicidae

    Directory of Open Access Journals (Sweden)

    J. Liebig

    1995-01-01

    Full Text Available Queens of Ponera coarctata show a pronounced variation in size as measured by ommatidia number and Weber's alitrunk length. Isometric size variation and the normal distribution of size categories indicate that, despite these differences, only one queen morph exists. Queen size varies less within colonies than between colonies, and thus appears to be colony specific. Ovary length apparently varies with queen size. Similar size variations as in queens also occured in males, but not in workers.

  15. Body size in early life and risk of breast cancer.

    Science.gov (United States)

    Shawon, Md Shajedur Rahman; Eriksson, Mikael; Li, Jingmei

    2017-07-21

    Body size in early life is inversely associated with adult breast cancer (BC) risk, but it is unclear whether the associations differ by tumor characteristics. In a pooled analysis of two Swedish population-based studies consisting of 6731 invasive BC cases and 28,705 age-matched cancer-free controls, we examined the associations between body size in early life and BC risk. Self-reported body sizes at ages 7 and 18 years were collected by a validated nine-level pictogram (aggregated into three categories: small, medium and large). Odds ratios (OR) and corresponding 95% confidence intervals (CI) were estimated from multivariable logistic regression models in case-control analyses, adjusting for study, age at diagnosis, age at menarche, number of children, hormone replacement therapy, and family history of BC. Body size change between ages 7 and 18 were also examined in relation to BC risk. Case-only analyses were performed to test whether the associations differed by tumor characteristics. Medium or large body size at age 7 and 18 was associated with a statistically significant decreased BC risk compared to small body size (pooled OR (95% CI): comparing large to small, 0.78 (0.70-0.86), P trend <0.001 and 0.72 (0.64-0.80), P trend <0.001, respectively). The majority of the women (~85%) did not change body size categories between age 7 and 18 . Women who remained medium or large between ages 7 and 18 had significantly decreased BC risk compared to those who remained small. A reduction in body size between ages 7 and 18 was also found to be inversely associated with BC risk (0.90 (0.81-1.00)). No significant association was found between body size at age 7 and tumor characteristics. Body size at age 18 was found to be inversely associated with tumor size (P trend  = 0.006), but not estrogen receptor status and lymph node involvement. For all analyses, the overall inferences did not change appreciably after further adjustment for adult body mass index. Our data

  16. Nonplantigrade Foot Posture: A Constraint on Dinosaur Body Size

    OpenAIRE

    Kubo, Tai; Kubo, Mugino O.

    2016-01-01

    Dinosaurs had functionally digitigrade or sub-unguligrade foot postures. With their immediate ancestors, dinosaurs were the only terrestrial nonplantigrades during the Mesozoic. Extant terrestrial mammals have different optimal body sizes according to their foot posture (plantigrade, digitigrade, and unguligrade), yet the relationship of nonplantigrade foot posture with dinosaur body size has never been investigated, even though the body size of dinosaurs has been studied intensively. Accordi...

  17. The effect of body size evolution and ecology on encephalization in cave bears and extant relatives.

    Science.gov (United States)

    Veitschegger, Kristof

    2017-06-05

    The evolution of larger brain volumes relative to body size in Mammalia is the subject of an extensive amount of research. Early on palaeontologists were interested in the brain of cave bears, Ursus spelaeus, and described its morphology and size. However, until now, it was not possible to compare the absolute or relative brain size in a phylogenetic context due to the lack of an established phylogeny, comparative material, and phylogenetic comparative methods. In recent years, many tools for comparing traits within phylogenies were developed and the phylogenetic position of cave bears was resolved based on nuclear as well as mtDNA. Cave bears exhibit significantly lower encephalization compared to their contemporary relatives and intraspecific brain mass variation remained rather small. Encephalization was correlated with the combined dormancy-diet score. Body size evolution was a main driver in the degree of encephalization in cave bears as it increased in a much higher pace than brain size. In Ursus spelaeus, brain and body size increase over time albeit differently paced. This rate pattern is different in the highest encephalized bear species within the dataset, Ursus malayanus. The brain size in this species increased while body size heavily decreased compared to its ancestral stage. Early on in the evolution of cave bears encephalization decreased making it one of the least encephalized bear species compared to extant and extinct members of Ursidae. The results give reason to suspect that as herbivorous animals, cave bears might have exhibited a physiological buffer strategy to survive the strong seasonality of their environment. Thus, brain size was probably affected by the negative trade-off with adipose tissue as well as diet. The decrease of relative brain size in the herbivorous Ursus spelaeus is the result of a considerable increase in body size possibly in combination with environmental conditions forcing them to rest during winters.

  18. How Big Is It Really? Assessing the Efficacy of Indirect Estimates of Body Size in Asian Elephants.

    Directory of Open Access Journals (Sweden)

    Simon N Chapman

    Full Text Available Information on an organism's body size is pivotal in understanding its life history and fitness, as well as helping inform conservation measures. However, for many species, particularly large-bodied wild animals, taking accurate body size measurements can be a challenge. Various means to estimate body size have been employed, from more direct methods such as using photogrammetry to obtain height or length measurements, to indirect prediction of weight using other body morphometrics or even the size of dung boli. It is often unclear how accurate these measures are because they cannot be compared to objective measures. Here, we investigate how well existing estimation equations predict the actual body weight of Asian elephants Elephas maximus, using body measurements (height, chest girth, length, foot circumference and neck circumference taken directly from a large population of semi-captive animals in Myanmar (n = 404. We then define new and better fitting formulas to predict body weight in Myanmar elephants from these readily available measures. We also investigate whether the important parameters height and chest girth can be estimated from photographs (n = 151. Our results show considerable variation in the ability of existing estimation equations to predict weight, and that the equations proposed in this paper predict weight better in almost all circumstances. We also find that measurements from standardised photographs reflect body height and chest girth after applying minor adjustments. Our results have implications for size estimation of large wild animals in the field, as well as for management in captive settings.

  19. Path loss variation of on-body UWB channel in the frequency bands of IEEE 802.15.6 standard.

    Science.gov (United States)

    Goswami, Dayananda; Sarma, Kanak C; Mahanta, Anil

    2016-06-01

    The wireless body area network (WBAN) has gaining tremendous attention among researchers and academicians for its envisioned applications in healthcare service. Ultra wideband (UWB) radio technology is considered as excellent air interface for communication among body area network devices. Characterisation and modelling of channel parameters are utmost prerequisite for the development of reliable communication system. The path loss of on-body UWB channel for each frequency band defined in IEEE 802.15.6 standard is experimentally determined. The parameters of path loss model are statistically determined by analysing measurement data. Both the line-of-sight and non-line-of-sight channel conditions are considered in the measurement. Variations of parameter values with the size of human body are analysed along with the variation of parameter values with the surrounding environments. It is observed that the parameters of the path loss model vary with the frequency band as well as with the body size and surrounding environment. The derived parameter values are specific to the particular frequency bands of IEEE 802.15.6 standard, which will be useful for the development of efficient UWB WBAN system.

  20. Being Barbie: The Size of One’s Own Body Determines the Perceived Size of the World

    Science.gov (United States)

    van der Hoort, Björn; Guterstam, Arvid; Ehrsson, H. Henrik

    2011-01-01

    A classical question in philosophy and psychology is if the sense of one's body influences how one visually perceives the world. Several theoreticians have suggested that our own body serves as a fundamental reference in visual perception of sizes and distances, although compelling experimental evidence for this hypothesis is lacking. In contrast, modern textbooks typically explain the perception of object size and distance by the combination of information from different visual cues. Here, we describe full body illusions in which subjects experience the ownership of a doll's body (80 cm or 30 cm) and a giant's body (400 cm) and use these as tools to demonstrate that the size of one's sensed own body directly influences the perception of object size and distance. These effects were quantified in ten separate experiments with complementary verbal, questionnaire, manual, walking, and physiological measures. When participants experienced the tiny body as their own, they perceived objects to be larger and farther away, and when they experienced the large-body illusion, they perceived objects to be smaller and nearer. Importantly, despite identical retinal input, this “body size effect” was greater when the participants experienced a sense of ownership of the artificial bodies compared to a control condition in which ownership was disrupted. These findings are fundamentally important as they suggest a causal relationship between the representations of body space and external space. Thus, our own body size affects how we perceive the world. PMID:21633503

  1. Pitch (F0) and formant profiles of human vowels and vowel-like baboon grunts: The role of vocalizer body size and voice-acoustic allometry

    Science.gov (United States)

    Rendall, Drew; Kollias, Sophie; Ney, Christina; Lloyd, Peter

    2005-02-01

    Key voice features-fundamental frequency (F0) and formant frequencies-can vary extensively between individuals. Much of the variation can be traced to differences in the size of the larynx and vocal-tract cavities, but whether these differences in turn simply reflect differences in speaker body size (i.e., neutral vocal allometry) remains unclear. Quantitative analyses were therefore undertaken to test the relationship between speaker body size and voice F0 and formant frequencies for human vowels. To test the taxonomic generality of the relationships, the same analyses were conducted on the vowel-like grunts of baboons, whose phylogenetic proximity to humans and similar vocal production biology and voice acoustic patterns recommend them for such comparative research. For adults of both species, males were larger than females and had lower mean voice F0 and formant frequencies. However, beyond this, F0 variation did not track body-size variation between the sexes in either species, nor within sexes in humans. In humans, formant variation correlated significantly with speaker height but only in males and not in females. Implications for general vocal allometry are discussed as are implications for speech origins theories, and challenges to them, related to laryngeal position and vocal tract length. .

  2. Overestimation of body size in eating disorders and its association to body-related avoidance behavior.

    Science.gov (United States)

    Vossbeck-Elsebusch, Anna N; Waldorf, Manuel; Legenbauer, Tanja; Bauer, Anika; Cordes, Martin; Vocks, Silja

    2015-06-01

    Body-related avoidance behavior, e.g., not looking in the mirror, is a common feature of eating disorders. It is assumed that it leads to insufficient feedback concerning one's own real body form and might thus contribute to distorted mental representation of one's own body. However, this assumption still lacks empirical foundation. Therefore, the aim of the present study was to examine the relationship between misperception of one's own body and body-related avoidance behavior in N = 78 female patients with Bulimia nervosa and eating disorder not otherwise specified. Body-size misperception was assessed using a digital photo distortion technique based on an individual picture of each participant which was taken in a standardized suit. In a regression analysis with body-related avoidance behavior, body mass index and weight and shape concerns as predictors, only body-related avoidance behavior significantly contributed to the explanation of body-size overestimation. This result supports the theoretical assumption that body-related avoidance behavior makes body-size overestimation more likely.

  3. Male songbird indicates body size with low-pitched advertising songs.

    Science.gov (United States)

    Hall, Michelle L; Kingma, Sjouke A; Peters, Anne

    2013-01-01

    Body size is a key sexually selected trait in many animal species. If size imposes a physical limit on the production of loud low-frequency sounds, then low-pitched vocalisations could act as reliable signals of body size. However, the central prediction of this hypothesis--that the pitch of vocalisations decreases with size among competing individuals--has limited support in songbirds. One reason could be that only the lowest-frequency components of vocalisations are constrained, and this may go unnoticed when vocal ranges are large. Additionally, the constraint may only be apparent in contexts when individuals are indeed advertising their size. Here we explicitly consider signal diversity and performance limits to demonstrate that body size limits song frequency in an advertising context in a songbird. We show that in purple-crowned fairy-wrens, Malurus coronatus coronatus, larger males sing lower-pitched low-frequency advertising songs. The lower frequency bound of all advertising song types also has a significant negative relationship with body size. However, the average frequency of all their advertising songs is unrelated to body size. This comparison of different approaches to the analysis demonstrates how a negative relationship between body size and song frequency can be obscured by failing to consider signal design and the concept of performance limits. Since these considerations will be important in any complex communication system, our results imply that body size constraints on low-frequency vocalisations could be more widespread than is currently recognised.

  4. Male songbird indicates body size with low-pitched advertising songs.

    Directory of Open Access Journals (Sweden)

    Michelle L Hall

    Full Text Available Body size is a key sexually selected trait in many animal species. If size imposes a physical limit on the production of loud low-frequency sounds, then low-pitched vocalisations could act as reliable signals of body size. However, the central prediction of this hypothesis--that the pitch of vocalisations decreases with size among competing individuals--has limited support in songbirds. One reason could be that only the lowest-frequency components of vocalisations are constrained, and this may go unnoticed when vocal ranges are large. Additionally, the constraint may only be apparent in contexts when individuals are indeed advertising their size. Here we explicitly consider signal diversity and performance limits to demonstrate that body size limits song frequency in an advertising context in a songbird. We show that in purple-crowned fairy-wrens, Malurus coronatus coronatus, larger males sing lower-pitched low-frequency advertising songs. The lower frequency bound of all advertising song types also has a significant negative relationship with body size. However, the average frequency of all their advertising songs is unrelated to body size. This comparison of different approaches to the analysis demonstrates how a negative relationship between body size and song frequency can be obscured by failing to consider signal design and the concept of performance limits. Since these considerations will be important in any complex communication system, our results imply that body size constraints on low-frequency vocalisations could be more widespread than is currently recognised.

  5. Do sex, body size and reproductive condition influence the thermal preferences of a large lizard? A study in Tupinambis merianae.

    Science.gov (United States)

    Cecchetto, Nicolas Rodolfo; Naretto, Sergio

    2015-10-01

    Body temperature is a key factor in physiological processes, influencing lizard performances; and life history traits are expected to generate variability of thermal preferences in different individuals. Gender, body size and reproductive condition may impose specific requirements on preferred body temperatures. If these three factors have different physiological functions and thermal requirements, then the preferred temperature may represent a compromise that optimizes these physiological functions. Therefore, the body temperatures that lizards select in a controlled environment may reflect a temperature that maximizes their physiological needs. The tegu lizard Tupinambis merianae is one of the largest lizards in South America and has wide ontogenetic variation in body size and sexual dimorphism. In the present study we evaluate intraspecific variability of thermal preferences of T. merianae. We determined the selected body temperature and the rate at which males and females attain their selected temperature, in relation to body size and reproductive condition. We also compared the behavior in the thermal gradient between males and females and between reproductive condition of individuals. Our study show that T. merianae selected body temperature within a narrow range of temperatures variation in the laboratory thermal gradient, with 36.24±1.49°C being the preferred temperature. We observed no significant differences between sex, body size and reproductive condition in thermal preferences. Accordingly, we suggest that the evaluated categories of T. merianae have similar thermal requirements. Males showed higher rates to obtain heat than females and reproductive females, higher rates than non-reproductive ones females. Moreover, males and reproductive females showed a more dynamic behavior in the thermal gradient. Therefore, even though they achieve the same selected temperature, they do it differentially. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Large-scale ocean connectivity and planktonic body size

    KAUST Repository

    Villarino, Ernesto; Watson, James R.; Jö nsson, Bror; Gasol, Josep M.; Salazar, Guillem; Acinas, Silvia G.; Estrada, Marta; Massana, Ramó n; Logares, Ramiro; Giner, Caterina R.; Pernice, Massimo C.; Olivar, M. Pilar; Citores, Leire; Corell, Jon; Rodrí guez-Ezpeleta, Naiara; Acuñ a, José Luis; Molina-Ramí rez, Axayacatl; Gonzá lez-Gordillo, J. Ignacio; Có zar, André s; Martí , Elisa; Cuesta, José A.; Agusti, Susana; Fraile-Nuez, Eugenio; Duarte, Carlos M.; Irigoien, Xabier; Chust, Guillem

    2018-01-01

    Global patterns of planktonic diversity are mainly determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size play in determining spatial patterns of diversity remains unclear. Here we analyse spatial community structure - β-diversity - for several planktonic and nektonic organisms from prokaryotes to small mesopelagic fishes collected during the Malaspina 2010 Expedition. β-diversity was compared to surface ocean transit times derived from a global circulation model, revealing a significant negative relationship that is stronger than environmental differences. Estimated dispersal scales for different groups show a negative correlation with body size, where less abundant large-bodied communities have significantly shorter dispersal scales and larger species spatial turnover rates than more abundant small-bodied plankton. Our results confirm that the dispersal scale of planktonic and micro-nektonic organisms is determined by local abundance, which scales with body size, ultimately setting global spatial patterns of diversity.

  7. Large-scale ocean connectivity and planktonic body size

    KAUST Repository

    Villarino, Ernesto

    2018-01-04

    Global patterns of planktonic diversity are mainly determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size play in determining spatial patterns of diversity remains unclear. Here we analyse spatial community structure - β-diversity - for several planktonic and nektonic organisms from prokaryotes to small mesopelagic fishes collected during the Malaspina 2010 Expedition. β-diversity was compared to surface ocean transit times derived from a global circulation model, revealing a significant negative relationship that is stronger than environmental differences. Estimated dispersal scales for different groups show a negative correlation with body size, where less abundant large-bodied communities have significantly shorter dispersal scales and larger species spatial turnover rates than more abundant small-bodied plankton. Our results confirm that the dispersal scale of planktonic and micro-nektonic organisms is determined by local abundance, which scales with body size, ultimately setting global spatial patterns of diversity.

  8. Body size mediates social and environmental effects on nest building behaviour in a fish with paternal care.

    Science.gov (United States)

    Lehtonen, Topi K; Lindström, Kai; Wong, Bob B M

    2015-07-01

    Body size, social setting, and the physical environment can all influence reproductive behaviours, but their interactions are not well understood. Here, we investigated how male body size, male-male competition, and water turbidity influence nest-building behaviour in the sand goby (Pomatoschistus minutus), a marine fish with exclusive paternal care. We found that environmental and social factors affected the nest characteristics of small and large males differently. In particular, association between male size and the level of nest elaboration (i.e. the amount of sand piled on top of the nest) was positive only under clear water conditions. Similarly, male size and nest entrance size were positively associated only in the absence of competition. Such interactions may, in turn, help to explain the persistence of variation in reproductive behaviours, which-due to their importance in offspring survival-are otherwise expected to be under strong balancing selection.

  9. Body size, performance and fitness in galapagos marine iguanas.

    Science.gov (United States)

    Wikelski, Martin; Romero, L Michael

    2003-07-01

    Complex organismal traits such as body size are influenced by innumerable selective pressures, making the prediction of evolutionary trajectories for those traits difficult. A potentially powerful way to predict fitness in natural systems is to study the composite response of individuals in terms of performance measures, such as foraging or reproductive performance. Once key performance measures are identified in this top-down approach, we can determine the underlying physiological mechanisms and gain predictive power over long-term evolutionary processes. Here we use marine iguanas as a model system where body size differs by more than one order of magnitude between island populations. We identified foraging efficiency as the main performance measure that constrains body size. Mechanistically, foraging performance is determined by food pasture height and the thermal environment, influencing intake and digestion. Stress hormones may be a flexible way of influencing an individual's response to low-food situations that may be caused by high population density, famines, or anthropogenic disturbances like oil spills. Reproductive performance, on the other hand, increases with body size and is mediated by higher survival of larger hatchlings from larger females and increased mating success of larger males. Reproductive performance of males may be adjusted via plastic hormonal feedback mechanisms that allow individuals to assess their social rank annually within the current population size structure. When integrated, these data suggest that reproductive performance favors increased body size (influenced by reproductive hormones), with an overall limit imposed by foraging performance (influenced by stress hormones). Based on our mechanistic understanding of individual performances we predicted an evolutionary increase in maximum body size caused by global warming trends. We support this prediction using specimens collected during 1905. We also show in a common

  10. Visual attention mediates the relationship between body satisfaction and susceptibility to the body size adaptation effect.

    Science.gov (United States)

    Stephen, Ian D; Sturman, Daniel; Stevenson, Richard J; Mond, Jonathan; Brooks, Kevin R

    2018-01-01

    Body size misperception-the belief that one is larger or smaller than reality-affects a large and growing segment of the population. Recently, studies have shown that exposure to extreme body stimuli results in a shift in the point of subjective normality, suggesting that visual adaptation may be a mechanism by which body size misperception occurs. Yet, despite being exposed to a similar set of bodies, some individuals within a given geographical area will develop body size misperception and others will not. The reason for these individual difference is currently unknown. One possible explanation stems from the observation that women with lower levels of body satisfaction have been found to pay more attention to images of thin bodies. However, while attention has been shown to enhance visual adaptation effects in low (e.g. rotational and linear motion) and high level stimuli (e.g., facial gender), it is not known whether this effect exists in visual adaptation to body size. Here, we test the hypothesis that there is an indirect effect of body satisfaction on the direction and magnitude of the body fat adaptation effect, mediated via visual attention (i.e., selectively attending to images of thin over fat bodies or vice versa). Significant mediation effects were found in both men and women, suggesting that observers' level of body satisfaction may influence selective visual attention to thin or fat bodies, which in turn influences the magnitude and direction of visual adaptation to body size. This may provide a potential mechanism by which some individuals develop body size misperception-a risk factor for eating disorders, compulsive exercise behaviour and steroid abuse-while others do not.

  11. Both natural selection and isolation by distance explain phenotypic divergence in bill size and body mass between South Australian little penguin colonies.

    Science.gov (United States)

    Colombelli-Négrel, Diane

    2016-11-01

    Morphological variation between populations of the same species can arise as a response to genetic variation, local environmental conditions, or a combination of both. In this study, I examined small-scale geographic variation in bill size and body mass in little penguins ( Eudyptula minor ) across five breeding colonies in South Australia separated by penguin colonies.

  12. Interspecific geographic range size-body size relationship and the diversification dynamics of Neotropical furnariid birds.

    Science.gov (United States)

    Inostroza-Michael, Oscar; Hernández, Cristián E; Rodríguez-Serrano, Enrique; Avaria-Llautureo, Jorge; Rivadeneira, Marcelo M

    2018-05-01

    Among the earliest macroecological patterns documented, is the range and body size relationship, characterized by a minimum geographic range size imposed by the species' body size. This boundary for the geographic range size increases linearly with body size and has been proposed to have implications in lineages evolution and conservation. Nevertheless, the macroevolutionary processes involved in the origin of this boundary and its consequences on lineage diversification have been poorly explored. We evaluate the macroevolutionary consequences of the difference (hereafter the distance) between the observed and the minimum range sizes required by the species' body size, to untangle its role on the diversification of a Neotropical species-rich bird clade using trait-dependent diversification models. We show that speciation rate is a positive hump-shaped function of the distance to the lower boundary. The species with highest and lowest distances to minimum range size had lower speciation rates, while species close to medium distances values had the highest speciation rates. Further, our results suggest that the distance to the minimum range size is a macroevolutionary constraint that affects the diversification process responsible for the origin of this macroecological pattern in a more complex way than previously envisioned. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

  13. Predictable variation of range-sizes across an extreme environmental gradient in a lizard adaptive radiation: evolutionary and ecological inferences.

    Directory of Open Access Journals (Sweden)

    Daniel Pincheira-Donoso

    Full Text Available Large-scale patterns of current species geographic range-size variation reflect historical dynamics of dispersal and provide insights into future consequences under changing environments. Evidence suggests that climate warming exerts major damage on high latitude and elevation organisms, where changes are more severe and available space to disperse tracking historical niches is more limited. Species with longer generations (slower adaptive responses, such as vertebrates, and with restricted distributions (lower genetic diversity, higher inbreeding in these environments are expected to be particularly threatened by warming crises. However, a well-known macroecological generalization (Rapoport's rule predicts that species range-sizes increase with increasing latitude-elevation, thus counterbalancing the impact of climate change. Here, I investigate geographic range-size variation across an extreme environmental gradient and as a function of body size, in the prominent Liolaemus lizard adaptive radiation. Conventional and phylogenetic analyses revealed that latitudinal (but not elevational ranges significantly decrease with increasing latitude-elevation, while body size was unrelated to range-size. Evolutionarily, these results are insightful as they suggest a link between spatial environmental gradients and range-size evolution. However, ecologically, these results suggest that Liolaemus might be increasingly threatened if, as predicted by theory, ranges retract and contract continuously under persisting climate warming, potentially increasing extinction risks at high latitudes and elevations.

  14. Taylor's law and body size in exploited marine ecosystems.

    Science.gov (United States)

    Cohen, Joel E; Plank, Michael J; Law, Richard

    2012-12-01

    Taylor's law (TL), which states that variance in population density is related to mean density via a power law, and density-mass allometry, which states that mean density is related to body mass via a power law, are two of the most widely observed patterns in ecology. Combining these two laws predicts that the variance in density is related to body mass via a power law (variance-mass allometry). Marine size spectra are known to exhibit density-mass allometry, but variance-mass allometry has not been investigated. We show that variance and body mass in unexploited size spectrum models are related by a power law, and that this leads to TL with an exponent slightly <2. These simulated relationships are disrupted less by balanced harvesting, in which fishing effort is spread across a wide range of body sizes, than by size-at-entry fishing, in which only fish above a certain size may legally be caught.

  15. Digestive enzymes and gut morphometric parameters of threespine stickleback (Gasterosteus aculeatus): Influence of body size and temperature.

    Science.gov (United States)

    Hani, Younes Mohamed Ismail; Marchand, Adrien; Turies, Cyril; Kerambrun, Elodie; Palluel, Olivier; Bado-Nilles, Anne; Beaudouin, Rémy; Porcher, Jean-Marc; Geffard, Alain; Dedourge-Geffard, Odile

    2018-01-01

    Determining digestive enzyme activity is of potential interest to obtain and understand valuable information about fish digestive physiology, since digestion is an elementary process of fish metabolism. We described for the first time (i) three digestive enzymes: amylase, trypsin and intestinal alkaline phosphatase (IAP), and (ii) three gut morphometric parameters: relative gut length (RGL), relative gut mass (RGM) and Zihler's index (ZI) in threespine stickleback (Gasterosteus aculeatus), and we studied the effect of temperature and body size on these parameters. When mimicking seasonal variation in temperature, body size had no effect on digestive enzyme activity. The highest levels of amylase and trypsin activity were observed at 18°C, while the highest IAP activity was recorded at 20°C. When sticklebacks were exposed to three constant temperatures (16, 18 and 21°C), a temporal effect correlated to fish growth was observed with inverse evolution patterns between amylase activity and the activities of trypsin and IAP. Temperature (in both experiments) had no effect on morphometric parameters. However, a temporal variation was recorded for both RGM (in the second experiment) and ZI (in both experiments), and the later was correlated to fish body mass.

  16. Digestive enzymes and gut morphometric parameters of threespine stickleback (Gasterosteus aculeatus): Influence of body size and temperature

    Science.gov (United States)

    Marchand, Adrien; Turies, Cyril; Kerambrun, Elodie; Palluel, Olivier; Bado-Nilles, Anne; Beaudouin, Rémy; Porcher, Jean-Marc; Geffard, Alain; Dedourge-Geffard, Odile

    2018-01-01

    Determining digestive enzyme activity is of potential interest to obtain and understand valuable information about fish digestive physiology, since digestion is an elementary process of fish metabolism. We described for the first time (i) three digestive enzymes: amylase, trypsin and intestinal alkaline phosphatase (IAP), and (ii) three gut morphometric parameters: relative gut length (RGL), relative gut mass (RGM) and Zihler’s index (ZI) in threespine stickleback (Gasterosteus aculeatus), and we studied the effect of temperature and body size on these parameters. When mimicking seasonal variation in temperature, body size had no effect on digestive enzyme activity. The highest levels of amylase and trypsin activity were observed at 18°C, while the highest IAP activity was recorded at 20°C. When sticklebacks were exposed to three constant temperatures (16, 18 and 21°C), a temporal effect correlated to fish growth was observed with inverse evolution patterns between amylase activity and the activities of trypsin and IAP. Temperature (in both experiments) had no effect on morphometric parameters. However, a temporal variation was recorded for both RGM (in the second experiment) and ZI (in both experiments), and the later was correlated to fish body mass. PMID:29614133

  17. Effect of size and composition of the body on absolute measurement of calcium in vivo

    International Nuclear Information System (INIS)

    Spinks, T.J.

    1979-01-01

    The effect of size and composition of the body on the measurement of total calcium in absolute units by neutron activation analysis is described. The neutron beam, produced from a cyclotron, was of mean energy 7.5 MeV. Counting of the activities induced in a patient was carried out with a multidetector whole body counter. Calibration of the system was achieved by using two phantoms of different sizes containing known quantities of calcium. The dimensions of various phantom sections were varied to determine the effect on efficiency of activation, an approximately linear relationship with body thickness being found. The influence of body habitus on counting efficiency was assessed by counting different patients who had been given known quantities of 42 K. The effects of (a) the non-uniform distribution of calcium and (b) the variation in density of different tissues on both activation and counting efficiency are discussed. It is estimated that the 68% confidence limits on the measurement of 49 Ca count rate per unit neutron fluence is +- 3.0% and on the measurement of calcium in grams +- 8.2%. (author)

  18. Evidence for the Higher Importance of Signal Size Over Body Size in Aposematic Signaling in Insects

    OpenAIRE

    Remmel, Triinu; Tammarub, Toomas

    2011-01-01

    To understand the evolution of warning coloration, it is important to distinguish between different aspects of conspicuous color patterns. As an example, both pattern element size and body size of prey have been shown to enhance the effectiveness of warning signals. However, it is unclear whether the effect of body size is merely a side effect of proportionally increasing pattern elements, or if there is an effect of body size per se. These possibilities were evaluated by offering different s...

  19. Seed predators exert selection on the subindividual variation of seed size.

    Science.gov (United States)

    Sobral, M; Guitián, J; Guitián, P; Larrinaga, A R

    2014-07-01

    Subindividual variation among repeated organs in plants constitutes an overlooked level of variation in phenotypic selection studies, despite being a major component of phenotypic variation. Animals that interact with plants could be selective agents on subindividual variation. This study examines selective pressures exerted during post-dispersal seed predation and germination on the subindividual variation of seed size in hawthorn (Crataegus monogyna). With a seed offering experiment and a germination test, we estimated phenotypic selection differentials for average and subindividual variation of seed size due to seed predation and germination. Seed size affects germination, growth rate and the probability of an individual seed of escaping predation. Longer seeds showed higher germination rates, but this did not result in significant selection on phenotypes of the maternal trees. On the other hand, seed predators avoided wider seeds, and by doing so exerted phenotypic selection on adult average and subindividual variation of seed size. The detected selection on subindividual variation suggests that the levels of phenotypic variation within individual plants may be, at least partly, the adaptive consequence of animal-mediated selection. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. Can blind persons accurately assess body size from the voice?

    Science.gov (United States)

    Pisanski, Katarzyna; Oleszkiewicz, Anna; Sorokowska, Agnieszka

    2016-04-01

    Vocal tract resonances provide reliable information about a speaker's body size that human listeners use for biosocial judgements as well as speech recognition. Although humans can accurately assess men's relative body size from the voice alone, how this ability is acquired remains unknown. In this study, we test the prediction that accurate voice-based size estimation is possible without prior audiovisual experience linking low frequencies to large bodies. Ninety-one healthy congenitally or early blind, late blind and sighted adults (aged 20-65) participated in the study. On the basis of vowel sounds alone, participants assessed the relative body sizes of male pairs of varying heights. Accuracy of voice-based body size assessments significantly exceeded chance and did not differ among participants who were sighted, or congenitally blind or who had lost their sight later in life. Accuracy increased significantly with relative differences in physical height between men, suggesting that both blind and sighted participants used reliable vocal cues to size (i.e. vocal tract resonances). Our findings demonstrate that prior visual experience is not necessary for accurate body size estimation. This capacity, integral to both nonverbal communication and speech perception, may be present at birth or may generalize from broader cross-modal correspondences. © 2016 The Author(s).

  1. Influence of body size on coexistence of bird species

    NARCIS (Netherlands)

    Leyequien Abarca, E.; Boer, de W.F.; Cleef, A.M.

    2007-01-01

    Theory suggests that body size is an important factor in determining interspecific competition and, ultimately, in structuring ecological communities. However, there is a lack of pragmatic studies linking body size and interspecific competition to patterns in ecological communities. The objective of

  2. Impact of ancestry and body size on sonographic ulnar nerve dimensions

    International Nuclear Information System (INIS)

    Childs, Jessie T.; Phillips, Maureen; Thoirs, Kerry A.

    2012-01-01

    Introduction: The purpose of this study was to investigate the impact that geographic ancestry and body size have on ultrasonographic measurements of the ulnar nerve size measured at the elbow. Materials and methods: We performed anthropometric measurements of body size and ultrasonographic measurements of the ulnar nerve at the elbow on 13 Vietnamese and 24 European participants. Regression analysis was used to determine the effect of body size and geographic ancestry on ulnar nerve size. Results: BMI had the greatest impact on ulnar nerve size. The short axis diameter was least resilient, and the long axis diameter was the most resilient to the effects of body size and geographic ancestry. Discussion: The long axis diameter has an apparent immunity to the influences of overall body size, arm size, or geographic ancestry and has the most potential as a sensitive discriminator between normal nerves and nerves affected by ulnar neuropathy at the elbow.

  3. Body size diversity and frequency distributions of Neotropical cichlid fishes (Cichliformes: Cichlidae: Cichlinae.

    Directory of Open Access Journals (Sweden)

    Sarah E Steele

    Full Text Available Body size is an important correlate of life history, ecology and distribution of species. Despite this, very little is known about body size evolution in fishes, particularly freshwater fishes of the Neotropics where species and body size diversity are relatively high. Phylogenetic history and body size data were used to explore body size frequency distributions in Neotropical cichlids, a broadly distributed and ecologically diverse group of fishes that is highly representative of body size diversity in Neotropical freshwater fishes. We test for divergence, phylogenetic autocorrelation and among-clade partitioning of body size space. Neotropical cichlids show low phylogenetic autocorrelation and divergence within and among taxonomic levels. Three distinct regions of body size space were identified from body size frequency distributions at various taxonomic levels corresponding to subclades of the most diverse tribe, Geophagini. These regions suggest that lineages may be evolving towards particular size optima that may be tied to specific ecological roles. The diversification of Geophagini appears to constrain the evolution of body size among other Neotropical cichlid lineages; non-Geophagini clades show lower species-richness in body size regions shared with Geophagini. Neotropical cichlid genera show less divergence and extreme body size than expected within and among tribes. Body size divergence among species may instead be present or linked to ecology at the community assembly scale.

  4. Emaciated mannequins: a study of mannequin body size in high street fashion stores.

    Science.gov (United States)

    Robinson, Eric; Aveyard, Paul

    2017-01-01

    There is concern that the body size of fashion store mannequins are too thin and promote unrealistic body ideals. To date there has been no systematic examination of the size of high street fashion store mannequins. We surveyed national fashion retailers located on the high street of two English cities. The body size of 'male' and 'female' mannequins was assessed by two blinded research assistants using visual rating scales. The average female mannequin body size was representative of a very underweight woman and 100% of female mannequins represented an underweight body size. The average male mannequin body size was significantly larger than the average female mannequin body size. Only 8% of male mannequins represented an underweight body size. The body size of mannequins used to advertise female fashion is unrealistic and would be considered medically unhealthy in humans.

  5. Genetics of human body size and shape: body proportions and indices.

    Science.gov (United States)

    Livshits, Gregory; Roset, A; Yakovenko, K; Trofimov, S; Kobyliansky, E

    2002-01-01

    The study of the genetic component in morphological variables such as body height and weight, head and chest circumference, etc. has a rather long history. However, only a few studies investigated body proportions and configuration. The major aim of the present study was to evaluate the extent of the possible genetic effects on the inter-individual variation of a number of body configuration indices amenable to clear functional interpretation. Two ethnically different pedigree samples were used in the study: (1) Turkmenians (805 individuals) from Central Asia, and (2) Chuvasha (732 individuals) from the Volga riverside, Russian Federation. To achieve the aim of the present study we proposed three new indices, which were subjected to a statistical-genetic analysis using modified version of "FISHER" software. The proposed indices were: (1) an integral index of torso volume (IND#1), an index reflecting a predisposition of body proportions to maintain a balance in a vertical position (IND#2), and an index of skeletal extremities volume (IND#3). Additionally, the first two principal factors (PF1 and PF2) obtained on 19 measurements of body length and breadth were subjected to genetic analysis. Variance decomposition analysis that simultaneously assess the contribution of gender, age, additive genetic effects and effects of environment shared by the nuclear family members, was applied to fit variation of the above three indices, and PF1 and PF2. The raw familial correlation of all study traits and in both samples showed: (1) all marital correlations did not differ significantly from zero; (2) parent-offspring and sibling correlations were all positive and statistically significant. The parameter estimates obtained in variance analyses showed that from 40% to 75% of inter-individual variation of the studied traits (adjusted for age and sex) were attributable to genetic effects. For PF1 and PF2 in both samples, and for IND#2 (in Chuvasha pedigrees), significant common sib

  6. Correlates of elemental-isotopic composition of stream fishes: the importance of land-use, species identity and body size.

    Science.gov (United States)

    Montaña, C G; Schalk, C M

    2018-04-01

    The isotopic (δ 13 C and δ 15 N) and stoichiometric (C:N:P) compositions of four fish species (Family Centrarchidae: Lepomis auritus, Lepomis cyanellus; Family Cyprinidae: Nocomis leptocephalus, Semotilus atromaculatus) were examined across four North Carolina Piedmont streams arrayed along an urbanization gradient. Both isotopic and stoichiometric composition of fishes appeared to track changes occurring in basal resource availability. Values of δ 13 C of basal resources and consumers were more enriched at the most urbanized streams. Similarly, basal resources and consumers were δ 15 N-enriched at more urbanized streams. Basal resource stoichiometry varied across streams, with periphyton being the most variable. Primary consumers stoichiometry also differed across streams. Intraspecific variation in fish stoichiometry correlated with the degree of urbanization, as the two cyprinids had higher N content and L. cyanellus had higher P content in more urbanized streams, probably due to enrichment of basal resources. Intrinsic factors, specifically species identity and body size also affected stoichiometric variation. Phosphorus (P) content increased significantly with body size in centrarchids, but not in cyprinids. These results suggest that although species identity and body size are important predictors of elemental stoichiometry, the complex nature of altered urban streams may yield imbalances in the elemental composition of consumers via their food resources. © 2018 The Fisheries Society of the British Isles.

  7. Perception of biological motion from size-invariant body representations

    Directory of Open Access Journals (Sweden)

    Markus eLappe

    2015-03-01

    Full Text Available The visual recognition of action is one of the socially most important and computationally demanding capacities of the human visual system. It combines visual shape recognition with complex non-rigid motion perception. Action presented as a point-light animation is a striking visual experience for anyone who sees it for the first time. Information about the shape and posture of the human body is sparse in point-light animations, but it is essential for action recognition. In the posturo-temporal filter model of biological motion perception posture information is picked up by visual neurons tuned to the form of the human body before body motion is calculated. We tested whether point-light stimuli are processed through posture recognition of the human body form by using a typical feature of form recognition, namely size invariance. We constructed a point-light stimulus that can only be perceived through a size-invariant mechanism. This stimulus changes rapidly in size from one image to the next. It thus disrupts continuity of early visuo-spatial properties but maintains continuity of the body posture representation. Despite this massive manipulation at the visuo-spatial level, size-changing point-light figures are spontaneously recognized by naive observers, and support discrimination of human body motion.

  8. Body Size, Extinction Risk and Knowledge Bias in New World Snakes

    Science.gov (United States)

    Vilela, Bruno; Villalobos, Fabricio; Rodríguez, Miguel Ángel; Terribile, Levi Carina

    2014-01-01

    Extinction risk and body size have been found to be related in various vertebrate groups, with larger species being more at risk than smaller ones. We checked whether this was also the case for snakes by investigating extinction risk–body size relationships in the New World's Colubroidea species. We used the IUCN Red List risk categories to assign each species to one of two broad levels of threat (Threatened and Non-Threatened) or to identify it as either Data Deficient or Not-Evaluated by the IUCN. We also included the year of description of each species in our analysis as this could affect the level of threat assigned to it (earlier described species had more time to gather information about them, which might have facilitated their evaluation). Also, species detectability could be a function of body size, with larger species tending to be described earlier, which could have an impact in extinction risk–body size relationships. We found a negative relationship between body size and description year, with large-bodied species being described earlier. Description year also varied among risk categories, with Non-Threatened species being described earlier than Threatened species and both species groups earlier than Data Deficient species. On average, Data Deficient species also presented smaller body sizes, while no size differences were detected between Threatened and Non-Threatened species. So it seems that smaller body sizes are related with species detectability, thus potentially affecting both when a species is described (smaller species tend to be described more recently) as well as the amount of information gathered about it (Data Deficient species tend to be smaller). Our data also indicated that if Data Deficient species were to be categorized as Threatened in the future, snake body size and extinction risk would be negatively related, contrasting with the opposite pattern commonly observed in other vertebrate groups. PMID:25409293

  9. Body size satisfaction and physical activity levels among men and women.

    Science.gov (United States)

    Kruger, Judy; Lee, Chong-Do; Ainsworth, Barbara E; Macera, Caroline A

    2008-08-01

    Body size satisfaction may be an important factor associated with physical activity. We analyzed data from the 2002 National Physical Activity and Weight Loss Survey (NPAWLS), a population-based cross-sectional telephone survey of US adults. Multiple logistic regression models were used to examine the association of body size satisfaction on being regularly active. Participants were aged > or =18 years with complete data on weight, race/ethnicity, physical activity level, and body size satisfaction (n = 10,021). More than half of men (55.8%) and women (53.3%) who reported being very satisfied with the body size were regularly active. After adjustment for covariates, participants who reported being somewhat or not satisfied with their body size had a 13 and 44% lower odds of being regularly active, respectively, compared with those very satisfied with their body size. When stratified by race/ethnicity, this association remained in whites (P for trend physical activity than those less satisfied. Further research is needed to explore predictors of physical activity to reduce health disparities.

  10. Visual diet versus associative learning as mechanisms of change in body size preferences.

    Directory of Open Access Journals (Sweden)

    Lynda G Boothroyd

    Full Text Available Systematic differences between populations in their preferences for body size may arise as a result of an adaptive 'prepared learning' mechanism, whereby cues to health or status in the local population are internalized and affect body preferences. Alternatively, differences between populations may reflect their 'visual diet' as a cognitive byproduct of mere exposure. Here we test the relative importance of these two explanations for variation in body preferences. Two studies were conducted where female observers were exposed to pictures of high or low BMI women which were either aspirational (healthy, attractive models in high status clothes or non-aspirational (eating disordered patients in grey leotards, or to combinations thereof, in order to manipulate their body-weight preferences which were tested at baseline and at post-test. Overall, results showed good support for visual diet effects (seeing a string of small or large bodies resulted in a change from pre- to post-test whether the bodies were aspirational or not and also some support for the associative learning explanation (exposure to aspirational images of overweight women induced a towards preferring larger bodies, even when accompanied by equal exposure to lower weight bodies in the non-aspirational category. Thus, both influences may act in parallel.

  11. Correlates of self-worth and body size dissatisfaction among obese Latino youth.

    Science.gov (United States)

    Mirza, Nazrat M; Mackey, Eleanor Race; Armstrong, Bridget; Jaramillo, Ana; Palmer, Matilde M

    2011-03-01

    The current study examined self-worth and body size dissatisfaction, and their association with maternal acculturation among obese Latino youth enrolled in a community-based obesity intervention program. Upon entry to the program, a sample of 113 participants reported global self-worth comparable to general population norms, but lower athletic competence and perception of physical appearance. Interestingly, body size dissatisfaction was more prevalent among younger respondents. Youth body size dissatisfaction was associated with less acculturated mothers and higher maternal dissatisfaction with their child's body size. By contrast, although global self-worth was significantly related to body dissatisfaction, it was not influenced by mothers' acculturation or dissatisfaction with their own or their child's body size. Obesity intervention programs targeted to Latino youth need to address self-worth concerns among the youth as well as addressing maternal dissatisfaction with their children's body size. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Human vocal attractiveness as signaled by body size projection.

    Directory of Open Access Journals (Sweden)

    Yi Xu

    Full Text Available Voice, as a secondary sexual characteristic, is known to affect the perceived attractiveness of human individuals. But the underlying mechanism of vocal attractiveness has remained unclear. Here, we presented human listeners with acoustically altered natural sentences and fully synthetic sentences with systematically manipulated pitch, formants and voice quality based on a principle of body size projection reported for animal calls and emotional human vocal expressions. The results show that male listeners preferred a female voice that signals a small body size, with relatively high pitch, wide formant dispersion and breathy voice, while female listeners preferred a male voice that signals a large body size with low pitch and narrow formant dispersion. Interestingly, however, male vocal attractiveness was also enhanced by breathiness, which presumably softened the aggressiveness associated with a large body size. These results, together with the additional finding that the same vocal dimensions also affect emotion judgment, indicate that humans still employ a vocal interaction strategy used in animal calls despite the development of complex language.

  13. Evolution of extreme body size disparity in monitor lizards (Varanus).

    Science.gov (United States)

    Collar, David C; Schulte, James A; Losos, Jonathan B

    2011-09-01

    Many features of species' biology, including life history, physiology, morphology, and ecology are tightly linked to body size. Investigation into the causes of size divergence is therefore critical to understanding the factors shaping phenotypic diversity within clades. In this study, we examined size evolution in monitor lizards (Varanus), a clade that includes the largest extant lizard species, the Komodo dragon (V. komodoensis), as well as diminutive species that are nearly four orders of magnitude smaller in adult body mass. We demonstrate that the remarkable body size disparity of this clade is a consequence of different selective demands imposed by three major habitat use patterns-arboreality, terrestriality, and rock-dwelling. We reconstructed phylogenetic relationships and ancestral habitat use and applied model selection to determine that the best-fitting evolutionary models for species' adult size are those that infer oppositely directed adaptive evolution associated with terrestriality and rock-dwelling, with terrestrial lineages evolving extremely large size and rock-dwellers becoming very small. We also show that habitat use affects the evolution of several ecologically important morphological traits independently of body size divergence. These results suggest that habitat use exerts a strong, multidimensional influence on the evolution of morphological size and shape disparity in monitor lizards. © 2011 The Author(s).

  14. Among-Individual Variation in Desert Iguanas (Squamata: Dipsosaurus dorsalis): Endurance Capacity Is Positively Related to Home Range Size.

    Science.gov (United States)

    Singleton, Jennifer M; Garland, Theodore

    Among species of lizards, endurance capacity measured on a motorized treadmill is positively related to daily movement distance and time spent moving, but few studies have addressed such relationships at the level of individual variation within a sex and age category in a single population. Both endurance capacity and home range size show substantial individual variation in lizards, rendering them suitable for such studies. We predicted that these traits would be positively related because endurance capacity is one of the factors that has the potential to limit home range size. We measured the endurance capacity and home range size of adult male desert iguanas (Dipsosaurus dorsalis). Lizards were field captured for measurements of endurance, and home range data were gathered using visual identification of previously marked individuals. Endurance was significantly repeatable between replicate trials, conducted 1-17 d apart ([Formula: see text] for log-transformed values, [Formula: see text], [Formula: see text]). The log of the higher of two endurance trials was positively but not significantly related to log body mass. The log of home range area was positively but not significantly related to log body mass, the number of sightings, or the time span from first to last sighting. As predicted, log endurance was positively correlated with log home range area ([Formula: see text], [Formula: see text], one-tailed [Formula: see text]; for body-mass residual endurance values: [Formula: see text], one-tailed [Formula: see text]). These results suggest that endurance capacity may have a permissive effect on home range size. Alternatively, individuals with larger home ranges may experience training effects (phenotypic plasticity) that increase their endurance.

  15. Rates of ecological divergence and body size evolution are correlated with species diversification in scaly tree ferns

    Science.gov (United States)

    Ramírez-Barahona, Santiago; Barrera-Redondo, Josué; Eguiarte, Luis E.

    2016-01-01

    Variation in species richness across regions and between different groups of organisms is a major feature of evolution. Several factors have been proposed to explain these differences, including heterogeneity in the rates of species diversification and the age of clades. It has been frequently assumed that rapid rates of diversification are coupled to high rates of ecological and morphological evolution, leading to a prediction that remains poorly explored for most species: the positive association between ecological niche divergence, morphological evolution and species diversification. We combined a time-calibrated phylogeny with distribution, ecological and body size data for scaly tree ferns (Cyatheaceae) to test whether rates of species diversification are predicted by the rates at which clades have evolved distinct ecological niches and body sizes. We found that rates of species diversification are positively correlated with rates of ecological and morphological evolution, with rapidly diversifying clades also showing rapidly evolving ecological niches and body sizes. Our results show that rapid diversification of scaly tree ferns is associated with the evolution of species with comparable morphologies that diversified into similar, yet distinct, environments. This suggests parallel evolutionary pathways opening in different tropical regions whenever ecological and geographical opportunities arise. Accordingly, rates of ecological niche and body size evolution are relevant to explain the current patterns of species richness in this ‘ancient’ fern lineage across the tropics. PMID:27412279

  16. Rates of ecological divergence and body size evolution are correlated with species diversification in scaly tree ferns.

    Science.gov (United States)

    Ramírez-Barahona, Santiago; Barrera-Redondo, Josué; Eguiarte, Luis E

    2016-07-13

    Variation in species richness across regions and between different groups of organisms is a major feature of evolution. Several factors have been proposed to explain these differences, including heterogeneity in the rates of species diversification and the age of clades. It has been frequently assumed that rapid rates of diversification are coupled to high rates of ecological and morphological evolution, leading to a prediction that remains poorly explored for most species: the positive association between ecological niche divergence, morphological evolution and species diversification. We combined a time-calibrated phylogeny with distribution, ecological and body size data for scaly tree ferns (Cyatheaceae) to test whether rates of species diversification are predicted by the rates at which clades have evolved distinct ecological niches and body sizes. We found that rates of species diversification are positively correlated with rates of ecological and morphological evolution, with rapidly diversifying clades also showing rapidly evolving ecological niches and body sizes. Our results show that rapid diversification of scaly tree ferns is associated with the evolution of species with comparable morphologies that diversified into similar, yet distinct, environments. This suggests parallel evolutionary pathways opening in different tropical regions whenever ecological and geographical opportunities arise. Accordingly, rates of ecological niche and body size evolution are relevant to explain the current patterns of species richness in this 'ancient' fern lineage across the tropics. © 2016 The Author(s).

  17. Variations in the size of focal nodular hyperplasia on magnetic resonance imaging.

    Science.gov (United States)

    Ramírez-Fuentes, C; Martí-Bonmatí, L; Torregrosa, A; Del Val, A; Martínez, C

    2013-01-01

    To evaluate the changes in the size of focal nodular hyperplasia (FNH) during long-term magnetic resonance imaging (MRI) follow-up. We reviewed 44 FNHs in 30 patients studied with MRI with at least two MRI studies at least 12 months apart. We measured the largest diameter of the lesion (inmm) in contrast-enhanced axial images and calculated the percentage of variation as the difference between the maximum diameter in the follow-up and the maximum diameter in the initial study. We defined significant variation in size as variation greater than 20%. We also analyzed predisposing hormonal factors. The mean interval between the two imaging studies was 35±2 months (range: 12-94). Most lesions (80%) remained stable during follow-up. Only 9 of the 44 lesions (20%) showed a significant variation in diameter: 7 (16%) decreased in size and 2 (4%) increased, with variations that reached the double of the initial size. The change in size was not related to pregnancy, menopause, or the use of birth control pills or corticoids. Changes in the size of FNHs during follow-up are relatively common and should not lead to a change in the diagnosis. These variations in size seem to be independent of hormonal factors that are considered to predispose. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

  18. Body size distributions signal a regime shift in a lake ...

    Science.gov (United States)

    Communities of organisms, from mammals to microorganisms, have discontinuous distributions of body size. This pattern of size structuring is a conservative trait of community organization and is a product of processes that occur at multiple spatial and temporal scales. In this study, we assessed whether body size patterns serve as an indicator of a threshold between alternative regimes. Over the past 7000 years, the biological communities of Foy Lake (Montana,USA) have undergone a major regime shift owing to climate change. We used a palaeoecological record of diatom communities to estimate diatom sizes, and then analysed the discontinuous distribution of organism sizes over time. We used Bayesian classification and regression tree models to determine that all time intervals exhibited aggregations of sizes separated by gaps in the distribution and found a significant change in diatom body size distributions approximately 150 years before the identified ecosystem regime shift. We suggest that discontinuity analysis is a useful addition to the suite of tools for the detection of early warning signals of regime shifts. Communities of organisms from mammals to microorganisms have discontinuous distributions of body size. This pattern of size structuring is a conservative trait of community organization and is a product of processes that occur at discrete spatial and temporal scales within ecosystems. Here, a paleoecological record of diatom community change is use

  19. Ontogenetic and evolutionary effects of predation and competition on nine-spined stickleback (Pungitius pungitius) body size.

    Science.gov (United States)

    Välimäki, Kaisa; Herczeg, Gábor

    2012-07-01

    1. Individual- and population-level variation in body size and growth often correlates with many fitness traits. Predation and food availability are expected to affect body size and growth as important agents of both natural selection and phenotypic plasticity. How differences in predation and food availability affect body size/growth during ontogeny in populations adapted to different predation and competition regimes is rarely studied. 2. Nine-spined stickleback (Pungitius pungitius) populations originating from habitats with varying levels of predation and competition are known to be locally adapted to their respective habitats in terms of body size and growth. Here, we studied how different levels of perceived predation risk and competition during ontogeny affect the reaction norms of body size and growth in (i) marine and pond populations adapted to different levels of predation and competition and (ii) different sexes. We reared nine-spined stickleback in a factorial experiment under two levels of perceived predation risk (present/absent) and competition (high/low food supply). 3. We found divergence in the reaction norms at two levels: (i) predation-adapted marine stickleback had stronger reactions to predatory cues than intraspecific competition-adapted pond stickleback, the latter being more sensitive to available food than the marine fish and (ii) females reacting more strongly to the treatments than males. 4. The repeated, habitat-dependent nature of the differences suggests that natural selection is the agent behind the observed patterns. Our results suggest that genetic adaptation to certain environmental factors also involves an increase in the range of expressible phenotypic plasticity. We found support for this phenomenon at two levels: (i) across populations driven by habitat type and (ii) within populations driven by sex. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

  20. The influence of personal BMI on body size estimations and sensitivity to body size change in anorexia spectrum disorders.

    OpenAIRE

    Cornelissen, Katri; Bester, Andre; Cairns, Paul; Tovee, Martin; Cornelissen, Piers

    2015-01-01

    In this cross-sectional study, we investigated the influence of personal BMI on body size estimation in 42 women who have symptoms of anorexia (referred to henceforth as anorexia spectrum disorders, ANSD), and 100 healthy controls. Low BMI control participants over-estimate their size and high BMI controls under-estimate, a pattern which is predicted by a perceptual phenomenon called contraction bias. In addition, control participants' sensitivity to size change declines as their BMI increase...

  1. Variability in human body size

    Science.gov (United States)

    Annis, J. F.

    1978-01-01

    The range of variability found among homogeneous groups is described and illustrated. Those trends that show significantly marked differences between sexes and among a number of racial/ethnic groups are also presented. Causes of human-body size variability discussed include genetic endowment, aging, nutrition, protective garments, and occupation. The information is presented to aid design engineers of space flight hardware and equipment.

  2. Hip fracture and anthropometric variations: dominance among trochanteric soft tissue thickness, body height and body weight during sideways fall.

    Science.gov (United States)

    Majumder, Santanu; Roychowdhury, Amit; Pal, Subrata

    2013-01-01

    Hip fracture depends on various anthropometric parameters such as trochanteric soft tissue thickness, body height and body weight. The objective was to evaluate the responses to the variations in anthropometric parameters during sideways fall, and to identify the most dominant parameter among them. Seven finite element models were developed having anthropometric variations in trochanteric soft tissue thickness (5-26 mm), body height (1.70-1.88 m), and body weight (63-93.37 kg). These were simulated for sideways fall with ANSYS-LS-DYNA® code. Significant effect of trochanteric soft tissue thickness variation was found on 'normalized peak impact force with respect to the body weight' (p=0.004, r²=0.808) and strain ratio (p=0.083, r²=0.829). But, variation in body height was found to be less significant on normalized peak impact force (p=0.478, r²=0.105) and strain ratio (p=0.292, r²=0.217). Same was true for the variation in body weight on normalized peak impact force (p=0.075, r²=0.456) and strain ratio (p=0.857, r²=0.007). The risk factor for fracture was also well correlated to the strain ratio for the inter-trochanteric zone (pfractures are clinically observed to happen. Trochanteric soft tissue thickness was found likely to be the most dominant parameter over body height and body weight, signifying that a slimmer elderly person, taller or shorter, with less trochanteric soft tissue thickness should be advised to take preventive measures against hip fracture under sideways fall. © 2013.

  3. Oxygen no longer plays a major role in Body Size Evolution

    Science.gov (United States)

    Datta, H.; Sachson, W.; Heim, N. A.; Payne, J.

    2015-12-01

    When observing the long-term relationship between atmospheric oxygen and the maximum size in organisms across the Geozoic (~3.8 Ga - present), it appears that as oxygen increases, organism size grows. However, during the Phanerozoic (541 Ma - Present) oxygen levels varied, so we set out to test the hypothesis that oxygen levels drive patterns marine animal body size evolution. Expected decreases in maximum size due to a lack of oxygen do not occur, and instead, body size continues to increase regardless. In the oxygen data, a relatively low atmospheric oxygen percentage can support increasing body size, so our research tries to determine whether lifestyle affects body size in marine organisms. The genera in the data set were organized based on their tiering, motility, and feeding, such as a pelagic, fully-motile, predator. When organisms fill a certain ecological niche to take advantage of resources, they will have certain life modes, rather than randomly selected traits. For example, even in terrestrial environments, large animals have to constantly feed themselves to support their expensive terrestrial lifestyle which involves fairly consistent movement, and the structural support necessary for that movement. Only organisms with access to high energy food sources or large amounts of food can support themselves, and that is before they expend energy elsewhere. Organisms that expend energy frugally when active or have slower metabolisms in comparison to body size have a more efficient lifestyle and are generally able to grow larger, while those who have higher energy demands like predators are limited to comparatively smaller sizes. Therefore, in respect to the fossil record and modern measurements of animals, the metabolism and lifestyle of an organism dictate its body size in general. With this further clarification on the patterns of evolution, it will be easier to observe and understand the reasons for the ecological traits of organisms today.

  4. Deforestation and stream warming affect body size of Amazonian fishes.

    Science.gov (United States)

    Ilha, Paulo; Schiesari, Luis; Yanagawa, Fernando I; Jankowski, KathiJo; Navas, Carlos A

    2018-01-01

    Declining body size has been suggested to be a universal response of organisms to rising temperatures, manifesting at all levels of organization and in a broad range of taxa. However, no study to date evaluated whether deforestation-driven warming could trigger a similar response. We studied changes in fish body size, from individuals to assemblages, in streams in Southeastern Amazonia. We first conducted sampling surveys to validate the assumption that deforestation promoted stream warming, and to test the hypothesis that warmer deforested streams had reduced fish body sizes relative to cooler forest streams. As predicted, deforested streams were up to 6 °C warmer and had fish 36% smaller than forest streams on average. This body size reduction could be largely explained by the responses of the four most common species, which were 43-55% smaller in deforested streams. We then conducted a laboratory experiment to test the hypothesis that stream warming as measured in the field was sufficient to cause a growth reduction in the dominant fish species in the region. Fish reared at forest stream temperatures gained mass, whereas those reared at deforested stream temperatures lost mass. Our results suggest that deforestation-driven stream warming is likely to be a relevant factor promoting observed body size reductions, although other changes in stream conditions, like reductions in organic matter inputs, can also be important. A broad scale reduction in fish body size due to warming may be occurring in streams throughout the Amazonian Arc of Deforestation, with potential implications for the conservation of Amazonian fish biodiversity and food supply for people around the Basin.

  5. Deforestation and stream warming affect body size of Amazonian fishes

    Science.gov (United States)

    Yanagawa, Fernando I.; Jankowski, KathiJo; Navas, Carlos A.

    2018-01-01

    Declining body size has been suggested to be a universal response of organisms to rising temperatures, manifesting at all levels of organization and in a broad range of taxa. However, no study to date evaluated whether deforestation-driven warming could trigger a similar response. We studied changes in fish body size, from individuals to assemblages, in streams in Southeastern Amazonia. We first conducted sampling surveys to validate the assumption that deforestation promoted stream warming, and to test the hypothesis that warmer deforested streams had reduced fish body sizes relative to cooler forest streams. As predicted, deforested streams were up to 6 °C warmer and had fish 36% smaller than forest streams on average. This body size reduction could be largely explained by the responses of the four most common species, which were 43–55% smaller in deforested streams. We then conducted a laboratory experiment to test the hypothesis that stream warming as measured in the field was sufficient to cause a growth reduction in the dominant fish species in the region. Fish reared at forest stream temperatures gained mass, whereas those reared at deforested stream temperatures lost mass. Our results suggest that deforestation-driven stream warming is likely to be a relevant factor promoting observed body size reductions, although other changes in stream conditions, like reductions in organic matter inputs, can also be important. A broad scale reduction in fish body size due to warming may be occurring in streams throughout the Amazonian Arc of Deforestation, with potential implications for the conservation of Amazonian fish biodiversity and food supply for people around the Basin. PMID:29718960

  6. Genetic integration of molar cusp size variation in baboons.

    Science.gov (United States)

    Koh, Christina; Bates, Elizabeth; Broughton, Elizabeth; Do, Nicholas T; Fletcher, Zachary; Mahaney, Michael C; Hlusko, Leslea J

    2010-06-01

    Many studies of primate diversity and evolution rely on dental morphology for insight into diet, behavior, and phylogenetic relationships. Consequently, variation in molar cusp size has increasingly become a phenotype of interest. In 2007 we published a quantitative genetic analysis of mandibular molar cusp size variation in baboons. Those results provided more questions than answers, as the pattern of genetic integration did not fit predictions from odontogenesis. To follow up, we expanded our study to include data from the maxillary molar cusps. Here we report on these later analyses, as well as inter-arch comparisons with the mandibular data. We analyzed variation in two-dimensional maxillary molar cusp size using data collected from a captive pedigreed breeding colony of baboons, Papio hamadryas, housed at the Southwest National Primate Research Center. These analyses show that variation in maxillary molar cusp size is heritable and sexually dimorphic. We also estimated additive genetic correlations between cusps on the same crown, homologous cusps along the tooth row, and maxillary and mandibular cusps. The pattern for maxillary molars yields genetic correlations of one between the paracone-metacone and protocone-hypocone. Bivariate analyses of cuspal homologues on adjacent teeth yield correlations that are high or not significantly different from one. Between dental arcades, the nonoccluding cusps consistently yield high genetic correlations, especially the metaconid-paracone and metaconid-metacone. This pattern of genetic correlation does not immediately accord with the pattern of development and/or calcification, however these results do follow predictions that can be made from the evolutionary history of the tribosphenic molar. Copyright 2009 Wiley-Liss, Inc.

  7. No Effect of Featural Attention on Body Size Aftereffects

    Directory of Open Access Journals (Sweden)

    Ian David Stephen

    2016-08-01

    Full Text Available Prolonged exposure to images of narrow bodies has been shown to induce a perceptual aftereffect, such that observers’ point of subjective normality (PSN for bodies shifts towards narrower bodies. The converse effect is shown for adaptation to wide bodies. In low-level stimuli, object attention (attention directed to the object and spatial attention (attention directed to the location of the object have been shown to increase the magnitude of visual aftereffects, while object-based attention enhances the adaptation effect in faces. It is not known whether featural attention (attention directed to a specific aspect of the object affects the magnitude of adaptation effects in body stimuli. Here, we manipulate the attention of Caucasian observers to different featural information in body images, by asking them to rate the fatness or sex typicality of male and female bodies manipulated to appear fatter or thinner than average. PSNs for body fatness were taken at baseline and after adaptation, and a change in PSN (ΔPSN was calculated. A body size adaptation effect was found, with observers who viewed fat bodies showing an increased PSN, and those exposed to thin bodies showing a reduced PSN. However, manipulations of featural attention to body fatness or sex typicality produced equivalent results, suggesting that featural attention may not affect the strength of the body size aftereffect.

  8. No Effect of Featural Attention on Body Size Aftereffects.

    Science.gov (United States)

    Stephen, Ian D; Bickersteth, Chloe; Mond, Jonathan; Stevenson, Richard J; Brooks, Kevin R

    2016-01-01

    Prolonged exposure to images of narrow bodies has been shown to induce a perceptual aftereffect, such that observers' point of subjective normality (PSN) for bodies shifts toward narrower bodies. The converse effect is shown for adaptation to wide bodies. In low-level stimuli, object attention (attention directed to the object) and spatial attention (attention directed to the location of the object) have been shown to increase the magnitude of visual aftereffects, while object-based attention enhances the adaptation effect in faces. It is not known whether featural attention (attention directed to a specific aspect of the object) affects the magnitude of adaptation effects in body stimuli. Here, we manipulate the attention of Caucasian observers to different featural information in body images, by asking them to rate the fatness or sex typicality of male and female bodies manipulated to appear fatter or thinner than average. PSNs for body fatness were taken at baseline and after adaptation, and a change in PSN (ΔPSN) was calculated. A body size adaptation effect was found, with observers who viewed fat bodies showing an increased PSN, and those exposed to thin bodies showing a reduced PSN. However, manipulations of featural attention to body fatness or sex typicality produced equivalent results, suggesting that featural attention may not affect the strength of the body size aftereffect.

  9. The Sex Determination Gene transformer Regulates Male-Female Differences in Drosophila Body Size.

    Science.gov (United States)

    Rideout, Elizabeth J; Narsaiya, Marcus S; Grewal, Savraj S

    2015-12-01

    Almost all animals show sex differences in body size. For example, in Drosophila, females are larger than males. Although Drosophila is widely used as a model to study growth, the mechanisms underlying this male-female difference in size remain unclear. Here, we describe a novel role for the sex determination gene transformer (tra) in promoting female body growth. Normally, Tra is expressed only in females. We find that loss of Tra in female larvae decreases body size, while ectopic Tra expression in males increases body size. Although we find that Tra exerts autonomous effects on cell size, we also discovered that Tra expression in the fat body augments female body size in a non cell-autonomous manner. These effects of Tra do not require its only known targets doublesex and fruitless. Instead, Tra expression in the female fat body promotes growth by stimulating the secretion of insulin-like peptides from insulin producing cells in the brain. Our data suggest a model of sex-specific growth in which body size is regulated by a previously unrecognized branch of the sex determination pathway, and identify Tra as a novel link between sex and the conserved insulin signaling pathway.

  10. The Sex Determination Gene transformer Regulates Male-Female Differences in Drosophila Body Size.

    Directory of Open Access Journals (Sweden)

    Elizabeth J Rideout

    2015-12-01

    Full Text Available Almost all animals show sex differences in body size. For example, in Drosophila, females are larger than males. Although Drosophila is widely used as a model to study growth, the mechanisms underlying this male-female difference in size remain unclear. Here, we describe a novel role for the sex determination gene transformer (tra in promoting female body growth. Normally, Tra is expressed only in females. We find that loss of Tra in female larvae decreases body size, while ectopic Tra expression in males increases body size. Although we find that Tra exerts autonomous effects on cell size, we also discovered that Tra expression in the fat body augments female body size in a non cell-autonomous manner. These effects of Tra do not require its only known targets doublesex and fruitless. Instead, Tra expression in the female fat body promotes growth by stimulating the secretion of insulin-like peptides from insulin producing cells in the brain. Our data suggest a model of sex-specific growth in which body size is regulated by a previously unrecognized branch of the sex determination pathway, and identify Tra as a novel link between sex and the conserved insulin signaling pathway.

  11. Carotid body size on CTA: Correlation with comorbidities

    International Nuclear Information System (INIS)

    Cramer, J.A.; Wiggins, R.H.; Fudim, M.; Engelman, Z.J.; Sobotka, P.A.; Shah, L.M.

    2014-01-01

    Aim: To test the hypothesis that computed tomographic angiography (CTA) can identify carotid body enlargement in patients with sympathetically mediated diseases. Materials and methods: A retrospective chart review of all patients obtaining CTAs of the cervical vasculature at University of Utah Health Sciences Center over a 6-month period was performed. Widest axial measurements of both carotid bodies were performed on a picture archiving and communication system (PACS). Statistical analysis was then performed to compare the mean carotid body size between control patients and patients with diabetes mellitus, hypertension, and congestive heart failure. Results: Measurements were performed on 288 patients, with 134 controls. Of the remaining 154, 72 patients had diabetes mellitus, 46 had congestive heart failure, and 130 had hypertension. The control patients had a mean carotid body diameter of 2.3 mm. There was a statistically significant (p < 0.01) 20–25% increase in mean diameter with diabetes mellitus (2.8 mm), hypertension (2.7 mm), and congestive heart failure (2.7 mm; p < 0.01). Conclusions: This study found a 20–25% larger mean carotid body size in patients with diabetes mellitus, hypertension, and congestive heart failure relative to controls. However, this small enlargement should not mimic other carotid body diseases, such as a paraganglionoma. Moreover, these findings further support the proposed functional relationship between the carotid body and sympathetically mediated disease states

  12. Stereometrical analysis of number and size of prolamellar bodies during pea chloroplast development

    Directory of Open Access Journals (Sweden)

    Agnieszka Mostowska

    2014-01-01

    Full Text Available The plastid prolamelar bodies in dark-grown pea seedlings undergo gradual transformation and decay after illumination with low intensity light. Random micrographs do not give direct information concerning the sizes and average numbers of prolamellar bodies in a plastid. These values were obtained after evaluation by a stereometrical method from the ratio of polamellar bodies sizes to the plastid size and from the frequency of prolamellar body sections of a given diameter. Plastids of dark-grown seedlings contained on the average at least one prolamellar body. After illumination the size of the bodies decreased rapidly owing to dispersion into primary thylakoids and split into much smaller numerous prolamellar bodies.

  13. Temporal, spatial, and body size effects on growth rates of loggerhead sea turtles (Caretta caretta) in the Northwest Atlantic

    Science.gov (United States)

    Bjorndal, Karen A.; Schroeder, Barbara A.; Foley, Allen M.; Witherington, Blair E.; Bresette, Michael; Clark, David; Herren, Richard M.; Arendt, Michael D.; Schmid, Jeffrey R.; Meylan, Anne B.; Meylan, Peter A.; Provancha, Jane A.; Hart, Kristen M.; Lamont, Margaret M.; Carthy, Raymond R.; Bolten, Alan B.

    2013-01-01

    In response to a call from the US National Research Council for research programs to combine their data to improve sea turtle population assessments, we analyzed somatic growth data for Northwest Atlantic (NWA) loggerhead sea turtles (Caretta caretta) from 10 research programs. We assessed growth dynamics over wide ranges of geography (9–33°N latitude), time (1978–2012), and body size (35.4–103.3 cm carapace length). Generalized additive models revealed significant spatial and temporal variation in growth rates and a significant decline in growth rates with increasing body size. Growth was more rapid in waters south of the USA (productivity to a common environmental change should be explored to determine whether somatic growth rates can help interpret population trends based on annual counts of nests or nesting females. Because of the significant spatial and temporal variation in growth rates, population models of NWA loggerheads should avoid employing growth data from restricted spatial or temporal coverage to calculate demographic metrics such as age at sexual maturity.

  14. Body Size Predicts Cardiac and Vascular Resistance Effects on Men's and Women's Blood Pressure

    Directory of Open Access Journals (Sweden)

    Joyce M. Evans

    2017-08-01

    Full Text Available Key Points SummaryWe report how blood pressure, cardiac output and vascular resistance are related to height, weight, body surface area (BSA, and body mass index (BMI in healthy young adults at supine rest and standing.Much inter-subject variability in young adult's blood pressure, currently attributed to health status, may actually result from inter-individual body size differences.Each cardiovascular variable is linearly related to height, weight and/or BSA (more than to BMI.When supine, cardiac output is positively related, while vascular resistance is negatively related, to body size. Upon standing, the change in vascular resistance is positively related to size.The height/weight relationships of cardiac output and vascular resistance to body size are responsible for blood pressure relationships to body size.These basic components of blood pressure could help distinguish normal from abnormal blood pressures in young adults by providing a more effective scaling mechanism.Introduction: Effects of body size on inter-subject blood pressure (BP variability are not well established in adults. We hypothesized that relationships linking stroke volume (SV, cardiac output (CO, and total peripheral resistance (TPR with body size would account for a significant fraction of inter-subject BP variability.Methods: Thirty-four young, healthy adults (19 men, 15 women participated in 38 stand tests during which brachial artery BP, heart rate, SV, CO, TPR, and indexes of body size were measured/calculated.Results: Steady state diastolic arterial BP was not significantly correlated with any index of body size when subjects were supine. However, upon standing, the more the subject weighed, or the taller s/he was, the greater the increase in diastolic pressure. Systolic pressure strongly correlated with body weight and height both supine and standing. Diastolic and systolic BP were more strongly related to height, weight and body surface area than to body mass

  15. Body size mediated coexistence in swans.

    Science.gov (United States)

    Engelhardt, Katharina A M; Ritchie, Mark E; Powell, James A

    2014-01-01

    Differences in body sizes may create a trade-off between foraging efficiency (foraging gains/costs) and access to resources. Such a trade-off provides a potential mechanism for ecologically similar species to coexist on one resource. We explored this hypothesis for tundra (Cygnus columbianus) and trumpeter swans (Cygnus buccinator), a federally protected species, feeding solely on sago pondweed (Stuckenia pectinata) tubers during fall staging and wintering in northern Utah. Foraging efficiency was higher for tundra swans because this species experienced lower foraging and metabolic costs relative to foraging gains; however, trumpeter swans (a) had longer necks and therefore had access to exclusive resources buried deep in wetland sediments and (b) were more aggressive and could therefore displace tundra swans from lucrative foraging locations. We conclude that body size differentiation is an important feature of coexistence among ecologically similar species feeding on one resource. In situations where resources are limiting and competition for resources is strong, conservation managers will need to consider the trade-off between foraging efficiency and access to resources to ensure ecologically similar species can coexist on a shared resource.

  16. Body size mediated coexistence of consumers competing for resources in space

    Science.gov (United States)

    Basset, A.; Angelis, D.L.

    2007-01-01

    Body size is a major phenotypic trait of individuals that commonly differentiates co-occurring species. We analyzed inter-specific competitive interactions between a large consumer and smaller competitors, whose energetics, selection and giving-up behaviour on identical resource patches scaled with individual body size. The aim was to investigate whether pure metabolic constraints on patch behaviour of vagile species can determine coexistence conditions consistent with existing theoretical and experimental evidence. We used an individual-based spatially explicit simulation model at a spatial scale defined by the home range of the large consumer, which was assumed to be parthenogenic and semelparous. Under exploitative conditions, competitive coexistence occurred in a range of body size ratios between 2 and 10. Asymmetrical competition and the mechanism underlying asymmetry, determined by the scaling of energetics and patch behaviour with consumer body size, were the proximate determinant of inter-specific coexistence. The small consumer exploited patches more efficiently, but searched for profitable patches less effectively than the larger competitor. Therefore, body-size related constraints induced niche partitioning, allowing competitive coexistence within a set of conditions where the large consumer maintained control over the small consumer and resource dynamics. The model summarises and extends the existing evidence of species coexistence on a limiting resource, and provides a mechanistic explanation for decoding the size-abundance distribution patterns commonly observed at guild and community levels. ?? Oikos.

  17. Does litter size variation affect models of terrestrial carnivore extinction risk and management?

    Directory of Open Access Journals (Sweden)

    Eleanor S Devenish-Nelson

    Full Text Available Individual variation in both survival and reproduction has the potential to influence extinction risk. Especially for rare or threatened species, reliable population models should adequately incorporate demographic uncertainty. Here, we focus on an important form of demographic stochasticity: variation in litter sizes. We use terrestrial carnivores as an example taxon, as they are frequently threatened or of economic importance. Since data on intraspecific litter size variation are often sparse, it is unclear what probability distribution should be used to describe the pattern of litter size variation for multiparous carnivores.We used litter size data on 32 terrestrial carnivore species to test the fit of 12 probability distributions. The influence of these distributions on quasi-extinction probabilities and the probability of successful disease control was then examined for three canid species - the island fox Urocyon littoralis, the red fox Vulpes vulpes, and the African wild dog Lycaon pictus. Best fitting probability distributions differed among the carnivores examined. However, the discretised normal distribution provided the best fit for the majority of species, because variation among litter-sizes was often small. Importantly, however, the outcomes of demographic models were generally robust to the distribution used.These results provide reassurance for those using demographic modelling for the management of less studied carnivores in which litter size variation is estimated using data from species with similar reproductive attributes.

  18. Neural substrate of body size: illusory feeling of shrinking of the waist.

    Directory of Open Access Journals (Sweden)

    H Henrik Ehrsson

    2005-12-01

    Full Text Available The perception of the size and shape of one's body (body image is a fundamental aspect of how we experience ourselves. We studied the neural correlates underlying perceived changes in the relative size of body parts by using a perceptual illusion in which participants felt that their waist was shrinking. We scanned the brains of the participants using functional magnetic resonance imaging. We found that activity in the cortices lining the left postcentral sulcus and the anterior part of the intraparietal sulcus reflected the illusion of waist shrinking, and that this activity was correlated with the reported degree of shrinking. These results suggest that the perceived changes in the size and shape of body parts are mediated by hierarchically higher-order somatosensory areas in the parietal cortex. Based on this finding we suggest that relative size of body parts is computed by the integration of more elementary somatic signals from different body segments.

  19. Dual Quaternion Variational Integrator for Rigid Body Dynamic Simulation

    OpenAIRE

    Xu, Jiafeng; Halse, Karl Henning

    2016-01-01

    In rigid body dynamic simulations, often the algorithm is required to deal with general situations where both reference point and inertia matrix are arbitrarily de- fined. We introduce a novel Lie group variational integrator using dual quaternion for simulating rigid body dynamics in all six degrees of freedom. Dual quaternion is used to represent rigid body kinematics and one-step Lie group method is used to derive dynamic equations. The combination of these two becomes the first Lie group ...

  20. Aortic valve replacement: is there an implant size variation across Europe?

    Science.gov (United States)

    Kapetanakis, Emmanouil I; Athanasiou, Thanos; Mestres, Carlos A; Nashef, Samer A M; Aagaard, Jan; Moritz, Anton; Van Ingen, Gerrit; Chronidou, Fany; Palatianos, George; Alivizatos, Peter A; Stavridis, George T

    2008-03-01

    Prompted by anecdotal evidence and observations by surgeons, an investigation was undertaken into the potential differences in implanted aortic valve prosthesis sizes, during aortic valve replacement (AVR) procedures, between northern and southern European countries. A multi-institutional, non-randomized, retrospective analysis was conducted among 2,932 patients who underwent AVR surgery at seven tertiary cardiac surgery centers throughout Europe. Demographic and perioperative variables including valve size and type, body surface area (BSA) and early mortality were collected. Group analysis by patient geographic distribution and by annular diameter of the prosthesis utilized was conducted. Patients with a manufacturer's labeled prosthesis size > or = 21 mm were assigned to the 'large' aortic size subset, while those with a prosthesis size < 21 mm were assigned to the 'small' aortic size subset. Effective orifice area indices were calculated for all patients to assess the geographic distribution of patient-prosthesis mismatch. Univariable and multivariable logistic regression analyses adjusting for possible confounding variables were performed. Prostheses with diameter < 21 mm were implanted at almost twice the rate in southern Europe compared to the north (56.4% versus 26.7%, p < 0.01). The mean valve size was also smaller in southern compared to northern European patients (21.6 +/- 2.1 mm versus 23.4 +/- 2.2 mm, p < 0.01). There were no regional differences in the distribution of either gender or BSA. In the multivariable model, south European patients were seven times more likely to receive a smaller-sized aortic valve (OR = 6.5, 95% CI = 4.82-8.83, p < 0.01), and thus the odds of developing patient-prosthesis mismatch were increased two-fold in southern European patients (OR = 1.9, 95% CI = 1.25-2.80, p = 0.02). However, neither geographic distribution nor valve size were significantly associated with operative mortality. The study results demonstrated

  1. The body size of the oil-collecting bee Tetrapedia diversipes (Apidae)

    OpenAIRE

    Pinto da Silva,Carlos; Silva,Adriana; Duran Cordeiro,Guaraci; Alves dos Santos ,Isabel

    2015-01-01

    The body size of bees can affect their fitness in many ways. There is an indirect relationship between the size of the mother and the size of her progeny. This is so because large mothers use larger nests and brood cells and have higher foraging capacity than small mothers, and consequently large mothers supply a larger amount of food to their larvae, which grow larger. We analyzed the relationship between body size of individual oil-collecting bees of the species Tetrapedia diversipes and th...

  2. The non-linear relationship between body size and function in parrotfishes

    Science.gov (United States)

    Lokrantz, J.; Nyström, M.; Thyresson, M.; Johansson, C.

    2008-12-01

    Parrotfishes are a group of herbivores that play an important functional role in structuring benthic communities on coral reefs. Increasingly, these fish are being targeted by fishermen, and resultant declines in biomass and abundance may have severe consequences for the dynamics and regeneration of coral reefs. However, the impact of overfishing extends beyond declining fish stocks. It can also lead to demographic changes within species populations where mean body size is reduced. The effect of reduced mean body size on population dynamics is well described in literature but virtually no information exists on how this may influence important ecological functions. The study investigated how one important function, scraping (i.e., the capacity to remove algae and open up bare substratum for coral larval settlement), by three common species of parrotfishes ( Scarus niger, Chlorurus sordidus, and Chlorurus strongylocephalus) on coral reefs at Zanzibar (Tanzania) was influenced by the size of individual fishes. There was a non-linear relationship between body size and scraping function for all species examined, and impact through scraping was also found to increase markedly when fish reached a size of 15 20 cm. Thus, coral reefs which have a high abundance and biomass of parrotfish may nonetheless be functionally impaired if dominated by small-sized individuals. Reductions in mean body size within parrotfish populations could, therefore, have functional impacts on coral reefs that previously have been overlooked.

  3. Body size ideals and dissatisfaction in Ghanaian adolescents: role of media, lifestyle and well-being.

    Science.gov (United States)

    Michels, N; Amenyah, S D

    2017-05-01

    To inspire effective health promotion campaigns, we tested the relationship of ideal body size and body size dissatisfaction with (1) the potential resulting health-influencing factors diet, physical activity and well-being; and (2) with media as a potential influencer of body ideals. This is a cross-sectional study in 370 Ghanaian adolescents (aged 11-18 years). Questionnaires included disordered eating (EAT26), diet quality (FFQ), physical activity (IPAQ), well-being (KINDL) and media influence on appearance (SATAQ: pressure, internalisation and information). Ideal body size and body size dissatisfaction were assessed using the Stunkard figure rating scale. Body mass index (BMI), skinfolds and waist were measured. Linear regressions were adjusted for gender, age and parental education. Also, mediation was tested: 'can perceived media influence play a role in the effects of actual body size on body size dissatisfaction?'. Body size dissatisfaction was associated with lower well-being and more media influence (pressure and internalisation) but not with physical activity, diet quality or disordered eating. An underweight body size ideal might worsen disordered eating but was not significantly related to the other predictors of interest. Only a partial mediation effect by media pressure was found: especially overweight adolescents felt media pressure, and this media pressure was associated with more body size dissatisfaction. To prevent disordered eating and low well-being, health messages should include strategies that reduce body size dissatisfaction and increase body esteem by not focussing on the thin body ideal. Changing body size ideals in the media might be an appropriate way since media pressure was a mediator in the BMI-dissatisfaction relation. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  4. Adjusting parameters of aortic valve stenosis severity by body size

    DEFF Research Database (Denmark)

    Minners, Jan; Gohlke-Baerwolf, Christa; Kaufmann, Beat A

    2014-01-01

    stenosis (jet velocity ≥2.5 m/s) and related to outcomes in a second cohort of 1525 patients from the Simvastatin/Ezetimibe in Aortic Stenosis (SEAS) study. RESULTS: Whereas jet velocity and MPG were independent of body size, AVA was significantly correlated with height, weight, BSA and BMI (Pearson...... correlation coefficient (r) 0.319, 0.281, 0.317 and 0.126, respectively, all pcorrelation between AVA and body size...

  5. Migrate small, sound big: functional constraints on body size promote tracheal elongation in cranes.

    Science.gov (United States)

    Jones, M R; Witt, C C

    2014-06-01

    Organismal traits often represent the outcome of opposing selection pressures. Although social or sexual selection can cause the evolution of traits that constrain function or survival (e.g. ornamental feathers), it is unclear how the strength and direction of selection respond to ecological shifts that increase the severity of the constraint. For example, reduced body size might evolve by natural selection to enhance flight performance in migratory birds, but social or sexual selection favouring large body size may provide a countervailing force. Tracheal elongation is a potential outcome of these opposing pressures because it allows birds to convey an auditory signal of exaggerated body size. We predicted that the evolution of migration in cranes has coincided with a reduction in body size and a concomitant intensification of social or sexual selection for apparent large body size via tracheal elongation. We used a phylogenetic comparative approach to examine the relationships among migration distance, body mass and trachea length in cranes. As predicted, we found that migration distance correlated negatively with body size and positively with proportional trachea length. This result was consistent with our hypothesis that evolutionary reductions in body size led to intensified selection for trachea length. The most likely ultimate causes of intensified positive selection on trachea length are the direct benefits of conveying a large body size in intraspecific contests for mates and territories. We conclude that the strength of social or sexual selection on crane body size is linked to the degree of functional constraint. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  6. Temporal variation of floc size and settling velocity in the Dollard estuary

    Science.gov (United States)

    Van der Lee, Willem T. B.

    2000-09-01

    Temporal changes in floc size and settling velocity were measured in the Dollard estuary with an under water video camera. The results show that the flocs in the Dollard are very heterogeneous and that larger flocs have much lower effective densities than smaller flocs. Due to this density decrease, floc settling velocities show only a minor increase with increasing floc size. Floc sizes and settling velocities correlate with the suspended sediment concentration (SSC) on a tidal time scale, but not on a seasonal time scale. On a seasonal time scale floc sizes depend on the binding properties of the sediment, while floc settling velocities show hardly any variation, as an increase in floc size is mainly counterbalanced by a decrease in floc density. Tidal variations in settling velocity occur but cannot be modeled solely as a function of SSC, as the relation between floc size/settling velocity and SSC constantly changes in time and space. Settling velocity variations throughout the tide can however be expressed as a function of tidal phase.

  7. Body Size Preference of Marine Animals in Relation to Extinction Selectivity

    Science.gov (United States)

    Sriram, A.; Idgunji, S.; Heim, N. A.; Payne, J.

    2014-12-01

    Our project encompasses an extremely specific aspect in relation to the five mass extinctions in geologic history. We asked ourselves whether larger or smaller body sizes would be better suited for surviving a mass extinction. To conduct research for our project, we used the body sizes of 17,172 marine animal genera as our primary data. These animals include echinoderms, arthropods, chordates, mollusks, and brachiopods. These creatures are perfect model organisms in terms of finding data on them because they have an excellent fossil record, and are well documented. We focused on the mean body size of these animals before and after each of the five mass extinctions (end-Ordovician, Late Devonian, end-Permian, end-Triassic, and end-Cretaceous). Our hypothesis was that the average biovolume of animals increased after each of the extinctions, with the mean size being greater after than it was before. Our size data is from the Ellis & Messina Catalogue of Ostracoda and the Treatise on Invertebrate Paleontology. We obtained stratigraphic range data The Treatise and Sepkoski (2002). In our analyses, we compared the mean size of the different animal genera before and after each extinction event. We further partitioned size change across mass extinction boundaries into three categories: the surviving genera, the extinct genera, and the newly originating genera that came about after the extinction. According to our analyses, the mean sizes did not change significantly from the genera living during the stages before the extinctions and after the extinctions. From our results, we can assume that there were not enough major increases in the overall volume of the organisms to warrant a definite conclusion that extinctions lead to larger body sizes. Further support for our findings came from the T-tests in our R code. Only the Cretaceous period showed true evidence for size changing because of the extinction; in this case, the mean size decreased. T-tests for the Cretaceous

  8. Illusory changes in body size modulate body satisfaction in a way that is related to non-clinical eating disorder psychopathology.

    Directory of Open Access Journals (Sweden)

    Catherine Preston

    Full Text Available Historically, body size overestimation has been linked to abnormal levels of body dissatisfaction found in eating disorders. However, recently this relationship has been called into question. Indeed, despite a link between how we perceive and how we feel about our body seeming intuitive, until now lack of an experimental method to manipulate body size has meant that a causal link, even in healthy participants, has remained elusive. Recent developments in body perception research demonstrate that the perceptual experience of the body can be readily manipulated using multisensory illusions. The current study exploits such illusions to modulate perceived body size in an attempt to influence body satisfaction. Participants were presented with stereoscopic video images of slimmer and wider mannequin bodies viewed through head-mounted displays from first person perspective. Illusory ownership was induced by synchronously stroking the seen mannequin body with the unseen real body. Pre and post-illusion affective and perceptual measures captured changes in perceived body size and body satisfaction. Illusory ownership of a slimmer body resulted in participants perceiving their actual body as slimmer and giving higher ratings of body satisfaction demonstrating a direct link between perceptual and affective body representations. Change in body satisfaction following illusory ownership of a wider body, however, was related to degree of (non-clinical eating disorder psychopathology, which can be linked to fluctuating body representations found in clinical samples. The results suggest that body perception is linked to body satisfaction and may be of importance for eating disorder symptomology.

  9. Illusory Changes in Body Size Modulate Body Satisfaction in a Way That Is Related to Non-Clinical Eating Disorder Psychopathology

    Science.gov (United States)

    Preston, Catherine; Ehrsson, H. Henrik

    2014-01-01

    Historically, body size overestimation has been linked to abnormal levels of body dissatisfaction found in eating disorders. However, recently this relationship has been called into question. Indeed, despite a link between how we perceive and how we feel about our body seeming intuitive, until now lack of an experimental method to manipulate body size has meant that a causal link, even in healthy participants, has remained elusive. Recent developments in body perception research demonstrate that the perceptual experience of the body can be readily manipulated using multisensory illusions. The current study exploits such illusions to modulate perceived body size in an attempt to influence body satisfaction. Participants were presented with stereoscopic video images of slimmer and wider mannequin bodies viewed through head-mounted displays from first person perspective. Illusory ownership was induced by synchronously stroking the seen mannequin body with the unseen real body. Pre and post-illusion affective and perceptual measures captured changes in perceived body size and body satisfaction. Illusory ownership of a slimmer body resulted in participants perceiving their actual body as slimmer and giving higher ratings of body satisfaction demonstrating a direct link between perceptual and affective body representations. Change in body satisfaction following illusory ownership of a wider body, however, was related to degree of (non-clinical) eating disorder psychopathology, which can be linked to fluctuating body representations found in clinical samples. The results suggest that body perception is linked to body satisfaction and may be of importance for eating disorder symptomology. PMID:24465698

  10. Aging and body size in solitary bees

    Science.gov (United States)

    Solitary bees are important pollinators of crops and non-domestic plants. Osmia lignaria is a native, commercially-reared solitary bee used to maximize pollination in orchard crops. In solitary bees, adult body size is extremely variable depending on the nutritional resources available to the develo...

  11. Body Size Mediated Coexistence in Swans

    Directory of Open Access Journals (Sweden)

    Katharina A. M. Engelhardt

    2014-01-01

    Full Text Available Differences in body sizes may create a trade-off between foraging efficiency (foraging gains/costs and access to resources. Such a trade-off provides a potential mechanism for ecologically similar species to coexist on one resource. We explored this hypothesis for tundra (Cygnus columbianus and trumpeter swans (Cygnus buccinator, a federally protected species, feeding solely on sago pondweed (Stuckenia pectinata tubers during fall staging and wintering in northern Utah. Foraging efficiency was higher for tundra swans because this species experienced lower foraging and metabolic costs relative to foraging gains; however, trumpeter swans (a had longer necks and therefore had access to exclusive resources buried deep in wetland sediments and (b were more aggressive and could therefore displace tundra swans from lucrative foraging locations. We conclude that body size differentiation is an important feature of coexistence among ecologically similar species feeding on one resource. In situations where resources are limiting and competition for resources is strong, conservation managers will need to consider the trade-off between foraging efficiency and access to resources to ensure ecologically similar species can coexist on a shared resource.

  12. Big or fast: two strategies in the developmental control of body size

    OpenAIRE

    Nijhout, H. Frederik

    2015-01-01

    Adult body size is controlled by the mechanisms that stop growth when a species-characteristic size has been reached. The mechanisms by which size is sensed and by which this information is transduced to the growth regulating system are beginning to be understood in a few species of insects. Two rather different strategies for control have been discovered; one favors large body size and the other favors rapid development.

  13. Body size and body esteem in women : The mediating role of possible self expectancy

    NARCIS (Netherlands)

    Dalley, Simon E.; Pollet, Thomas V.; Vidal, Jose

    We predicted that an expectancy of acquiring a feared fat self and an expectancy of acquiring a hoped-for thin self both mediate the impact of body size on women's body esteem. We also predicted that the mediating pathway through the feared fat self would be stronger than that through the hoped-for

  14. Body size and body esteem in women: The mediating role of possible self expectancy

    NARCIS (Netherlands)

    Dalley, S.E.; Pollet, T.V.; Vidal, J.

    2013-01-01

    We predicted that an expectancy of acquiring a feared fat self and an expectancy of acquiring a hoped-for thin self both mediate the impact of body size on women's body esteem. We also predicted that the mediating pathway through the feared fat self would be stronger than that through the hoped-for

  15. Body size limits dim-light foraging activity in stingless bees (Apidae: Meliponini).

    Science.gov (United States)

    Streinzer, Martin; Huber, Werner; Spaethe, Johannes

    2016-10-01

    Stingless bees constitute a species-rich tribe of tropical and subtropical eusocial Apidae that act as important pollinators for flowering plants. Many foraging tasks rely on vision, e.g. spatial orientation and detection of food sources and nest entrances. Meliponini workers are usually small, which sets limits on eye morphology and thus quality of vision. Limitations are expected both on acuity, and thus on the ability to detect objects from a distance, as well as on sensitivity, and thus on the foraging time window at dusk and dawn. In this study, we determined light intensity thresholds for flight under dim light conditions in eight stingless bee species in relation to body size in a Neotropical lowland rainforest. Species varied in body size (0.8-1.7 mm thorax-width), and we found a strong negative correlation with light intensity thresholds (0.1-79 lx). Further, we measured eye size, ocelli diameter, ommatidia number, and facet diameter. All parameters significantly correlated with body size. A disproportionately low light intensity threshold in the minute Trigonisca pipioli, together with a large eye parameter P eye suggests specific adaptations to circumvent the optical constraints imposed by the small body size. We discuss the implications of body size in bees on foraging behavior.

  16. Low level of polyandry constrains phenotypic plasticity of male body size in mites.

    Directory of Open Access Journals (Sweden)

    Peter Schausberger

    Full Text Available Polyandry, i.e. females mating with multiple males, is more common than previously anticipated and potentially provides both direct and indirect fitness benefits to females. The level of polyandry (defined by the lifetime number of male mates of a female is an important determinant of the occurrence and intensity of sexual selection acting on male phenotypes. While the forces of sexual selection acting on phenotypic male traits such as body size are relatively well understood, sexual selection acting on phenotypic plasticity of these traits is unexplored. We tackled this issue by scrutinizing the link between polyandry and phenotypic plasticity of male body size in two sympatric plant-inhabiting predatory mite species, Phytoseiulus persimilis and Neoseiulus californicus. These two species are similar in life history, ecological niche requirements, mating behavior, polygyny and female body size plasticity but strikingly differ in the level of both polyandry and phenotypic plasticity of male body size (both lower in P. persimilis. We hypothesized that deviations from standard body size, i.e. the size achieved under favorable conditions, incur higher costs for males in the less polyandrous P. persimilis. To test our hypotheses, we conducted two experiments on (i the effects of male body size on spermatophore transfer in singly mating females and (ii the effects of mate sequence (switching the order of standard-sized and small males on mating behavior and paternity success in doubly mating females. In P. persimilis but not N. californicus, small males transferred fewer but larger spermatophores to the females; in both species, females re-mated more likely with standard-sized following small than small following standard-sized males; in P. persimilis, first standard-sized males sired a higher proportion of offspring produced after re-mating by the female than first small males, whereas in N. californicus the paternity success of small and standard-sized

  17. Low level of polyandry constrains phenotypic plasticity of male body size in mites.

    Science.gov (United States)

    Schausberger, Peter; Walzer, Andreas; Murata, Yasumasa; Osakabe, Masahiro

    2017-01-01

    Polyandry, i.e. females mating with multiple males, is more common than previously anticipated and potentially provides both direct and indirect fitness benefits to females. The level of polyandry (defined by the lifetime number of male mates of a female) is an important determinant of the occurrence and intensity of sexual selection acting on male phenotypes. While the forces of sexual selection acting on phenotypic male traits such as body size are relatively well understood, sexual selection acting on phenotypic plasticity of these traits is unexplored. We tackled this issue by scrutinizing the link between polyandry and phenotypic plasticity of male body size in two sympatric plant-inhabiting predatory mite species, Phytoseiulus persimilis and Neoseiulus californicus. These two species are similar in life history, ecological niche requirements, mating behavior, polygyny and female body size plasticity but strikingly differ in the level of both polyandry and phenotypic plasticity of male body size (both lower in P. persimilis). We hypothesized that deviations from standard body size, i.e. the size achieved under favorable conditions, incur higher costs for males in the less polyandrous P. persimilis. To test our hypotheses, we conducted two experiments on (i) the effects of male body size on spermatophore transfer in singly mating females and (ii) the effects of mate sequence (switching the order of standard-sized and small males) on mating behavior and paternity success in doubly mating females. In P. persimilis but not N. californicus, small males transferred fewer but larger spermatophores to the females; in both species, females re-mated more likely with standard-sized following small than small following standard-sized males; in P. persimilis, first standard-sized males sired a higher proportion of offspring produced after re-mating by the female than first small males, whereas in N. californicus the paternity success of small and standard-sized males was

  18. Body composition of freshwater Wallago attu in relation to body size ...

    African Journals Online (AJOL)

    Wallago attu is one of the large freshwater catfish found in Pakistan. The rapid growth and high nutritional quality encouraged investigation into the aquaculture potential of this excellent food fish. It was observed that body size had a positive influence on percent ash, percent fat and percent protein contents (wet weight) but ...

  19. Comparing fishers' and scientific estimates of size at maturity and maximum body size as indicators for overfishing.

    Science.gov (United States)

    Mclean, Elizabeth L; Forrester, Graham E

    2018-04-01

    We tested whether fishers' local ecological knowledge (LEK) of two fish life-history parameters, size at maturity (SAM) at maximum body size (MS), was comparable to scientific estimates (SEK) of the same parameters, and whether LEK influenced fishers' perceptions of sustainability. Local ecological knowledge was documented for 82 fishers from a small-scale fishery in Samaná Bay, Dominican Republic, whereas SEK was compiled from the scientific literature. Size at maturity estimates derived from LEK and SEK overlapped for most of the 15 commonly harvested species (10 of 15). In contrast, fishers' maximum size estimates were usually lower than (eight species), or overlapped with (five species) scientific estimates. Fishers' size-based estimates of catch composition indicate greater potential for overfishing than estimates based on SEK. Fishers' estimates of size at capture relative to size at maturity suggest routine inclusion of juveniles in the catch (9 of 15 species), and fishers' estimates suggest that harvested fish are substantially smaller than maximum body size for most species (11 of 15 species). Scientific estimates also suggest that harvested fish are generally smaller than maximum body size (13 of 15), but suggest that the catch is dominated by adults for most species (9 of 15 species), and that juveniles are present in the catch for fewer species (6 of 15). Most Samaná fishers characterized the current state of their fishery as poor (73%) and as having changed for the worse over the past 20 yr (60%). Fishers stated that concern about overfishing, catching small fish, and catching immature fish contributed to these perceptions, indicating a possible influence of catch-size composition on their perceptions. Future work should test this link more explicitly because we found no evidence that the minority of fishers with more positive perceptions of their fishery reported systematically different estimates of catch-size composition than those with the more

  20. Prolificacy and Its Relationship with Age, Body Weight, Parity, Previous Litter Size and Body Linear Type Traits in Meat-type Goats

    Directory of Open Access Journals (Sweden)

    Avijit Haldar

    2014-05-01

    Full Text Available Data on age and body weight at breeding, parity, previous litter size, days open and some descriptive body linear traits from 389 meat-type, prolific Black Bengal goats in Tripura State of India, were collected for 3 and 1/2 years (2007 to 2010 and analyzed using logistic regression model. The objectives of the study were i to evaluate the effect of age and body weight at breeding, parity, previous litter size and days open on litter size of does; and ii to investigate if body linear type traits influenced litter size in meat-type, prolific goats. The incidence of 68.39% multiple births with a prolificacy rate of 175.07% was recorded. Higher age (>2.69 year, higher parity order (>2.31, more body weight at breeding (>20.5 kg and larger previous litter size (>1.65 showed an increase likelihood of multiple litter size when compared to single litter size. There was a strong, positive relationship between litter size and various body linear type traits like neck length (>22.78 cm, body length (>54.86 cm, withers height (>48.85 cm, croup height (>50.67 cm, distance between tuber coxae bones (>11.38 cm and distance between tuber ischii bones (>4.56 cm for discriminating the goats bearing multiple fetuses from those bearing a single fetus.

  1. Temperature-size responses match latitudinal-size clines in arthropods, revealing critical differences between aquatic and terrestrial species

    DEFF Research Database (Denmark)

    Horne, C.R.; Hirst, Andrew G.; Atkinson, D.

    2015-01-01

    of these gradients to date, and find that their direction and magnitude co-vary among 12 arthropod orders (r2 = 0.72). Body size in aquatic species generally reduces with both warming and decreasing latitude, whereas terrestrial species have much reduced and even opposite gradients. These patterns support...... the prediction that oxygen limitation is a major controlling factor in water, but not in air. Furthermore, voltinism explains much of the variation in T-S and L-S patterns in terrestrial but not aquatic species. While body size decreases with warming and with decreasing latitude in multivoltine terrestrial......Two major intraspecific patterns of adult size variation are plastic temperature-size (T-S) responses and latitude-size (L-S) clines. Yet, the degree to which these co-vary and share explanatory mechanisms has not been systematically evaluated. We present the largest quantitative comparison...

  2. The evolution of body size in extant groups of North American freshwater fishes: speciation, size distributions, and Cope's rule.

    Science.gov (United States)

    Knouft, Jason H; Page, Lawrence M

    2003-03-01

    Change in body size within an evolutionary lineage over time has been under investigation since the synthesis of Cope's rule, which suggested that there is a tendency for mammals to evolve larger body size. Data from the fossil record have subsequently been examined for several other taxonomic groups to determine whether they also displayed an evolutionary increase in body size. However, we are not aware of any species-level study that has investigated the evolution of body size within an extant continental group. Data acquired from the fossil record and data derived from the evolutionary relationships of extant species are not similar, with each set exhibiting both strengths and weaknesses related to inferring evolutionary patterns. Consequently, expectation that general trends exhibited in the fossil record will correspond to patterns in extant groups is not necessarily warranted. Using phylogenetic relationships of extant species, we show that five of nine families of North American freshwater fishes exhibit an evolutionary trend of decreasing body size. These trends result from the basal position of large species and the more derived position of small species within families. Such trends may be caused by the invasion of small streams and subsequent isolation and speciation. This pattern, potentially influenced by size-biased dispersal rates and the high percentage of small streams in North America, suggests a scenario that could result in the generation of the size-frequency distribution of North American freshwater fishes.

  3. Climate alters intraspecific variation in copepod effect traits through pond food webs.

    Science.gov (United States)

    Charette, Cristina; Derry, Alison M

    2016-05-01

    Essential fatty acids (EFAs) are primarily generated by phytoplankton in aquatic ecosystems, and can limit the growth, development, and reproduction of higher consumers. Among the most critical of the EFAs are highly unsaturated fatty acids (HUFAs), which are only produced by certain groups of phytoplankton. Changing environmental conditions can alter phytoplankton community and fatty acid composition and affect the HUFA content of higher trophic levels. Almost no research has addressed intraspecific variation in HUFAs in zooplankton, nor intraspecific relationships of HUFAs with body size and fecundity. This is despite that intraspecific variation in HUFAs can exceed interspecific variation and that intraspecific trait variation in body size and fecundity is increasingly recognized to have an important role in food web ecology (effect traits). Our study addressed the relative influences of abiotic selection and food web effects associated with climate change on intraspecific differences and interrelationships between HUFA content, body size, and fecundity of freshwater copepods. We applied structural equation modeling and regression analyses to intraspecific variation in a dominant calanoid copepod, Leptodiatomus minutus, among a series of shallow north-temperate ponds. Climate-driven diurnal temperature fluctuations favored the coexistence of diversity of phytoplankton groups with different temperature optima and nutritive quality. This resulted in unexpected positive relationships between temperature, copepod DHA content and body size. Temperature correlated positively with diatom biovolume, and mediated relationships between copepod HUFA content and body size, and between copepod body size and fecundity. The presence of brook trout further accentuated these positive effects in warm ponds, likely through nutrient cycling and stimulation of phytoplankton resources. Climate change may have previously unrecognized positive effects on freshwater copepod DHA content

  4. Monte Carlo simulation of calibration of shadow shield scanning bed whole body monitor using different size BOMAB phantoms

    International Nuclear Information System (INIS)

    Bhati, S.; Patni, H.K.; Singh, I.S.; Garg, S.P.

    2005-01-01

    A shadow shield scanning bed whole body monitor incorporating a (102 mm dia x 76 mm thick) NaI(Tl) detector, is employed for assessment of high-energy photon emitters at BARC. The monitor is calibrated using a Reference BOMAB phantom representative of an average Indian radiation worker. However to account for the size variation in the physique of workers, it is required to calibrate the system with different size BOMAB phantoms which is both difficult and expensive. Therefore, a theoretical approach based on Monte Carlo techniques has been employed to calibrate the system with BOMAB phantoms of different sizes for several radionuclides of interest. A computer program developed for this purpose, simulates the scanning geometry of the whole body monitor and computes detection efficiencies for the BARC Reference phantom (63 kg/168 cm), ICRP Reference phantom (70 kg/170 cm) and several of its scaled versions covering a wide range of body builds. The detection efficiencies computed for different photon energies for BARC Reference phantom were found to be in very good agreement with experimental data, thus validating the Monte Carlo scheme used in the computer code. The results from this study could be used for assessment of internal contamination due to high-energy photon emitters for radiation workers of different physiques. (author)

  5. The body teaching male: its variations and (in conformities

    Directory of Open Access Journals (Sweden)

    Rogério Machado Rosa

    2013-01-01

    Full Text Available In this text we attempt to map from a dialogue with authors such as Deleuze, Guattari and Nietzsche the process of change-shift-multiplication of the male body teaching, aesthetic sensibilities and bodily assemblages that inspire pedagogical meetings. The body-teaching-male and its variations (in conformities will be taken like a registration plan and vehicle of emotional and vibratory forces which pass by and turn him on territorialisation, deterritorialization and reterritorialization movement. So, we question the pedagogical meeting place as a possible device mechanic, pointing to the idea that the assemblages produced from this place operate in the creation of body experiences that move the male body from the places consecrated by the standard approach to the male-body-marginal, replete with becoming and organized: body without organs.

  6. Body shape and size depictions of African American women in JET magazine, 1953-2006.

    Science.gov (United States)

    Dawson-Andoh, Nana A; Gray, James J; Soto, José A; Parker, Scott

    2011-01-01

    Depictions of Caucasian women in the mainstream media have become increasingly thinner in size and straighter in shape. These changes may be inconsistent with the growing influence of African American beauty ideals, which research has established as more accepting of larger body sizes and more curvaceous body types than Caucasians. The present study looked at trends in the portrayal of African American women featured in JET magazine from 1953 to 2006. Beauty of the Week (BOW) images were collected and analyzed to examine body size (estimated by independent judges) and body shape (estimated by waist-to-hip ratio). We expected body sizes to increase and body shapes to become more curvaceous. Results revealed a rise in models' body size consistent with expectations, but an increase in waist-to-hip ratio, contrary to prediction. Our findings suggest that the African American feminine beauty ideal reflects both consistencies with and departures from mainstream cultural ideals. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Can foraging ecology drive the evolution of body size in a diving endotherm?

    Directory of Open Access Journals (Sweden)

    Timothée R Cook

    Full Text Available Within a single animal species, different morphs can allow for differential exploitation of foraging niches between populations, while sexual size dimorphism can provide each sex with access to different resources. Despite being potentially important agents of evolution, resource polymorphisms, and the way they operate in wild populations, remain poorly understood. In this study, we examine how trophic factors can select for different body sizes between populations and sexes in a diving endotherm. Dive depth and duration are positively related to body size in diving birds and mammals, a relationship explained by a lower mass-specific metabolic rate and greater oxygen stores in larger individuals. Based on this allometry, we predict that selection for exploiting resources situated at different depths can drive the evolution of body size in species of diving endotherms at the population and sexual level. To test this prediction, we studied the foraging ecology of Blue-eyed Shags, a group of cormorants with male-biased sexual size dimorphism from across the Southern Ocean. We found that mean body mass and relative difference in body mass between sexes varied by up to 77% and 107% between neighbouring colonies, respectively. Birds from colonies with larger individuals dived deeper than birds from colonies with smaller individuals, when accounting for sex. In parallel, males dived further offshore and deeper than females and the sexual difference in dive depth reflected the level of sexual size dimorphism at each colony. We argue that body size in this group of birds is under intense selection for diving to depths of profitable benthic prey patches and that, locally, sexual niche divergence selection can exaggerate the sexual size dimorphism of Blue-eyed Shags initially set up by sexual selection. Our findings suggest that trophic resources can select for important geographic micro-variability in body size between populations and sexes.

  8. Variation of sup 137 Cs levels between sexes, body sizes and collection localities of mosquitofish, Gambusia holbrooki (Girard 1859), inhabiting a reactor cooling reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Newman, M.C.; Brisbin, I.L. Jr. (Savannah River Ecology Lab., Aiken, SC (USA))

    1990-01-01

    Whole body concentrations of {sup 137}Cs were determined for 190 mosquitofish (Gambusia holbrooki) collected in April 1987 from three locations in a former cooling reservoir which had been contaminated with {sup 137}Cs from production reactor effluents between 1961 and 1964. Male fish collected near the point where the reactor effluent had entered the reservoir tended to have higher {sup 137}Cs concentrations than those from the other locations. Females did not differ in {sup 137}Cs concentrations between the three locations. Females at the site of contaminant entry tended to decrease in {sup 137}Cs concentration as body size increased. These results suggest that that radionuclide whole body concentrations may vary in unexpected ways between sex or size classes within a given species and that such differences may also vary within microgeographic scales. (author).

  9. What women like: influence of motion and form on esthetic body perception

    Directory of Open Access Journals (Sweden)

    Valentina eCazzato

    2012-07-01

    Full Text Available Several studies have shown the distinct contribution of motion and form to the esthetic evaluation of female bodies. Here, we investigated how variations of implied motion and body size interact in the esthetic evaluation of female and male bodies in a sample of young healthy women. Participants provided attractiveness, beauty, and liking ratings for the shape and posture of virtual renderings of human bodies with variable body size and implied motion. The esthetic judgments for both shape and posture of human models were influenced by body size and implied motion, with a preference for thinner and more dynamic stimuli. Implied motion, however, attenuated the impact of extreme body size on the esthetic evaluation of body postures, and body size variations did not affect the preference for more dynamic stimuli. Results show that body form and action cues interact in esthetic perception, but the final esthetic appreciation of human bodies is predicted by a mixture of perceptual and affective evaluative components.

  10. Effects of within-colony competition on body size asymmetries and reproductive skew in a social spider

    DEFF Research Database (Denmark)

    Grinsted, Lena; Bilde, Trine

    2013-01-01

    Reproductive partitioning is a key component of social organization in groups of cooperative organisms. In colonies of permanently social spiders of the genus Stegodyphus less than half of the females reproduce, while all females, including nonreproducers, perform suicidal allo-maternal care. Some...... not increase over the course of the experiment, suggesting that body size variation is shaped at an early stage. This might facilitate task specialization within colonies and ensure colony-level reproductive output by early allocation of reproductive roles. We suggest that reproductive skew in social spiders...

  11. Body size correlates with fertilization success but not gonad size in grass goby territorial males.

    Directory of Open Access Journals (Sweden)

    Jose Martin Pujolar

    Full Text Available In fish species with alternative male mating tactics, sperm competition typically occurs when small males that are unsuccessful in direct contests steal fertilization opportunities from large dominant males. In the grass goby Zosterisessor ophiocephalus, large territorial males defend and court females from nest sites, while small sneaker males obtain matings by sneaking into nests. Parentage assignment of 688 eggs from 8 different nests sampled in the 2003-2004 breeding season revealed a high level of sperm competition. Fertilization success of territorial males was very high but in all nests sneakers also contributed to the progeny. In territorial males, fertilization success correlated positively with male body size. Gonadal investment was explored in a sample of 126 grass gobies collected during the period 1995-1996 in the same area (61 territorial males and 65 sneakers. Correlation between body weight and testis weight was positive and significant for sneaker males, while correlation was virtually equal to zero in territorial males. That body size in territorial males is correlated with fertilization success but not gonad size suggests that males allocate much more energy into growth and relatively little into sperm production once the needed size to become territorial is attained. The increased paternity of larger territorial males might be due to a more effective defense of the nest in comparison with smaller territorial males.

  12. Body size correlates with fertilization success but not gonad size in grass goby territorial males.

    Science.gov (United States)

    Pujolar, Jose Martin; Locatello, Lisa; Zane, Lorenzo; Mazzoldi, Carlotta

    2012-01-01

    In fish species with alternative male mating tactics, sperm competition typically occurs when small males that are unsuccessful in direct contests steal fertilization opportunities from large dominant males. In the grass goby Zosterisessor ophiocephalus, large territorial males defend and court females from nest sites, while small sneaker males obtain matings by sneaking into nests. Parentage assignment of 688 eggs from 8 different nests sampled in the 2003-2004 breeding season revealed a high level of sperm competition. Fertilization success of territorial males was very high but in all nests sneakers also contributed to the progeny. In territorial males, fertilization success correlated positively with male body size. Gonadal investment was explored in a sample of 126 grass gobies collected during the period 1995-1996 in the same area (61 territorial males and 65 sneakers). Correlation between body weight and testis weight was positive and significant for sneaker males, while correlation was virtually equal to zero in territorial males. That body size in territorial males is correlated with fertilization success but not gonad size suggests that males allocate much more energy into growth and relatively little into sperm production once the needed size to become territorial is attained. The increased paternity of larger territorial males might be due to a more effective defense of the nest in comparison with smaller territorial males.

  13. Nest predation risk explains variation in avian clutch size

    Science.gov (United States)

    Dillon, Kristen G.; Conway, Courtney J.

    2018-01-01

    Questions about the ecological drivers of, and mechanistic constraints on, productivity have driven research on life-history evolution for decades. Resource availability and offspring mortality are considered among the 2 most important influences on the number of offspring per reproductive attempt. We used a factorial experimental design to manipulate food abundance and perceived offspring predation risk in a wild avian population (red-faced warblers; Cardellina rubrifrons) to identify the mechanistic cause of variation in avian clutch size. Additionally, we tested whether female quality helped explain the extant variation in clutch size. We found no support for the Food Limitation or Female Quality Hypotheses, but we did find support for both predictions of the Nest Predation Risk Hypothesis. Females that experienced an experimentally heightened perception of offspring predation risk responded by laying a smaller clutch than females in the control group. Additionally, predation rates at artificial nests were highest where red-faced warbler clutch size was smallest (at high elevations). Life-history theory predicts that an individual should invest less in reproduction when high nest predation risk reduces the likely benefit from that nesting attempt and, indeed, we found that birds exhibit phenotypic plasticity in clutch size by laying fewer eggs in response to increasing nest predation risk.

  14. Galectin-3 levels relate in children to total body fat, abdominal fat, body fat distribution, and cardiac size.

    Science.gov (United States)

    Dencker, Magnus; Arvidsson, Daniel; Karlsson, Magnus K; Wollmer, Per; Andersen, Lars B; Thorsson, Ola

    2018-03-01

    Galectin-3 has recently been proposed as a novel biomarker for cardiovascular disease in adults. The purpose of this investigation was to assess relationships between galectin-3 levels and total body fat, abdominal fat, body fat distribution, aerobic fitness, blood pressure, left ventricular mass, left atrial size, and increase in body fat over a 2-year period in a population-based sample of children. Our study included 170 children aged 8-11 years. Total fat mass and abdominal fat were measured by dual-energy x-ray absorptiometry (DXA). Body fat distribution was expressed as abdominal fat/total fat mass. Maximal oxygen uptake was assessed by indirect calorimetry during a maximal exercise test and scaled to body mass. Systolic and diastolic blood pressure and pulse pressure were measured. Left atrial size, left ventricular mass, and relative wall thickness were measured by echocardiography. Frozen serum samples were analyzed for galectin-3 by the Proximity Extension Assay technique. A follow-up DXA scan was performed in 152 children 2 years after the baseline exam. Partial correlations, with adjustment for sex and age, between galectin-3 versus body fat measurements indicated weak to moderate relationships. Moreover, left atrial size, left ventricular mass, and relative wall thickness and pulse pressure were also correlated with galectin-3. Neither systolic blood pressure nor maximal oxygen uptake was correlated with galectin-3. There was also a correlation between galectin-3 and increase in total body fat over 2 years, while no such correlations were found for the other fat measurements. More body fat and abdominal fat, more abdominal body fat distribution, more left ventricular mass, and increased left atrial size were all associated with higher levels of galectin-3. Increase in total body fat over 2 years was also associated with higher levels of galectin-3. What is Known: • Galectin-3 has been linked to obesity and been proposed to be a novel biomarker

  15. A pilot study on body image, attractiveness and body size in Gambians living in an urban community.

    Science.gov (United States)

    Siervo, M; Grey, P; Nyan, O A; Prentice, A M

    2006-06-01

    We investigated the attitudinal and perceptual components of body image and its link with body mass index (BMI) in a sample of urban Gambians. We also looked at cross-cultural differences in body image and views on attractiveness between Gambians and Americans. Four groups of 50 subjects were assessed: men 14- 25y (YM); women 14-25y (YW); men 35-50y (OM); women 35-50y (OW). Socio-economic status, education, healthy lifestyle and western influences were investigated. Height and weight were measured. Body dissatisfaction was assessed with the body dissatisfaction scale of the Eating Disorder Inventory. Perceptions of body image and attractiveness were assessed using the Body Image Assessment for Obesity (BIA-O) and Figure Rating Scale (FRS). Different generations of Gambians had very different perceptions and attitudes towards obesity. Current body size was realistically perceived and largely well tolerated. Older women had a higher body discrepancy (current minus ideal body size) than other groups (pbody size until they were overweight (BMI=27.8 kg/m2), whilst OM, YM and YW started to be concerned at a BMI respectively of 22.9, 19.8 and 21.5 kg/m2. A cross-cultural comparison using published data on FRS showed that Gambians were more obesity tolerant than black and white Americans. The Gambia is a country in the early stage of demographic transitions but in urban areas there is an increase in obesity prevalence. Inherent tensions between the preservation of cultural values and traditional habits, and raising awareness of the risks of obesity, may limit health interventions to prevent weight gain.

  16. Survival Times of Meter-Sized Rock Boulders on the Surface of Airless Bodies

    Science.gov (United States)

    Basilevsky, A. T.; Head, J. W.; Horz, F.; Ramsley, K.

    2015-01-01

    This study considers the survival times of meter-sized rock boulders on the surfaces of several airless bodies. As the starting point, we employ estimates of the survival times of such boulders on the surface of the Moon by[1], then discuss the role of destruction due to day-night temperature cycling, consider the meteorite bombardment environment on the considered bodies in terms of projectile flux and velocities and finally estimate the survival times. Survival times of meter-sized rocks on lunar surface: The survival times of hand specimen-sized rocks exposed to the lunar surface environment were estimated based on experiments modeling the destruction of rocks by meteorite impacts, combined with measurements of the lunar surface meteorite flux, (e.g.,[2]). For estimations of the survival times of meter-sized lunar boulders, [1] suggested a different approach based on analysis of the spatial density of boulders on the rims of small lunar craters of known absolute age. It was found that for a few million years, only a small fraction of the boulders ejected by cratering process are destroyed, for several tens of million years approx.50% are destroyed, and for 200-300 Ma, 90 to 99% are destroyed. Following [2] and other works, [1] considered that the rocks are mostly destroyed by meteorite impacts. Destruction of rocks by thermal-stress. However, high diurnal temperature variations on the surface of the Moon and other airless bodies imply that thermal stresses may also be a cause of surface rock destruction. Delbo et al. [3] interpreted the observed presence of fine debris on the surface of small asteroids as due to thermal surface cycling. They stated that because of the very low gravity on the surface of these bodies, ejecta from meteorite impacts should leave the body, so formation there of fine debris has to be due to thermal cycling. Based on experiments on heating-cooling of cm-scale pieces of ordinary and carbonaceous chondrites and theoretical modeling of

  17. Environmental, biological and anthropogenic effects on grizzly bear body size: temporal and spatial considerations.

    Science.gov (United States)

    Nielsen, Scott E; Cattet, Marc R L; Boulanger, John; Cranston, Jerome; McDermid, Greg J; Shafer, Aaron B A; Stenhouse, Gordon B

    2013-09-08

    Individual body growth is controlled in large part by the spatial and temporal heterogeneity of, and competition for, resources. Grizzly bears (Ursus arctos L.) are an excellent species for studying the effects of resource heterogeneity and maternal effects (i.e. silver spoon) on life history traits such as body size because their habitats are highly variable in space and time. Here, we evaluated influences on body size of grizzly bears in Alberta, Canada by testing six factors that accounted for spatial and temporal heterogeneity in environments during maternal, natal and 'capture' (recent) environments. After accounting for intrinsic biological factors (age, sex), we examined how body size, measured in mass, length and body condition, was influenced by: (a) population density; (b) regional habitat productivity; (c) inter-annual variability in productivity (including silver spoon effects); (d) local habitat quality; (e) human footprint (disturbances); and (f) landscape change. We found sex and age explained the most variance in body mass, condition and length (R(2) from 0.48-0.64). Inter-annual variability in climate the year before and of birth (silver spoon effects) had detectable effects on the three-body size metrics (R(2) from 0.04-0.07); both maternal (year before birth) and natal (year of birth) effects of precipitation and temperature were related with body size. Local heterogeneity in habitat quality also explained variance in body mass and condition (R(2) from 0.01-0.08), while annual rate of landscape change explained additional variance in body length (R(2) of 0.03). Human footprint and population density had no observed effect on body size. These results illustrated that body size patterns of grizzly bears, while largely affected by basic biological characteristics (age and sex), were also influenced by regional environmental gradients the year before, and of, the individual's birth thus illustrating silver spoon effects. The magnitude of the silver

  18. Genetic and environmental factors affecting birth size variation

    DEFF Research Database (Denmark)

    Yokoyama, Yoshie; Jelenkovic, Aline; Hur, Yoon-Mi

    2018-01-01

    Background: The genetic architecture of birth size may differ geographically and over time. We examined differences in the genetic and environmental contributions to birthweight, length and ponderal index (PI) across geographical-cultural regions (Europe, North America and Australia, and East Asia......) and across birth cohorts, and how gestational age modifies these effects. Methods: Data from 26 twin cohorts in 16 countries including 57 613 monozygotic and dizygotic twin pairs were pooled. Genetic and environmental variations of birth size were estimated using genetic structural equation modelling....... Results: The variance of birthweight and length was predominantly explained by shared environmental factors, whereas the variance of PI was explained both by shared and unique environmental factors. Genetic variance contributing to birth size was small. Adjusting for gestational age decreased...

  19. No evidence that sex and transposable elements drive genome size variation in evening primroses.

    Science.gov (United States)

    Ågren, J Arvid; Greiner, Stephan; Johnson, Marc T J; Wright, Stephen I

    2015-04-01

    Genome size varies dramatically across species, but despite an abundance of attention there is little agreement on the relative contributions of selective and neutral processes in governing this variation. The rate of sex can potentially play an important role in genome size evolution because of its effect on the efficacy of selection and transmission of transposable elements (TEs). Here, we used a phylogenetic comparative approach and whole genome sequencing to investigate the contribution of sex and TE content to genome size variation in the evening primrose (Oenothera) genus. We determined genome size using flow cytometry for 30 species that vary in genetic system and find that variation in sexual/asexual reproduction cannot explain the almost twofold variation in genome size. Moreover, using whole genome sequences of three species of varying genome sizes and reproductive system, we found that genome size was not associated with TE abundance; instead the larger genomes had a higher abundance of simple sequence repeats. Although it has long been clear that sexual reproduction may affect various aspects of genome evolution in general and TE evolution in particular, it does not appear to have played a major role in genome size evolution in the evening primroses. © 2015 The Author(s).

  20. Body size reductions in nonmammalian eutheriodont therapsids (Synapsida) during the end-Permian mass extinction.

    Science.gov (United States)

    Huttenlocker, Adam K

    2014-01-01

    The extent to which mass extinctions influence body size evolution in major tetrapod clades is inadequately understood. For example, the 'Lilliput effect,' a common feature of mass extinctions, describes a temporary decrease in body sizes of survivor taxa in post-extinction faunas. However, its signature on existing patterns of body size evolution in tetrapods and the persistence of its impacts during post-extinction recoveries are virtually unknown, and rarely compared in both geologic and phylogenetic contexts. Here, I evaluate temporal and phylogenetic distributions of body size in Permo-Triassic therocephalian and cynodont therapsids (eutheriodonts) using a museum collections-based approach and time series model fitting on a regional stratigraphic sequence from the Karoo Basin, South Africa. I further employed rank order correlation tests on global age and clade rank data from an expanded phylogenetic dataset, and performed evolutionary model testing using Brownian (passive diffusion) models. Results support significant size reductions in the immediate aftermath of the end-Permian mass extinction (ca. 252.3 Ma) consistent with some definitions of Lilliput effects. However, this temporal succession reflects a pattern that was underscored largely by Brownian processes and constructive selectivity. Results also support two recent contentions about body size evolution and mass extinctions: 1) active, directional evolution in size traits is rare over macroevolutionary time scales and 2) geologically brief size reductions may be accomplished by the ecological removal of large-bodied species without rapid originations of new small-bodied clades or shifts from long-term evolutionary patterns.

  1. Latitudinal cogradient variation of development time and growth rate and a negative latitudinal body weight cline in a widely distributed cabbage beetle.

    Directory of Open Access Journals (Sweden)

    Jianjun Tang

    Full Text Available The evolutionary and phenotypic responses to environmental gradients are often assumed to be the same, a phenomenon known as "cogradient variation". However, only a few insect species display cogradient variation in physiological traits along a latitudinal gradient. We found evidence for such a response in the examination of the life history traits of the cabbage beetle Colaphellus bowringi from 6 different geographical populations at 16, 19, 22, 24, 26 and 28°C. Our results showed that larval and pupal development times significantly decreased as rearing temperature increased, and that growth rates were positively correlated with temperature. Body weight tended to decrease with increasing temperature, consistent with the general pattern in ectothermic animals. Larval development time was positively correlated with latitude, whereas the growth rate decreased as latitude increased, showing an example of latitudinal cogradient variation. Body weight significantly decreased with increasing latitude in a stepwise manner, showing a negative latitudinal body weight cline. Females were significantly larger than males, consistent with the female biased sex dimorphism in insects. Body weight tended to decrease with increasing rearing temperature, whereas the differences in sexual size dimorphism (SSD tended to decrease with increasing body weight, which biased our results toward acceptance of Rensch's rule. We found that weight loss was an important regulator of SSD, and because male pupae lost significantly more weight at metamorphosis than female pupae, SSD was greater in adults than in pupae. Overall, our data provide a new example that a latitudinal cogradient variation in physiological traits is associated with a negative latitudinal body weight cline.

  2. Patterns of diversity in soft-bodied meiofauna: dispersal ability and body size matter.

    Science.gov (United States)

    Curini-Galletti, Marco; Artois, Tom; Delogu, Valentina; De Smet, Willem H; Fontaneto, Diego; Jondelius, Ulf; Leasi, Francesca; Martínez, Alejandro; Meyer-Wachsmuth, Inga; Nilsson, Karin Sara; Tongiorgi, Paolo; Worsaae, Katrine; Todaro, M Antonio

    2012-01-01

    Biogeographical and macroecological principles are derived from patterns of distribution in large organisms, whereas microscopic ones have often been considered uninteresting, because of their supposed wide distribution. Here, after reporting the results of an intensive faunistic survey of marine microscopic animals (meiofauna) in Northern Sardinia, we test for the effect of body size, dispersal ability, and habitat features on the patterns of distribution of several groups. As a dataset we use the results of a workshop held at La Maddalena (Sardinia, Italy) in September 2010, aimed at studying selected taxa of soft-bodied meiofauna (Acoela, Annelida, Gastrotricha, Nemertodermatida, Platyhelminthes and Rotifera), in conjunction with data on the same taxa obtained during a previous workshop hosted at Tjärnö (Western Sweden) in September 2007. Using linear mixed effects models and model averaging while accounting for sampling bias and potential pseudoreplication, we found evidence that: (1) meiofaunal groups with more restricted distribution are the ones with low dispersal potential; (2) meiofaunal groups with higher probability of finding new species for science are the ones with low dispersal potential; (3) the proportion of the global species pool of each meiofaunal group present in each area at the regional scale is negatively related to body size, and positively related to their occurrence in the endobenthic habitat. Our macroecological analysis of meiofauna, in the framework of the ubiquity hypothesis for microscopic organisms, indicates that not only body size but mostly dispersal ability and also occurrence in the endobenthic habitat are important correlates of diversity for these understudied animals, with different importance at different spatial scales. Furthermore, since the Western Mediterranean is one of the best-studied areas in the world, the large number of undescribed species (37%) highlights that the census of marine meiofauna is still very far

  3. Body size and longitudinal body weight changes do not increase mortality in incident peritoneal dialysis patients of the Brazilian peritoneal dialysis multicenter study

    Science.gov (United States)

    da Silva Fernandes, Natália Maria; Bastos, Marcus Gomes; Franco, Márcia Regina Gianotti; Chaoubah, Alfredo; da Glória Lima, Maria; Divino-Filho, José Carolino; Qureshi, Abdul Rashid

    2013-01-01

    OBJECTIVES: To determine the roles of body size and longitudinal body weight changes in the survival of incident peritoneal dialysis patients. PATIENTS AND METHODS: Patients (n = 1911) older than 18 years of age recruited from 114 dialysis centers (Dec/2004-Oct/2007) and participating in the Brazilian Peritoneal Dialysis Multicenter Cohort Study were included. Clinical and laboratory data were collected monthly (except if the patient received a transplant, recovered renal function, was transferred to hemodialysis, or died). RESULTS: Survival analyses were performed using Kaplan-Meier survival curves and Cox proportional hazards. Total follow-up was 34 months. The mean age was 59 years (54% female). The weight category percentages were as follows: underweight: 8%; normal: 51%; overweight: 29%; and obese 12%. The multivariate model showed a higher risk of death for a body mass index 30 kg/m2. Patients were divided into five categories according to quintiles of body weight changes during the first year of dialysis: +7.1%. Patients in the lowest quintile had significantly higher mortality, whereas no negative impact was observed in the other quintiles. CONCLUSION: These findings suggest that overweight/obesity and a positive body weight variation during the first year of peritoneal dialysis therapy do not increase mortality in incident dialysis patients in Brazil. PMID:23420157

  4. Influences of sex, ontogeny and body size on the thermal ecology of Liolaemus lutzae (Squamata, Liolaemidae) in a restinga remnant in Southeastern Brazil.

    Science.gov (United States)

    Maia-Carneiro, Thiago; Rocha, Carlos Frederico Duarte

    2013-01-01

    Variations in body temperature (Tb) of lizards can be partially explained by intrinsic factors such as sex, ontogeny and body size. Liolaemus lutzae is a lizard species restricted to restingas in the Brazilian coast in the state of Rio de Janeiro. Herein, we studied sexual dimorphism and influences of sex, ontogeny, and body size to the Tb of L. lutzae. Adult males were larger than adult females, probably due to both intersexual selection and intra-sexual selection. There was intersexual difference in lizards' Tb (males hotter than females), but Tb did not differ after factored out for the effects of body size. The mean Tb of juvenile lizards was higher than that of adults after factored out for the effect of body mass. It is possible that adults may have excluded juveniles from microhabitats with better thermal regimes. Also, this might have occurred due to requirements of juveniles to maintain high growth rates. Forage searching for prey by juveniles also exposes them to high environmental temperatures. Juveniles also may have higher Tb than co-specific adults (relative to body mass) to favor prey capture. In absolute values, adult lizards tended to use microhabitats with lower temperatures than that used by juveniles, possibly to avoid risks of overheating and death. Body temperature and snout-vent length were positively related, as well as body temperature and body mass, presumably caused by the thermal inertia of the bodies (trend of a body to resist to changes in its temperature). Intrinsic factors such as sex, ontogeny and body size can affect the thermal ecology of L. lutzae, despite coastal habitat features to which they are exposed also influences the body temperature of active lizards in restinga habitats. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. A Prospective Investigation of Body Size, Body Fat Composition and Colorectal Cancer Risk in the UK Biobank.

    Science.gov (United States)

    Ortega, Luisa Saldana; Bradbury, Kathryn E; Cross, Amanda J; Morris, Jessica S; Gunter, Marc J; Murphy, Neil

    2017-12-19

    Obesity has been consistently associated with a greater colorectal cancer risk, but this relationship is weaker among women. In the UK Biobank, we investigated the associations between body size (body mass index [BMI], height, waist circumference, and waist-to-hip ratio) and body fat composition (total body fat percentage and trunk fat percentage) measurements with colorectal cancer risk among 472,526 men and women followed for 5.6 years on average. Multivariable hazard ratios (HRs) and 95% confidence intervals (95%CI) for developing colorectal cancer (2,636 incident cases) were estimated using Cox proportional hazards models. Among men, when the highest and lowest fifths were compared, BMI (HR = 1.35, 95%CI: 1.13-1.61; P trend  body fat percentage (HR = 1.27, 95%CI: 1.06-1.53; P trend  = 0.002), and trunk fat percentage (HR = 1.31, 95%CI: 1.09-1.58; P trend  = 0.002) were associated with greater colorectal cancer risk. For women, only waist-to-hip ratio (HR for highest versus lowest fifth = 1.33, 95%CI: 1.08-1.65; P trend  = 0.005) was positively associated with colorectal cancer risk. Greater body size (overall and abdominal adiposity) was positively associated with colorectal cancer development in men. For women, abdominal adiposity, rather than overall body size, was associated with a greater colorectal cancer risk.

  6. Body size, swimming speed, or thermal sensitivity? Predator-imposed selection on amphibian larvae.

    Science.gov (United States)

    Gvoždík, Lumír; Smolinský, Radovan

    2015-11-02

    Many animals rely on their escape performance during predator encounters. Because of its dependence on body size and temperature, escape velocity is fully characterized by three measures, absolute value, size-corrected value, and its response to temperature (thermal sensitivity). The primary target of the selection imposed by predators is poorly understood. We examined predator (dragonfly larva)-imposed selection on prey (newt larvae) body size and characteristics of escape velocity using replicated and controlled predation experiments under seminatural conditions. Specifically, because these species experience a wide range of temperatures throughout their larval phases, we predict that larvae achieving high swimming velocities across temperatures will have a selective advantage over more thermally sensitive individuals. Nonzero selection differentials indicated that predators selected for prey body size and both absolute and size-corrected maximum swimming velocity. Comparison of selection differentials with control confirmed selection only on body size, i.e., dragonfly larvae preferably preyed on small newt larvae. Maximum swimming velocity and its thermal sensitivity showed low group repeatability, which contributed to non-detectable selection on both characteristics of escape performance. In the newt-dragonfly larvae interaction, body size plays a more important role than maximum values and thermal sensitivity of swimming velocity during predator escape. This corroborates the general importance of body size in predator-prey interactions. The absence of an appropriate control in predation experiments may lead to potentially misleading conclusions about the primary target of predator-imposed selection. Insights from predation experiments contribute to our understanding of the link between performance and fitness, and further improve mechanistic models of predator-prey interactions and food web dynamics.

  7. Experimental Investigation of Subject-Specific On-Body Radio Propagation Channels for Body-Centric Wireless Communications

    Directory of Open Access Journals (Sweden)

    Mohammad Monirujjaman Khan

    2014-01-01

    Full Text Available In this paper, subject-specific narrowband (2.45 GHz and ultra-wideband (3–10.6 GHz on-body radio propagation studies in wireless body area networks (WBANs were performed by characterizing the path loss for eight different human subjects of different shapes and sizes. The body shapes and sizes of the test subjects used in this study are characterised as thin, medium build, fatty, shorter, average height and taller. Experimental investigation was made in an indoor environment using a pair of printed monopoles (for the narrowband case and a pair of tapered slot antennas (for the ultra-wideband (UWB case. Results demonstrated that, due to the different sizes, heights and shapes of the test subjects, the path loss exponent value varies up to maximum of 0.85 for the narrowband on-body case, whereas a maximum variation of the path loss exponent value of 1.15 is noticed for the UWB case. In addition, the subject-specific behaviour of the on-body radio propagation channels was compared between narrowband and UWB systems, and it was deduced that the on-body radio channels are subject-specific for both narrowband and UWB system cases, when the same antennas (same characteristics are used. The effect of the human body shape and size variations on the eight different on-body radio channels is also studied for both the narrowband and UWB cases.

  8. Body size reductions in nonmammalian eutheriodont therapsids (Synapsida during the end-Permian mass extinction.

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    Adam K Huttenlocker

    Full Text Available The extent to which mass extinctions influence body size evolution in major tetrapod clades is inadequately understood. For example, the 'Lilliput effect,' a common feature of mass extinctions, describes a temporary decrease in body sizes of survivor taxa in post-extinction faunas. However, its signature on existing patterns of body size evolution in tetrapods and the persistence of its impacts during post-extinction recoveries are virtually unknown, and rarely compared in both geologic and phylogenetic contexts. Here, I evaluate temporal and phylogenetic distributions of body size in Permo-Triassic therocephalian and cynodont therapsids (eutheriodonts using a museum collections-based approach and time series model fitting on a regional stratigraphic sequence from the Karoo Basin, South Africa. I further employed rank order correlation tests on global age and clade rank data from an expanded phylogenetic dataset, and performed evolutionary model testing using Brownian (passive diffusion models. Results support significant size reductions in the immediate aftermath of the end-Permian mass extinction (ca. 252.3 Ma consistent with some definitions of Lilliput effects. However, this temporal succession reflects a pattern that was underscored largely by Brownian processes and constructive selectivity. Results also support two recent contentions about body size evolution and mass extinctions: 1 active, directional evolution in size traits is rare over macroevolutionary time scales and 2 geologically brief size reductions may be accomplished by the ecological removal of large-bodied species without rapid originations of new small-bodied clades or shifts from long-term evolutionary patterns.

  9. Body Size Reductions in Nonmammalian Eutheriodont Therapsids (Synapsida) during the End-Permian Mass Extinction

    Science.gov (United States)

    Huttenlocker, Adam K.

    2014-01-01

    The extent to which mass extinctions influence body size evolution in major tetrapod clades is inadequately understood. For example, the ‘Lilliput effect,’ a common feature of mass extinctions, describes a temporary decrease in body sizes of survivor taxa in post-extinction faunas. However, its signature on existing patterns of body size evolution in tetrapods and the persistence of its impacts during post-extinction recoveries are virtually unknown, and rarely compared in both geologic and phylogenetic contexts. Here, I evaluate temporal and phylogenetic distributions of body size in Permo-Triassic therocephalian and cynodont therapsids (eutheriodonts) using a museum collections-based approach and time series model fitting on a regional stratigraphic sequence from the Karoo Basin, South Africa. I further employed rank order correlation tests on global age and clade rank data from an expanded phylogenetic dataset, and performed evolutionary model testing using Brownian (passive diffusion) models. Results support significant size reductions in the immediate aftermath of the end-Permian mass extinction (ca. 252.3 Ma) consistent with some definitions of Lilliput effects. However, this temporal succession reflects a pattern that was underscored largely by Brownian processes and constructive selectivity. Results also support two recent contentions about body size evolution and mass extinctions: 1) active, directional evolution in size traits is rare over macroevolutionary time scales and 2) geologically brief size reductions may be accomplished by the ecological removal of large-bodied species without rapid originations of new small-bodied clades or shifts from long-term evolutionary patterns. PMID:24498335

  10. Variations in serving sizes of Australian snack foods and confectionery.

    Science.gov (United States)

    Watson, Wendy L; Kury, Alexandra; Wellard, Lyndal; Hughes, Clare; Dunford, Elizabeth; Chapman, Kathy

    2016-01-01

    This study examined the serving size and energy content per serving of Australian packaged snack foods and confectionery products. Nutrition Information Panel data for 23 sub-categories of packaged snack foods (n = 3481) were extracted from The George Institute for Global Health's 2013 branded food composition database. Variations in serving size and energy content per serving were examined. Energy contents per serving were compared to recommendations in the Australian Dietary Guidelines. Serving sizes varied within and between snack food categories. Mean energy content per serving varied from 320 kJ to 899 kJ. More energy per serving than the recommended 600 kJ was displayed by 22% (n = 539) of snack foods classified in the Australian Dietary Guidelines as discretionary foods. The recommendation for energy content per serving was exceeded in 60% (n = 635) of snack foods from the Five Food Groups. Only 37% (n = 377) of confectionery products displayed the industry-agreed serving size of 25 g. Energy content per serving of many packaged snack foods do not align with the Australian Dietary Guidelines and the industry agreed serving size has not been taken up widely within the confectionery category. Given the inconsistencies in serving sizes, featuring serving size in front-of-pack information may hinder the objective of a clear and simple nutrition message. Messaging to help consumers make healthier choices should consider the variation in serving sizes on packaged snack foods. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Intraspecific variation in erythrocyte sizes among populations of Hypsiboas cordobas (Anura: Hylidae

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    Mariana Baraquet

    2013-12-01

    Full Text Available We studied the morphology and size of erythrocytes of H. cordobae, and analysed the geographic variation of this character along the distribution of the species, in relation to the latitudinal and altitudinal distances. Erythrocyte shape of the H. cordobae is ellipsoidal and the nuclei are also ellipsoidal and centrally oriented. Erythrocyte and nuclear size showed significant differences among populations, with the highest mean size corresponding to the population of Achiras (low altitude site and the lowest mean size to Los Linderos (high altitude site. There was no significant relationship between the latitude of each population and the both erythrocyte and nuclear size. The altitudinal variation in erythrocyte cell size may be attributable to the surface available for gas exchange; a small erythrocyte offers a possibility of greater rate of exchange than a larger one. Our results are consistent with studies of other amphibians, where intraspecific comparisons of populations at different altitudes show that individuals at higher altitudes are characterized by smaller erythrocytes.

  12. Elliptic Fourier Analysis of body shape variation of Hippocampus spp. (seahorse in Danajon Bank, Philippines

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    S. R. M. Tabugo-Rico

    2017-12-01

    Full Text Available Seahorses inhabit various ecosystems hence, had become a flagship species of the marine environment. The Philippines as a hot spot of biodiversity in Asia holds a number of species of seahorses. This serve as an exploratory study to describe body shape variation of selected common seahorse species: Hippocampus comes, Hippocampus histrix, Hippocampus spinosissimus and Hippocampus kuda from Danajon bank using Elliptic Fourier Analysis. The method was done to test whether significant yet subtle differences in body shape variation can be species-specific, habitat-influenced and provide evidence of sexual dimorphism. It is hypothesized that phenotypic divergence may provide evidence for genetic differentiation or mere adaptations to habitat variation. Results show significant considerable differences in the body shapes of the five populations based on the canonical variate analysis (CVA and multivariate analysis of variance (MANOVA with significant p values. Populations were found to be distinct from each other suggesting that body shape variation is species-specific, habitat-influenced and provided evidence for sexual dimorphism. Results of discriminant analysis show further support for species specific traits and sexual dimorphism. This study shows the application of the method of geometric morphometrics specifically elliptic fourier analysis in describing subtle body shape variation of selected Hippocampus species.

  13. Three-month-old human infants use vocal cues of body size.

    Science.gov (United States)

    Pietraszewski, David; Wertz, Annie E; Bryant, Gregory A; Wynn, Karen

    2017-06-14

    Differences in vocal fundamental ( F 0 ) and average formant ( F n ) frequencies covary with body size in most terrestrial mammals, such that larger organisms tend to produce lower frequency sounds than smaller organisms, both between species and also across different sex and life-stage morphs within species. Here we examined whether three-month-old human infants are sensitive to the relationship between body size and sound frequencies. Using a violation-of-expectation paradigm, we found that infants looked longer at stimuli inconsistent with the relationship-that is, a smaller organism producing lower frequency sounds, and a larger organism producing higher frequency sounds-than at stimuli that were consistent with it. This effect was stronger for fundamental frequency than it was for average formant frequency. These results suggest that by three months of age, human infants are already sensitive to the biologically relevant covariation between vocalization frequencies and visual cues to body size. This ability may be a consequence of developmental adaptations for building a phenotype capable of identifying and representing an organism's size, sex and life-stage. © 2017 The Author(s).

  14. Allometric scaling of population variance with mean body size is predicted from Taylor's law and density-mass allometry.

    Science.gov (United States)

    Cohen, Joel E; Xu, Meng; Schuster, William S F

    2012-09-25

    Two widely tested empirical patterns in ecology are combined here to predict how the variation of population density relates to the average body size of organisms. Taylor's law (TL) asserts that the variance of the population density of a set of populations is a power-law function of the mean population density. Density-mass allometry (DMA) asserts that the mean population density of a set of populations is a power-law function of the mean individual body mass. Combined, DMA and TL predict that the variance of the population density is a power-law function of mean individual body mass. We call this relationship "variance-mass allometry" (VMA). We confirmed the theoretically predicted power-law form and the theoretically predicted parameters of VMA, using detailed data on individual oak trees (Quercus spp.) of Black Rock Forest, Cornwall, New York. These results connect the variability of population density to the mean body mass of individuals.

  15. [Influences of ration level and initial body weight on growth and size hierarchy of hybrid tilapia, Oreochromis mossambicus x O. niloticus].

    Science.gov (United States)

    Wang, Yan

    2003-02-01

    72 hybrid tilapia were distributed into twelve tanks, each stocked in six fish (A, B, C, D, E, F) with different body size. The initial body weight was 62.69 +/- 1.46 g for fish A, 56.48 +/- 1.30 g for B, 50.75 +/- 1.19 g for C, 35.56 +/- 1.18 g for D, 31.05 +/- 0.88 g for E, and 27.35 +/- 0.95 g for F (mean +/- SE). The fish were reared under four ration levels (deprived of feed, fed at 1.5% body weight per day (BW.d-1), fed at 3.0% BW.d-1, or fed excess) throughout four weeks, respectively. The specific growth rate (SGR) and feed efficiency (FE) of the fish increased with increasing ration level up to 3.0% BW.d-1, and then, SGR maintained at a constant level while FE dropped with continuing increase of ration. The variance coefficient of SGR and final body weight was relatively high in the fish that fed at 1.5% BW.d-1. For fish A, SGR was not significantly different, between 1.5% BW.d-1, 3.0% BW.d-1 and fed excess, while in fish F, relatively high variations were found among different ration treatments. This experiment revealed that the growth and size hierarchy of hybrid tilapia were related to their ration level and initial body size. Under ration levels more than 3.0% BW.d-1, SGR was usually high, and size hierarchy was relatively weak.

  16. Island Rule, quantitative genetics and brain-body size evolution in Homo floresiensis.

    Science.gov (United States)

    Diniz-Filho, José Alexandre Felizola; Raia, Pasquale

    2017-06-28

    Colonization of islands often activate a complex chain of adaptive events that, over a relatively short evolutionary time, may drive strong shifts in body size, a pattern known as the Island Rule. It is arguably difficult to perform a direct analysis of the natural selection forces behind such a change in body size. Here, we used quantitative evolutionary genetic models, coupled with simulations and pattern-oriented modelling, to analyse the evolution of brain and body size in Homo floresiensis , a diminutive hominin species that appeared around 700 kya and survived up to relatively recent times (60-90 kya) on Flores Island, Indonesia. The hypothesis of neutral evolution was rejected in 97% of the simulations, and estimated selection gradients are within the range found in living natural populations. We showed that insularity may have triggered slightly different evolutionary trajectories for body and brain size, which means explaining the exceedingly small cranial volume of H. floresiensis requires additional selective forces acting on brain size alone. Our analyses also support previous conclusions that H. floresiensis may be most likely derived from an early Indonesian H. erectus , which is coherent with currently accepted biogeographical scenario for Homo expansion out of Africa. © 2017 The Author(s).

  17. Mammal extinctions, body size, and paleotemperature.

    Science.gov (United States)

    Bown, T M; Holroyd, P A; Rose, K D

    1994-10-25

    There is a general inverse relationship between the natural logarithm of tooth area (a body size indicator) of some fossil mammals and paleotemperature during approximately 2.9 million years of the early Eocene in the Bighorn Basin of northwest Wyoming. When mean temperatures became warmer, tooth areas tended to become smaller. During colder times, larger species predominated; these generally became larger or remained the same size. Paleotemperature trends also markedly affected patterns of local (and, perhaps, regional) extinction and immigration. New species appeared as immigrants during or near the hottest (smaller forms) and coldest (larger forms) intervals. Paleotemperature trend reversals commonly resulted in the ultimate extinction of both small forms (during cooling intervals) and larger forms (during warming intervals). These immigrations and extinctions mark faunal turnovers that were also modulated by sharp increases in sediment accumulation rate.

  18. Determination of subcellular compartment sizes for estimating dose variations in radiotherapy

    International Nuclear Information System (INIS)

    Poole, Christopher M.; Ahnesjo, Anders; Enger, Shirin A.

    2015-01-01

    The variation in specific energy absorbed to different cell compartments caused by variations in size and chemical composition is poorly investigated in radiotherapy. The aim of this study was to develop an algorithm to derive cell and cell nuclei size distributions from 2D histology samples, and build 3D cellular geometries to provide Monte Carlo (MC)-based dose calculation engines with a morphologically relevant input geometry. Stained and unstained regions of the histology samples are segmented using a Gaussian mixture model, and individual cell nuclei are identified via thresholding. Delaunay triangulation is applied to determine the distribution of distances between the centroids of nearest neighbour cells. A pouring simulation is used to build a 3D virtual tissue sample, with cell radii randomised according to the cell size distribution determined from the histology samples. A slice with the same thickness as the histology sample is cut through the 3D data and characterised in the same way as the measured histology. The comparison between this virtual slice and the measured histology is used to adjust the initial cell size distribution into the pouring simulation. This iterative approach of a pouring simulation with adjustments guided by comparison is continued until an input cell size distribution is found that yields a distribution in the sliced geometry that agrees with the measured histology samples. The thus obtained morphologically realistic 3D cellular geometry can be used as input to MC-based dose calculation programs for studies of dose response due to variations in morphology and size of tumour/healthy tissue cells/nuclei, and extracellular material. (authors)

  19. Cultural constructions of "obesity": understanding body size, social class and gender in Morocco.

    Science.gov (United States)

    Batnitzky, Adina K

    2011-01-01

    This article presents data from an in-depth qualitative study of overweight and diabetic women in Morocco, a North African country experiencing a rapid increase in obesity according to national statistics. This case study explores the heterogeneous relationship among health, culture and religion in Morocco by highlighting the relationship between the intricacies of women's everyday lives and their body sizes. My findings suggest that although the Body Mass Index (BMI) of adult women has been documented to have increased in Morocco along with other macroeconomic changes (i.e., increases in urbanization, etc.), "obesity" has yet to be universally medicalized in the Moroccan context. As such women do not generally utilize a medicalized concept of obesity in reference to their larger body sizes. Rather, cultural constructions of "obesity" are understood through cultural understandings of a larger body size, religious beliefs about health and illness, and the nature of women's religious participation. This stands in contrast to dominant accounts about the region that promote an overall veneration of a larger body size for women. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. The Relationship of Body Size and Adiposity to Source of Self-Esteem in College Women

    Science.gov (United States)

    Moncur, Breckann; Bailey, Bruce W.; Lockhart, Barbara D.; LeCheminant, James D.; Perkins, Annette E.

    2013-01-01

    Background: Studies looking at self-esteem and body size or adiposity generally demonstrate a negative relationship. However, the relationship between the source of self-esteem and body size has not been examined in college women. Purpose: The purpose of this study was to evaluate the relationship of body size and adiposity to source of…

  1. The evolution of body size under environmental gradients in ectotherms: why should Bergmann's rule apply to lizards?

    Directory of Open Access Journals (Sweden)

    Tregenza Tom

    2008-02-01

    Full Text Available Abstract Background The impact of environmental gradients on the evolution of life history traits is a central issue in macroecology and evolutionary biology. A number of hypotheses have been formulated to explain factors shaping patterns of variation in animal mass. One such example is Bergmann's rule, which predicts that body size will be positively correlated with latitude and elevation, and hence, with decreasing environmental temperatures. A generally accepted explanation for this phenotypic response is that as body mass increases, body surface area gets proportionally smaller, which contributes to reduced rates of heat-loss. Phylogenetic and non-phylogenetic evidence reveals that endotherms follow Bergmann's rule. In contrast, while previous non-phylogenetic studies supported this prediction in up to 75% of ectotherms, recent phylogenetic comparative analyses suggest that its validity for these organisms is controversial and less understood. Moreover, little attention has been paid to why some ectotherms conform to this rule, while others do not. Here, we investigate Bergmann's rule in the six main clades forming the Liolaemus genus, one of the largest and most environmentally diverse genera of terrestrial vertebrates. A recent study conducted on some species belonging to four of these six clades concluded that Liolaemus species follow Bergmann's rule, representing the only known phylogenetic support for this model in lizards. However, a later reassessment of this evidence, performed on one of the four analysed clades, produced contrasting conclusions. Results Our results fail to support Bergmann's rule in Liolaemus lizards. Non-phylogenetic and phylogenetic analyses showed that none of the studied clades experience increasing body size with increasing latitude and elevation. Conclusion Most physiological and behavioural processes in ectotherms depend directly upon their body temperature. In cold environments, adaptations to gain heat

  2. Obesity Bias in Children: The Role of Actual and Perceived Body Size

    Science.gov (United States)

    Kornilaki, Ekaterina N.

    2015-01-01

    The aim of this study was to examine how children perceive their body size and whether their actual or perceived body size can explain their anti-fat views. Four hundred and fourteen 5-6, 7-8 and 9-10-year-old children were read short vignettes depicting two characters, one possessing a positive and the other a negative quality. Following each…

  3. Temporal profile of body temperature in acute ischemic stroke: relation to infarct size and outcome.

    Science.gov (United States)

    Geurts, Marjolein; Scheijmans, Féline E V; van Seeters, Tom; Biessels, Geert J; Kappelle, L Jaap; Velthuis, Birgitta K; van der Worp, H Bart

    2016-11-21

    High body temperatures after ischemic stroke have been associated with larger infarct size, but the temporal profile of this relation is unknown. We assess the relation between temporal profile of body temperature and infarct size and functional outcome in patients with acute ischemic stroke. In 419 patients with acute ischemic stroke we assessed the relation between body temperature on admission and during the first 3 days with both infarct size and functional outcome. Infarct size was measured in milliliters on CT or MRI after 3 days. Poor functional outcome was defined as a modified Rankin Scale score ≥3 at 3 months. Body temperature on admission was not associated with infarct size or poor outcome in adjusted analyses. By contrast, each additional 1.0 °C in body temperature on day 1 was associated with 0.31 ml larger infarct size (95% confidence interval (CI) 0.04-0.59), on day 2 with 1.13 ml larger infarct size(95% CI, 0.83-1.43), and on day 3 with 0.80 ml larger infarct size (95% CI, 0.48-1.12), in adjusted linear regression analyses. Higher peak body temperatures on days two and three were also associated with poor outcome (adjusted relative risks per additional 1.0 °C in body temperature, 1.52 (95% CI, 1.17-1.99) and 1.47 (95% CI, 1.22-1.77), respectively). Higher peak body temperatures during the first days after ischemic stroke, rather than on admission, are associated with larger infarct size and poor functional outcome. This suggests that prevention of high temperatures may improve outcome if continued for at least 3 days.

  4. Waif goodbye! Average-size female models promote positive body image and appeal to consumers.

    Science.gov (United States)

    Diedrichs, Phillippa C; Lee, Christina

    2011-10-01

    Despite consensus that exposure to media images of thin fashion models is associated with poor body image and disordered eating behaviours, few attempts have been made to enact change in the media. This study sought to investigate an effective alternative to current media imagery, by exploring the advertising effectiveness of average-size female fashion models, and their impact on the body image of both women and men. A sample of 171 women and 120 men were assigned to one of three advertisement conditions: no models, thin models and average-size models. Women and men rated average-size models as equally effective in advertisements as thin and no models. For women with average and high levels of internalisation of cultural beauty ideals, exposure to average-size female models was associated with a significantly more positive body image state in comparison to exposure to thin models and no models. For men reporting high levels of internalisation, exposure to average-size models was also associated with a more positive body image state in comparison to viewing thin models. These findings suggest that average-size female models can promote positive body image and appeal to consumers.

  5. Reduced body size and cub recruitment in polar bears associated with sea ice decline

    Science.gov (United States)

    Rode, Karyn D.; Amstrup, Steven C.; Regehr, Eric V.

    2010-01-01

    Rates of reproduction and survival are dependent upon adequate body size and condition of individuals. Declines in size and condition have provided early indicators of population decline in polar bears (Ursus maritimus) near the southern extreme of their range. We tested whether patterns in body size, condition, and cub recruitment of polar bears in the southern Beaufort Sea of Alaska were related to the availability of preferred sea ice habitats and whether these measures and habitat availability exhibited trends over time, between 1982 and 2006. The mean skull size and body length of all polar bears over three years of age declined over time, corresponding with long‐term declines in the spatial and temporal availability of sea ice habitat. Body size of young, growing bears declined over time and was smaller after years when sea ice availability was reduced. Reduced litter mass and numbers of yearlings per female following years with lower availability of optimal sea ice habitat, suggest reduced reproductive output and juvenile survival. These results, based on analysis of a long‐term data set, suggest that declining sea ice is associated with nutritional limitations that reduced body size and reproduction in this population.

  6. ZResponse to selection, heritability and genetic correlations between body weight and body size in Pacific white shrimp, Litopenaeus vannamei

    Science.gov (United States)

    Andriantahina, Farafidy; Liu, Xiaolin; Huang, Hao; Xiang, Jianhai

    2012-03-01

    To quantify the response to selection, heritability and genetic correlations between weight and size of Litopenaeus vannamei, the body weight (BW), total length (TL), body length (BL), first abdominal segment depth (FASD), third abdominal segment depth (TASD), first abdominal segment width (FASW), and partial carapace length (PCL) of 5-month-old parents and of offspnng were measured by calculating seven body measunngs of offspnng produced by a nested mating design. Seventeen half-sib families and 42 full-sib families of L. vannamei were produced using artificial fertilization from 2-4 dams by each sire, and measured at around five months post-metamorphosis. The results show that hentabilities among vanous traits were high: 0.515±0.030 for body weight and 0.394±0.030 for total length. After one generation of selection. the selection response was 10.70% for offspring growth. In the 5th month, the realized heritability for weight was 0.296 for the offspnng generation. Genetic correlations between body weight and body size were highly variable. The results indicate that external morphological parameters can be applied dunng breeder selection for enhancing the growth without sacrificing animals for determining the body size and breed ability; and selective breeding can be improved significantly, simultaneously with increased production.

  7. Host genetic variation impacts microbiome composition across human body sites.

    Science.gov (United States)

    Blekhman, Ran; Goodrich, Julia K; Huang, Katherine; Sun, Qi; Bukowski, Robert; Bell, Jordana T; Spector, Timothy D; Keinan, Alon; Ley, Ruth E; Gevers, Dirk; Clark, Andrew G

    2015-09-15

    The composition of bacteria in and on the human body varies widely across human individuals, and has been associated with multiple health conditions. While microbial communities are influenced by environmental factors, some degree of genetic influence of the host on the microbiome is also expected. This study is part of an expanding effort to comprehensively profile the interactions between human genetic variation and the composition of this microbial ecosystem on a genome- and microbiome-wide scale. Here, we jointly analyze the composition of the human microbiome and host genetic variation. By mining the shotgun metagenomic data from the Human Microbiome Project for host DNA reads, we gathered information on host genetic variation for 93 individuals for whom bacterial abundance data are also available. Using this dataset, we identify significant associations between host genetic variation and microbiome composition in 10 of the 15 body sites tested. These associations are driven by host genetic variation in immunity-related pathways, and are especially enriched in host genes that have been previously associated with microbiome-related complex diseases, such as inflammatory bowel disease and obesity-related disorders. Lastly, we show that host genomic regions associated with the microbiome have high levels of genetic differentiation among human populations, possibly indicating host genomic adaptation to environment-specific microbiomes. Our results highlight the role of host genetic variation in shaping the composition of the human microbiome, and provide a starting point toward understanding the complex interaction between human genetics and the microbiome in the context of human evolution and disease.

  8. Big bees do a better job: intraspecific size variation influences pollination effectiveness

    Directory of Open Access Journals (Sweden)

    Pat Willmer

    2014-09-01

    Full Text Available 1. Bumblebees (Bombus spp. are efficient pollinators of many flowering plants, yet the pollen deposition performance of individual bees has not been investigated. Worker bumblebees exhibit large intraspecific and intra-nest size variation, in contrast with other eusocial bees; and their size influences collection and deposition of pollen grains. 2. Laboratory studies with B. terrestris workers and Vinca minor flowers showed that pollination effectiveness PE, as measured from pollen grains deposited on stigmas in single visits (SVD, was significantly positively related to bee size; larger bees deposited more grains, while the smallest individuals, with proportionally shorter tongues, were unable to collect or deposit pollen in these flowers. Individuals did not increase their pollen deposition over time, so handling experience does not influence SVD in Vinca minor. 3. Field studies using Geranium sanguineum and Echium vulgare, and multiple visiting species, confirmed that individual size affects SVD. All bumblebee species showed positive SVD/size effects, though even the smallest individuals did deposit pollen. Apis with its limited size variation showed no such detectable effect when visiting Geranium flowers. Two abundant hoverfly species also showed size effects, particularly when feeding for nectar on Echium. 4. Mean size of foragers also varied diurnally, with larger individuals active earlier and later, so that pollination effectiveness varies through a day; flowers routinely pollinated by bees may best be served by early morning dehiscence and visits from larger individuals. 5. Thus, while there are well-documented species-level variations in pollination effectiveness, the fine-scale individual differences between foragers should also be taken into account when assessing the reproductive outputs of biotically-pollinated plants.

  9. Thermal phenotypic plasticity of body size in Drosophila ...

    Indian Academy of Sciences (India)

    ... body size in Drosophila melanogaster: sexual dimorphism and genetic correlations. Jean R. David, Amir Yassin, Jean-Claude Moreteau, Helene Legout and Brigitte Moreteau. J. Genet. 90, 295–302. Table 1. Correlations between wing and thorax length at the within (n = 420) and between line level (n = 30). Temperature.

  10. Proximate composition of Mystus bleekeri in relation to body size ...

    African Journals Online (AJOL)

    Proximate composition of small catfish, Mystus bleekeri, from Nala Daik, Sialkot, Pakistan was investigated and fluctuation in relation to body size and condition factor was carried out. Mean percentages for water, fat, protein and ash contents in the whole wet body weight of wild M. bleekeri were 77.87, 3.26, 15.01 and ...

  11. Bet hedging in a warming ocean: predictability of maternal environment shapes offspring size variation in marine sticklebacks.

    Science.gov (United States)

    Shama, Lisa N S

    2015-12-01

    Bet hedging at reproduction is expected to evolve when mothers are exposed to unpredictable cues for future environmental conditions, whereas transgenerational plasticity (TGP) should be favoured when cues reliably predict the environment offspring will experience. Since climate predictions forecast an increase in both temperature and climate variability, both TGP and bet hedging are likely to become important strategies to mediate climate change effects. Here, the potential to produce variably sized offspring in both warming and unpredictable environments was tested by investigating whether stickleback (Gasterosteus aculeatus) mothers adjusted mean offspring size and within-clutch variation in offspring size in response to experimental manipulation of maternal thermal environment and predictability (alternating between ambient and elevated water temperatures). Reproductive output traits of F1 females were influenced by both temperature and environmental predictability. Mothers that developed at ambient temperature (17 °C) produced larger, but fewer eggs than mothers that developed at elevated temperature (21 °C), implying selection for different-sized offspring in different environments. Mothers in unpredictable environments had smaller mean egg sizes and tended to have greater within-female egg size variability, especially at 21 °C, suggesting that mothers may have dynamically modified the variance in offspring size to spread the risk of incorrectly predicting future environmental conditions. Both TGP and diversification influenced F2 offspring body size. F2 offspring reared at 21 °C had larger mean body sizes if their mother developed at 21 °C, but this TGP benefit was not present for offspring of 17 °C mothers reared at 17 °C, indicating that maternal TGP will be highly relevant for ocean warming scenarios in this system. Offspring of variable environment mothers were smaller but more variable in size than offspring from constant environment

  12. Host body size and the diversity of tick assemblages on Neotropical vertebrates

    Directory of Open Access Journals (Sweden)

    Helen J. Esser

    2016-12-01

    Full Text Available Identifying the factors that influence the species diversity and distribution of ticks (Acari: Ixodida across vertebrate host taxa is of fundamental ecological and medical importance. Host body size is considered one of the most important determinants of tick abundance, with larger hosts having higher tick burdens. The species diversity of tick assemblages should also be greater on larger-bodied host species, but empirical studies testing this hypothesis are lacking. Here, we evaluate this relationship using a comparative dataset of feeding associations from Panama between 45 tick species and 171 host species that range in body size by three orders of magnitude. We found that tick species diversity increased with host body size for adult ticks but not for immature ticks. We also found that closely related host species tended to have similar tick species diversity, but correcting for host phylogeny did not alter the relationships between host body size and tick species diversity. The distribution of tick species was highly aggregated, with approximately 20% of the host species harboring 80% of all tick species, following the Pareto principle or 20/80 Rule. Thus, the aggregated pattern commonly observed for tick burdens and disease transmission also holds for patterns of tick species richness. Our finding that the adult ticks in this system preferentially parasitize large-bodied host species suggests that the ongoing anthropogenic loss of large-bodied vertebrates is likely to result in host-tick coextinction events, even when immature stages feed opportunistically. As parasites play critical roles in ecological and evolutionary processes, such losses may profoundly affect ecosystem functioning and services.

  13. Transposable element distribution, abundance and role in genome size variation in the genus Oryza.

    Science.gov (United States)

    Zuccolo, Andrea; Sebastian, Aswathy; Talag, Jayson; Yu, Yeisoo; Kim, HyeRan; Collura, Kristi; Kudrna, Dave; Wing, Rod A

    2007-08-29

    The genus Oryza is composed of 10 distinct genome types, 6 diploid and 4 polyploid, and includes the world's most important food crop - rice (Oryza sativa [AA]). Genome size variation in the Oryza is more than 3-fold and ranges from 357 Mbp in Oryza glaberrima [AA] to 1283 Mbp in the polyploid Oryza ridleyi [HHJJ]. Because repetitive elements are known to play a significant role in genome size variation, we constructed random sheared small insert genomic libraries from 12 representative Oryza species and conducted a comprehensive study of the repetitive element composition, distribution and phylogeny in this genus. Particular attention was paid to the role played by the most important classes of transposable elements (Long Terminal Repeats Retrotransposons, Long interspersed Nuclear Elements, helitrons, DNA transposable elements) in shaping these genomes and in their contributing to genome size variation. We identified the elements primarily responsible for the most strikingly genome size variation in Oryza. We demonstrated how Long Terminal Repeat retrotransposons belonging to the same families have proliferated to very different extents in various species. We also showed that the pool of Long Terminal Repeat Retrotransposons is substantially conserved and ubiquitous throughout the Oryza and so its origin is ancient and its existence predates the speciation events that originated the genus. Finally we described the peculiar behavior of repeats in the species Oryza coarctata [HHKK] whose placement in the Oryza genus is controversial. Long Terminal Repeat retrotransposons are the major component of the Oryza genomes analyzed and, along with polyploidization, are the most important contributors to the genome size variation across the Oryza genus. Two families of Ty3-gypsy elements (RIRE2 and Atlantys) account for a significant portion of the genome size variations present in the Oryza genus.

  14. Body Size Estimation from Early to Middle Childhood: Stability of Underestimation, BMI, and Gender Effects

    Directory of Open Access Journals (Sweden)

    Silje Steinsbekk

    2017-11-01

    Full Text Available Individuals who are overweight are more likely to underestimate their body size than those who are normal weight, and overweight underestimators are less likely to engage in weight loss efforts. Underestimation of body size might represent a barrier to prevention and treatment of overweight; thus insight in how underestimation of body size develops and tracks through the childhood years is needed. The aim of the present study was therefore to examine stability in children’s underestimation of body size, exploring predictors of underestimation over time. The prospective path from underestimation to BMI was also tested. In a Norwegian cohort of 6 year olds, followed up at ages 8 and 10 (analysis sample: n = 793 body size estimation was captured by the Children’s Body Image Scale, height and weight were measured and BMI calculated. Overall, children were more likely to underestimate than overestimate their body size. Individual stability in underestimation was modest, but significant. Higher BMI predicted future underestimation, even when previous underestimation was adjusted for, but there was no evidence for the opposite direction of influence. Boys were more likely than girls to underestimate their body size at ages 8 and 10 (age 8: 38.0% vs. 24.1%; Age 10: 57.9% vs. 30.8% and showed a steeper increase in underestimation with age compared to girls. In conclusion, the majority of 6, 8, and 10-year olds correctly estimate their body size (prevalence ranging from 40 to 70% depending on age and gender, although a substantial portion perceived themselves to be thinner than they actually were. Higher BMI forecasted future underestimation, but underestimation did not increase the risk for excessive weight gain in middle childhood.

  15. Habitat degradation and fishing effects on the size structure of coral reef fish communities.

    Science.gov (United States)

    Wilson, S K; Fisher, R; Pratchett, M S; Graham, N A J; Dulvy, N K; Turner, R A; Cakacaka, A; Polunin, N V C

    2010-03-01

    Overfishing and habitat degradation through climate change pose the greatest threats to sustainability of marine resources on coral reefs. We examined how changes in fishing pressure and benthic habitat composition influenced the size spectra of island-scale reef fish communities in Lau, Fiji. Between 2000 and 2006 fishing pressure declined in the Lau Islands due to declining human populations and reduced demand for fresh fish. At the same time, coral cover declined and fine-scale architectural complexity eroded due to coral bleaching and outbreaks of crown-of-thorns starfish, Acanthaster planci. We examined the size distribution of reef fish communities using size spectra analysis, the linearized relationship between abundance and body size class. Spatial variation in fishing pressure accounted for 31% of the variation in the slope of the size spectra in 2000, higher fishing pressure being associated with a steeper slope, which is indicative of fewer large-bodied fish and/or more small-bodied fish. Conversely, in 2006 spatial variation in habitat explained 53% of the variation in the size spectra slopes, and the relationship with fishing pressure was much weaker (approximately 12% of variation) than in 2000. Reduced cover of corals and lower structural complexity was associated with less steep size spectra slopes, primarily due to reduced abundance of fish < 20 cm. Habitat degradation will compound effects of fishing on coral reefs as increased fishing reduces large-bodied target species, while habitat loss results in fewer small-bodied juveniles and prey that replenish stocks and provide dietary resources for predatory target species. Effective management of reef resources therefore depends on both reducing fishing pressure and maintaining processes that encourage rapid recovery of coral habitat.

  16. Associations among body size across the life course, adult height and endometriosis.

    Science.gov (United States)

    Farland, L V; Missmer, S A; Bijon, A; Gusto, G; Gelot, A; Clavel-Chapelon, F; Mesrine, S; Boutron-Ruault, M C; Kvaskoff, M

    2017-08-01

    Are body size across the life course and adult height associated with endometriosis? Endometriosis is associated with lean body size during childhood, adolescence and adulthood; tall total adult height; and tall sitting height. The literature suggests that both adult body size and height are associated with endometriosis risk, but few studies have investigated the role of body size across the life course. Additionally, no study has investigated the relationships between components of height and endometriosis. We used a nested case-control design within E3N (Etude Epidémiologique auprès de femmes de l'Education Nationale), a prospective cohort of French women. Data were updated every 2-3 years through self-administered questionnaires. Odds ratios (ORs) and 95% CIs were computed using logistic regression models adjusted for a priori confounding factors. A total of 2416 endometriosis cases were reported as surgically ascertained among the 61 208 included women. The odds of endometriosis were lower among women who reported having a large versus lean body size at 8 years (P for trend = 0.003), at menarche (P for trend endometriosis compared to those in the lowest (endometriosis. Endometriosis cases may be prone to misclassification; however, we restricted our case definition to surgically-confirmed cases, which showed a high validation rate. Body size is based on retrospective self-report, which may be subject to recall bias. The results of this study suggest that endometriosis is positively associated with lean body size across the life course and total adult height. They also suggest that components of height are associated with endometriosis, which should be investigated further. The Mutuelle Générale de l'Education Nationale (MGEN); the European Community; the French League against Cancer (LNCC); Gustave Roussy; the French Institute of Health and Medical Research (Inserm). L.V.F. was supported by a T32 grant (#HD060454) in reproductive, perinatal and pediatric

  17. Climate change and body size shift in Mediterranean bivalve assemblages: unexpected role of biological invasions.

    Science.gov (United States)

    Nawrot, Rafał; Albano, Paolo G; Chattopadhyay, Devapriya; Zuschin, Martin

    2017-08-16

    Body size is a synthetic functional trait determining many key ecosystem properties. Reduction in average body size has been suggested as one of the universal responses to global warming in aquatic ecosystems. Climate change, however, coincides with human-enhanced dispersal of alien species and can facilitate their establishment. We address effects of species introductions on the size structure of recipient communities using data on Red Sea bivalves entering the Mediterranean Sea through the Suez Canal. We show that the invasion leads to increase in median body size of the Mediterranean assemblage. Alien species are significantly larger than native Mediterranean bivalves, even though they represent a random subset of the Red Sea species with respect to body size. The observed patterns result primarily from the differences in the taxonomic composition and body-size distributions of the source and recipient species pools. In contrast to the expectations based on the general temperature-size relationships in marine ectotherms, continued warming of the Mediterranean Sea indirectly leads to an increase in the proportion of large-bodied species in bivalve assemblages by accelerating the entry and spread of tropical aliens. These results underscore complex interactions between changing climate and species invasions in driving functional shifts in marine ecosystems. © 2017 The Author(s).

  18. All rights reserved Variation in Body Weight, Organ Weight and ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Variation in Body Weight, Organ Weight and Haematological Parameters of Rats Fed ... ABSTRACT: Food insecurity is a major problem of the developing nations. ... Except for the values of haemoglobin and packed cell volume that were ...

  19. Variation in thickness of the large cryosections cut for whole-body autoradiography

    International Nuclear Information System (INIS)

    Ito, Tsunao; Brill, A.B.

    1991-01-01

    A method to assess variation in thickness of the large cryosections for whole-body autoradiography (WBARG) was described, and the degree of intraslice and interslice variations were determined for our cryomicrotome system (LKB PMV-2250). Intraslice variation in thickness of the 180 x 80 mm cryosection was 0.72-0.92 μm within the range of section thickness for WBARG (15-50 μm), and interslice variation was 0.89-1.21 μm. These potential variations in section thickness should be kept in mind whenever working with quantitative WBARG. (author)

  20. How well can body size represent effects of the environment on demographic rates? Disentangling correlated explanatory variables.

    Science.gov (United States)

    Brooks, Mollie E; Mugabo, Marianne; Rodgers, Gwendolen M; Benton, Timothy G; Ozgul, Arpat

    2016-03-01

    Demographic rates are shaped by the interaction of past and current environments that individuals in a population experience. Past environments shape individual states via selection and plasticity, and fitness-related traits (e.g. individual size) are commonly used in demographic analyses to represent the effect of past environments on demographic rates. We quantified how well the size of individuals captures the effects of a population's past and current environments on demographic rates in a well-studied experimental system of soil mites. We decomposed these interrelated sources of variation with a novel method of multiple regression that is useful for understanding nonlinear relationships between responses and multicollinear explanatory variables. We graphically present the results using area-proportional Venn diagrams. Our novel method was developed by combining existing methods and expanding upon them. We showed that the strength of size as a proxy for the past environment varied widely among vital rates. For instance, in this organism with an income breeding life history, the environment had more effect on reproduction than individual size, but with substantial overlap indicating that size encompassed some of the effects of the past environment on fecundity. This demonstrates that the strength of size as a proxy for the past environment can vary widely among life-history processes within a species, and this variation should be taken into consideration in trait-based demographic or individual-based approaches that focus on phenotypic traits as state variables. Furthermore, the strength of a proxy will depend on what state variable(s) and what demographic rate is being examined; that is, different measures of body size (e.g. length, volume, mass, fat stores) will be better or worse proxies for various life-history processes. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

  1. Synopsis of the temporal variation of particulate matter composition and size.

    Science.gov (United States)

    Demerjian, Kenneth L; Mohnen, Volker A

    2008-02-01

    A synopsis of the detailed temporal variation of the size and number distribution of particulate matter (PM) and its chemical composition on the basis of measurements performed by several regional research consortia funded by the U.S. Environmental Protection Agency (EPA) PM Supersite Program is presented. This program deployed and evaluated a variety of research and emerging commercial measurement technologies to investigate the physical and chemical properties of atmospheric aerosols at a level of detail never before achieved. Most notably these studies demonstrated that systematic size-segregated measurements of mass, number, and associated chemical composition of the fine (PM2.5) and ultrafine (PM0.1) fraction of ambient aerosol with a time resolution down to minutes and less is achievable. A wealth of new information on the temporal variation of aerosol has been added to the existing knowledge pool that can be mined to resolve outstanding research and policy-related questions. This paper explores the nature of temporal variations (on time scales from several minutes to hours) in the chemical and physical properties of PM and its implications in the identification of PM formation processes, and source attribution (primary versus secondary), the contribution of local versus transported PM and the development of effective PM control strategies. The PM Supersite results summarized indicate that location, time of day, and season significantly influence not only the mass and chemical composition but also the size-resolved chemical/elemental composition of PM. Ambient measurements also show that ultrafine particles have different compositions and make up only a small portion of the PM mass concentration compared with inhalable coarse and fine particles, but their number concentration is significantly larger than their coarse or fine counterparts. PM size classes show differences in the relative amounts of nitrates, sulfates, crustal materials, and most especially

  2. Breaking Haller's rule: brain-body size isometry in a minute parasitic wasp.

    NARCIS (Netherlands)

    Woude, van der E.; Smid, H.M.; Chittka, L.; Huigens, M.E.

    2013-01-01

    Throughout the animal kingdom, Haller's rule holds that smaller individuals have larger brains relative to their body than larger-bodied individuals. Such brain-body size allometry is documented for all animals studied to date, ranging from small ants to the largest mammals. However, through

  3. Body Size as a Driver of Scavenging in Theropod Dinosaurs.

    Science.gov (United States)

    Kane, Adam; Healy, Kevin; Ruxton, Graeme D; Jackson, Andrew L

    2016-06-01

    Theropod dinosaurs dominated Earth's terrestrial ecosystem as a diverse group of predators for more than 160 million years, yet little is known about their foraging ecology. Maintaining a balanced energy budget presented a major challenge for therapods, which ranged from the chicken-sized Microraptor up to the whale-sized Giganotosaurus, in the face of intense competition and the demands of ontogenetic growth. Facultative scavenging, a behavior present in almost all modern predators, may have been important in supplementing energetically expensive lifestyles. By using agent-based models based on the allometric relationship between size and foraging behaviors, we show that theropods between 27 and 1,044 kg would have gained a significant energetic advantage over individuals at both the small and large extremes of theropod body mass through their scavenging efficiency. These results were robust to rate of competition, primary productivity, and detection distance. Our models demonstrate the potential importance of facultative scavenging in theropods and the role of body size in defining its prevalence in Mesozoic terrestrial systems.

  4. Size-density scaling in protists and the links between consumer-resource interaction parameters.

    Science.gov (United States)

    DeLong, John P; Vasseur, David A

    2012-11-01

    Recent work indicates that the interaction between body-size-dependent demographic processes can generate macroecological patterns such as the scaling of population density with body size. In this study, we evaluate this possibility for grazing protists and also test whether demographic parameters in these models are correlated after controlling for body size. We compiled data on the body-size dependence of consumer-resource interactions and population density for heterotrophic protists grazing algae in laboratory studies. We then used nested dynamic models to predict both the height and slope of the scaling relationship between population density and body size for these protists. We also controlled for consumer size and assessed links between model parameters. Finally, we used the models and the parameter estimates to assess the individual- and population-level dependence of resource use on body-size and prey-size selection. The predicted size-density scaling for all models matched closely to the observed scaling, and the simplest model was sufficient to predict the pattern. Variation around the mean size-density scaling relationship may be generated by variation in prey productivity and area of capture, but residuals are relatively insensitive to variation in prey size selection. After controlling for body size, many consumer-resource interaction parameters were correlated, and a positive correlation between residual prey size selection and conversion efficiency neutralizes the apparent fitness advantage of taking large prey. Our results indicate that widespread community-level patterns can be explained with simple population models that apply consistently across a range of sizes. They also indicate that the parameter space governing the dynamics and the steady states in these systems is structured such that some parts of the parameter space are unlikely to represent real systems. Finally, predator-prey size ratios represent a kind of conundrum, because they are

  5. Fluctuating survival selection explains variation in avian group size.

    Science.gov (United States)

    Brown, Charles R; Brown, Mary Bomberger; Roche, Erin A; O'Brien, Valerie A; Page, Catherine E

    2016-05-03

    Most animal groups vary extensively in size. Because individuals in certain sizes of groups often have higher apparent fitness than those in other groups, why wide group size variation persists in most populations remains unexplained. We used a 30-y mark-recapture study of colonially breeding cliff swallows (Petrochelidon pyrrhonota) to show that the survival advantages of different colony sizes fluctuated among years. Colony size was under both stabilizing and directional selection in different years, and reversals in the sign of directional selection regularly occurred. Directional selection was predicted in part by drought conditions: birds in larger colonies tended to be favored in cooler and wetter years, and birds in smaller colonies in hotter and drier years. Oscillating selection on colony size likely reflected annual differences in food availability and the consequent importance of information transfer, and/or the level of ectoparasitism, with the net benefit of sociality varying under these different conditions. Averaged across years, there was no net directional change in selection on colony size. The wide range in cliff swallow group size is probably maintained by fluctuating survival selection and represents the first case, to our knowledge, in which fitness advantages of different group sizes regularly oscillate over time in a natural vertebrate population.

  6. Correlation between Leukocyte Numbers and Body Size of Rainbow Trout

    DEFF Research Database (Denmark)

    Mohammad, Rezkar Jaafar; Otani, Maki; Kania, Per Walter

    2016-01-01

    wild and cultured fish and we show that the size of the leukocyte population increases exponentially with body size of rainbow trout. Four groups (5 fish/group) of naive rainbow trout (Oncorhynchus mykiss) with a mean body weight of 2 - 4 g (group I), 4 - 6 g (group II), 25 - 30 g (group III), and 650...... towards an antigen to be initiated even in fry. The number of leukocytes in individual fish at different developmental stages is likely to influence the capacity of the fish to respond simultaneously to several antigens (pathogens and vaccine components). This parameter may therefore be crucial for both...... - 780 g (group IV) were investigated. The number of lymphocytes was generally higher in head kidney compared to blood and spleen but they dominated in all samples (blood, head kidney and spleen) and their numbers increased exponentially with fish size. Percentages of lymphocytes in relation...

  7. Women Build Long Bones With Less Cortical Mass Relative to Body Size and Bone Size Compared With Men.

    Science.gov (United States)

    Jepsen, Karl J; Bigelow, Erin M R; Schlecht, Stephen H

    2015-08-01

    The twofold greater lifetime risk of fracturing a bone for white women compared with white men and black women has been attributed in part to differences in how the skeletal system accumulates bone mass during growth. On average, women build more slender long bones with less cortical area compared with men. Although slender bones are known to have a naturally lower cortical area compared with wider bones, it remains unclear whether the relatively lower cortical area of women is consistent with their increased slenderness or is reduced beyond that expected for the sex-specific differences in bone size and body size. Whether this sexual dimorphism is consistent with ethnic background and is recapitulated in the widely used mouse model also remains unclear. We asked (1) do black women build bones with reduced cortical area compared with black men; (2) do white women build bones with reduced cortical area compared with white men; and (3) do female mice build bones with reduced cortical area compared with male mice? Bone strength and cross-sectional morphology of adult human and mouse bone were calculated from quantitative CT images of the femoral midshaft. The data were tested for normality and regression analyses were used to test for differences in cortical area between men and women after adjusting for body size and bone size by general linear model (GLM). Linear regression analysis showed that the femurs of black women had 11% lower cortical area compared with those of black men after adjusting for body size and bone size (women: mean=357.7 mm2; 95% confidence interval [CI], 347.9-367.5 mm2; men: mean=400.1 mm2; 95% CI, 391.5-408.7 mm2; effect size=1.2; pbone size (women: mean=350.1 mm2; 95% CI, 340.4-359.8 mm2; men: mean=394.3 mm2; 95% CI, 386.5-402.1 mm2; effect size=1.3; pbone size (female: mean=0.73 mm2; 95% CI, 0.71-0.74 mm2; male: mean=0.70 mm2; 95% CI, 0.68-0.71 mm2; effect size=0.74; p=0.04, GLM). Female femurs are not simply a more slender version of male

  8. Evolution of bill size in relation to body size in toucans and hornbills (Aves: Piciformes and Bucerotiformes

    Directory of Open Access Journals (Sweden)

    Austin L. Hughes

    2014-06-01

    Full Text Available Evidence that the bill of the Toco Toucan, Ramphastos toco Statius Muller, 1776, has a specialized role in heat dissipation suggests a new function for the large and light-weight bill of the toucan family (Piciformes: Ramphastidae. A prediction of this hypothesis is that bill length in toucans will increase with body mass at a rate greater than the isometric expectation. This hypothesis was tested in a phylogenetic context with measurements of skeletal elements in adult males of 21 toucan species. In these species, 64.3% of variance in relative skeletal measurements was accounted for by the contrast between bill and body size. Maxilla length and depth increased with body mass at a greater than isometric rate relative to both body mass and other linear skeletal measures. By contrast, no such trend was seen in a parallel analysis of 24 hornbill species (Bucerotiformes, sometimes considered ecological equivalents of toucans. The unique relationship between bill size and body mass in toucans supports the hypothesis that the evolution of a heat dissipation function has been a persistent theme of bill evolution in toucans.

  9. Attention biases in preoccupation with body image: An ERP study of the role of social comparison and automaticity when processing body size.

    Science.gov (United States)

    Uusberg, Helen; Peet, Krista; Uusberg, Andero; Akkermann, Kirsti

    2018-03-17

    Appearance-related attention biases are thought to contribute to body image disturbances. We investigated how preoccupation with body image is associated with attention biases to body size, focusing on the role of social comparison processes and automaticity. Thirty-six women varying on self-reported preoccupation compared their actual body size to size-modified images of either themselves or a figure-matched peer. Amplification of earlier (N170, P2) and later (P3, LPP) ERP components recorded under low vs. high concurrent working memory load were analyzed. Women with high preoccupation exhibited an earlier bias to larger bodies of both self and peer. During later processing stages, they exhibited a stronger bias to enlarged as well as reduced self-images and a lack of sensitivity to size-modifications of the peer-image. Working memory load did not affect these biases systematically. Current findings suggest that preoccupation with body image involves an earlier attention bias to weight increase cues and later over-engagement with own figure. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. A simple genetic architecture underlies morphological variation in dogs.

    Directory of Open Access Journals (Sweden)

    Adam R Boyko

    2010-08-01

    Full Text Available Domestic dogs exhibit tremendous phenotypic diversity, including a greater variation in body size than any other terrestrial mammal. Here, we generate a high density map of canine genetic variation by genotyping 915 dogs from 80 domestic dog breeds, 83 wild canids, and 10 outbred African shelter dogs across 60,968 single-nucleotide polymorphisms (SNPs. Coupling this genomic resource with external measurements from breed standards and individuals as well as skeletal measurements from museum specimens, we identify 51 regions of the dog genome associated with phenotypic variation among breeds in 57 traits. The complex traits include average breed body size and external body dimensions and cranial, dental, and long bone shape and size with and without allometric scaling. In contrast to the results from association mapping of quantitative traits in humans and domesticated plants, we find that across dog breeds, a small number of quantitative trait loci (< or = 3 explain the majority of phenotypic variation for most of the traits we studied. In addition, many genomic regions show signatures of recent selection, with most of the highly differentiated regions being associated with breed-defining traits such as body size, coat characteristics, and ear floppiness. Our results demonstrate the efficacy of mapping multiple traits in the domestic dog using a database of genotyped individuals and highlight the important role human-directed selection has played in altering the genetic architecture of key traits in this important species.

  11. Interactive effects of body-size structure and adaptive foraging on food-web stability.

    Science.gov (United States)

    Heckmann, Lotta; Drossel, Barbara; Brose, Ulrich; Guill, Christian

    2012-03-01

    Body-size structure of food webs and adaptive foraging of consumers are two of the dominant concepts of our understanding how natural ecosystems maintain their stability and diversity. The interplay of these two processes, however, is a critically important yet unresolved issue. To fill this gap in our knowledge of ecosystem stability, we investigate dynamic random and niche model food webs to evaluate the proportion of persistent species. We show that stronger body-size structures and faster adaptation stabilise these food webs. Body-size structures yield stabilising configurations of interaction strength distributions across food webs, and adaptive foraging emphasises links to resources closer to the base. Moreover, both mechanisms combined have a cumulative effect. Most importantly, unstructured random webs evolve via adaptive foraging into stable size-structured food webs. This offers a mechanistic explanation of how size structure adaptively emerges in complex food webs, thus building a novel bridge between these two important stabilising mechanisms. © 2012 Blackwell Publishing Ltd/CNRS.

  12. Vocal tract length and formant frequency dispersion correlate with body size in rhesus macaques.

    Science.gov (United States)

    Fitch, W T

    1997-08-01

    Body weight, length, and vocal tract length were measured for 23 rhesus macaques (Macaca mulatta) of various sizes using radiographs and computer graphic techniques. linear predictive coding analysis of tape-recorded threat vocalizations were used to determine vocal tract resonance frequencies ("formants") for the same animals. A new acoustic variable is proposed, "formant dispersion," which should theoretically depend upon vocal tract length. Formant dispersion is the averaged difference between successive formant frequencies, and was found to be closely tied to both vocal tract length and body size. Despite the common claim that voice fundamental frequency (F0) provides an acoustic indication of body size, repeated investigations have failed to support such a relationship in many vertebrate species including humans. Formant dispersion, unlike voice pitch, is proposed to be a reliable predictor of body size in macaques, and probably many other species.

  13. Copepod community growth rates in relation to body size, temperature, and food availability in the East China Sea: a test of metabolic theory of ecology

    Directory of Open Access Journals (Sweden)

    K. Y. Lin

    2013-03-01

    Full Text Available Zooplankton play an essential role in marine food webs, and understanding how community-level growth rates of zooplankton vary in the field is critical for predicting how marine ecosystem function may vary in the face of environmental changes. Here, we used the artificial cohort method to examine the effects of temperature, body size, and chlorophyll concentration (a proxy for food on weight-specific growth rates for copepod communities in the East China Sea. Specifically, we tested the hypothesis that copepod community growth rates can be described by the metabolic theory of ecology (MTE, linking spatio-temporal variation of copepod growth rate with temperature and their body size. Our results generally agree with predictions made by the MTE and demonstrate that weight-specific growth rates of copepod communities in our study area are positively related with temperature and negatively related to body size. However, the regression coefficients of body size do not approach the theoretical predictions. Furthermore, we find that the deviation from the MTE predictions may be partly attributed to the effect of food availability (which is not explicitly accounted for by the MTE. In addition, significant difference in the coefficients of temperature and body size exists among taxonomic groups. Our results suggest that considering the effects of food limitation and taxonomy is necessary to better understand copepod growth rates under in situ conditions, and such effects on the MTE-based predictions need further investigation.

  14. Relative Importance of Sex, Pre-Starvation Body Mass and Structural Body Size in the Determination of Exceptional Starvation Resistance of Anchomenus dorsalis (Coleoptera: Carabidae.

    Directory of Open Access Journals (Sweden)

    Michal Knapp

    Full Text Available In nature, almost all animals have to cope with periods of food shortage during their lifetimes. Starvation risks are especially high for carnivorous predatory species, which often experience long intervals between stochastic prey capturing events. A laboratory experiment using the common predatory carabid beetle Anchomenus dorsalis revealed an exceptional level of starvation resistance in this species: males survived up to 137 days and females up to 218 days without food at 20°C. Individual starvation resistance was strongly positively affected by pre-starvation body mass but only slightly by beetle structural body size per se. Females outperformed males even when the effect of gender was corrected for the effects of structural body size and pre-starvation body mass. The better performance of females compared to males and of beetles with higher relative pre-starvation body mass could be linked to higher fat content and lean dry mass before starvation, followed by a greater decrease in both during starvation. There was also a difference between the sexes in the extent of body mass changes both during ad libitum feeding and following starvation; the body masses of females fluctuated more compared to males. This study stresses the need to distinguish between body mass and structural body size when investigating the ecological and evolutionary consequences of body size. Investigation of the net effects of body size and sex is necessary to disentangle the causes of differences in individual performances in studies of species with significant sexual size dimorphism.

  15. Body size and growth in 0- to 4-year-old children and the relation to body size in primary school age

    NARCIS (Netherlands)

    Stocks, T.; Renders, C.M.; Bulk-Bunschoten, A.M.W.; Hirasing, R.A.; Buuren, S. van; Seidell, J.C.

    2011-01-01

    Excess weight in early life is believed to increase susceptibility to obesity, and in support of such theory, excess weight and fast weight gain in early childhood have been related to overweight later in life. The aim of this study was to review the literature on body size and growth in 0- to

  16. Body size and growth in 0- to 4-year-old children and the relation to body size in primary school age

    NARCIS (Netherlands)

    Stocks, T; Renders, C M; Bulk-Bunschoten, A.M.W.; HiraSing, R.A.; van Buuren, S.; Seidell, J C

    Excess weight in early life is believed to increase susceptibility to obesity, and in support of such theory, excess weight and fast weight gain in early childhood have been related to overweight later in life. The aim of this study was to review the literature on body size and growth in 0- to

  17. Rhythmic 24 h variation of core body temperature and locomotor activity in a subterranean rodent (Ctenomys aff. knighti, the tuco-tuco.

    Directory of Open Access Journals (Sweden)

    Patricia Tachinardi

    Full Text Available The tuco-tuco Ctenomys aff. knighti is a subterranean rodent which inhabits a semi-arid area in Northwestern Argentina. Although they live in underground burrows where environmental cycles are attenuated, they display robust, 24 h locomotor activity rhythms that are synchronized by light/dark cycles, both in laboratory and field conditions. The underground environment also poses energetic challenges (e.g. high-energy demands of digging, hypoxia, high humidity, low food availability that have motivated thermoregulation studies in several subterranean rodent species. By using chronobiological protocols, the present work aims to contribute towards these studies by exploring day-night variations of thermoregulatory functions in tuco-tucos, starting with body temperature and its temporal relationship to locomotor activity. Animals showed daily, 24 h body temperature rhythms that persisted even in constant darkness and temperature, synchronizing to a daily light/dark cycle, with highest values occurring during darkness hours. The range of oscillation of body temperature was slightly lower than those reported for similar-sized and dark-active rodents. Most rhythmic parameters, such as period and phase, did not change upon removal of the running wheel. Body temperature and locomotor activity rhythms were robustly associated in time. The former persisted even after removal of the acute effects of intense activity on body temperature by a statistical method. Finally, regression gradients between body temperature and activity were higher in the beginning of the night, suggesting day-night variation in thermal conductance and heat production. Consideration of these day-night variations in thermoregulatory processes is beneficial for further studies on thermoregulation and energetics of subterranean rodents.

  18. Effect of meal size and body size on specific dynamic action and gastric processing in decapod crustaceans.

    Science.gov (United States)

    McGaw, Iain J; Curtis, Daniel L

    2013-11-01

    Meal size and animal size are important factors affecting the characteristics of the specific dynamic action (SDA) response across a variety of taxa. The effects of these two variables on the SDA of decapod crustaceans are based on just a couple of articles, and are not wholly consistent with the responses reported for other aquatic ectotherms. Therefore, the effects of meal size and animal size on the characteristics of SDA response were investigated in a variety of decapod crustaceans from different families. A 6 fold increase in meal size (0.5%-3% body mass) resulted a pronounced increase in the duration of increased oxygen consumption, resulting in an increase in the SDA of Callinectes sapidus, Cancer gracilis, Hemigrapsus nudus, Homarus americanus, Pugettia producta and Procambarus clarkii. Unlike many other aquatic ectotherms a substantial increase between meal sizes was required, with meal size close to their upper feeding limit (3% body mass), before changes were evident. In many organisms increases in both duration and scope contribute to the overall SDA, here changes in scope as a function of meal size were weak, suggesting that a similar amount of energy is required to upregulate gastric processes, regardless of meal size. The SDA characteristics were less likely to be influenced by the size of the animal, and there was no difference in the SDA (kJ) as a function of size in H. americanus or Cancer irroratus when analysed as mass specific values. In several fish species characteristics of the SDA response are more closely related to the transit times of food, rather than the size of a meal. To determine if a similar trend occurred in crustaceans, the transit rates of different sized meals were followed through the digestive system using a fluoroscope. Although there was a trend towards larger meals taking longer to pass through the gut, this was only statistically significant for P. clarkii. There were some changes in transit times as a function of animal

  19. Genome size variation among and within Camellia species by using flow cytometric analysis.

    Directory of Open Access Journals (Sweden)

    Hui Huang

    Full Text Available BACKGROUND: The genus Camellia, belonging to the family Theaceae, is economically important group in flowering plants. Frequent interspecific hybridization together with polyploidization has made them become taxonomically "difficult taxa". The DNA content is often used to measure genome size variation and has largely advanced our understanding of plant evolution and genome variation. The goals of this study were to investigate patterns of interspecific and intraspecific variation of DNA contents and further explore genome size evolution in a phylogenetic context of the genus. METHODOLOGY/PRINCIPAL FINDINGS: The DNA amount in the genus was determined by using propidium iodide flow cytometry analysis for a total of 139 individual plants representing almost all sections of the two subgenera, Camellia and Thea. An improved WPB buffer was proven to be suitable for the Camellia species, which was able to counteract the negative effects of secondary metabolite and generated high-quality results with low coefficient of variation values (CV <5%. Our results showed trivial effects on different tissues of flowers, leaves and buds as well as cytosolic compounds on the estimation of DNA amount. The DNA content of C. sinensis var. assamica was estimated to be 1C = 3.01 pg by flow cytometric analysis, which is equal to a genome size of about 2940 Mb. CONCLUSION: Intraspecific and interspecific variations were observed in the genus Camellia, and as expected, the latter was larger than the former. Our study suggests a directional trend of increasing genome size in the genus Camellia probably owing to the frequent polyploidization events.

  20. Genetics of body shape and armour variation in threespine sticklebacks.

    Science.gov (United States)

    Leinonen, T; Cano, J M; Merilä, J

    2011-01-01

    Patterns of genetic variation and covariation can influence the rate and direction of phenotypic evolution. We explored the possibility that the parallel morphological evolution seen in threespine stickleback (Gasterosteus aculeatus) populations colonizing freshwater environments is facilitated by patterns of genetic variation and covariation in the ancestral (marine) population. We estimated the genetic (G) and phenotypic (P) covariance matrices and directions of maximum additive genetic (g(max) ) and phenotypic (p(max) ) covariances of body shape and armour traits. Our results suggest a role for the ancestral G in explaining parallel morphological evolution in freshwater populations. We also found evidence of genetic constraints owing to the lack of variance in the ancestral G. Furthermore, strong genetic covariances and correlations among traits revealed that selective factors responsible for threespine stickleback body shape and armour divergence may be difficult to disentangle. The directions of g(max) and p(max) were correlated, but the correlations were not high enough to imply that phenotypic patterns of trait variation and covariation within populations are very informative of underlying genetic patterns. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  1. My 'Fat Girl Complex': a preliminary investigation of sexual health and body image in women of size.

    Science.gov (United States)

    Satinsky, Sonya; Dennis, Barbara; Reece, Michael; Sanders, Stephanie; Bardzell, Shaowen

    2013-01-01

    Women of size who inhabit non-normative bodies may have different experiences with body image and sexual health than women of average body size. In this exploratory study, we interviewed four women of size recruited from a larger mixed-methodological study of body image and sexuality. Each woman was interviewed twice on topics of body image, sexuality and sexual health. Reconstructive Horizon Analysis was used to analyse the content of the interviews. Women who expressed that their bodies had inherent personal and social value regardless of size did not articulate connections between body size and their sexual health. However, those women who looked externally for validation of their attractiveness struggled with acceptance of their sexuality and bodies and spoke of ways in which their body size and appearance hindered them from having the sexually healthy lives that they wanted. Findings highlight two important components of women's sexual health as participants related them to body image: the right to pleasure and the right to engage only in wanted sexual activity. Participants described how negative body attitudes affected both of these aspects of their sexual health. Interventions targeting weight-based stigma may offer a means of indirectly promoting sexual health and autonomy in women.

  2. Mammal Reproductive Strategies Driven by Offspring Mortality-Size Relationships

    DEFF Research Database (Denmark)

    Sibly, Richard M.; Brown, James H.

    2009-01-01

    Trade-offs have long been a major theme in life-history theory, but they have been hard to document. We introduce a new method that reveals patterns of divergent trade-offs after adjusting for the pervasive variation in rate of resource allocation to offspring as a function of body size and lifes......Trade-offs have long been a major theme in life-history theory, but they have been hard to document. We introduce a new method that reveals patterns of divergent trade-offs after adjusting for the pervasive variation in rate of resource allocation to offspring as a function of body size...

  3. Effects of seed predators of different body size on seed mortality in Bornean logged forest.

    Science.gov (United States)

    Hautier, Yann; Saner, Philippe; Philipson, Christopher; Bagchi, Robert; Ong, Robert C; Hector, Andy

    2010-07-19

    The Janzen-Connell hypothesis proposes that seed and seedling enemies play a major role in maintaining high levels of tree diversity in tropical forests. However, human disturbance may alter guilds of seed predators including their body size distribution. These changes have the potential to affect seedling survival in logged forest and may alter forest composition and diversity. We manipulated seed density in plots beneath con- and heterospecific adult trees within a logged forest and excluded vertebrate predators of different body sizes using cages. We show that small and large-bodied predators differed in their effect on con- and heterospecific seedling mortality. In combination small and large-bodied predators dramatically decreased both con- and heterospecific seedling survival. In contrast, when larger-bodied predators were excluded small-bodied predators reduced conspecific seed survival leaving seeds coming from the distant tree of a different species. Our results suggest that seed survival is affected differently by vertebrate predators according to their body size. Therefore, changes in the body size structure of the seed predator community in logged forests may change patterns of seed mortality and potentially affect recruitment and community composition.

  4. Equal temperature-size responses of the sexes are widespread within arthropod species

    DEFF Research Database (Denmark)

    Hirst, Andrew G.; Horne, Curtis; Atkinson, David

    2015-01-01

    Sexual size dimorphism (SSD) is often affected by environmental conditions, but the effect of temperature on SSD in ectotherms still requires rigorous investigation. We compared the plastic responses of size-at-maturity to temperature between males and females within 85 diverse arthropod species...... of animal body sizes, variation in degree of SSD and differences in the sign of the T-S response. We find no support for Rensch's rule, which predicts greater variation in male size, or indeed the reverse, greater female size variation. SSD shows no systematic temperature dependence in any of the 17...

  5. Body Size Perceptions and Weight Status of Adults in a Nigerian ...

    African Journals Online (AJOL)

    Subjects and Methods: A cross‑sectional sample of 183 adults living in a rural community, South‑West Nigeria was randomly recruited into the study. Their verbal and visual body size perceptions were assessed through structured questions and body images. Descriptive and inferential statistics were used to analyze the ...

  6. Causes and consequences of range size variation: the influence of traits, speciation, and extinction

    Directory of Open Access Journals (Sweden)

    Steven M. Vamosi

    2012-12-01

    Full Text Available The tremendous variation in species richness observed among related clades across the tree of life has long caught the imagination of biologists. Recently, there has been growing attention paid to the possible contribution of range size variation, either alone or in combination with putative key innovations, to these patterns. Here, we review three related topics relevant to range size evolution, speciation, and extinction. First, we provide a brief overview of the debate surrounding patterns and mechanisms for phylogenetic signal in range size. Second, we discuss some recent findings regarding the joint influence of traits and range size on diversification. Finally, we present the preliminary results of a study investigating whether range size is negatively correlated with contemporary extinction risk in flowering plants.

  7. Temporal gene expression variation associated with eyespot size plasticity in Bicyclus anynana.

    Directory of Open Access Journals (Sweden)

    Jeffrey C Oliver

    Full Text Available Seasonal polyphenism demonstrates an organism's ability to respond to predictable environmental variation with alternative phenotypes, each presumably better suited to its respective environment. However, the molecular mechanisms linking environmental variation to alternative phenotypes via shifts in development remain relatively unknown. Here we investigate temporal gene expression variation in the seasonally polyphenic butterfly Bicyclus anynana. This species shows drastic changes in eyespot size depending on the temperature experienced during larval development. The wet season form (larvae reared over 24°C has large ventral wing eyespots while the dry season form (larvae reared under 19°C has much smaller eyespots. We compared the expression of three proteins, Notch, Engrailed, and Distal-less, in the future eyespot centers of the two forms to determine if eyespot size variation is associated with heterochronic shifts in the onset of their expression. For two of these proteins, Notch and Engrailed, expression in eyespot centers occurred earlier in dry season than in wet season larvae, while Distal-less showed no temporal difference between the two forms. These results suggest that differences between dry and wet season adult wings could be due to a delay in the onset of expression of these eyespot-associated genes. Early in eyespot development, Notch and Engrailed may be functioning as repressors rather than activators of the eyespot gene network. Alternatively, temporal variation in the onset of early expressed genes between forms may have no functional consequences to eyespot size regulation and may indicate the presence of an 'hourglass' model of development in butterfly eyespots.

  8. Sexual Size Dimorphism and Body Condition in the Australasian Gannet.

    Directory of Open Access Journals (Sweden)

    Lauren P Angel

    Full Text Available Sexual size dimorphism is widespread throughout seabird taxa and several drivers leading to its evolution have been hypothesised. While the Australasian Gannet (Morus serrator has previously been considered nominally monomorphic, recent studies have documented sexual segregation in diet and foraging areas, traits often associated with size dimorphism. The present study investigated the sex differences in body mass and structural size of this species at two colonies (Pope's Eye, PE; Point Danger, PD in northern Bass Strait, south-eastern Australia. Females were found to be 3.1% and 7.3% heavier (2.74 ± 0.03, n = 92; 2.67 ± 0.03 kg, n = 43 than males (2.66 ± 0.03, n = 92; 2.48 ± 0.03 kg, n = 43 at PE and PD, respectively. Females were also larger in wing ulna length (0.8% both colonies but smaller in bill depth (PE: 2.2%; PD: 1.7% than males. Despite this dimorphism, a discriminant function provided only mild accuracy in determining sex. A similar degree of dimorphism was also found within breeding pairs, however assortative mating was not apparent at either colony (R2 < 0.04. Using hydrogen isotope dilution, a body condition index was developed from morphometrics to estimate total body fat (TBF stores, where TBF(% = 24.43+1.94*(body mass/wing ulna length - 0.58*tarsus length (r2 = 0.84, n = 15. This index was used to estimate body composition in all sampled individuals. There was no significant difference in TBF(% between the sexes for any stage of breeding or in any year of the study at either colony suggesting that, despite a greater body mass, females were not in a better condition than males. While the driving mechanism for sexual dimorphism in this species is currently unknown, studies of other Sulids indicate segregation in foraging behaviour, habitat and diet may be a contributing factor.

  9. Understanding mismatches in body size, speed and power among adolescent rugby union players.

    Science.gov (United States)

    Krause, Lyndon M; Naughton, Geraldine A; Denny, Greg; Patton, Declan; Hartwig, Tim; Gabbett, Tim J

    2015-05-01

    With adolescent sport increasingly challenged by mismatches in size, new strategies are important to maximize participation. The objectives were to (1) improve the understanding of mismatches in physical size, speed and power in adolescent rugby union players, (2) explore associations between size and performance with demographic, playing-history, and injury profiles, and (3) explore the applicability of existing criteria for age/body mass-based dispensation (playing-down) strategies. Cross-sectional study. Four hundred and eighty-five male community rugby union players were recruited from three Australian states selected to represent community-based U12, U13, U14 and U15 players. Body mass, stature, speed (10, 30, and 40 m sprints) and lower-leg power (relative peak power and relative peak force) were measured. Independent student t-tests, linear regressions and Chi square analyses were undertaken. Mean values in age groups for size, speed and power masked considerable overlap in the ranges within specific age groups of adolescent rugby players. Only a small proportion of players (approximately 5%) shared the highest and lowest tertiles for speed, relative peak power and body mass. Physical size was not related to injury. The mean body mass of current community rugby union players was above the 75th percentile on normative growth-charts. The notion that bigger, faster, and more powerful characteristics occur simultaneously in adolescent rugby players was not supported in the present study. Current practices in body mass-based criteria for playing down an age group lack a sufficient evidence for decision-making. Dispensation solely based on body mass may not address mismatch in junior rugby union. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  10. Determining the influence of Korean population variation on whole-body average SAR.

    Science.gov (United States)

    Lee, Ae-Kyoung; Choi, Hyung-Do

    2012-05-07

    Compliance of the ICNIRP reference and IEEE action levels with the basic restrictions on whole-body average (WBA) SAR was investigated based on age, physique, and posture under isolated and grounded conditions. First, Korean male models 1, 3, 5, 7, and 20 years of age with body sizes in the 50th percentile were developed and used as the test subjects: 1y(50th), 3y(50th), 5y(50th), 7y(50th), and 20y(50th). The effects of age-dependent dielectric properties due to the water content of the tissue on WBA SAR were analysed, and showed that the changes in WBA SAR are marginal. At the ages of 1, 5, and 20, thin models 1y(10th), 5y(10th), and 20y(10th) with body sizes in the 10th percentile for the horizontal plane were added in order to determine the influence of physical variations of the population. We considered standing postures with arms up and arms down. The WBA SAR for each human model was calculated when exposed to a vertically polarized plane wave in the frequency range of 10 MHz-3 GHz using the finite-difference time-domain method. The evaluated WBA SAR-based safety factor of each model is discussed for exposure to the ICNIRP reference and IEEE action levels. Finally, the lowest external electric field strength required to produce the basic restrictions on the WBA SAR, 0.08 W kg(-1), was obtained. The results showed that the ICNIRP public reference level is not conservative in the frequency range of 20-200 MHz for an arms-up posture, in the range of 40-200 MHz for an arms-down posture, and above 1 GHz for both postures. The IEEE action level is different from the ICNIRP reference level below 30 MHz, where most cases showed a safety factor of less than 50, which is the minimum value compliant with the basic restrictions for exposure to the general public.

  11. Genetic basis for body size variation between an anadromous and two derived lacustrine populations of threespine stickleback Gasterosteus aculeatus in southwest Alaska.

    Science.gov (United States)

    Bowles, Ella; Johnston, Rebecca A; Vanderzwan, Stevi L; Rogers, Sean M

    2016-02-01

    Body size is a highly variable trait among geographically separated populations. Size-assortative reproductive isolation has been linked to recent adaptive radiations of threespine stickleback ( Gasterosteus aculeatus ) into freshwater, but the genetic basis of the commonly found size difference between anadromous and derived lacustrine sticklebacks has not been tested. We studied the genetic basis of size differences between recently diverging stickleback lineages in southwest Alaska using a common environment experiment. We crossed stickleback within one anadromous (Naknek River) and one lake (Pringle Lake) population and between the anadromous and two lake populations (Pringle and JoJo Lakes), and raised them in a salinity of 4-6 ppt. The F1 anadromous and freshwater forms differed significantly in size, whereas hybrids were intermediate or exhibited dominance toward the anadromous form. Additionally, the size of freshwater F1s differed from their wild counterparts, with within-population F1s from Pringle Lake growing larger than their wild counterparts, while there was no size difference between lab-raised and wild anadromous fish. Sexual dimorphism was always present in anadromous fish, but not in freshwater, and not always in the hybrid crosses. These results, along with parallel changes among anadromous and freshwater forms in other regions, suggest that this heritable trait is both plastic and may be under divergent and/or sexual selection.

  12. Body size evolution in an old insect order: No evidence for Cope's Rule in spite of fitness benefits of large size.

    Science.gov (United States)

    Waller, John T; Svensson, Erik I

    2017-09-01

    We integrate field data and phylogenetic comparative analyses to investigate causes of body size evolution and stasis in an old insect order: odonates ("dragonflies and damselflies"). Fossil evidence for "Cope's Rule" in odonates is weak or nonexistent since the last major extinction event 65 million years ago, yet selection studies show consistent positive selection for increased body size among adults. In particular, we find that large males in natural populations of the banded demoiselle (Calopteryx splendens) over several generations have consistent fitness benefits both in terms of survival and mating success. Additionally, there was no evidence for stabilizing or conflicting selection between fitness components within the adult life-stage. This lack of stabilizing selection during the adult life-stage was independently supported by a literature survey on different male and female fitness components from several odonate species. We did detect several significant body size shifts among extant taxa using comparative methods and a large new molecular phylogeny for odonates. We suggest that the lack of Cope's rule in odonates results from conflicting selection between fitness advantages of large adult size and costs of long larval development. We also discuss competing explanations for body size stasis in this insect group. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  13. Mammal body size evolution in North America and Europe over 20 Myr: similar trends generated by different processes.

    Science.gov (United States)

    Huang, Shan; Eronen, Jussi T; Janis, Christine M; Saarinen, Juha J; Silvestro, Daniele; Fritz, Susanne A

    2017-02-22

    Because body size interacts with many fundamental biological properties of a species, body size evolution can be an essential component of the generation and maintenance of biodiversity. Here we investigate how body size evolution can be linked to the clade-specific diversification dynamics in different geographical regions. We analyse an extensive body size dataset of Neogene large herbivores (covering approx. 50% of the 970 species in the orders Artiodactyla and Perissodactyla) in Europe and North America in a Bayesian framework. We reconstruct the temporal patterns of body size in each order on each continent independently, and find significant increases of minimum size in three of the continental assemblages (except European perissodactyls), suggesting an active selection for larger bodies. Assessment of trait-correlated birth-death models indicates that the common trend of body size increase is generated by different processes in different clades and regions. Larger-bodied artiodactyl species on both continents tend to have higher origination rates, and both clades in North America show strong links between large bodies and low extinction rate. Collectively, our results suggest a strong role of species selection and perhaps of higher-taxon sorting in driving body size evolution, and highlight the value of investigating evolutionary processes in a biogeographic context. © 2017 The Author(s).

  14. Carotid body size measured by computed tomographic angiography in individuals born prematurely.

    Science.gov (United States)

    Bates, Melissa L; Welch, Brian T; Randall, Jess T; Petersen-Jones, Humphrey G; Limberg, Jacqueline K

    2018-05-24

    We tested the hypothesis that the carotid bodies would be smaller in individuals born prematurely or exposed to perinatal oxygen therapy when compared individuals born full term that did not receive oxygen therapy. A retrospective chart review was conducted on patients who underwent head/neck computed tomography angiography (CTA) at the Mayo Clinic between 10 and 40 years of age (n = 2503). Patients were identified as premature ( body images captured during the CTA were performed. Carotid body visualization was possible in 43% of patients and 52% of age, sex, and body mass index (BMI)-matched controls but only 17% of juvenile preterm subjects (p = 0.07). Of the carotid bodies that could be visualized, widest axial measurements of the carotid bodies in individuals born prematurely (n = 7, 34 ± 4 weeks gestation, birth weight: 2460 ± 454 g; average size: 2.5 ± 0.2 cm) or individuals exposed to perinatal oxygen therapy (n = 3, 38 ± 2 weeks gestation, Average size: 2.2 ± 0.1 cm) were not different when compared to controls (2.3 ± 0.2 cm and 2.3 ± 0.2 cm, respectively, p > 0.05). Carotid body size, as measured using CTA, is not smaller in adults born prematurely or exposed to perinatal oxygen therapy when compared to sex, age, and BMI-matched controls. However, carotid body visualization was lower in juvenile premature patients. The decreased ability to visualize the carotid bodies in these individuals may be a result of their prematurity. Copyright © 2018. Published by Elsevier B.V.

  15. Habitat structure and body size distributions: Cross-ecosystem comparison for taxa with determinate and indeterminate growth

    Science.gov (United States)

    Nash, Kirsty L.; Allen, Craig R.; Barichievy, Chris; Nystrom, Magnus; Sundstrom, Shana M.; Graham, Nicholas A.J.

    2014-01-01

    Habitat structure across multiple spatial and temporal scales has been proposed as a key driver of body size distributions for associated communities. Thus, understanding the relationship between habitat and body size is fundamental to developing predictions regarding the influence of habitat change on animal communities. Much of the work assessing the relationship between habitat structure and body size distributions has focused on terrestrial taxa with determinate growth, and has primarily analysed discontinuities (gaps) in the distribution of species mean sizes (species size relationships or SSRs). The suitability of this approach for taxa with indeterminate growth has yet to be determined. We provide a cross-ecosystem comparison of bird (determinate growth) and fish (indeterminate growth) body mass distributions using four independent data sets. We evaluate three size distribution indices: SSRs, species size–density relationships (SSDRs) and individual size–density relationships (ISDRs), and two types of analysis: looking for either discontinuities or abundance patterns and multi-modality in the distributions. To assess the respective suitability of these three indices and two analytical approaches for understanding habitat–size relationships in different ecosystems, we compare their ability to differentiate bird or fish communities found within contrasting habitat conditions. All three indices of body size distribution are useful for examining the relationship between cross-scale patterns of habitat structure and size for species with determinate growth, such as birds. In contrast, for species with indeterminate growth such as fish, the relationship between habitat structure and body size may be masked when using mean summary metrics, and thus individual-level data (ISDRs) are more useful. Furthermore, ISDRs, which have traditionally been used to study aquatic systems, present a potentially useful common currency for comparing body size distributions

  16. Body size and symbiotic status influence gonad development in Aiptasia pallida anemones.

    Science.gov (United States)

    Carlisle, Judith F; Murphy, Grant K; Roark, Alison M

    2017-01-01

    Pale anemones ( Aiptasia pallida ) coexist with dinoflagellates (primarily Symbiodinium minutum ) in a mutualistic relationship. The purpose of this study was to investigate the role of these symbionts in gonad development of anemone hosts. Symbiotic and aposymbiotic anemones were subjected to light cycles that induced gametogenesis. These anemones were then sampled weekly for nine weeks, and gonad development was analyzed histologically. Anemone size was measured as mean body column diameter, and oocytes or sperm follicles were counted for each anemone. Generalized linear models were used to evaluate the influence of body size and symbiotic status on whether gonads were present and on the number of oocytes or sperm follicles produced. Body size predicted whether gonads were present, with larger anemones being more likely than smaller anemones to develop gonads. Both body size and symbiotic status predicted gonad size, such that larger and symbiotic anemones produced more oocytes and sperm follicles than smaller and aposymbiotic anemones. Overall, only 22 % of aposymbiotic females produced oocytes, whereas 63 % of symbiotic females produced oocytes. Similarly, 6 % of aposymbiotic males produced sperm follicles, whereas 60 % of symbiotic males produced sperm follicles. Thus, while gonads were present in 62 % of symbiotic anemones, they were present in only 11 % of aposymbiotic anemones. These results indicate that dinoflagellate symbionts influence gonad development and thus sexual maturation in both female and male Aiptasia pallida anemones. This finding substantiates and expands our current understanding of the importance of symbionts in the development and physiology of cnidarian hosts.

  17. Optimization of the variational basis in the three body problem

    International Nuclear Information System (INIS)

    Simenog, I.V.; Pushkash, O.M.; Bestuzheva, A.B.

    1995-01-01

    The procedure of variational oscillator basis optimization is proposed to the calculation the energy spectra of three body systems. The hierarchy of basis functions is derived and energies of ground and excited states for three gravitating particles is obtained with high accuracy. 12 refs

  18. Macroscale patterns in body size of intertidal crustaceans provide insights on climate change effects

    Science.gov (United States)

    Dugan, Jenifer E.; Hubbard, David M.; Contreras, Heraldo; Duarte, Cristian; Acuña, Emilio; Schoeman, David S.

    2017-01-01

    Predicting responses of coastal ecosystems to altered sea surface temperatures (SST) associated with global climate change, requires knowledge of demographic responses of individual species. Body size is an excellent metric because it scales strongly with growth and fecundity for many ectotherms. These attributes can underpin demographic as well as community and ecosystem level processes, providing valuable insights for responses of vulnerable coastal ecosystems to changing climate. We investigated contemporary macroscale patterns in body size among widely distributed crustaceans that comprise the majority of intertidal abundance and biomass of sandy beach ecosystems of the eastern Pacific coasts of Chile and California, USA. We focused on ecologically important species representing different tidal zones, trophic guilds and developmental modes, including a high-shore macroalga-consuming talitrid amphipod (Orchestoidea tuberculata), two mid-shore scavenging cirolanid isopods (Excirolana braziliensis and E. hirsuticauda), and a low-shore suspension-feeding hippid crab (Emerita analoga) with an amphitropical distribution. Significant latitudinal patterns in body sizes were observed for all species in Chile (21° - 42°S), with similar but steeper patterns in Emerita analoga, in California (32°- 41°N). Sea surface temperature was a strong predictor of body size (-4% to -35% °C-1) in all species. Beach characteristics were subsidiary predictors of body size. Alterations in ocean temperatures of even a few degrees associated with global climate change are likely to affect body sizes of important intertidal ectotherms, with consequences for population demography, life history, community structure, trophic interactions, food-webs, and indirect effects such as ecosystem function. The consistency of results for body size and temperature across species with different life histories, feeding modes, ecological roles, and microhabitats inhabiting a single widespread coastal

  19. Immobilization thresholds of electrofishing relative to fish size

    Science.gov (United States)

    Dolan, C.R.; Miranda, L.E.

    2003-01-01

    Fish size and electrical waveforms have frequently been associated with variation in electrofishing effectiveness. Under controlled laboratory conditions, we measured the electrical power required by five electrical waveforms to immobilize eight fish species of diverse sizes and shapes. Fish size was indexed by total body length, surface area, volume, and weight; shape was indexed by the ratio of body length to body depth. Our objectives were to identify immobilization thresholds, elucidate the descriptors of fish size that were best associated with those immobilization thresholds, and determine whether the vulnerability of a species relative to other species remained constant across electrical treatments. The results confirmed that fish size is a key variable controlling the immobilization threshold and further suggested that the size descriptor best related to immobilization is fish volume. The peak power needed to immobilize fish decreased rapidly with increasing fish volume in small fish but decreased slowly for fish larger than 75-100 cm 3. Furthermore, when we controlled for size and shape, different waveforms did not favor particular species, possibly because of the overwhelming effect of body size. Many of the immobilization inconsistencies previously attributed to species might simply represent the effect of disparities in body size.

  20. Beauty, body size and wages: Evidence from a unique data set.

    Science.gov (United States)

    Oreffice, Sonia; Quintana-Domeque, Climent

    2016-09-01

    We analyze how attractiveness rated at the start of the interview in the German General Social Survey is related to weight, height, and body mass index (BMI), separately by gender and accounting for interviewers' characteristics or fixed effects. We show that height, weight, and BMI all strongly contribute to male and female attractiveness when attractiveness is rated by opposite-sex interviewers, and that anthropometric characteristics are irrelevant to male interviewers when assessing male attractiveness. We also estimate whether, controlling for beauty, body size measures are related to hourly wages. We find that anthropometric attributes play a significant role in wage regressions in addition to attractiveness, showing that body size cannot be dismissed as a simple component of beauty. Our findings are robust to controlling for health status and accounting for selection into working. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Huntingtin gene repeat size variations affect risk of lifetime depression

    DEFF Research Database (Denmark)

    Gardiner, Sarah L.; van Belzen, Martine J.; Boogaard, Merel W.

    2017-01-01

    Huntington disease (HD) is a severe neuropsychiatric disorder caused by a cytosine-adenine-guanine (CAG) repeat expansion in the HTT gene. Although HD is frequently complicated by depression, it is still unknown to what extent common HTT CAG repeat size variations in the normal range could affect...

  2. Neighborhood size and local geographic variation of health and social determinants

    Directory of Open Access Journals (Sweden)

    Emch Michael

    2005-06-01

    Full Text Available Abstract Background Spatial filtering using a geographic information system (GIS is often used to smooth health and ecological data. Smoothing disease data can help us understand local (neighborhood geographic variation and ecological risk of diseases. Analyses that use small neighborhood sizes yield individualistic patterns and large sizes reveal the global structure of data where local variation is obscured. Therefore, choosing an optimal neighborhood size is important for understanding ecological associations with diseases. This paper uses Hartley's test of homogeneity of variance (Fmax as a methodological solution for selecting optimal neighborhood sizes. The data from a study area in Vietnam are used to test the suitability of this method. Results The Hartley's Fmax test was applied to spatial variables for two enteric diseases and two socioeconomic determinants. Various neighbourhood sizes were tested by using a two step process to implement the Fmaxtest. First the variance of each neighborhood was compared to the highest neighborhood variance (upper, Fmax1 and then they were compared with the lowest neighborhood variance (lower, Fmax2. A significant value of Fmax1 indicates that the neighborhood does not reveal the global structure of data, and in contrast, a significant value in Fmax2 implies that the neighborhood data are not individualistic. The neighborhoods that are between the lower and the upper limits are the optimal neighbourhood sizes. Conclusion The results of tests provide different neighbourhood sizes for different variables suggesting that optimal neighbourhood size is data dependent. In ecology, it is well known that observation scales may influence ecological inference. Therefore, selecting optimal neigborhood size is essential for understanding disease ecologies. The optimal neighbourhood selection method that is tested in this paper can be useful in health and ecological studies.

  3. Factors determining the average body size of geographically separated Arctodiaptomus salinus (Daday, 1885) populations

    OpenAIRE

    Anufriieva, Elena V.; Shadrin, Nickolai V.

    2014-01-01

    Arctodiaptomus salinus inhabits water bodies across Eurasia and North Africa. Based on our own data and that from the literature, we analyzed the influences of several factors on the intra- and inter-population variability of this species. A strong negative linear correlation between temperature and average body size in the Crimean and African populations was found, in which the parameters might be influenced by salinity. Meanwhile, asignificant negative correlation between female body size a...

  4. Microsatellite frequencies vary with body mass and body temperature in mammals, suggesting correlated variation in mutation rate

    Directory of Open Access Journals (Sweden)

    William Amos

    2014-11-01

    Full Text Available Substitution rate is often found to correlate with life history traits such as body mass, a predictor of population size and longevity, and body temperature. The underlying mechanism is unclear but most models invoke either natural selection or factors such as generation length that change the number of mutation opportunities per unit time. Here we use published genome sequences from 69 mammals to ask whether life history traits impact another form of genetic mutation, the high rates of predominantly neutral slippage in microsatellites. We find that the length-frequency distributions of three common dinucleotide motifs differ greatly between even closely related species. These frequency differences correlate with body mass and body temperature and can be used to predict the phenotype of an unknown species. Importantly, different length microsatellites show complicated patterns of excess and deficit that cannot be explained by a simple model where species with short generation lengths have experienced more mutations. Instead, the patterns probably require changes in mutation rate that impact alleles of different length to different extents. Body temperature plausibly influences mutation rate by modulating the propensity for slippage. Existing hypotheses struggle to account for a link between body mass and mutation rate. However, body mass correlates inversely with population size, which in turn predicts heterozygosity. We suggest that heterozygote instability, HI, the idea that heterozygous sites show increased mutability, could provide a plausible link between body mass and mutation rate.

  5. Consequences of intraspecific seed-size variation in Sparganium emersum for dispersal by fish

    NARCIS (Netherlands)

    Pollux, B.J.A.; Ouborg, J.; Van Groenendael, J.M.; Klaassen, M.R.J.

    2007-01-01

    The potential for seed dispersal by fish (ichthyochory) is likely to vary within aquatic plant species, depending on intraspecific variation in phenotypic seed traits. 2. We studied the effect of seed size variation within the unbranched burreed (Sparganium emersum) on the potential for internal

  6. Dental size variation in the Atapuerca-SH Middle Pleistocene hominids.

    Science.gov (United States)

    Bermúdez de Castro, J M; Sarmiento, S; Cunha, E; Rosas, A; Bastir, M

    2001-09-01

    The Middle Pleistocene Atapuerca-Sima de los Huesos (SH) site in Spain has yielded the largest sample of fossil hominids so far found from a single site and belonging to the same biological population. The SH dental sample includes a total of 452 permanent and deciduous teeth, representing a minimum of 27 individuals. We present a study of the dental size variation in these hominids, based on the analysis of the mandibular permanent dentition: lateral incisors, n=29; canines, n=27; third premolars, n=30; fourth premolars, n=34; first molars, n=38; second molars, n=38. We have obtained the buccolingual diameter and the crown area (measured on occlusal photographs) of these teeth, and used the bootstrap method to assess the amount of variation in the SH sample compared with the variation of a modern human sample from the Museu Antropologico of the Universidade of Coimbra (Portugal). The SH hominids have, in general terms, a dental size variation higher than that of the modern human sample. The analysis is especially conclusive for the canines. Furthermore, we have estimated the degree of sexual dimorphism of the SH sample by obtaining male and female dental subsamples by means of sexing the large sample of SH mandibular specimens. We obtained the index of sexual dimorphism (ISD=male mean/female mean) and the values were compared with those obtained from the sexed modern human sample from Coimbra, and with data found in the literature concerning several recent human populations. In all tooth classes the ISD of the SH hominids was higher than that of modern humans, but the differences were generally modest, except for the canines, thus suggesting that canine size sexual dimorphism in Homo heidelbergensis was probably greater than that of modern humans. Since the approach of sexing fossil specimens has some obvious limitations, these results should be assessed with caution. Additional data from SH and other European Middle Pleistocene sites would be necessary to test

  7. Histologically Measured Cardiomyocyte Hypertrophy Correlates with Body Height as Strongly as with Body Mass Index

    Directory of Open Access Journals (Sweden)

    Richard E. Tracy

    2011-01-01

    Full Text Available Cardiac myocytes are presumed to enlarge with left ventricular hypertrophy (LVH. This study correlates histologically measured myocytes with lean and fat body mass. Cases of LVH without coronary heart disease and normal controls came from forensic autopsies. The cross-sectional widths of myocytes in H&E-stained paraffin sections followed log normal distributions almost to perfection in all 104 specimens, with constant coefficient of variation across the full range of ventricular weight, as expected if myocytes of all sizes contribute proportionately to hypertrophy. Myocyte sizes increased with height. By regression analysis, height2.7 as a proxy for lean body mass and body mass index (BMI as a proxy for fat body mass, exerted equal effects in the multiple correlation with myocyte volume, and the equation rejected race and sex. In summary, myocyte sizes, as indexes of LVH, suggest that lean and fat body mass may contribute equally.

  8. Are rates of species diversification and body size evolution coupled in the ferns?

    Science.gov (United States)

    Testo, Weston L; Sundue, Michael A

    2018-03-01

    Understanding the relationship between phenotypic evolution and lineage diversification is a central goal of evolutionary biology. To extend our understanding of the role morphological evolution plays in the diversification of plants, we examined the relationship between leaf size evolution and lineage diversification across ferns. We tested for an association between body size evolution and lineage diversification using a comparative phylogenetic approach that combined a time-calibrated phylogeny and leaf size data set for 2654 fern species. Rates of leaf size change and lineage diversification were estimated using BAMM, and rate correlations were performed for rates obtained for all families and individual species. Rates and patterns of rate-rate correlation were also analyzed separately for terrestrial and epiphytic taxa. We find no significant correlation between rates of leaf area change and lineage diversification, nor was there a difference in this pattern when growth habit is considered. Our results are consistent with the findings of an earlier study that reported decoupled rates of body size evolution and diversification in the Polypodiaceae, but conflict with a recent study that reported a positive correlation between body size evolution and lineage diversification rates in the tree fern family Cyatheaceae. Our findings indicate that lineage diversification in ferns is largely decoupled from shifts in body size, in contrast to several other groups of organisms. Speciation in ferns appears to be primarily driven by hybridization and isolation along elevational gradients, rather than adaptive radiations featuring prominent morphological restructuring. The exceptional diversity of leaf morphologies in ferns appears to reflect a combination of ecophysiological constraints and adaptations that are not key innovations. © 2018 Botanical Society of America.

  9. Life course evolution of body size and breast cancer survival in the E3N cohort.

    Science.gov (United States)

    His, Mathilde; Le Guélennec, Marine; Mesrine, Sylvie; Boutron-Ruault, Marie-Christine; Clavel-Chapelon, Françoise; Fagherazzi, Guy; Dossus, Laure

    2018-04-15

    Although adult obesity has been associated with poor breast cancer survival, data on adiposity at different periods in life and its lifelong evolution are scarce. Our aims were to assess the associations between breast cancer survival and body size during childhood, puberty and early adulthood and body size trajectories from childhood to adulthood. Self-assessed body size at age 8, at puberty, at age 20-25 and at age 35-40 and trajectories of body size of 4,662 breast cancer survivors from the prospective E3N cohort were studied in relation to risk of death from any cause, death from breast cancer and second invasive cancer event using multivariate Cox regression models. Four trajectories of body size were identified (T1 "moderate increase," T2 "stable/low increase," T3 "increase at puberty" and T4 "constantly high"). Compared with stable body size, an increase in body size during adult life was associated with an increased risk of death from any cause (HR T1 vs. T2 = 1.27; 95% CI = 1.01-1.60) and an increased risk of second invasive cancer event (HR T1 vs. T2 = 1.25; 95% CI = 1.06-1.47). Silhouettes at various ages were not associated with survival. Our results suggest that the evolution of body size from childhood to adulthood has a long-term influence on breast cancer survival. Although these results need to be confirmed, this work sheds light on the need to combine lifelong approaches to current BMI to better identify breast cancer survivors who are at higher risk of recurrence or second primary cancer, or of death. © 2017 UICC.

  10. "Life history space": a multivariate analysis of life history variation in extant and extinct Malagasy lemurs.

    Science.gov (United States)

    Catlett, Kierstin K; Schwartz, Gary T; Godfrey, Laurie R; Jungers, William L

    2010-07-01

    Studies of primate life history variation are constrained by the fact that all large-bodied extant primates are haplorhines. However, large-bodied strepsirrhines recently existed. If we can extract life history information from their skeletons, these species can contribute to our understanding of primate life history variation. This is particularly important in light of new critiques of the classic "fast-slow continuum" as a descriptor of variation in life history profiles across mammals in general. We use established dental histological methods to estimate gestation length and age at weaning for five extinct lemur species. On the basis of these estimates, we reconstruct minimum interbirth intervals and maximum reproductive rates. We utilize principal components analysis to create a multivariate "life history space" that captures the relationships among reproductive parameters and brain and body size in extinct and extant lemurs. Our data show that, whereas large-bodied extinct lemurs can be described as "slow" in some fashion, they also varied greatly in their life history profiles. Those with relatively large brains also weaned their offspring late and had long interbirth intervals. These were not the largest of extinct lemurs. Thus, we distinguish size-related life history variation from variation that linked more strongly to ecological factors. Because all lemur species larger than 10 kg, regardless of life history profile, succumbed to extinction after humans arrived in Madagascar, we argue that large body size increased the probability of extinction independently of reproductive rate. We also provide some evidence that, among lemurs, brain size predicts reproductive rate better than body size. (c) 2010 Wiley-Liss, Inc.

  11. Habitat disturbance and hydrological parameters determine the body size and reproductive strategy of alluvial ground beetles.

    Science.gov (United States)

    Gerisch, Michael

    2011-01-01

    Environmental variability is the main driver for the variation of biological characteristics (life-history traits) of species. Therefore, life-history traits are particularly suited to identify mechanistic linkages between environmental variability and species occurrence and can help in explaining ecological patterns. For ground beetles, few studies directly related species traits to environmental variables. This study aims to analyse how life-history traits of alluvial ground beetles are controlled by environmental factors. I expected that the occurrence of species and the occurrence of specific traits are closely related to hydrological and disturbance parameters. Furthermore I expected most of the trait-variation to be explained by a combination of environmental variables, rather than by their isolated effects. Ground beetles were sampled in the year 2005 in floodplain grassland along the Elbe River in Germany. I used redundancy analysis to quantify the effects of hydrological, sediment, and disturbance related parameters on both species occurrence and species traits. I applied variation partitioning to analyse which environmental compartments explain most of the trait variation. Species occurrence and trait variation were both mainly controlled by hydrological and flood disturbance parameters. I could clearly identify reproductive traits and body size as key traits for floodplain ground beetles to cope with the environmental variability. Furthermore, combinations of hydrological, habitat disturbance, habitat type, and species diversity parameters, rather than their isolated effects, explained large parts of ground beetle trait variation. Thus, a main conclusion of this study is that ground beetle occurrence is mainly determined by complex, multi-scale interactions between environmental variability and their life-history traits.

  12. Morphological variation of Nile tilapia populations from major water ...

    African Journals Online (AJOL)

    ... by hatchery operators throughout the country and in the East African region. ... there was high morphological variation among the different populations of Nile tilapia ... Most of the variation (86.97%) was associated with the fish body size, the ...

  13. Body size and mating success in Drosophila willistoni are ...

    Indian Academy of Sciences (India)

    Mating activity and wing length were investigated in the F1 progeny of Drosophila willistoni females collected in the field to examine any possible relationship between body size and mating success. The flies were observed in a mating chamber under laboratory conditions. No significant differences in wing length were ...

  14. Color variability and body size of larvae of two Epomis species (Coleoptera: Carabidae in Israel

    Directory of Open Access Journals (Sweden)

    Gil Wizen

    2011-07-01

    Full Text Available Species identification using the characteristics of developmental stages is challenging. However, for insect taxonomy the coloration of larval stages can be an informative feature. The use of live specimens is recommended for this because the color fades in preserved specimens. In this study we examine the possibility of using variation in coloration and color pattern of larvae in order to distinguish between two ground beetles species Epomis dejeani Dejean, 1831 and E. circumscriptus Duftschmid, 1812. We present an atlas and describe the coloration and body size of the three larval stages of the above species based on live specimens. The first instar larvae of the two Epomis species can be easily distinguished based on their color. From the second instar on, the variability in coloration and color patterns increases, creating an overlap in these attributes between larvae of the two species. Except for minor differences in color of the antennae and the base of the mandibles, larvae of the two species are indistinguishable at the second and third larval stages. To the best of our knowledge this is the first attempt to use variation in coloration and color pattern in live larvae in order to identify coleopterans. The color atlas of the larvae enables simple separation of the two Epomis species without requiring sophisticated magnifying devices, although it is less straightforward at the second and third larval stages. We found similar body lengths between the two species for all developmental stages, except for third instar larvae prior to pupation. In the two species the difference in larval body length before pupation positively correlated with that of the adult beetles. More than 70% of the adults' length can be explained by the length of the late third-instar larva; i.e. the large larvae develop into large adults. The larger specimens are the females.

  15. The role of underestimating body size for self-esteem and self-efficacy among grade five children in Canada.

    Science.gov (United States)

    Maximova, Katerina; Khan, Mohammad K A; Austin, S Bryn; Kirk, Sara F L; Veugelers, Paul J

    2015-10-01

    Underestimating body size hinders healthy behavior modification needed to prevent obesity. However, initiatives to improve body size misperceptions may have detrimental consequences on self-esteem and self-efficacy. Using sex-specific multiple mixed-effect logistic regression models, we examined the association of underestimating versus accurate body size perceptions with self-esteem and self-efficacy in a provincially representative sample of 5075 grade five school children. Body size perceptions were defined as the standardized difference between the body mass index (BMI, from measured height and weight) and self-perceived body size (Stunkard body rating scale). Self-esteem and self-efficacy for physical activity and healthy eating were self-reported. Most of overweight boys and girls (91% and 83%); and most of obese boys and girls (93% and 90%) underestimated body size. Underestimating weight was associated with greater self-efficacy for physical activity and healthy eating among normal-weight children (odds ratio: 1.9 and 1.6 for boys, 1.5 and 1.4 for girls) and greater self-esteem among overweight and obese children (odds ratio: 2.0 and 6.2 for boys, 2.0 and 3.4 for girls). Results highlight the importance of developing optimal intervention strategies as part of targeted obesity prevention efforts that de-emphasize the focus on body weight, while improving body size perceptions. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. The Genetic Basis of Baculum Size and Shape Variation in Mice

    Directory of Open Access Journals (Sweden)

    Nicholas G. Schultz

    2016-05-01

    Full Text Available The rapid divergence of male genitalia is a preeminent evolutionary pattern. This rapid divergence is especially striking in the baculum, a bone that occurs in the penis of many mammalian species. Closely related species often display diverse baculum morphology where no other morphological differences can be discerned. While this fundamental pattern of evolution has been appreciated at the level of gross morphology, nearly nothing is known about the genetic basis of size and shape divergence. Quantifying the genetic basis of baculum size and shape variation has been difficult because these structures generally lack obvious landmarks, so comparing them in three dimensions is not straightforward. Here, we develop a novel morphometric approach to quantify size and shape variation from three-dimensional micro-CT scans taken from 369 bacula, representing 75 distinct strains of the BXD family of mice. We identify two quantitative trait loci (QTL that explain ∼50% of the variance in baculum size, and a third QTL that explains more than 20% of the variance in shape. Together, our study demonstrates that baculum morphology may diverge relatively easily, with mutations at a few loci of large effect that independently modulate size and shape. Based on a combination of bioinformatic investigations and new data on RNA expression, we prioritized these QTL to 16 candidate genes, which have hypothesized roles in bone morphogenesis and may enable future genetic manipulation of baculum morphology.

  17. High variation in manufacturer-declared serving size of packaged discretionary foods in Australia.

    Science.gov (United States)

    Haskelberg, Hila; Neal, Bruce; Dunford, Elizabeth; Flood, Victoria; Rangan, Anna; Thomas, Beth; Cleanthous, Xenia; Trevena, Helen; Zheng, Jazzmin Miaobing; Louie, Jimmy Chun Yu; Gill, Timothy; Wu, Jason H Y

    2016-05-28

    Despite the potential of declared serving size to encourage appropriate portion size consumption, most countries including Australia have not developed clear reference guidelines for serving size. The present study evaluated variability in manufacturer-declared serving size of discretionary food and beverage products in Australia, and how declared serving size compared with the 2013 Australian Dietary Guideline (ADG) standard serve (600 kJ). Serving sizes were obtained from the Nutrition Information Panel for 4466 packaged, discretionary products in 2013 at four large supermarkets in Sydney, Australia, and categorised into fifteen categories in line with the 2013 ADG. For unique products that were sold in multiple package sizes, the percentage difference between the minimum and the maximum serving size across different package sizes was calculated. A high variation in serving size was found within the majority of food and beverage categories - for example, among 347 non-alcoholic beverages (e.g. soft drinks), the median for serving size was 250 (interquartile range (IQR) 250, 355) ml (range 100-750 ml). Declared serving size for unique products that are available in multiple package sizes also showed high variation, particularly for chocolate-based confectionery, with median percentage difference between minimum and maximum serving size of 183 (IQR 150) %. Categories with a high proportion of products that exceeded the 600 kJ ADG standard serve included cakes and muffins, pastries and desserts (≥74 % for each). High variability in declared serving size may confound interpretation and understanding of consumers interested in standardising and controlling their portion selection. Future research is needed to assess if and how standardising declared serving size might affect consumer behaviour.

  18. Diabetes Awareness and Body Size Perceptions of Cree Schoolchildren

    Science.gov (United States)

    Willows, Noreen D.; Marshall, Dru; Raine, Kim; Ridley, Denise C.

    2009-01-01

    Native American Indians and First Nations are predisposed to obesity and diabetes. A study was done to understand Cree schoolchildren's diabetes awareness and body size perceptions in two communities that had diabetes awareness-raising activities in the Province of Quebec, Canada. Children (N = 203) in grades 4-6 were classified into weight…

  19. Habitat area and climate stability determine geographical variation in plant species range sizes

    DEFF Research Database (Denmark)

    Morueta-Holme, Naia; Enquist, Brian J.; McGill, Brian J.

    2013-01-01

    Despite being a fundamental aspect of biodiversity, little is known about what controls species range sizes. This is especially the case for hyperdiverse organisms such as plants. We use the largest botanical data set assembled to date to quantify geographical variation in range size for ~85,000 ...

  20. Increased body size along urbanization gradients at both community and intraspecific level in macro-moths.

    Science.gov (United States)

    Merckx, Thomas; Kaiser, Aurélien; Van Dyck, Hans

    2018-05-23

    Urbanization involves a cocktail of human-induced rapid environmental changes and is forecasted to gain further importance. Urban-heat-island effects result in increased metabolic costs expected to drive shifts towards smaller body sizes. However, urban environments are also characterized by strong habitat fragmentation, often selecting for dispersal phenotypes. Here, we investigate to what extent, and at which spatial scale(s), urbanization drives body size shifts in macro-moths-an insect group characterized by positive size-dispersal links-at both the community and intraspecific level. Using light and bait trapping as part of a replicated, spatially nested sampling design, we show that despite the observed urban warming of their woodland habitat, macro-moth communities display considerable increases in community-weighted mean body size because of stronger filtering against small species along urbanization gradients. Urbanization drives intraspecific shifts towards increased body size too, at least for a third of species analysed. These results indicate that urbanization drives shifts towards larger, and hence, more mobile species and individuals in order to mitigate low connectivity of ecological resources in urban settings. Macro-moths are a key group within terrestrial ecosystems, and since body size is central to species interactions, such urbanization-driven phenotypic change may impact urban ecosystem functioning, especially in terms of nocturnal pollination and food web dynamics. Although we show that urbanization's size-biased filtering happens simultaneously and coherently at both the inter- and intraspecific level, we demonstrate that the impact at the community level is most pronounced at the 800 m radius scale, whereas species-specific size increases happen at local and landscape scales (50-3,200 m radius), depending on the species. Hence, measures-such as creating and improving urban green infrastructure-to mitigate the effects of urbanization on

  1. Temporal profile of body temperature in acute ischemic stroke: Relation to infarct size and outcome

    NARCIS (Netherlands)

    M. Geurts (Marjolein); Scheijmans, F.E.V. (Féline E.V.); T. van Seeters (Tom); G.J. Biessels; L.J. Kappelle (Jaap); B.K. Velthuis (Birgitta K.); H.B. van der Worp (Bart); C.B. Majoie (Charles); Y.B.W.E.M. Roos (Yvo); L.E.M. Duijm (Lucien); K. Keizer (Koos); A. van der Lugt (Aad); D.W.J. Dippel (Diederik); Greve, D. (Droogh-de); H.P. Bienfait (Henri); M.A.A. van Walderveen (Marianne); M.J.H. Wermer (Marieke); G.J. Lycklama à Nijeholt (Geert); J. Boiten (Jelis); A. Duyndam (Anita); V.I.H. Kwa; F.J. Meijer (F.); E.J. van Dijk (Ewoud); A.M. Kesselring (Anouk); J. Hofmeijer; J.A. Vos (Jan Albert); W.J. Schonewille (Wouter); W.J. van Rooij (W.); P.L.M. de Kort (Paul); C.C. Pleiter (C.); S.L.M. Bakker (Stef); Bot, J.; M.C. Visser (Marieke); B.K. Velthuis (Birgitta); I.C. van der Schaaf (Irene); J.W. Dankbaar (Jan); W.P. Mali (Willem); van Seeters, T.; A.D. Horsch (Alexander D.); J.M. Niesten (Joris); G.J. Biessels (Geert Jan); L.J. Kappelle (Jaap); J.S.K. Luitse; Y. van der Graaf (Yolanda)

    2016-01-01

    textabstractBackground: High body temperatures after ischemic stroke have been associated with larger infarct size, but the temporal profile of this relation is unknown. We assess the relation between temporal profile of body temperature and infarct size and functional outcome in patients with acute

  2. Ontogeny of metabolic rate and red blood cell size in eyelid geckos: species follow different paths.

    Directory of Open Access Journals (Sweden)

    Zuzana Starostová

    Full Text Available While metabolism is a fundamental feature of all organisms, the causes of its scaling with body mass are not yet fully explained. Nevertheless, observations of negative correlations between red blood cell (RBC size and the rate of metabolism suggest that size variation of these cells responsible for oxygen supply may play a crucial role in determining metabolic rate scaling in vertebrates. Based on a prediction derived from the Cell Metabolism Hypothesis, metabolic rate should increase linearly with body mass in species with RBC size invariance, and slower than linearly when RBC size increases with body mass. We found support for that prediction in five species of eyelid geckos (family Eublepharidae with different patterns of RBC size variation during ontogenetic growth. During ontogeny, metabolic rate increases nearly linearly with body mass in those species of eyelid geckos where there is no correlation between RBC size and body mass, whereas non-linearity of metabolic rate scaling is evident in those species with ontogenetic increase of RBC size. Our findings provide evidence that ontogenetic variability in RBC size, possibly correlating with sizes of other cell types, could have important physiological consequences and can contribute to qualitatively different shape of the intraspecific relationship between metabolic rate and body mass.

  3. Ontogeny of metabolic rate and red blood cell size in eyelid geckos: species follow different paths.

    Science.gov (United States)

    Starostová, Zuzana; Konarzewski, Marek; Kozłowski, Jan; Kratochvíl, Lukáš

    2013-01-01

    While metabolism is a fundamental feature of all organisms, the causes of its scaling with body mass are not yet fully explained. Nevertheless, observations of negative correlations between red blood cell (RBC) size and the rate of metabolism suggest that size variation of these cells responsible for oxygen supply may play a crucial role in determining metabolic rate scaling in vertebrates. Based on a prediction derived from the Cell Metabolism Hypothesis, metabolic rate should increase linearly with body mass in species with RBC size invariance, and slower than linearly when RBC size increases with body mass. We found support for that prediction in five species of eyelid geckos (family Eublepharidae) with different patterns of RBC size variation during ontogenetic growth. During ontogeny, metabolic rate increases nearly linearly with body mass in those species of eyelid geckos where there is no correlation between RBC size and body mass, whereas non-linearity of metabolic rate scaling is evident in those species with ontogenetic increase of RBC size. Our findings provide evidence that ontogenetic variability in RBC size, possibly correlating with sizes of other cell types, could have important physiological consequences and can contribute to qualitatively different shape of the intraspecific relationship between metabolic rate and body mass.

  4. Body condition variation in kestrel (Falco tinnunculus) nestlings in relation to breeding conditions

    NARCIS (Netherlands)

    Costantini, David; Casagrande, Stefania; Carello, Livia; Dell'Omo, Giacomo

    2009-01-01

    The body condition index (i.e., body mass corrected for age or size differences) is commonly used to investigate offspring condition in nestling birds. The body condition index reflects different parameters related to the general nutritional state of nestlings and may predict survival prospects.

  5. A longitudinal study of the relationships between the Big Five personality traits and body size perception.

    Science.gov (United States)

    Hartmann, Christina; Siegrist, Michael

    2015-06-01

    The present study investigated the longitudinal development of body size perception in relation to different personality traits. A sample of Swiss adults (N=2905, 47% men), randomly selected from the telephone book, completed a questionnaire on two consecutive years (2012, 2013). Body size perception was assessed with the Contour Drawing Rating Scale and personality traits were assessed with a short version of the Big Five Inventory. Longitudinal analysis of change indicated that men and women scoring higher on conscientiousness perceived themselves as thinner one year later. In contrast, women scoring higher on neuroticism perceived their body size as larger one year later. No significant effect was observed for men scoring higher on neuroticism. These results were independent of weight changes, body mass index, age, and education. Our findings suggest that personality traits contribute to body size perception among adults. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. A macroevolutionary explanation for energy equivalence in the scaling of body size and population density.

    Science.gov (United States)

    Damuth, John

    2007-05-01

    Across a wide array of animal species, mean population densities decline with species body mass such that the rate of energy use of local populations is approximately independent of body size. This "energetic equivalence" is particularly evident when ecological population densities are plotted across several or more orders of magnitude in body mass and is supported by a considerable body of evidence. Nevertheless, interpretation of the data has remained controversial, largely because of the difficulty of explaining the origin and maintenance of such a size-abundance relationship in terms of purely ecological processes. Here I describe results of a simulation model suggesting that an extremely simple mechanism operating over evolutionary time can explain the major features of the empirical data. The model specifies only the size scaling of metabolism and a process where randomly chosen species evolve to take resource energy from other species. This process of energy exchange among particular species is distinct from a random walk of species abundances and creates a situation in which species populations using relatively low amounts of energy at any body size have an elevated extinction risk. Selective extinction of such species rapidly drives size-abundance allometry in faunas toward approximate energetic equivalence and maintains it there.

  7. Risk of breast cancer in young women in relation to body size and weight gain in adolescence and early adulthood.

    Science.gov (United States)

    Coates, R J; Uhler, R J; Hall, H I; Potischman, N; Brinton, L A; Ballard-Barbash, R; Gammon, M D; Brogan, D R; Daling, J R; Malone, K E; Schoenberg, J B; Swanson, C A

    1999-09-01

    Findings have been inconsistent on effects of adolescent body size and adult weight gain on risk of breast cancer in young women. These relations were examined in a population-based case control study of 1590 women less than 45 years of age newly diagnosed with breast cancer during 1990-1992 in three areas of the US and an age-matched control group of 1390 women. Height and weight were measured at interview and participants asked to recall information about earlier body size. Logistic regression was used to estimate the relative risk of breast cancer adjusted for other risk factors. Women who were either much heavier or lighter than average in adolescence or at age 20 were at reduced risk. Weight gain after age 20 resulted in reduced risk, but the effect was confined to early-stage and, more specifically, lower grade breast cancer. Neither the risk reduction nor the variation by breast cancer stage or grade was explained by the method of cancer detection or by prior mammography history. These findings suggest that relations between breast cancer risk in young women and body weight at different ages is complex and that the risk reduction with adult weight gain is confined to less aggressive cancers.

  8. Interdependent effects of male and female body size plasticity on mating behaviour of predatory mites.

    Science.gov (United States)

    Walzer, Andreas; Schausberger, Peter

    2015-02-01

    The adaptive canalization hypothesis predicts that traits with low phenotypic plasticity are more fitness relevant, because they have been canalized via strong past selection, than traits with high phenotypic plasticity. Based on differing male body size plasticities of the predatory mites Phytoseiulus persimilis (low plasticity) and Neoseiulus californicus (high plasticity), we accordingly hypothesized that small male body size entails higher costs in female choice and male-male competition in P. persimilis than N. californicus . Males of both species are highly polygynous but females differ in the level of polyandry (low level in P. persimilis ; medium level in N. californicus ). We videotaped the mating interactions in triplets of either P. persimilis or N. californicus , consisting of a virgin female (small or standard-sized) and a small and a standard-sized male. Mating by both small and standard-sized P. persimilis females was biased towards standard-sized males, resulting from the interplay between female preference for standard-sized males and the inferiority of small males in male-male competition. In contrast, mating by N. californicus females was equally balanced between small and standard-sized males. Small N. californicus males were more aggressive ('Napoleon complex') in male-male competition, reducing the likelihood of encounter between the standard-sized male and the female, and thus counterbalancing female preference for standard-sized males. Our results support the hypothesis that male body size is more important to fitness in the low-level polyandrous P. persimilis than in the medium-level polyandrous N. californicus and provide a key example of the implications of sexually selected body size plasticity on mating behaviour.

  9. The tempo and mode of evolution: body sizes of island mammals.

    Science.gov (United States)

    Raia, Pasquale; Meiri, Shai

    2011-07-01

    The tempo and mode of body size evolution on islands are believed to be well known. It is thought that body size evolves relatively quickly on islands toward the mammalian modal value, thus generating extreme cases of size evolution and the island rule. Here, we tested both theories in a phylogenetically explicit context, by using two different species-level mammalian phylogenetic hypotheses limited to sister clades dichotomizing into an exclusively insular and an exclusively mainland daughter nodes. Taken as a whole, mammals were found to show a largely punctuational mode of size evolution. We found that, accounting for this, and regardless of the phylogeny used, size evolution on islands is no faster than on the continents. We compared different selection regimes using a set of Ornstein-Uhlenbeck models to examine the effects of insularity of the mode of evolution. The models strongly supported clade-specific selection regimes. Under this regime, however, an evolutionary model allowing insular species to evolve differently from their mainland relatives performs worse than a model that ignores insularity as a factor. Thus, insular taxa do not experience statistically different selection from their mainland relatives. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  10. Role of media and peers on body change strategies among adult men: is body size important?

    Science.gov (United States)

    McCabe, Marita P; McGreevy, Shauna J

    2011-01-01

    There has been limited previous research that has examined the role of sociocultural influences on body change strategies among adult men. The current study investigated the role of specific types of messages (encouragement, teasing and modelling) from peers and the media on the strategies to change weight among adult men. Differences were evaluated between 526 men aged from 18 to 60 years from three groups (normal weight, overweight and obese) on body image, body change strategies and messages about their body received from peers and the media. Men were primarily drawn from United States, Australia and Europe. Results showed that messages received by men regarding losing weight or increasing muscle size differed according to weight. Body image and media messages were the strongest predictors of losing weight, whereas body image importance and messages from peers were the strongest predictors of increasing muscles. These findings highlight the importance of sociocultural influences on body change strategies among adult males. Copyright © 2010 John Wiley & Sons, Ltd and Eating Disorders Association.

  11. Adaptive evolution of body size subject to indirect effect in trophic cascade system.

    Science.gov (United States)

    Wang, Xin; Fan, Meng; Hao, Lina

    2017-09-01

    Trophic cascades represent a classic example of indirect effect and are wide-spread in nature. Their ecological impact are well established, but the evolutionary consequences have received even less theoretical attention. We theoretically and numerically investigate the trait (i.e., body size of consumer) evolution in response to indirect effect in a trophic cascade system. By applying the quantitative trait evolutionary theory and the adaptive dynamic theory, we formulate and explore two different types of eco-evolutionary resource-consumer-predator trophic cascade model. First, an eco-evolutionary model incorporating the rapid evolution is formulated to investigate the effect of rapid evolution of the consumer's body size, and to explore the impact of density-mediate indirect effect on the population dynamics and trait dynamics. Next, by employing the adaptive dynamic theory, a long-term evolutionary model of consumer body size is formulated to evaluate the effect of long-term evolution on the population dynamics and the effect of trait-mediate indirect effect. Those models admit rich dynamics that has not been observed yet in empirical studies. It is found that, both in the trait-mediated and density-mediated system, the body size of consumer in predator-consumer-resource interaction (indirect effect) evolves smaller than that in consumer-resource and predator-consumer interaction (direct effect). Moreover, in the density-mediated system, we found that the evolution of consumer body size contributes to avoiding consumer extinction (i.e., evolutionary rescue). The trait-mediate and density-mediate effects may produce opposite evolutionary response. This study suggests that the trophic cascade indirect effect affects consumer evolution, highlights a more comprehensive mechanistic understanding of the intricate interplay between ecological and evolutionary force. The modeling approaches provide avenue for study on indirect effects from an evolutionary perspective

  12. Circumpolar variation in morphological characteristics of Greater White-fronted Geese Anser albifrons

    Science.gov (United States)

    Ely, Craig R.; Fox, A.D.; Alisauskas, R.T.; Andreev, A.; Bromley, R.G.; Degtyarev, Andrei G.; Ebbinge, B.; Gurtovaya, E.N.; Kerbes, R.; Kondratyev, Alexander V.; Kostin, I.; Krechmar, A.V.; Litvin, K.E.; Miyabayashi, Y.; Moou, J.H.; Oates, R.M.; Orthmeyer, D.L.; Sabano, Yutaka; Simpson, S.G.; Solovieva, D.V.; Spindler, Michael A.; Syroechkovsky, Y.V.; Takekawa, John Y.; Walsh, A.

    2005-01-01

    Capsule: Greater White-fronted Geese show significant variation in body size from sampling locations throughout their circumpolar breeding range. Aims: To determine the degree of geographical variation in body size of Greater White-fronted Geese and identify factors contributing to any apparent patterns in variation. Methods: Structural measures of >3000 geese from 16 breeding areas throughout the Holarctic breeding range of the species were compared statistically. Results: Palearctic forms varied clinally, and increased in size from the smallest forms on the Kanin and Taimyr peninsulas in western Eurasia to the largest forms breeding in the Anadyr Lowlands of eastern Chukotka. Clinal variation was less apparent in the Nearctic, as both the smallest form in the Nearctic and the largest form overall (the Tule Goose) were from different breeding areas in Alaska. The Tule Goose was 25% larger than the smallest form. Birds from Greenland (A. a. flavirostris) were the second largest, although only slightly larger than geese from several North American populations. Body size was not correlated with breeding latitude but was positively correlated with temperature on the breeding grounds, breeding habitat, and migration distance. Body mass of Greater White-fronted Geese from all populations remained relatively constant during the period of wing moult. Morphological distinctness of eastern and western Palearctic forms concurs with earlier findings of complete range disjunction. Conclusions: Patterns of morphological variation in Greater White-fronted Geese across the Holarctic can be generally attributed to adaptation to variable breeding environments, migration requirements, and phylo-geographical histories. 

  13. Comparison of variations between percentage of body fat, body mass index and daily physical activity among young Japanese and Thai female students

    Directory of Open Access Journals (Sweden)

    Morinaka Tomoko

    2012-08-01

    Full Text Available Abstract Background In our series of investigations concerning the causes of seasonal change in fat accumulation in young university students, we could not find any contribution of seasonal variation in the ratio of carbohydrate and fat metabolism to that of body fat percentage in Japanese and Thai participants. After our previous study, we examined the effect of daily physical activity on body fat percentage to look for the major causes of seasonal change in fat accumulation in young university students. Findings In this study, we measured participants’ (young Japanese and Thai university students daily physical activity by a uniaxial accelerometer in addition to the measurements of body fat percentage and body mass index by a bioelectrical impedance meter. We found that there was significant and moderate negative correlation between body fat percentage and daily step counts among Japanese but not Thai participants. We observed significant, moderate and positive correlations between the percentage of body fat and body mass index among Japanese and Thai participants. Conclusions Daily physical activity plays an important role in the seasonal variation of body fat percentage of Japanese female students. Our present study also confirmed the importance of daily physical activity for controlling body mass index and for the prevention of obesity.

  14. Urbanization disrupts latitude-size rule in 17-year cicadas.

    Science.gov (United States)

    Beasley, DeAnna E; Penick, Clint A; Boateng, Nana S; Menninger, Holly L; Dunn, Robert R

    2018-03-01

    Many ectotherms show a decrease in body size with increasing latitude due to changes in climate, a pattern termed converse Bergmann's rule. Urban conditions-particularly warmer temperatures and fragmented landscapes-may impose stresses on development that could disrupt these body size patterns. To test the impact of urbanization on development and latitudinal trends in body size, we launched a citizen science project to collect periodical cicadas ( Magicicada septendecim ) from across their latitudinal range during the 2013 emergence of Brood II. Periodical cicadas are long-lived insects whose distribution spans a broad latitudinal range covering both urban and rural habitats. We used a geometric morphometric approach to assess body size and developmental stress based on fluctuating asymmetry in wing shape. Body size of rural cicadas followed converse Bergmann's rule, but this pattern was disrupted in urban habitats. In the north, urban cicadas were larger than their rural counterparts, while southern populations showed little variation in body size between habitats. We detected no evidence of differences in developmental stress due to urbanization. To our knowledge, this is the first evidence that urbanization disrupts biogeographical trends in body size, and this pattern highlights how the effects of urbanization may differ over a species' range.

  15. Race differences in accuracy of self-reported childhood body size among white and black women

    NARCIS (Netherlands)

    Field, AE; Franko, DL; Striegel-Moore, RH; Schreiber, GB; Crawford, PB; Daniels, [No Value

    Objective: To assess the relation of self-reported current and recalled preadolescent body size to measured BMI (kilograms per meter squared) and interviewer's assessment of body size. 4Research Methods and Procedures: This was a prospective cohort study of 1890 white and black women who were 9 to

  16. The island rule of body size demonstrated on individual hosts

    NARCIS (Netherlands)

    Molleman, Freerk; Depoilly, Alexandre; Vernon, Philippe; Müller, Jörg; Bailey, Richard; Jarzabek-Müller, Andrea; Prinzing, Andreas

    2016-01-01

    Aim: Under spatial isolation on oceanic islands, species tend to show extreme body sizes. From the point of view of many colonizers, individual hosts surrounded by phylogenetically distant neighbours are phylogenetically isolated. This study addresses for the first time how phylogenetic isolation

  17. Penis size interacts with body shape and height to influence male attractiveness.

    Science.gov (United States)

    Mautz, Brian S; Wong, Bob B M; Peters, Richard A; Jennions, Michael D

    2013-04-23

    Compelling evidence from many animal taxa indicates that male genitalia are often under postcopulatory sexual selection for characteristics that increase a male's relative fertilization success. There could, however, also be direct precopulatory female mate choice based on male genital traits. Before clothing, the nonretractable human penis would have been conspicuous to potential mates. This observation has generated suggestions that human penis size partly evolved because of female choice. Here we show, based upon female assessment of digitally projected life-size, computer-generated images, that penis size interacts with body shape and height to determine male sexual attractiveness. Positive linear selection was detected for penis size, but the marginal increase in attractiveness eventually declined with greater penis size (i.e., quadratic selection). Penis size had a stronger effect on attractiveness in taller men than in shorter men. There was a similar increase in the positive effect of penis size on attractiveness with a more masculine body shape (i.e., greater shoulder-to-hip ratio). Surprisingly, larger penis size and greater height had almost equivalent positive effects on male attractiveness. Our results support the hypothesis that female mate choice could have driven the evolution of larger penises in humans. More broadly, our results show that precopulatory sexual selection can play a role in the evolution of genital traits.

  18. Sexual selection on male size drives the evolution of male-biased sexual size dimorphism via the prolongation of male development.

    Science.gov (United States)

    Rohner, Patrick T; Blanckenhorn, Wolf U; Puniamoorthy, Nalini

    2016-06-01

    Sexual size dimorphism (SSD) arises when the net effects of natural and sexual selection on body size differ between the sexes. Quantitative SSD variation between taxa is common, but directional intraspecific SSD reversals are rare. We combined micro- and macroevolutionary approaches to study geographic SSD variation in closely related black scavenger flies. Common garden experiments revealed stark intra- and interspecific variation: Sepsis biflexuosa is monomorphic across the Holarctic, while S. cynipsea (only in Europe) consistently exhibits female-biased SSD. Interestingly, S. neocynipsea displays contrasting SSD in Europe (females larger) and North America (males larger), a pattern opposite to the geographic reversal in SSD of S. punctum documented in a previous study. In accordance with the differential equilibrium model for the evolution of SSD, the intensity of sexual selection on male size varied between continents (weaker in Europe), whereas fecundity selection on female body size did not. Subsequent comparative analyses of 49 taxa documented at least six independent origins of male-biased SSD in Sepsidae, which is likely caused by sexual selection on male size and mediated by bimaturism. Therefore, reversals in SSD and the associated changes in larval development might be much more common and rapid and less constrained than currently assumed. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  19. Does the experience of ownership over a rubber hand change body size perception in anorexia nervosa patients?

    NARCIS (Netherlands)

    Keizer, Anouk; Smeets, Monique A M; Postma, Albert; van Elburg, Annemarie; Dijkerman, H. Chris

    Anorexia nervosa (AN) patients show disturbances in body size experience. Here, malleability of body representation was assessed by inducing the Rubber Hand Illusion (RHI). Specifically the impact of the illusion on body size estimation was investigated.Thirty AN patients and thirty healthy females

  20. Genetic variation in a member of the laminin gene family affects variation in body composition in Drosophila and humans

    Directory of Open Access Journals (Sweden)

    Hunter Gary R

    2008-08-01

    Full Text Available Abstract Background The objective of the present study was to map candidate loci influencing naturally occurring variation in triacylglycerol (TAG storage using quantitative complementation procedures in Drosophila melanogaster. Based on our results from Drosophila, we performed a human population-based association study to investigate the effect of natural variation in LAMA5 gene on body composition in humans. Results We identified four candidate genes that contributed to differences in TAG storage between two strains of D. melanogaster, including Laminin A (LanA, which is a member of the α subfamily of laminin chains. We confirmed the effects of this gene using a viable LanA mutant and showed that female flies homozygous for the mutation had significantly lower TAG storage, body weight, and total protein content than control flies. Drosophila LanA is closely related to human LAMA5 gene, which maps to the well-replicated obesity-linkage region on chromosome 20q13.2-q13.3. We tested for association between three common single nucleotide polymorphisms (SNPs in the human LAMA5 gene and variation in body composition and lipid profile traits in a cohort of unrelated women of European American (EA and African American (AA descent. In both ethnic groups, we found that SNP rs659822 was associated with weight (EA: P = 0.008; AA: P = 0.05 and lean mass (EA: P= 0.003; AA: P = 0.03. We also found this SNP to be associated with height (P = 0.01, total fat mass (P = 0.01, and HDL-cholesterol (P = 0.003 but only in EA women. Finally, significant associations of SNP rs944895 with serum TAG levels (P = 0.02 and HDL-cholesterol (P = 0.03 were observed in AA women. Conclusion Our results suggest an evolutionarily conserved role of a member of the laminin gene family in contributing to variation in weight and body composition.

  1. Insect temperature-body size trends common to laboratory, latitudinal and seasonal gradients are not found across altitudes

    DEFF Research Database (Denmark)

    Horne, Curtis R.; Hirst, Andrew G.; Atkinson, David

    2018-01-01

    Body size affects rates of most biological and ecological processes, from individual performance to ecosystem function, and is fundamentally linked to organism fitness. Within species, size at maturity can vary systematically with environmental temperature in the laboratory and across seasons...... altitude. Although the general direction of body size clines along altitudinal gradients has been examined previously, to our knowledge altitude-body size (A-S) clines have never been synthesised quantitatively, nor compared with temperature-size (T-S) responses measured under controlled laboratory......, as well as over latitudinal gradients. Recent meta-analyses have revealed a close match in the magnitude and direction of these size gradients in various arthropod orders, suggesting that these size responses share common drivers. As with increasing latitude, temperature also decreases with increasing...

  2. Disentangling the phylogenetic and ecological components of spider phenotypic variation.

    Science.gov (United States)

    Gonçalves-Souza, Thiago; Diniz-Filho, José Alexandre Felizola; Romero, Gustavo Quevedo

    2014-01-01

    An understanding of how the degree of phylogenetic relatedness influences the ecological similarity among species is crucial to inferring the mechanisms governing the assembly of communities. We evaluated the relative importance of spider phylogenetic relationships and ecological niche (plant morphological variables) to the variation in spider body size and shape by comparing spiders at different scales: (i) between bromeliads and dicot plants (i.e., habitat scale) and (ii) among bromeliads with distinct architectural features (i.e., microhabitat scale). We partitioned the interspecific variation in body size and shape into phylogenetic (that express trait values as expected by phylogenetic relationships among species) and ecological components (that express trait values independent of phylogenetic relationships). At the habitat scale, bromeliad spiders were larger and flatter than spiders associated with the surrounding dicots. At this scale, plant morphology sorted out close related spiders. Our results showed that spider flatness is phylogenetically clustered at the habitat scale, whereas it is phylogenetically overdispersed at the microhabitat scale, although phylogenic signal is present in both scales. Taken together, these results suggest that whereas at the habitat scale selective colonization affect spider body size and shape, at fine scales both selective colonization and adaptive evolution determine spider body shape. By partitioning the phylogenetic and ecological components of phenotypic variation, we were able to disentangle the evolutionary history of distinct spider traits and show that plant architecture plays a role in the evolution of spider body size and shape. We also discussed the relevance in considering multiple scales when studying phylogenetic community structure.

  3. Regulation of Caenorhabditis elegans body size and male tail development by the novel gene lon-8

    Directory of Open Access Journals (Sweden)

    Korswagen Hendrik C

    2007-03-01

    Full Text Available Abstract Background In C. elegans and other nematode species, body size is determined by the composition of the extracellular cuticle as well as by the nuclear DNA content of the underlying hypodermis. Mutants that are defective in these processes can exhibit either a short or a long body size phenotype. Several mutations that give a long body size (Lon phenotype have been characterized and found to be regulated by the DBL-1/TGF-β pathway, that controls post-embryonic growth and male tail development. Results Here we characterize a novel gene affecting body size. lon-8 encodes a secreted product of the hypodermis that is highly conserved in Rhabditid nematodes. lon-8 regulates larval elongation as well as male tail development. In both processes, lon-8 appears to function independently of the Sma/Mab pathway. Rather, lon-8 genetically interacts with dpy-11 and dpy-18, which encode cuticle collagen modifying enzymes. Conclusion The novel gene lon-8 encodes a secreted product of the hypodermis that controls body size and male ray morphology in C. elegans. lon-8 genetically interacts with enzymes that affect the composition of the cuticle.

  4. Explaining brain size variation: from social to cultural brain.

    Science.gov (United States)

    van Schaik, Carel P; Isler, Karin; Burkart, Judith M

    2012-05-01

    Although the social brain hypothesis has found near-universal acceptance as the best explanation for the evolution of extensive variation in brain size among mammals, it faces two problems. First, it cannot account for grade shifts, where species or complete lineages have a very different brain size than expected based on their social organization. Second, it cannot account for the observation that species with high socio-cognitive abilities also excel in general cognition. These problems may be related. For birds and mammals, we propose to integrate the social brain hypothesis into a broader framework we call cultural intelligence, which stresses the importance of the high costs of brain tissue, general behavioral flexibility and the role of social learning in acquiring cognitive skills. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Assessment of Body Reserves in Camels

    Directory of Open Access Journals (Sweden)

    B. Faye

    2002-01-01

    Full Text Available Herbivores manage their body reserves in a way that helps them respond to variations in the quality and accessibility of feed resources. Assessing these reserves provides farmers with a decision-making tool. Almost no data are available on these aspects of the camel. The present article summarizes several works on weight estimations that are used to assess the volume and weight of the hump (main location of fat reserves, relationships between hump measurements and carcass weight, and between hump weight and perirenal fat weight. Assessing the number and size of adipocytes is a means to test the relevance of these types of fat storage. There is in particular a positive relationship between the size and number of adipocytes in the hump and those in the perirenal fat. The age and sex effects were very pronounced for some of the criteria. A body condition score was established for this species based on the assessment of selected body parts. Results however showed that the hump was not a good bodycondition indicator because of variations in its weight as well as in the size of its adipocytes.

  6. Silk elasticity as a potential constraint on spider body size.

    Science.gov (United States)

    Rodríguez-Gironés, Miguel A; Corcobado, Guadalupe; Moya-Laraño, Jordi

    2010-10-07

    Silk is known for its strength and extensibility and has played a key role in the radiation of spiders. Individual spiders use different glands to produce silk types with unique sets of proteins. Most research has studied the properties of major ampullate and capture spiral silks and their ecological implications, while little is known about minor ampullate silk, the type used by those spider species studied to date for bridging displacements. A biomechanical model parameterised with available data shows that the minimum radius of silk filaments required for efficient bridging grows with the square root of the spider's body mass, faster than the radius of minor ampullate silk filaments actually produced by spiders. Because the morphology of spiders adapted to walking along or under silk threads is ill suited for moving on a solid surface, for these species there is a negative relationship between body mass and displacement ability. As it stands, the model suggests that spiders that use silk for their displacements are prevented from attaining a large body size if they must track their resources in space. In particular, silk elasticity would favour sexual size dimorphism because males that must use bridging lines to search for females cannot grow large. 2010 Elsevier Ltd. All rights reserved.

  7. Variation in size and growth of the great scallop Pecten maximus along a latitudinal gradient.

    Directory of Open Access Journals (Sweden)

    Laurent Chauvaud

    Full Text Available Understanding the relationship between growth and temperature will aid in the evaluation of thermal stress and threats to ectotherms in the context of anticipated climate changes. Most Pecten maximus scallops living at high latitudes in the northern hemisphere have a larger maximum body size than individuals further south, a common pattern among many ectotherms. We investigated differences in daily shell growth among scallop populations along the Northeast Atlantic coast from Spain to Norway. This study design allowed us to address precisely whether the asymptotic size observed along a latitudinal gradient, mainly defined by a temperature gradient, results from differences in annual or daily growth rates, or a difference in the length of the growing season. We found that low annual growth rates in northern populations are not due to low daily growth values, but to the smaller number of days available each year to achieve growth compared to the south. We documented a decrease in the annual number of growth days with age regardless of latitude. However, despite initially lower annual growth performances in terms of growing season length and growth rate, differences in asymptotic size as a function of latitude resulted from persistent annual growth performances in the north and sharp declines in the south. Our measurements of daily growth rates throughout life in a long-lived ectothermic species provide new insight into spatio-temporal variations in growth dynamics and growing season length that cannot be accounted for by classical growth models that only address asymptotic size and annual growth rate.

  8. Effect of host plant on body size of Frankliniella occidentalis and its correlation with reproductive capacity

    NARCIS (Netherlands)

    Kogel, de W.J.; Bosco, D.; Hoek, van der M.; Mollema, C.

    1999-01-01

    The effect of different host plants on Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) body size was investigated. Thrips from three different populations, from the Netherlands, Italy, and USA, achieved greater body sizes when reared on cucumber than on bean. The same thrips grew

  9. Body Image Issues In Lithuanian Magazines Aimed For Children And Adolescents In Relation To Body Mass Index And Body Size Perception Of 16-19 Y. Old Girls During The Last 15 Years

    OpenAIRE

    Tutkuviene, Janina

    2017-01-01

    Mass media plays an important role in forming body image and makes the significant impact on body size perception in children and adolescents. The aim of present study was to reveal trends in depiction of body image cues in Lithuanian magazines aimed for children and adolescents in relation to changes of real body mass index (BMI) and body size perception of 16-19 y. old girls in the year 2000 and the 2015. Three popular journals published both in the year 2000 and the 2015, were chosen for i...

  10. Paradoxical reproduction and body size in the rock lizard, Agama ...

    African Journals Online (AJOL)

    1993-07-05

    Jul 5, 1993 ... The rock lizard Agama atra atra from Namaqualand differs in both body size and reproduction from other populations of this species occurring elsewhere in southern Africa. Both sexes from Namaqualand are significantly larger than their counterparts in the south-western Cape. While reproduction in this ...

  11. Freshwater fishes in Greek lakes: Species richness and body size patterns

    Directory of Open Access Journals (Sweden)

    Anthi Oikonomou

    2015-11-01

    Full Text Available Freshwater ecosystems are widely recognised as hotspots of biodiversity and endemism; thus they are of great value for conservation biogeography. Amongst the taxa found in freshwater ecosystems, fish are the ideal biological model for testing biogeographical patterns and have often been used in large-scale ecological and biogeographical analyses. Lakes of Greece provide a unique opportunity to test biogeographical theories, however, biogeographical studies in Greece at broader, regional, scales, based on the distribution of freshwater species, species richness and endemism, are scarce. The aim of the current study is to test the effect of key environmental factors and spatial variables on species richness of lacustrine fishes and to test their effect on species’ size distributions. We assembled datasets of species richness and body size and environmental (predictor factors for 13 Greek lakes. Model selection procedures revealed that fish species richness increased with ecosystem area and decreased with altitude. In addition, our results showed that latitude per se is a good predictor of body size. Indeed, the mean size of lacustrine communities in the northern and southern lake ecosystems differed significantly. These patterns reflect the biogeographical history of these areas and highlight the crucial role connectivity plays in communities’ species composition.

  12. Balancing the dilution and oddity effects: decisions depend on body size.

    Directory of Open Access Journals (Sweden)

    Gwendolen M Rodgers

    Full Text Available Grouping behaviour, common across the animal kingdom, is known to reduce an individual's risk of predation; particularly through dilution of individual risk and predator confusion (predator inability to single out an individual for attack. Theory predicts greater risk of predation to individuals more conspicuous to predators by difference in appearance from the group (the 'oddity' effect. Thus, animals should choose group mates close in appearance to themselves (eg. similar size, whilst also choosing a large group.We used the Trinidadian guppy (Poecilia reticulata, a well known model species of group-living freshwater fish, in a series of binary choice trials investigating the outcome of conflict between preferences for large and phenotypically matched groups along a predation risk gradient. We found body-size dependent differences in the resultant social decisions. Large fish preferred shoaling with size-matched individuals, while small fish demonstrated no preference. There was a trend towards reduced preferences for the matched shoal under increased predation risk. Small fish were more active than large fish, moving between shoals more frequently. Activity levels increased as predation risk decreased. We found no effect of unmatched shoal size on preferences or activity.Our results suggest that predation risk and individual body size act together to influence shoaling decisions. Oddity was more important for large than small fish, reducing in importance at higher predation risks. Dilution was potentially of limited importance at these shoal sizes. Activity levels may relate to how much sampling of each shoal was needed by the test fish during decision making. Predation pressure may select for better decision makers to survive to larger size, or that older, larger fish have learned to make shoaling decisions more efficiently, and this, combined with their size relative to shoal-mates, and attractiveness as prey items influences shoaling

  13. Porters of the eastern hills of Nepal: Body size and load weight.

    Science.gov (United States)

    Malville, Nancy J.

    1999-01-01

    This study documents the activities of 635 porters transporting goods along three traditional trade routes of eastern Nepal. Nearly 95% of the porters were male. They ranged in age from 10-65 years, and most of them had begun to perform long-distance portage at 12-15 years of age. Mean body mass and height of adult males in the combined sample (n = 438) was 49.7 +/- 5.0 kg and 155.5 +/- 6.5 cm, respectively. Adult males age 20-49 years carried loads of 73 +/- 15 kg, equivalent to 146% +/- 30% of body mass. Body size of adult males was not a strong predictor of load weight. The correlation between body mass and load was r = 0.24 (P porters to carry such large loads in spite of their small body size is the ability to pace themselves by making frequent rest stops. Heart rate monitoring of 26 adult male commercial porters demonstrated how porters regulate heart rate and energy expenditure by resting the load every two to three minutes on the T-headed walking stick (tokma) and by setting the load periodically on load-resting platforms (chautaras) for longer recovery periods. Am. J. Hum. Biol. 11:1-11, 1999. Copyright 1999 Wiley-Liss, Inc.

  14. Intra- and trans-generational costs of reduced female body size caused by food limitation early in life in mites.

    Directory of Open Access Journals (Sweden)

    Andreas Walzer

    Full Text Available Food limitation early in life may be compensated for by developmental plasticity resulting in accelerated development enhancing survival at the expense of small adult body size. However and especially for females in non-matching maternal and offspring environments, being smaller than the standard may incur considerable intra- and trans-generational costs.Here, we evaluated the costs of small female body size induced by food limitation early in life in the sexually size-dimorphic predatory mite Phytoseiulus persimilis. Females are larger than males. These predators are adapted to exploit ephemeral spider mite prey patches. The intra- and trans-generational effects of small maternal body size manifested in lower maternal survival probabilities, decreased attractiveness for males, and a reduced number and size of eggs compared to standard-sized females. The trans-generational effects of small maternal body size were sex-specific with small mothers producing small daughters but standard-sized sons.Small female body size apparently intensified the well-known costs of sexual activity because mortality of small but not standard-sized females mainly occurred shortly after mating. The disadvantages of small females in mating and egg production may be generally explained by size-associated morphological and physiological constraints. Additionally, size-assortative mate preferences of standard-sized mates may have rendered small females disproportionally unattractive mating partners. We argue that the sex-specific trans-generational effects were due to sexual size dimorphism - females are the larger sex and thus more strongly affected by maternal stress than the smaller males - and to sexually selected lower plasticity of male body size.

  15. Intra- and trans-generational costs of reduced female body size caused by food limitation early in life in mites.

    Science.gov (United States)

    Walzer, Andreas; Schausberger, Peter

    2013-01-01

    Food limitation early in life may be compensated for by developmental plasticity resulting in accelerated development enhancing survival at the expense of small adult body size. However and especially for females in non-matching maternal and offspring environments, being smaller than the standard may incur considerable intra- and trans-generational costs. Here, we evaluated the costs of small female body size induced by food limitation early in life in the sexually size-dimorphic predatory mite Phytoseiulus persimilis. Females are larger than males. These predators are adapted to exploit ephemeral spider mite prey patches. The intra- and trans-generational effects of small maternal body size manifested in lower maternal survival probabilities, decreased attractiveness for males, and a reduced number and size of eggs compared to standard-sized females. The trans-generational effects of small maternal body size were sex-specific with small mothers producing small daughters but standard-sized sons. Small female body size apparently intensified the well-known costs of sexual activity because mortality of small but not standard-sized females mainly occurred shortly after mating. The disadvantages of small females in mating and egg production may be generally explained by size-associated morphological and physiological constraints. Additionally, size-assortative mate preferences of standard-sized mates may have rendered small females disproportionally unattractive mating partners. We argue that the sex-specific trans-generational effects were due to sexual size dimorphism - females are the larger sex and thus more strongly affected by maternal stress than the smaller males - and to sexually selected lower plasticity of male body size.

  16. The erratic mitochondrial clock: variations of mutation rate, not population size, affect mtDNA diversity across birds and mammals

    Directory of Open Access Journals (Sweden)

    Galtier Nicolas

    2009-03-01

    Full Text Available Abstract Background During the last ten years, major advances have been made in characterizing and understanding the evolution of mitochondrial DNA, the most popular marker of molecular biodiversity. Several important results were recently reported using mammals as model organisms, including (i the absence of relationship between mitochondrial DNA diversity and life-history or ecological variables, (ii the absence of prominent adaptive selection, contrary to what was found in invertebrates, and (iii the unexpectedly large variation in neutral substitution rate among lineages, revealing a possible link with species maximal longevity. We propose to challenge these results thanks to the bird/mammal comparison. Direct estimates of population size are available in birds, and this group presents striking life-history trait differences with mammals (higher mass-specific metabolic rate and longevity. These properties make birds the ideal model to directly test for population size effects, and to discriminate between competing hypotheses about the causes of substitution rate variation. Results A phylogenetic analysis of cytochrome b third-codon position confirms that the mitochondrial DNA mutation rate is quite variable in birds, passerines being the fastest evolving order. On average, mitochondrial DNA evolves slower in birds than in mammals of similar body size. This result is in agreement with the longevity hypothesis, and contradicts the hypothesis of a metabolic rate-dependent mutation rate. Birds show no footprint of adaptive selection on cytochrome b evolutionary patterns, but no link between direct estimates of population size and cytochrome b diversity. The mutation rate is the best predictor we have of within-species mitochondrial diversity in birds. It partly explains the differences in mitochondrial DNA diversity patterns observed between mammals and birds, previously interpreted as reflecting Hill-Robertson interferences with the W

  17. Microscopic description of nuclear few-body systems with the stochastic variational method

    International Nuclear Information System (INIS)

    Suzuki, Yasuyuki

    2000-01-01

    A simple gambling procedure called the stochastic variational method can be applied, together with appropriate variational trial functions, to solve a few-body system where the correlation between the constituents plays an important role in determining its structure. The usefulness of the method is tested by comparing to other accurate solutions for Coulombic systems. Examples of application shown here include few-nucleon systems interacting with realistic forces and few-cluster systems with the Pauli principle being taken into account properly. These examples confirm the power of the stochastic variational method. There still remain many problems for extending to a system consisting of more particles. (author)

  18. Body Image Issues In Lithuanian Magazines Aimed For Children And Adolescents In Relation To Body Mass Index And Body Size Perception Of 16-19 Y. Old Girls During The Last 15 Years.

    Science.gov (United States)

    Tutkuviene, Janina; Misiute, Agne; Strupaite, Ieva; Paulikaite, Gintare; Pavlovskaja, Erika

    2017-03-01

    Mass media plays an important role in forming body image and makes the significant impact on body size perception in children and adolescents. The aim of present study was to reveal trends in depiction of body image cues in Lithuanian magazines aimed for children and adolescents in relation to changes of real body mass index (BMI) and body size perception of 16-19 y. old girls in the year 2000 and the 2015. Three popular journals published both in the year 2000 and the 2015, were chosen for in-depth analysis of their contents (the periodicity of different topics was counted and compared). Attention given to a healthy body image has increased and the promotion of especially skinny females’ body has decreased during the last 15 years from the dominant type in the year 2000 to depiction of slightly thin or normal body build in the 2015. However, the real BMI of 16-19 y. old Lithuanian girls has significantly increased during the 2000-2015 period (from 20.09 till 21.32 kg/m²; pimage issues in mass media (magazines aimed for adolescent girls) were in parallel with the proper self-esteem of body size in adolescent girls.

  19. Phylogenetic diversity does not capture body size variation at risk in the world's mammals

    DEFF Research Database (Denmark)

    Fritz, Susanne A; Purvis, Andy

    2010-01-01

    Mammals contribute to important ecosystem processes and services, but many mammalian species are threatened with extinction. We compare how global patterns in three measures of mammalian diversity--species richness, phylogenetic diversity (PD) and body mass variance (BMV)--would change if all...... currently threatened species were lost. Given that many facets of species' ecology and life history scale predictably with body mass, the BMV in a region roughly reflects the diversity of species' roles within ecosystems and so is a simple proxy for functional diversity (FD). PD is also often considered...... more BMV than under random extinction, while only 11 per cent would lose significantly more PD. Ecosystem consequences of these selective losses may be profound, especially throughout the tropics, but are not captured by PD. This low surrogacy stresses a need for conservation prioritization based...

  20. Some like it hot... : the evolution and genetics of temperature dependent body size in Drosophila melanogaster

    NARCIS (Netherlands)

    Bochdanovits, Z. (Zoltán)

    2003-01-01

    Body size is one of the most obvious and most important characteristic of any organism. A thorough understanding of how and why a certain individual obtains a specific body size, given its evolutionary history and ecological context, is a fundamental question in biology. One special case of

  1. Depictive and metric body size estimation in anorexia nervosa and bulimia nervosa: A systematic review and meta-analysis.

    Science.gov (United States)

    Mölbert, Simone Claire; Klein, Lukas; Thaler, Anne; Mohler, Betty J; Brozzo, Chiara; Martus, Peter; Karnath, Hans-Otto; Zipfel, Stephan; Giel, Katrin Elisabeth

    2017-11-01

    A distorted representation of one's own body is a diagnostic criterion and core psychopathology of both anorexia nervosa (AN) and bulimia nervosa (BN). Despite recent technical advances in research, it is still unknown whether this body image disturbance is characterized by body dissatisfaction and a low ideal weight and/or includes a distorted perception or processing of body size. In this article, we provide an update and meta-analysis of 42 articles summarizing measures and results for body size estimation (BSE) from 926 individuals with AN, 536 individuals with BN and 1920 controls. We replicate findings that individuals with AN and BN overestimate their body size as compared to controls (ES=0.63). Our meta-regression shows that metric methods (BSE by direct or indirect spatial measures) yield larger effect sizes than depictive methods (BSE by evaluating distorted pictures), and that effect sizes are larger for patients with BN than for patients with AN. To interpret these results, we suggest a revised theoretical framework for BSE that accounts for differences between depictive and metric BSE methods regarding the underlying body representations (conceptual vs. perceptual, implicit vs. explicit). We also discuss clinical implications and argue for the importance of multimethod approaches to investigate body image disturbance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. A global synthesis of seasonal temperature-size responses in copepods

    DEFF Research Database (Denmark)

    Horne, Curtis R.; Hirst, Andrew G.; Atkinson, David

    2016-01-01

    is that calanoid copepods, which utilize feeding currents to capture prey, exhibit a four-fold greater reduction in adult body mass per degrees C (-3.66%) compared with cyclopoid copepods (-0.91%), which are ambush feeders. By contrast, species body size or reproductive strategy did not explain variation...

  3. Body size, skills, and income: evidence from 150,000 teenage siblings.

    Science.gov (United States)

    Lundborg, Petter; Nystedt, Paul; Rooth, Dan-Olof

    2014-10-01

    We provide new evidence on the long-run labor market penalty of teenage overweight and obesity using unique and large-scale data on 150,000 male siblings from the Swedish military enlistment. Our empirical analysis provides four important results. First, we provide the first evidence of a large adult male labor market penalty for being overweight or obese as a teenager. Second, we replicate this result using data from the United States and the United Kingdom. Third, we note a strikingly strong within-family relationship between body size and cognitive skills/noncognitive skills. Fourth, a large part of the estimated body-size penalty reflects lower skill acquisition among overweight and obese teenagers. Taken together, these results reinforce the importance of policy combating early-life obesity in order to reduce healthcare expenditures as well as poverty and inequalities later in life.

  4. Effect of directional selection for body size on fluctuating asymmetry ...

    Indian Academy of Sciences (India)

    In this study, we investigated whether stress caused by artificial bidirectional selection for body size has any effect on the levels of FA of different morphological traits in Drosophila ananassae. The realised heritability (h2) was higher in low-line females and high-line males, which suggests an asymmetrical response to ...

  5. Intra- and Trans-Generational Costs of Reduced Female Body Size Caused by Food Limitation Early in Life in Mites

    Science.gov (United States)

    Walzer, Andreas; Schausberger, Peter

    2013-01-01

    Background Food limitation early in life may be compensated for by developmental plasticity resulting in accelerated development enhancing survival at the expense of small adult body size. However and especially for females in non-matching maternal and offspring environments, being smaller than the standard may incur considerable intra- and trans-generational costs. Methodology/Principal Findings Here, we evaluated the costs of small female body size induced by food limitation early in life in the sexually size-dimorphic predatory mite Phytoseiulus persimilis. Females are larger than males. These predators are adapted to exploit ephemeral spider mite prey patches. The intra- and trans-generational effects of small maternal body size manifested in lower maternal survival probabilities, decreased attractiveness for males, and a reduced number and size of eggs compared to standard-sized females. The trans-generational effects of small maternal body size were sex-specific with small mothers producing small daughters but standard-sized sons. Conclusions/Significance Small female body size apparently intensified the well-known costs of sexual activity because mortality of small but not standard-sized females mainly occurred shortly after mating. The disadvantages of small females in mating and egg production may be generally explained by size-associated morphological and physiological constraints. Additionally, size-assortative mate preferences of standard-sized mates may have rendered small females disproportionally unattractive mating partners. We argue that the sex-specific trans-generational effects were due to sexual size dimorphism – females are the larger sex and thus more strongly affected by maternal stress than the smaller males – and to sexually selected lower plasticity of male body size. PMID:24265745

  6. The Effect of Body Size in Mercury Accumulation Biokinetic of Cockle Shell (Anadara Granosa)

    International Nuclear Information System (INIS)

    Wahyu Retno Prihatiningsih

    2007-01-01

    Accumulation of mercury biokinetic in cockle shell (Anadara granosa) through water pathway has been investigated under laboratory condition. The objective of research is to find the effect of body size in mercury biokinetic of Anadara granosa and to find bioindicator based on biokinetic parameter. The research shows that body size of Anadara granosa give an effect to concentration factor and could barrier mercury contaminant. Concentration factor for size 1.9, 2.5 and 3.9 cm of biota moving high and reach steady state condition after 24 days. Concentration factor of Anadara granosa in size 1.9, 2.5 and 3.9 is 0.1476, 0.1645 and 0.2573 day. Based on mechanism of mercury biokinetic process, it was proof that Anadara granosa is an ideal invertebrate for bioindicator. (author)

  7. Gill rakers in six teleost species: influence of feeding habit and body size

    Directory of Open Access Journals (Sweden)

    Ana Paula Gottlieb Almeida

    2013-12-01

    Full Text Available This study analyzed the structure of the gill rakers of Parapimelodus valenciennis and Parapimelodus nigribarbis (planktivorous, Serrasalmus maculatus and Hoplias malabaricus (piscivorous, Iheringichthys labrosus (benthophagous and Hypostomus commersonii (detritivorous and related it with the body size and feeding habits of these species. The species of Parapimelodus and H. commersonii showed long, filiform and closely spaced gill rakers, similar to those of species that use the gill rakers as a filter to assist in the retention of small particles. The widely spaced gill rakers of I. labrosus probably allow the retention of insect larvae, but not particles of inorganic matter. In H. malabaricus and S. maculatus the gill rakers are most likely related to prey capture and swallowing, as observed in other piscivorous species. In general, gill raker length and the distance between gill rakers have a positive relationship with fish length. The gill rakers show adaptations related to the diet of the fish, but morphological variation may occur even between species whose feeding habits are the same.

  8. Body Size of Contemporary Youth in Different Parts of the World

    Science.gov (United States)

    Meredith, Howard V.

    1969-01-01

    Based on body size measurements accumulated between 1950-1960, comparisons were made of 13-year-old girls and 15-year-old boys from North and South America, northern, central, and southwest Asia, Oceania, Australia, Africa, the Near East, and Europe. (DO)

  9. Density, body size, and reproduction of feral house mice on Gough ...

    African Journals Online (AJOL)

    1991-05-02

    May 2, 1991 ... 1992,27(1). Density, body size, and reproduction of feral house mice on Gough Island ... and mean monthly air temperatures (at sea level) range between 9°C ..... Concern about the adverse effect of introduced mice on island.

  10. Seed crop size variation in the dominant South American conifer Araucaria angustifolia

    Science.gov (United States)

    Souza, Alexandre F.; Uarte de Matos, Daniele; Forgiarini, Cristiane; Martinez, Jaime

    2010-01-01

    Temporal variation in seed crop size of the long-lived pioneer conifer Araucaria angustifolia was studied in subtropical South America. We evaluated the expectations that: 1) A. angustifolia presents highly variable seed production (mast seeding behavior); 2) A. angustifolia has endogenous cycles of reproduction of two or three years; 3) There is a tendency for a high seed production year to be followed by an unusually low production year; 4) populations show synchrony in seed production at a geographical scale; 5) seed crop size is influenced by distinct climatic factors occurring during "key" reproductive stages and 6) as an expression of plant productivity, seed crop size should depend on integrated resource availability during the reproductive cycle. We obtained data from two distinct sources: 1) seed harvesting records from a private forest (14 years), and 2) commercial data from 22 municipalities in the Rio Grande do Sul State. Expectations 1, 2, 3 and 5 were not met, while expectations 4 and 6 were supported by the data. A. angustifolia showed environmentally triggered, continuous, moderately fluctuating, and regionally synchronous reproduction. Seed set seems to track variations in resource abundance as well as respond continuously to improved opportunities for successful regeneration.

  11. The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape

    DEFF Research Database (Denmark)

    Winkler, Thomas W; Justice, Anne E; Graff, Mariaelisa

    2015-01-01

    Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially...... (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR... effects on WHRadjBMI. These results may provide further insights into the biology that underlies weight change with age or the sexually dimorphism of body shape....

  12. Interannual variations in the hatching pattern, larval growth and otolith size of a sand-dwelling fish from central Chile

    Science.gov (United States)

    Rodríguez-Valentino, Camilo; Landaeta, Mauricio F.; Castillo-Hidalgo, Gissella; Bustos, Claudia A.; Plaza, Guido; Ojeda, F. Patricio

    2015-09-01

    The interannual variation (2010-2013) of larval abundance, growth and hatching patterns of the Chilean sand stargazer Sindoscopus australis (Pisces: Dactyloscopidae) was investigated through otolith microstructure analysis from samples collected nearshore (otolith size (radius, perimeter and area), related to body length of larvae, significantly decreased from 2010 to 2012, but increases significantly in 2013. Although the mean values of microincrement widths of sagitta otoliths were similar between 2010 and 2011 (around 0.6-0.7 μm), the interindividual variability increases in 2011 and 2013, suggesting large environmental variability experienced by larvae during these years. Finally, the hatching pattern of S. australis changed significantly from semi-lunar to lunar cycle after 2012.

  13. Contrasting Food Web Factor and Body Size Relationships with Hg and Se Concentrations in Marine Biota

    Science.gov (United States)

    Karimi, Roxanne; Frisk, Michael; Fisher, Nicholas S.

    2013-01-01

    Marine fish and shellfish are primary sources of human exposure to mercury, a potentially toxic metal, and selenium, an essential element that may protect against mercury bioaccumulation and toxicity. Yet we lack a thorough understanding of Hg and Se patterns in common marine taxa, particularly those that are commercially important, and how food web and body size factors differ in their influence on Hg and Se patterns. We compared Hg and Se content among marine fish and invertebrate taxa collected from Long Island, NY, and examined associations between Hg, Se, body length, trophic level (measured by δ15N) and degree of pelagic feeding (measured by δ13C). Finfish, particularly shark, had high Hg content whereas bivalves generally had high Se content. Both taxonomic differences and variability were larger for Hg than Se, and Hg content explained most of the variation in Hg:Se molar ratios among taxa. Finally, Hg was more strongly associated with length and trophic level across taxa than Se, consistent with a greater degree of Hg bioaccumulation in the body over time, and biomagnification through the food web, respectively. Overall, our findings indicate distinct taxonomic and ecological Hg and Se patterns in commercially important marine biota, and these patterns have nutritional and toxicological implications for seafood-consuming wildlife and humans. PMID:24019976

  14. Contrasting food web factor and body size relationships with Hg and Se concentrations in marine biota.

    Directory of Open Access Journals (Sweden)

    Roxanne Karimi

    Full Text Available Marine fish and shellfish are primary sources of human exposure to mercury, a potentially toxic metal, and selenium, an essential element that may protect against mercury bioaccumulation and toxicity. Yet we lack a thorough understanding of Hg and Se patterns in common marine taxa, particularly those that are commercially important, and how food web and body size factors differ in their influence on Hg and Se patterns. We compared Hg and Se content among marine fish and invertebrate taxa collected from Long Island, NY, and examined associations between Hg, Se, body length, trophic level (measured by δ(15N and degree of pelagic feeding (measured by δ(13C. Finfish, particularly shark, had high Hg content whereas bivalves generally had high Se content. Both taxonomic differences and variability were larger for Hg than Se, and Hg content explained most of the variation in Hg:Se molar ratios among taxa. Finally, Hg was more strongly associated with length and trophic level across taxa than Se, consistent with a greater degree of Hg bioaccumulation in the body over time, and biomagnification through the food web, respectively. Overall, our findings indicate distinct taxonomic and ecological Hg and Se patterns in commercially important marine biota, and these patterns have nutritional and toxicological implications for seafood-consuming wildlife and humans.

  15. Seasonal and annual variation in Chilean hake Merluccius gayi spawning locations and egg size off central Chile

    Science.gov (United States)

    Landaeta, Mauricio F.; Castro, Leonardo R.

    2012-01-01

    Variability in Chilean hake reproductive tactics off central Chile was assessed by analyzing ichthyoplankton samples from nine oceanographic cruises (1996-2005) and through experimental trials with early life stages (eggs, yolk-sac larvae) during the main (austral spring) and secondary (late summer-early autumn) spawning seasons. Abundant eggs in the plankton (1300-2000 eggs per 10 m 2) and historical adult reproductive data showed the highest reproductive activity in austral spring, with large egg aggregations near shelf break (50-100 m depth). Large, recently spawned eggs (1.15-1.20 mm diameter) were advected nearshore by coastward subsurface flows in the spring upwelling season. Experimental trials indicated that recently hatched larvae (3.4-3.5 mm) consumed their yolk-sac (0.17-0.41 mm 3) in 3-4 days at 10-12 °C; plankton sampling indicated that larval hake remained at mid-depth (50-100 m) without showing daily vertical migrations until completing their caudal fin formation (∼15 mm). During the secondary reproductive peak, hake spawned nearshore, when smaller eggs (0.95-1.13 mm) and recently hatched larvae (2.2-2.6 mm notochord length) occurred in surface waters (0-10 m depth). Their relatively large yolk-sac volumes (0.57 ± 0.11 mm 3) provided endogenous nourishment for at least 5 days at 10 °C, according to experiments. In the field, preflexion larvae occurred mainly in the mixed layer (0-25 m) and started ontogenetic daily vertical migrations at 7 mm. A strong decline occurred after 2002 in the adult Chilean hake biomass (estimated by hydroacoustic surveys) and body size, coinciding with variations in spawning locations (more coastward in early spring 2004 and 2005) and decline in egg size. Thus, recent variations in Chilean hake reproductive tactics may reflect an indirect effect of declines in the parental population size.

  16. Ancestral Variations in the Shape and Size of the Zygoma.

    Science.gov (United States)

    Oettlé, Anna C; Demeter, Fabrice P; L'abbé, Ericka N

    2017-01-01

    The variable development of the zygoma, dictating its shape and size variations among ancestral groups, has important clinical implications and valuable anthropological and evolutionary inferences. The purpose of the study was to review the literature regarding the variations in the zygoma with ancestry. Ancestral variation in the zygoma reflects genetic variations because of genetic drift as well as natural selection and epigenetic changes to adapt to diet and climate variations with possible intensification by isolation. Prominence of the zygoma, zygomaxillary tuberosity, and malar tubercle have been associated with Eastern Asian populations in whom these features intensified. Prominence of the zygoma is also associated with groups from Eastern Europe and the rest of Asia. Diffusion of these traits occurred across the Behring Sea to the Arctic areas and to North and South America. The greatest zygomatic projections are exhibited in Arctic groups as an adaptation to extreme cold conditions, while Native South American groups also present with other features of facial robusticity. Groups from Australia, Malaysia, and Oceania show prominence of the zygoma to a certain extent, possibly because of archaic occupations by undifferentiated Southeast Asian populations. More recent interactions with Chinese groups might explain the prominent cheekbones noted in certain South African groups. Many deductions regarding evolutionary processes and diversifications of early groups have been made. Cognisance of these ancestral variations also have implications for forensic anthropological assessments as well as plastic and reconstructive surgery. More studies are needed to improve accuracy of forensic anthropological identification techniques. Anat Rec, 300:196-208, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Scaling of lifting forces in relation to object size in whole body lifting

    NARCIS (Netherlands)

    Kingma, I.; van Dieen, J.H.; Toussaint, H.M.

    2005-01-01

    Subjects prepare for a whole body lifting movement by adjusting their posture and scaling their lifting forces to the expected object weight. The expectancy is based on visual and haptic size cues. This study aimed to find out whether lifting force overshoots related to object size cues disappear or

  18. Efficiency Calibration of Phantom Family for Use in Direct Bioassay of Radionuclide in the Body

    International Nuclear Information System (INIS)

    Kim, Ji Seok; Ha, Wi Ho; Kim, Hyun Ki; Park, Gyung Deok; Lee, Jai Ki

    2008-01-01

    A major source of uncertainties of in vivo bioassay using a whole body counter calibrated against a body phantom containing known radioactivities is variation of counting geometry caused by the differences in body size of the subject from that of the phantom. Phantoms such as the BOMAB phantom are based on the body size of the reference man and usually single phantom is used in usual calibration of the counter. This is because it is difficult to apply a set of phantoms having different sizes. In order to reduce the potential errors due to variation of counting geometry, use of a set of phantoms having different body-shapes have been attempted. The efficiency files are stored in the computer analyzing the measurement data and a suitable one is retrieved for the specific subject. Experimental or computational approach can be employed in generation of the efficiency files. Carlan et al. demonstrated that Monte Carlo simulations can provide acceptable efficiencies by use of the IGOR phantom family. The body size of the individual subject undergoing in vivo bioassay should be determined by an appropriate method

  19. Survival of radio-implanted drymarchon couperi (Eastern Indigo Snake) in relation to body size and sex

    Science.gov (United States)

    Hyslop, N.L.; Meyers, J.M.; Cooper, R.J.; Norton, Terry M.

    2009-01-01

    Drymarchon couperi (eastern indigo snake) has experienced population declines across its range primarily as a result of extensive habitat loss, fragmentation, and degradation. Conservation efforts for D. couperi have been hindered, in part, because of informational gaps regarding the species, including a lack of data on population ecology and estimates of demographic parameters such as survival. We conducted a 2- year radiotelemetry study of D. couperi on Fort Stewart Military Reservation and adjacent private lands located in southeastern Georgia to assess individual characteristics associated with probability of survival. We used known-fate modeling to estimate survival, and an information-theoretic approach, based on a priori hypotheses, to examine intraspecific differences in survival probabilities relative to individual covariates (sex, size, size standardized by sex, and overwintering location). Annual survival in 2003 and 2004 was 0.89 (95% CI = 0.73-0.97, n = 25) and 0.72 (95% CI = 0.52-0.86; n = 27), respectively. Results indicated that body size, standardized by sex, was the most important covariate determining survival of adult D. couperi, suggesting lower survival for larger individuals within each sex. We are uncertain of the mechanisms underlying this result, but possibilities may include greater resource needs for larger individuals within each sex, necessitating larger or more frequent movements, or a population with older individuals. Our results may also have been influenced by analysis limitations because of sample size, other sources of individual variation, or environmental conditions. ?? 2009 by The Herpetologists' League, Inc.

  20. Body size shifts and early warning signals precede the historic collapse of whale stocks.

    Science.gov (United States)

    Clements, Christopher F; Blanchard, Julia L; Nash, Kirsty L; Hindell, Mark A; Ozgul, Arpat

    2017-06-22

    Predicting population declines is a key challenge in the face of global environmental change. Abundance-based early warning signals have been shown to precede population collapses; however, such signals are sensitive to the low reliability of abundance estimates. Here, using historical data on whales harvested during the 20th century, we demonstrate that early warning signals can be present not only in the abundance data, but also in the more reliable body size data of wild populations. We show that during the period of commercial whaling, the mean body size of caught whales declined dramatically (by up to 4 m over a 70-year period), leading to early warning signals being detectable up to 40 years before the global collapse of whale stocks. Combining abundance and body size data can reduce the length of the time series required to predict collapse, and decrease the chances of false positive early warning signals.

  1. Interrelationships of Hormones, Diet, Body Size and Breast Cancer among Hispanic Women

    National Research Council Canada - National Science Library

    Peltz, Gerson

    2005-01-01

    ...). The training program will focus on breast cancer etiology, specifically the interrelationships between hormones, diet, body size, and breast cancer among Hispanic women in the Lower Rio Grande Valley (LRGV...

  2. Size relationships of different body parts in the three dipteran species Drosophila melanogaster, Ceratitis capitata and Musca domestica.

    Science.gov (United States)

    Siomava, Natalia; Wimmer, Ernst A; Posnien, Nico

    2016-06-01

    Body size is an integral feature of an organism that influences many aspects of life such as fecundity, life span and mating success. Size of individual organs and the entire body size represent quantitative traits with a large reaction norm, which are influenced by various environmental factors. In the model system Drosophila melanogaster, pupal size and adult traits, such as tibia and thorax length or wing size, accurately estimate the overall body size. However, it is unclear whether these traits can be used in other flies. Therefore, we studied changes in size of pupae and adult organs in response to different rearing temperatures and densities for D. melanogaster, Ceratitis capitata and Musca domestica. We confirm a clear sexual size dimorphism (SSD) for Drosophila and show that the SSD is less uniform in the other species. Moreover, the size response to changing growth conditions is sex dependent. Comparison of static and evolutionary allometries of the studied traits revealed that response to the same environmental variable is genotype specific but has similarities between species of the same order. We conclude that the value of adult traits as estimators of the absolute body size may differ among species and the use of a single trait may result in wrong assumptions. Therefore, we suggest using a body size coefficient computed from several individual measurements. Our data is of special importance for monitoring activities of natural populations of the three dipteran flies, since they are harmful species causing economical damage (Drosophila, Ceratitis) or transferring diseases (Musca).

  3. Disentangling the effects of species diversity, and intraspecific and interspecific tree size variation on aboveground biomass in dry zone homegarden agroforestry systems.

    Science.gov (United States)

    Ali, Arshad; Mattsson, Eskil

    2017-11-15

    The biodiversity - aboveground biomass relationship has been intensively studied in recent decades. However, no consensus has been arrived to consider the interplay of species diversity, and intraspecific and interspecific tree size variation in driving aboveground biomass, after accounting for the effects of plot size heterogeneity, soil fertility and stand quality in natural forest including agroforests. We tested the full, partial and no mediations effects of species diversity, and intraspecific and interspecific tree size variation on aboveground biomass by employing structural equation models (SEMs) using data from 45 homegarden agroforestry systems in Sri Lanka. The full mediation effect of either species diversity or intraspecific and interspecific tree size variation was rejected, while the partial and no mediation effects were accepted. In the no mediation SEM, homegarden size had the strongest negative direct effect (β=-0.49) on aboveground biomass (R 2 =0.65), followed by strong positive direct effect of intraspecific tree size variation (β=0.32), species diversity (β=0.29) and interspecific tree size variation (β=0.28). Soil fertility had a negative direct effect on interspecific tree size variation (β=-0.31). Stand quality had a significant positive total effect on aboveground biomass (β=0.28), but homegarden size had a significant negative total effect (β=-0.62), while soil fertility had a non-significant total effect on aboveground biomass. Similar to the no mediation SEM, the partial mediation SEMs had explained almost similar variation in aboveground biomass because species diversity, and intraspecific and interspecific tree size variation had non-significant indirect effects on aboveground biomass via each other. Our results strongly suggest that a multilayered tree canopy structure, due to high intraspecific and interspecific tree size variation, increases light capture and efficient utilization of resources among component species, and

  4. Weber's Illusion and Body Shape: Anisotropy of Tactile Size Perception on the Hand

    Science.gov (United States)

    Longo, Matthew R.; Haggard, Patrick

    2011-01-01

    The perceived distance between touches on a single skin surface is larger on regions of high tactile sensitivity than those with lower acuity, an effect known as "Weber's illusion". This illusion suggests that tactile size perception involves a representation of the perceived size of body parts preserving characteristics of the somatosensory…

  5. Tuber size variation and organ preformation constrain growth responses of a spring geophyte.

    Science.gov (United States)

    Werger, Marinus J A; Huber, Heidrun

    2006-03-01

    Functional responses to environmental variation do not only depend on the genetic potential of a species to express different trait values, but can also be limited by characteristics, such as the timing of organ (pre-) formation, aboveground longevity or the presence of a storage organ. In this experiment we tested to what degree variation in tuber size and organ preformation constrain the responsiveness to environmental quality and whether responsiveness is modified by the availability of stored resources by exposing the spring geophyte Bunium bulbocastanum to different light and nutrient regimes. Growth and biomass partitioning were affected by initial tuber size and resource availability. On average, tuber weight amounted to 60%, but never less than 30% of the total plant biomass. Initial tuber size, considered an estimate of the total carbon pool available at the onset of treatments, affected plant growth and reproduction throughout the experiment but had little effect on the responsiveness of plants to the treatments. The responsiveness was partly constrained by organ preformation: in the second year variation of leaf number was considerably larger than in the first year of the treatments. The results indicate that a spring geophyte with organ preformation has only limited possibilities to respond to short-term fluctuations of the environment, as all leaves and the inflorescence are preformed in the previous growing season and resources stored in tubers are predominantly used for survival during dormancy and are not invested into plastic adjustments to environmental quality. Such spring geophytes have only limited possibilities to buffer environmental variation. This explains their restriction to habitats characterized by predictable changes of the environmental conditions.

  6. The bold and the beautiful. Influence of body size of televised media models on body dissatisfaction and actual food intake

    NARCIS (Netherlands)

    Anschutz, Doeschka J; Engels, Rutger C M E; Becker, Eni S; van Strien, Tatjana

    2008-01-01

    The effects of exposure to televised thin and average size models on body dissatisfaction and actual food intake were examined. Normal weight female students (N=104) were exposed to a 30-min movie clip featuring beautiful girls. Half of them viewed the movie clip in normal screen size (4:3) and the

  7. Incorporation of the Pore Size Variation to Modeling of the Elastic Behavior of Metallic Open-Cell Foams

    Directory of Open Access Journals (Sweden)

    Ćwieka K.

    2017-03-01

    Full Text Available In the present paper we present the approach for modeling of the elastic behavior of open-cell metallic foams concerning non-uniform pore size distribution. This approach combines design of foam structures and numerical simulations of compression tests using finite element method (FEM. In the design stage, Laguerre-Voronoi tessellations (LVT were performed on several sets of packed spheres with defined variation of radii, bringing about a set of foam structures with porosity ranging from 74 to 98% and different pore size variation quantified by the coefficient of pore volume variation, CV(V, from 0.5 to 2.1. Each structure was numerically subjected to uni-axial compression test along three directions within the elastic region. Basing on the numerical response, the effective Young’s modulus, Eeff, was calculated for each structure. It is shown that the Eeff is not only dependent on the porosity but also on the pore size variation.

  8. Effects of undernutrition and litter size on material variables and pup development.

    Science.gov (United States)

    Jen, K C; Wehmer, F; Morofski, J

    1978-05-01

    Differential effects of maternal nutrition and litter size variation were examined in a 2 x 2 factorial design in which undernourished or lib fed mothers nursed litters of 4 or 12. Litter size accounted for a greater proportion of pup body weight a weaning than did maternal nutrition. When the mother was fed ad lib, birth weight of individual pups and later body weight were correlated regardless of litter size. When the mother was undernourished, these correlations were not found. Enlargement of littersize increased the pup weight coefficient of variability only when the mother was fed ad lib. Size of the litter did not influence the maternal variables under study: open field behavior, adrenal weight, and body weight.

  9. Size Effect of the 2-D Bodies on the Geothermal Gradient and Q-A Plot

    Science.gov (United States)

    Thakur, M.; Blackwell, D. D.

    2009-12-01

    Using numerical models we have investigated some of the criticisms on the Q-A plot of related to the effect of size of the body on the slope and reduced heat flow. The effects of horizontal conduction depend on the relative difference of radioactivity between the body and the country rock (assuming constant thermal conductivity). Horizontal heat transfer due to different 2-D bodies was numerically studied in order to quantify resulting temperature differences at the Moho and errors on the predication of Qr (reduced heat flow). Using the two end member distributions of radioactivity, the step model (thickness 10km) and exponential model, different 2-D models of horizontal scale (width) ranging from 10 -500 km were investigated. Increasing the horizontal size of the body tends to move observations closer towards the 1-D solution. A temperature difference of 50 oC is produced (for the step model) at Moho between models of width 10 km versus 500 km. In other words the 1-D solution effectively provides large scale averaging in terms of heat flow and temperature field in the lithosphere. For bodies’ ≤ 100 km wide the geotherms at shallower levels are affected, but at depth they converge and are 50 oC lower than that of the infinite plate model temperature. In case of 2-D bodies surface heat flow is decreased due to horizontal transfer of heat, which will shift the Q-A point vertically downward on the Q-A plot. The smaller the size of the body, the more will be the deviation from the 1-D solution and the more will be the movement of Q-A point downwards on a Q-A plot. On the Q-A plot, a limited points of bodies of different sizes with different radioactivity contrast (for the step and exponential model), exactly reproduce the reduced heat flow Qr. Thus the size of the body can affect the slope on a Q-A plot but Qr is not changed. Therefore, Qr ~ 32 mWm-2 obtained from the global terrain average Q-A plot represents the best estimate of stable continental mantle heat

  10. Analysis of Long-Term Temperature Variations in the Human Body.

    Science.gov (United States)

    Dakappa, Pradeepa Hoskeri; Mahabala, Chakrapani

    2015-01-01

    Body temperature is a continuous physiological variable. In normal healthy adults, oral temperature is estimated to vary between 36.1°C and 37.2°C. Fever is a complex host response to many external and internal agents and is a potential contributor to many clinical conditions. Despite being one of the foremost vital signs, temperature and its analysis and variations during many pathological conditions has yet to be examined in detail using mathematical techniques. Classical fever patterns based on recordings obtained every 8-12 h have been developed. However, such patterns do not provide meaningful information in diagnosing diseases. Because fever is a host response, it is likely that there could be a unique response to specific etiologies. Continuous long-term temperature monitoring and pattern analysis using specific analytical methods developed in engineering and physics could aid in revealing unique fever responses of hosts and in different clinical conditions. Furthermore, such analysis can potentially be used as a novel diagnostic tool and to study the effect of pharmaceutical agents and other therapeutic protocols. Thus, the goal of our article is to present a comprehensive review of the recent relevant literature and analyze the current state of research regarding temperature variations in the human body.

  11. Myonuclear domain size and myosin isoform expression in muscle fibres from mammals representing a 100,000-fold difference in body size.

    Science.gov (United States)

    Liu, Jing-Xia; Höglund, Anna-Stina; Karlsson, Patrick; Lindblad, Joakim; Qaisar, Rizwan; Aare, Sudhakar; Bengtsson, Ewert; Larsson, Lars

    2009-01-01

    This comparative study of myonuclear domain (MND) size in mammalian species representing a 100,000-fold difference in body mass, ranging from 25 g to 2500 kg, was undertaken to improve our understanding of myonuclear organization in skeletal muscle fibres. Myonuclear domain size was calculated from three-dimensional reconstructions in a total of 235 single muscle fibre segments at a fixed sarcomere length. Irrespective of species, the largest MND size was observed in muscle fibres expressing fast myosin heavy chain (MyHC) isoforms, but in the two smallest mammalian species studied (mouse and rat), MND size was not larger in the fast-twitch fibres expressing the IIA MyHC isofom than in the slow-twitch type I fibres. In the larger mammals, the type I fibres always had the smallest average MND size, but contrary to mouse and rat muscles, type IIA fibres had lower mitochondrial enzyme activities than type I fibres. Myonuclear domain size was highly dependent on body mass in the two muscle fibre types expressed in all species, i.e. types I and IIA. Myonuclear domain size increased in muscle fibres expressing both the beta/slow (type I; r = 0.84, P fast IIA MyHC isoform (r = 0.90; P muscle fibre type, independent of species. However, myosin isoform expression is not the sole protein determining MND size, and other protein systems, such as mitochondrial proteins, may be equally or more important determinants of MND size.

  12. Spatial and temporal variation in size of polar bear (Ursus maritimus) sexual organs and its use in pollution and climate change studies.

    Science.gov (United States)

    Sonne, Christian; Dietz, Rune; Born, Erik W; Riget, Frank F; Leifsson, Pall S; Bechshøft, Thea Ø; Kirkegaard, Maja

    2007-11-15

    Sexual organs and their development are susceptible to atmospheric transported environmental xenoendocrine pollutants and climate change (food availability). We therefore investigated sexual organs from 55 male and 44 female East Greenland polar bears (Ursus maritimus) to obtain information about growth/size and sexual maturity. Then, the genitalia size was compared with those previously reported from Canadian and Svalbard polar bears. Growth models showed that East Greenland male polar bears reached sexual maturity around 7 years of age and females around 4 years of age. When comparing East Greenland and Svalbard polar bears, the size of baculum and uterus were significantly lower in the East Greenland polar bears (ANOVA: all p polar bears, a similar baculum pattern was found for East Greenland vs. Canadian polar bears. It is speculated whether this could be a result of the general high variation in polar bear body size, temporal distribution patterns of anthropogenic long-range transported persistent organic pollutants or climate change (decreasing food availability). The present investigation represents conservation and background data for future spatial and temporal assessments of hunting, pollution and climate change scenarios.

  13. Dietary protein content affects evolution for body size, body fat and viability in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Kristensen, Torsten N; Overgaard, Johannes; Loeschcke, Volker

    2011-01-01

    The ability to use different food sources is likely to be under strong selection if organisms are faced with natural variation in macro-nutrient (protein, carbohydrate and lipid) availabilities. Here, we use experimental evolution to study how variable dietary protein content affects adult body...... composition and developmental success in Drosophila melanogaster. We reared flies on either a standard diet or a protein-enriched diet for 17 generations before testing them on both diet types. Flies from lines selected on protein-rich diet produced phenotypes with higher total body mass and relative lipid...... content when compared with those selected on a standard diet, irrespective of which of the two diets they were tested on. However, selection on protein-rich diet incurred a cost as flies reared on this diet had markedly lower developmental success in terms of egg-to-adult viability on both medium types...

  14. What doesn't kill you might make you stronger: functional basis for variation in body armour.

    Science.gov (United States)

    Broeckhoven, Chris; Diedericks, Genevieve; Mouton, P le Fras N

    2015-09-01

    1. Predation has been proposed to be a selective agent in the evolution of morphological antipredator strategies in prey. Among vertebrates, one of the morphological traits that evolved multiple times is body armour, including carapaces, thickened keratinized scales and plates of dermal bone. 2. It has been generally assumed that body armour provides protection against a predatory attack; yet, few explicit tests of the hypothesis exist. Cordylidae, a relatively small family of southern African lizards, show considerable variation in the degree of body armour. Hence, this family provides an opportunity to test the hypothesis that body armour serves as protection against predators. 3. Experiments were conducted to test whether the bite forces of four species of mammalian predators were high enough to penetrate the skins of Karusasaurus polyzonus, Namazonurus peersi, Cordylus cordylus and Cordylus macropholis, as well as those of Ouroborus cataphractus individuals originating from three localities that differed in their predator diversity. Furthermore, histological techniques were used to test whether variation in skin toughness was associated with concomitant changes in the degree of epidermal (i.e. β-keratin) and dermal (i.e. osteoderm) armour. 4. The skin toughness values for four out of five cordylid lizards tested in this study were well below the bite forces of the mammalian predators. In contrast, the thick osteoderms in the dermis of O. cataphractus can withstand bites from several mongoose species. However, the significant variation in body armour that is present between the three populations of O. cataphractus does not seem to be related to predator diversity. 5. It is concluded that body armour can serve as protection against predation in O. cataphractus, but that alternative selection pressures, such as thermoregulation or predation by snakes, presumably underlie variation in defensive morphology in the other cordylid lizards. © 2015 The Authors. Journal

  15. Season, molt, and body size influence mercury concentrations in grebes

    Science.gov (United States)

    Hartman, Christopher; Ackerman, Joshua T.; Herzog, Mark; Eagles-Smith, Collin A.

    2017-01-01

    We studied seasonal and physiological influences on mercury concentrations in western grebes (Aechmophorus occidentalis) and Clark's grebes (A. occidentalis) across 29 lakes and reservoirs in California, USA. Additionally, at three of these lakes, we conducted a time series study, in which we repeatedly sampled grebe blood mercury concentrations during the spring, summer, and early fall. Grebe blood mercury concentrations were higher among males (0.61 ± 0.12 μg/g ww) than females (0.52 ± 0.10 μg/g ww), higher among Clark's grebes (0.58 ± 0.12 μg/g ww) than western grebes (0.51 ± 0.10 μg/g ww), and exhibited a strong seasonal pattern (decreasing by 60% from spring to fall). Grebe blood THg concentrations exhibited a shallow, inverse U-shaped pattern with body size, and was lowest among the smallest and largest grebes. Further, the relationship between grebe blood mercury concentrations and wing primary feather molt exhibited a shallow U-shaped pattern, where mercury concentrations were highest among birds that had not yet begun molting, decreased approximately 24% between pre-molt and late molt, and increased approximately 19% from late molt to post-molt. Because grebes did not begin molting until mid-summer, lower grebe blood mercury concentrations observed in late summer and early fall were consistent with the onset of primary feather molt. However, because sampling date was a much stronger predictor of grebe mercury concentrations than molt, other seasonally changing environmental factors likely played a larger role than molt in the seasonal variation in grebe mercury concentrations. In the time series study, we found that seasonal trends in grebe mercury concentrations were not consistent among lakes, indicating that lake-specific variation in mercury dynamics influence the overall seasonal decline in grebe blood mercury concentrations. These results highlight the importance of accounting for sampling date, as well as ecological processes that may

  16. Ideal Body Size as a Mediator for the Gender-Specific Association Between Socioeconomic Status and Body Mass Index: Evidence From an Upper-Middle-Income Country in the African Region.

    OpenAIRE

    Yepes Maryam; Maurer Jürgen; Stringhini Silvia; Viswanathan Barathi; Gedeon Jude; Bovet Pascal

    2016-01-01

    While obesity continues to rise globally the associations between body size gender and socioeconomic status (SES) seem to vary in different populations and little is known on the contribution of perceived ideal body size in the social disparity of obesity in African countries. We examined the gender and socioeconomic patterns of body mass index (BMI) and perceived ideal body size in the Seychelles a middle income small island state in the African region. We also assessed the potential role of...

  17. Generating size-controlled embryoid bodies using laser direct-write

    International Nuclear Information System (INIS)

    Dias, A D; Corr, D T; Unser, A M; Xie, Y; Chrisey, D B

    2014-01-01

    Embryonic stem cells (ESCs) have the potential to self-renew and differentiate into any specialized cell type. One common method to differentiate ESCs in vitro is through embryoid bodies (EBs), three-dimensional cellular aggregates that spontaneously self-assemble and generally express markers for the three germ layers, endoderm, ectoderm, and mesoderm. It has been previously shown that both EB size and 2D colony size each influence differentiation. We hypothesized that we could control the size of the EB formed by mouse ESCs (mESCs) by using a cell printing method, laser direct-write (LDW), to control both the size of the initial printed colony and the local cell density in printed colonies. After printing mESCs at various printed colony sizes and printing densities, two-way ANOVAs indicated that the EB diameter was influenced by printing density after three days (p = 0.0002), while there was no effect of the printed colony diameter on the EB diameter at the same timepoint (p = 0.74). There was no significant interaction between these two factors. Tukey's honestly significant difference test showed that high-density colonies formed significantly larger EBs, suggesting that printed mESCs quickly aggregate with nearby cells. Thus, EBs can be engineered to a desired size by controlling printing density, which will influence the design of future differentiation studies. Herein, we highlight the capacity of LDW to control the local cell density and colony size independently, at prescribed spatial locations, potentially leading to better stem cell maintenance and directed differentiation. (paper)

  18. Geographic variation in age structure and longevity in the nine-spined stickleback (Pungitius pungitius.

    Directory of Open Access Journals (Sweden)

    Jacquelin DeFaveri

    Full Text Available Variation in age and size of mature nine-spined sticklebacks (Pungitius pungitius within and among 16 Fennoscandian populations were assessed using skeletochronology. The average age of individuals in a given population varied from 1.7 to 4.7 years. Fish from pond populations were on average older than those from lake and marine populations, and females tended to be older than males. Reproduction in marine and lake populations commenced typically at an age of two years, whereas that in ponds at an age of three years. The maximum life span of the fish varied from 3 to 7 years. Mean body size within and among populations increased with increasing age, but the habitat and population differences in body size persisted even after accounting for variation in population age (and sex structure. Hence, the population differences in mean body size are not explainable by age differences alone. As such, much of the pronounced intraspecific variation in population age structure can be attributed to delayed maturation and extended longevity of the pond fish. The results are contrasted and discussed in the context of similar data from the three-spined stickleback (Gasterosteus aculeatus occupying the same geographic area.

  19. Body Size and the Risk of Primary Hyperparathyroidism in Women: A Cohort Study.

    Science.gov (United States)

    Vaidya, Anand; Curhan, Gary C; Paik, Julie M; Wang, Molin; Taylor, Eric N

    2017-09-01

    Greater body weight and fat mass have been associated with higher serum parathyroid hormone levels and a higher prevalence of primary hyperparathyroidism (P-HPTH) in women. However, prospective studies to evaluate whether greater body size associates with a higher incidence of developing P-HPTH have not been reported. We investigated whether greater body size was independently associated with a higher risk for developing P-HPTH in women. We conducted a prospective cohort study of 85,013 female participants in the Nurses' Health Study I followed for up to 26 years. Body size was measured via multiple metrics: weight, body mass index (BMI), and waist circumference (WC). Weight and BMI were assessed every 2 years from 1986 to 2012, and WC was assessed in 1986, 1996, and 2000. Detailed dietary and demographic exposures were quantified via validated biennial questionnaires. Incident cases of P-HPTH were confirmed by individual medical record review. Cox proportional hazards models were used to evaluate whether WC, weight, and BMI were independent risk factors for developing P-HPTH. Models were adjusted for demographic variables, comorbidities, medications, intakes of calcium and vitamin D, and exposure to ultraviolet light. We confirmed 491 incident cases of P-HPTH during 2,128,068 person-years of follow-up. The multivariable-adjusted relative risks for incident P-HPTH increased across quartiles of WC: Q1, ref; Q2, 1.34 (0.97, 1.86); Q3, 1.70 (1.24, 2.31); Q4, 2.27 (1.63, 3.18); p trend < 0.001. Similarly, the multivariable-adjusted risks for incident P-HPTH increased across quartiles of weight: Q1, ref; Q2, 1.23 (0.92, 1.65); Q3, 1.63 (1.24, 2.14); Q4, 1.65 (1.24, 2.19); p trend < 0.001. A similar but statistically non-significant trend was observed across quartiles of BMI (p trend = 0.07). In summary, body size may be an independent and modifiable risk factor for developing P-HPTH in women. © 2017 American Society for Bone and Mineral Research. © 2017 American

  20. A Single IGF1 Allele Is a Major Determinant of Small Size in Dogs

    Science.gov (United States)

    Sutter, Nathan B.; Bustamante, Carlos D.; Chase, Kevin; Gray, Melissa M.; Zhao, Keyan; Zhu, Lan; Padhukasahasram, Badri; Karlins, Eric; Davis, Sean; Jones, Paul G.; Quignon, Pascale; Johnson, Gary S.; Parker, Heidi G.; Fretwell, Neale; Mosher, Dana S.; Lawler, Dennis F.; Satyaraj, Ebenezer; Nordborg, Magnus; Lark, K. Gordon; Wayne, Robert K.; Ostrander, Elaine A.

    2009-01-01

    The domestic dog exhibits greater diversity in body size than any other terrestrial vertebrate. We used a strategy that exploits the breed structure of dogs to investigate the genetic basis of size. First, through a genome-wide scan, we identified a major quantitative trait locus (QTL) on chromosome 15 influencing size variation within a single breed. Second, we examined genetic variation in the 15-megabase interval surrounding the QTL in small and giant breeds and found marked evidence for a selective sweep spanning a single gene (IGF1), encoding insulin-like growth factor 1. A single IGF1 single-nucleotide polymorphism haplotype is common to all small breeds and nearly absent from giant breeds, suggesting that the same causal sequence variant is a major contributor to body size in all small dogs. PMID:17412960

  1. Estimation of body-size traits by photogrammetry in large mammals to inform conservation.

    Science.gov (United States)

    Berger, Joel

    2012-10-01

    Photography, including remote imagery and camera traps, has contributed substantially to conservation. However, the potential to use photography to understand demography and inform policy is limited. To have practical value, remote assessments must be reasonably accurate and widely deployable. Prior efforts to develop noninvasive methods of estimating trait size have been motivated by a desire to answer evolutionary questions, measure physiological growth, or, in the case of illegal trade, assess economics of horn sizes; but rarely have such methods been directed at conservation. Here I demonstrate a simple, noninvasive photographic technique and address how knowledge of values of individual-specific metrics bears on conservation policy. I used 10 years of data on juvenile moose (Alces alces) to examine whether body size and probability of survival are positively correlated in cold climates. I investigated whether the presence of mothers improved juvenile survival. The posited latter relation is relevant to policy because harvest of adult females has been permitted in some Canadian and American jurisdictions under the assumption that probability of survival of young is independent of maternal presence. The accuracy of estimates of head sizes made from photographs exceeded 98%. The estimates revealed that overwinter juvenile survival had no relation to the juvenile's estimated mass (p < 0.64) and was more strongly associated with maternal presence (p < 0.02) than winter snow depth (p < 0.18). These findings highlight the effects on survival of a social dynamic (the mother-young association) rather than body size and suggest a change in harvest policy will increase survival. Furthermore, photographic imaging of growth of individual juvenile muskoxen (Ovibos moschatus) over 3 Arctic winters revealed annual variability in size, which supports the idea that noninvasive monitoring may allow one to detect how some environmental conditions ultimately affect body growth.

  2. Metabolic 'engines' of flight drive genome size reduction in birds.

    Science.gov (United States)

    Wright, Natalie A; Gregory, T Ryan; Witt, Christopher C

    2014-03-22

    The tendency for flying organisms to possess small genomes has been interpreted as evidence of natural selection acting on the physical size of the genome. Nonetheless, the flight-genome link and its mechanistic basis have yet to be well established by comparative studies within a volant clade. Is there a particular functional aspect of flight such as brisk metabolism, lift production or maneuverability that impinges on the physical genome? We measured genome sizes, wing dimensions and heart, flight muscle and body masses from a phylogenetically diverse set of bird species. In phylogenetically controlled analyses, we found that genome size was negatively correlated with relative flight muscle size and heart index (i.e. ratio of heart to body mass), but positively correlated with body mass and wing loading. The proportional masses of the flight muscles and heart were the most important parameters explaining variation in genome size in multivariate models. Hence, the metabolic intensity of powered flight appears to have driven genome size reduction in birds.

  3. Patterns of sexual size dimorphism in horseshoe bats: Testing Rensch's rule and potential causes.

    Science.gov (United States)

    Wu, Hui; Jiang, Tinglei; Huang, Xiaobin; Feng, Jiang

    2018-02-08

    Rensch's rule, stating that sexual size dimorphism (SSD) becomes more evident and male-biased with increasing body size, has been well supported for taxa that exhibit male-biased SSD. Bats, primarily having female-biased SSD, have so far been tested for whether SSD allometry conforms to Rensch's rule in only three studies. However, these studies did not consider phylogeny, and thus the mechanisms underlying SSD variations in bats remain unclear. Thus, the present study reviewed published and original data, including body size, baculum size, and habitat types in 45 bats of the family Rhinolophidae to determine whether horseshoe bats follow Rensch's rule using a phylogenetic comparative framework. We also investigated the potential effect of postcopulatory sexual selection and habitat type on SSD. Our findings indicated that Rensch's rule did not apply to Rhinolophidae, suggesting that SSD did not significantly vary with increasing size. This pattern may be attributable interactions between weak sexual selection to male body size and strong fecundity selection for on female body size. The degree of SSD among horseshoe bats may be attributed to a phylogenetic effect rather than to the intersexual competition for food or to baculum length. Interestingly, we observed that species in open habitats exhibited greater SSD than those in dense forests, suggesting that habitat types may be associated with variations in SSD in horseshoe bats.

  4. Childhood Body Size and the Risk of Malignant Melanoma in Adulthood

    DEFF Research Database (Denmark)

    Meyle, Kathrine D; Gamborg, Michael; Sørensen, Thorkild I A

    2017-01-01

    years and age 13 years had a significantly increased MM risk compared with children who grew taller between those ages. Birth weight was positively associated with MM. We conclude that associations between body size and MM originate early in life and are driven largely by height and birth weight...

  5. General variational many-body theory with complete self-consistency for trapped bosonic systems

    International Nuclear Information System (INIS)

    Streltsov, Alexej I.; Alon, Ofir E.; Cederbaum, Lorenz S.

    2006-01-01

    In this work we develop a complete variational many-body theory for a system of N trapped bosons interacting via a general two-body potential. The many-body solution of this system is expanded over orthogonal many-body basis functions (configurations). In this theory both the many-body basis functions and the respective expansion coefficients are treated as variational parameters. The optimal variational parameters are obtained self-consistently by solving a coupled system of noneigenvalue--generally integro-differential--equations to get the one-particle functions and by diagonalizing the secular matrix problem to find the expansion coefficients. We call this theory multiconfigurational Hartree theory for bosons or MCHB(M), where M specifies explicitly the number of one-particle functions used to construct the configurations. General rules for evaluating the matrix elements of one- and two-particle operators are derived and applied to construct the secular Hamiltonian matrix. We discuss properties of the derived equations. We show that in the limiting cases of one configuration the theory boils down to the well-known Gross-Pitaevskii and the recently developed multi-orbital mean fields. The invariance of the complete solution with respect to unitary transformations of the one-particle functions is utilized to find the solution with the minimal number of contributing configurations. In the second part of our work we implement and apply the developed theory. It is demonstrated that for any practical computation where the configurational space is restricted, the description of trapped bosonic systems strongly depends on the choice of the many-body basis set used, i.e., self-consistency is of great relevance. As illustrative examples we consider bosonic systems trapped in one- and two-dimensional symmetric and asymmetric double well potentials. We demonstrate that self-consistency has great impact on the predicted physical properties of the ground and excited states

  6. Nasonia Parasitic Wasps Escape from Haller's Rule by Diphasic, Partially Isometric Brain-Body Size Scaling and Selective Neuropil Adaptations

    NARCIS (Netherlands)

    Groothuis, Jitte; Smid, Hans M.

    2017-01-01

    Haller's rule states that brains scale allometrically with body size in all animals, meaning that relative brain size increases with decreasing body size. This rule applies both on inter- and intraspecific comparisons. Only 1 species, the extremely small parasitic wasp Trichogramma evanescens, is

  7. Spatial and body-size dependent response of marine pelagic communities to projected global climate change.

    Science.gov (United States)

    Lefort, Stelly; Aumont, Olivier; Bopp, Laurent; Arsouze, Thomas; Gehlen, Marion; Maury, Olivier

    2015-01-01

    Temperature, oxygen, and food availability directly affect marine life. Climate models project a global warming of the ocean's surface (~+3 °C), a de-oxygenation of the ocean's interior (~-3%) and a decrease in total marine net primary production (~-8%) under the 'business as usual' climate change scenario (RCP8.5). We estimated the effects of these changes on biological communities using a coupled biogeochemical (PISCES)--ecosystems (APECOSM) model forced by the physical outputs of the last generation of the IPSL-CM Earth System Model. The APECOSM model is a size-structured bio-energetic model that simulates the 3D dynamical distributions of three interactive pelagic communities (epipelagic, mesopelagic, and migratory) under the effects of multiple environmental factors. The PISCES-APECOSM model ran from 1850 to 2100 under historical forcing followed by RCP8.5. Our RCP8.5 simulation highlights significant changes in the spatial distribution, biomass, and maximum body-size of the simulated pelagic communities. Biomass and maximum body-size increase at high latitude over the course of the century, reflecting the capacity of marine organisms to respond to new suitable environment. At low- and midlatitude, biomass and maximum body-size strongly decrease. In those regions, large organisms cannot maintain their high metabolic needs because of limited and declining food availability. This resource reduction enhances the competition and modifies the biomass distribution among and within the three communities: the proportion of small organisms increases in the three communities and the migrant community that initially comprised a higher proportion of small organisms is favored. The greater resilience of small body-size organisms resides in their capacity to fulfill their metabolic needs under reduced energy supply and is further favored by the release of predation pressure due to the decline of large organisms. These results suggest that small body-size organisms might be

  8. Speciation in little: the role of range and body size in the diversification of Malagasy mantellid frogs

    Directory of Open Access Journals (Sweden)

    Vences Miguel

    2011-07-01

    Full Text Available Abstract Background The rate and mode of lineage diversification might be shaped by clade-specific traits. In Madagascar, many groups of organisms are characterized by tiny distribution ranges and small body sizes, and this high degree of microendemism and miniaturization parallels a high species diversity in some of these groups. We here investigate the geographic patterns characterizing the radiation of the frog family Mantellidae that is virtually endemic to Madagascar. We integrate a newly reconstructed near-complete species-level timetree of the Mantellidae with georeferenced distribution records and maximum male body size data to infer the influence of these life-history traits on each other and on mantellid diversification. Results We reconstructed a molecular phylogeny based on nuclear and mitochondrial DNA for 257 species and candidate species of the mantellid frog radiation. Based on this phylogeny we identified 53 well-supported pairs of sister species that we used for phylogenetic comparative analyses, along with whole tree-based phylogenetic comparative methods. Sister species within the Mantellidae diverged at 0.2-14.4 million years ago and more recently diverged sister species had geographical range centroids more proximate to each other, independently of their current sympatric or allopatric occurrence. The largest number of sister species pairs had non-overlapping ranges, but several examples of young microendemic sister species occurring in full sympatry suggest the possibility of non-allopatric speciation. Range sizes of species included in the sister species comparisons increased with evolutionary age, as did range size differences between sister species, which rejects peripatric speciation. For the majority of mantellid sister species and the whole mantellid radiation, range and body sizes were associated with each other and small body sizes were linked to higher mitochondrial nucleotide substitution rates and higher clade

  9. Choosing representative body sizes for reference adults and children

    International Nuclear Information System (INIS)

    Cristy, M.

    1992-01-01

    In 1975 the International Commission on Radiological Protection published a report on Reference Man (ICRP Publication 23), and a task group of the ICRP is now revising that report. Currently 'Reference Man [adult male] is defined as being between 20-30 years of age, weighing 70 kg, is 170 cm in height, is a Caucasian and is a Western European or North American in habitat and custom' (ICRP 23, p. 4). A reference adult female (58 kg, 160 cm) was also defined and data on the fetus and children were given, but with less detail and fewer specific reference values because the focus of the ICRP at that time was on young male radiation workers. The 70-kg Reference Man (earlier called Standard Man) has been used in radiation protection for 40 years, including the dosimetric schema for nuclear medicine, and this 70-kg reference has been used since at least the 1920's in physiological models. As is well known, humans in most parts of the world have increased in size (height and weight) since this standard was first adopted. Taking modern European populations as a reference and expanding the age range to 20-50 years, the author now suggests 176 cm height and 73-75 kg weight for adult males and 163 cm and about 60 kg for adult females would be more appropriate. The change in height is particularly important because many anatomical and physiological parameters - e.g., lean body mass, skeletal weight, total body water, blood volume, respiratory volumes - are correlated more closely with height than with weight. The difference in lean body mass between Asian and Caucasian persons, for example, is largely or wholly due to the difference in body height. Many equations for mean body water and other whole-body measures use body height as the only or the most important parameter, and so it is important that reference body height be chosen well

  10. Tactic changes in dusky frillgoby Bathygobius fuscus sneaker males: effects of body size and nest availability.

    Science.gov (United States)

    Takegaki, T; Kaneko, T; Matsumoto, Y

    2013-02-01

    Field and laboratory studies were conducted to examine the effects of nest availability and body size on changes in male mating tactics from sneaking to nest-holding in the dusky frillgoby Bathygobius fuscus. In the field, the body size of nest-holding males decreased from early to mid-breeding season, suggesting the possibility of a change in the tactics of sneaker males to nest-holding. Many sneaker males did not use vacant spawning nests even when size-matched nests were available, but they continued to reproduce as sneakers. Similarly, in aquarium experiments with available vacant nests, some sneaker males became nest-holders irrespective of their body size, but some did not. These results showed that nest availability is not a limiting factor for changes in tactics by sneaker males in this species. Because tactic-unchanged sneaker males were co-housed with larger nest-holding males in the tanks, the body size of nearby nest-holding males may have affected the decision to change tactics for sneaker males. Moreover, smaller individuals among tactic-changed males tended to spend more time until spawning, probably because they had relatively larger costs and smaller benefits of reproduction as nest-holding males compared to larger males. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  11. Distribution and diversity of cytotypes in Dianthus broteri as evidenced by genome size variations.

    Science.gov (United States)

    Balao, Francisco; Casimiro-Soriguer, Ramón; Talavera, María; Herrera, Javier; Talavera, Salvador

    2009-10-01

    Studying the spatial distribution of cytotypes and genome size in plants can provide valuable information about the evolution of polyploid complexes. Here, the spatial distribution of cytological races and the amount of DNA in Dianthus broteri, an Iberian carnation with several ploidy levels, is investigated. Sample chromosome counts and flow cytometry (using propidium iodide) were used to determine overall genome size (2C value) and ploidy level in 244 individuals of 25 populations. Both fresh and dried samples were investigated. Differences in 2C and 1Cx values among ploidy levels within biogeographical provinces were tested using ANOVA. Geographical correlations of genome size were also explored. Extensive variation in chromosomes numbers (2n = 2x = 30, 2n = 4x = 60, 2n = 6x = 90 and 2n = 12x =180) was detected, and the dodecaploid cytotype is reported for the first time in this genus. As regards cytotype distribution, six populations were diploid, 11 were tetraploid, three were hexaploid and five were dodecaploid. Except for one diploid population containing some triploid plants (2n = 45), the remaining populations showed a single cytotype. Diploids appeared in two disjunct areas (south-east and south-west), and so did tetraploids (although with a considerably wider geographic range). Dehydrated leaf samples provided reliable measurements of DNA content. Genome size varied significantly among some cytotypes, and also extensively within diploid (up to 1.17-fold) and tetraploid (1.22-fold) populations. Nevertheless, variations were not straightforwardly congruent with ecology and geographical distribution. Dianthus broteri shows the highest diversity of cytotypes known to date in the genus Dianthus. Moreover, some cytotypes present remarkable internal genome size variation. The evolution of the complex is discussed in terms of autopolyploidy, with primary and secondary contact zones.

  12. Nutritional status and the influence of TV consumption on female body size ideals in populations recently exposed to the media.

    Science.gov (United States)

    Jucker, Jean-Luc; Thornborrow, Tracey; Beierholm, Ulrik; Burt, D Michael; Barton, Robert A; Evans, Elizabeth H; Jamieson, Mark A; Tovée, Martin J; Boothroyd, Lynda G

    2017-08-16

    Television consumption influences perceptions of attractive female body size. However, cross-cultural research examining media influence on body ideals is typically confounded by differences in the availability of reliable and diverse foodstuffs. 112 participants were recruited from 3 Nicaraguan villages that differed in television consumption and nutritional status, such that the contribution of both factors could be revealed. Participants completed a female figure preference task, reported their television consumption, and responded to several measures assessing nutritional status. Communities with higher television consumption and/or higher nutritional status preferred thinner female bodies than communities with lower television consumption and/or lower nutritional status. Bayesian mixed models estimated the plausible range of effects for television consumption, nutritional status, and other relevant variables on individual preferences. The model explained all meaningful differences between our low-nutrition villages, and television consumption, after sex, was the most likely of these predictors to contribute to variation in preferences (probability mass >95% when modelling only variables with zero-order associations with preferences, but only 90% when modelling all possible predictors). In contrast, we found no likely link with nutritional status. We thus found evidence that where media access and nutritional status are confounded, media is the more likely predictor of body ideals.

  13. A Single IGF1 Allele Is a Major Determinant of Small Size in Dogs

    OpenAIRE

    Sutter, Nathan B.; Bustamante, Carlos D.; Chase, Kevin; Gray, Melissa M.; Zhao, Keyan; Zhu, Lan; Padhukasahasram, Badri; Karlins, Eric; Davis, Sean; Jones, Paul G.; Quignon, Pascale; Johnson, Gary S.; Parker, Heidi G.; Fretwell, Neale; Mosher, Dana S.

    2007-01-01

    The domestic dog exhibits greater diversity in body size than any other terrestrial vertebrate. We used a strategy that exploits the breed structure of dogs to investigate the genetic basis of size. First, through a genome-wide scan, we identified a major quantitative trait locus (QTL) on chromosome 15 influencing size variation within a single breed. Second, we examined genetic variation in the 15-megabase interval surrounding the QTL in small and giant breeds and found marked evidence for a...

  14. Grain-size variations on a longitudinal dune and a barchan dune

    Science.gov (United States)

    Watson, Andrew

    1986-01-01

    The grain-size characteristics of the sand upon two dunes—a 40 m high longitudinal dune in the central Namib Desert and a 6.0 m high barchan in the Jafurah sand sea of Saudi Arabia—vary with position on the dunes. On the longitudinal dune, median grain size decreases, sorting improves and the grain-size distributions are less skewed and more normalized toward the crest. Though sand at the windward toe is distinct, elsewhere on the dune the changes in grain-size characteristics are gradual. An abrupt change in grain size and sorting near the crest—as described by Bagnold (1941, pp. 226-229)—is not well represented on this dune. Coarse grains remain as a lag on concave slope units and small particles are winnowed from the sand on the steepest windward slopes near the crest. Avalanching down slipfaces at the crest acts only as a supplementary grading mechanism. On the barchan dune median grain size also decreases near the crest, but sorting becomes poorer, though the grain-size distributions are more symmetric and more normalized. The dune profile is a Gaussian curve with a broad convex zone at the apex upon which topset beds had accreted prior to sampling. Grain size increases and sorting improves down the dune's slipface. However, this grading mechanism does not influence sand on the whole dune because variations in wind regime bring about different modes of dune accretion. On both dunes, height and morphology appear to influence significantly the grain-size characteristics.

  15. Secular trends of body sizes in Korean children and adolescents: from 1965 to 2010

    Directory of Open Access Journals (Sweden)

    Jin Soo Moon

    2011-11-01

    Full Text Available An anthropometric survey is one of the most important approaches to use when evaluating the health status of children. Secular trends in body sizes, such as height, weight, head circumference, chest circumference, and body mass index showed significant changes over 40 years in Korea. A series of periodic surveys were conducted in 1967, 1975, 1985, 1997, and 2005 by the Korean Pediatric Society and Ministry of Health and Welfare. The quality of data from school health examinations and the Korea National Health and Nutrition Examination Survey has improved, so we can use them now as resources for anthropometric analysis. The final height differences between 1965 and 1997 were 4.5 cm both in boys (168.9 cm in 1965; 173.4 cm in 1997 and girls (155.9 cm in 1965; 160.4 cm in 1997. The differences between 1997 and 2005 were 0.9 cm in boys (174.3cm in 2005 and 0.8 cm in girls (161.2 cm in 2005. There was no difference in final height measurements between 2005 and 2010. An increase in body size at earlier teen ages was pronounced during these decades compared to the previous generation; however, little change has been identified more recently. Body size has been increasing, and obesity has become more prevalent. Systems that gather data should be updated in order to cope with these secular trends. In an upcoming era of secular trends that would be in a slow transition, several surveys that include body measurements should be prepared to meet future needs.

  16. Influence of Compositional Variations on Floc Size and Strength

    Science.gov (United States)

    Yin, H.; Tan, X.; Reed, A. H.; Furukawa, Y.; Zhang, G.

    2010-12-01

    Clay-biopolymer micro aggregates or flocs are abundant in waters, including rivers, lakes, and oceans. Owing to their small size and charged surfaces, fine-grained inorganic sediment particles, mainly clays, interact actively with organic substances, such as organic matter and biogenic polymers, to form aggregates or flocs, typically in the size of 10-1000 μm. The flocs in ocean waters are also termed “marine snow”. These flocs are typically porous, tenuous, and soft in nature. During transport in suspension, they may breakdown and decrease in size if the turbulent shear stress exceeds their strength. They may also collide and form larger ones if the shear stress is relatively small. Since flocs of different size and structure settle at different velocities, understanding their strength is also of essential importance for sediment hydrodynamics, transport, and management. Our study focuses on investigating the influence of compositional variations on floc size and strength so that a better understanding of floc dynamics can be achieved. A laser diffraction-based Cilas® particle size and shape analyzer with controllable fluid circulation velocity was employed to conduct floc size measurements and shape imaging, the latter achieved by a high resolution inverted optical microscope, which is also installed with the size analyzer. Totally two clay minerals, kaolinite and illite, were tested as the model inorganic solid skeleton minerals for floc formation, and two biopolymers, anionic xanthan gum and neutral guar gum, were chosen as analogs of naturally occurring organic matter or biopolymers to simulate clay-biopolymer floc formation. Moreover, the concentration of both organic and inorganic phases was varied. The floc breakage or tensile strength was indirectly estimated by the varied fluid flow velocity in the particle size analyzer’s circulation system. For each individual composition, stable flocs were formed by three different fluid circulating velocities

  17. Geographical variation in larval host-plant use by Heliconius erato (Lepidoptera: Nymphalidae and consequences for adult life history

    Directory of Open Access Journals (Sweden)

    RODRIGUES D.

    2002-01-01

    Full Text Available Adult body size, one of the most important life-history components, varies strongly within and between Heliconius erato phyllis (Lepidoptera: Nymphalidae populations. This study determines if this variation is caused by geographical changes in host-plant used by the larval stage, whose reproductive parameters are influenced by female body size, with estimates of the corresponding heritability. The variation in adult body size was determined together with a survey of passion vine species (Passifloraceae used by the larvae in seven localities in Rio Grande do Sul State: three located in the urban area of Porto Alegre and Triunfo Counties, two within Eucalyptus plantations (Barba Negra Forest, Barra do Ribeiro County, and Águas Belas Experimental Station -- Viamão County, one in a Myrtaceae Forest (Itapuã State Park -- Itapuã County and one in the Atlantic Rain Forest (Maquiné Experimental Station -- Maquiné County. Effects of female body size on fecundity, egg size and egg viability were determined in an outdoor insectary. Size heritability was estimated by rearing in the laboratory offspring of individuals maintained in an insectary. The data showed that adults from populations where larvae feed only upon Passiflora suberosa are smaller than those that feed on Passiflora misera. The larvae prefer P. misera even when the dominant passion vine in a given place is P. suberosa. Fecundity increases linearly with the increase in size of females, but there is no size effect on egg size or viability. Size heritability is null for the adult size range occurring in the field. Thus, the geographical variation of H. erato phyllis adult size is primarily determined by the type, corresponding availability and quality of host-plants used by the larval stage. Within the natural size range of H. erato phyllis, the variation related to this caracter is not genetically based, thus being part of H. erato phyllis phenotypic plasticity.

  18. The influence of tested body size upon longitudinal ultrasonic pulse velocity

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2001-01-01

    Low ultrasonic frequencies are used in nondestructive testing of heterogeneous materials,such as concrete,rocks and timber.When frequencies are low enough,size and shape of tested bodies may influence measured longitudinal pulse velocities(geometric dispersion).A simplified mathematical model is developed from known experimental and theoretical results obtained for elastic wave propagation in rods of uniform circular cross section.Wave propagation is described by a spatial averaged dilatational field in an approach which is named quasi fluid.A formula is obtained which relates group velocity with an effective lateral size of the body,with transducers a frequency,with a non-dimensional parameter and with asymptotic P-wave velocity.In principle it can be applied to bars of any uniform cross section.The limitations of this formula are discussed in relation to path length,threshold of detection,patterns of radiation and reception and other variables.A more general formula is proposed.Practical application of this formula is briefly exemplified using some experimental data obtained by the author.The problem of longitudinal pulse propagation in reinforcing steel bars embedded in concrete is briefly considered

  19. Chromosome Numbers and Genome Size Variation in Indian Species of Curcuma (Zingiberaceae)

    Science.gov (United States)

    Leong-Škorničková, Jana; Šída, Otakar; Jarolímová, Vlasta; Sabu, Mamyil; Fér, Tomáš; Trávníček, Pavel; Suda, Jan

    2007-01-01

    Background and Aims Genome size and chromosome numbers are important cytological characters that significantly influence various organismal traits. However, geographical representation of these data is seriously unbalanced, with tropical and subtropical regions being largely neglected. In the present study, an investigation was made of chromosomal and genome size variation in the majority of Curcuma species from the Indian subcontinent, and an assessment was made of the value of these data for taxonomic purposes. Methods Genome size of 161 homogeneously cultivated plant samples classified into 51 taxonomic entities was determined by propidium iodide flow cytometry. Chromosome numbers were counted in actively growing root tips using conventional rapid squash techniques. Key Results Six different chromosome counts (2n = 22, 42, 63, >70, 77 and 105) were found, the last two representing new generic records. The 2C-values varied from 1·66 pg in C. vamana to 4·76 pg in C. oligantha, representing a 2·87-fold range. Three groups of taxa with significantly different homoploid genome sizes (Cx-values) and distinct geographical distribution were identified. Five species exhibited intraspecific variation in nuclear DNA content, reaching up to 15·1 % in cultivated C. longa. Chromosome counts and genome sizes of three Curcuma-like species (Hitchenia caulina, Kaempferia scaposa and Paracautleya bhatii) corresponded well with typical hexaploid (2n = 6x = 42) Curcuma spp. Conclusions The basic chromosome number in the majority of Indian taxa (belonging to subgenus Curcuma) is x = 7; published counts correspond to 6x, 9x, 11x, 12x and 15x ploidy levels. Only a few species-specific C-values were found, but karyological and/or flow cytometric data may support taxonomic decisions in some species alliances with morphological similarities. Close evolutionary relationships among some cytotypes are suggested based on the similarity in homoploid genome sizes and geographical grouping

  20. Concerted evolution of body mass and cell size: similar patterns among species of birds (Galliformes) and mammals (Rodentia)

    Science.gov (United States)

    Dragosz-Kluska, Dominika; Pis, Tomasz; Pawlik, Katarzyna; Kapustka, Filip; Kilarski, Wincenty M.; Kozłowski, Jan

    2018-01-01

    ABSTRACT Cell size plays a role in body size evolution and environmental adaptations. Addressing these roles, we studied body mass and cell size in Galliformes birds and Rodentia mammals, and collected published data on their genome sizes. In birds, we measured erythrocyte nuclei and basal metabolic rates (BMRs). In birds and mammals, larger species consistently evolved larger cells for five cell types (erythrocytes, enterocytes, chondrocytes, skin epithelial cells, and kidney proximal tubule cells) and evolved smaller hepatocytes. We found no evidence that cell size differences originated through genome size changes. We conclude that the organism-wide coordination of cell size changes might be an evolutionarily conservative characteristic, and the convergent evolutionary body size and cell size changes in Galliformes and Rodentia suggest the adaptive significance of cell size. Recent theory predicts that species evolving larger cells waste less energy on tissue maintenance but have reduced capacities to deliver oxygen to mitochondria and metabolize resources. Indeed, birds with larger size of the abovementioned cell types and smaller hepatocytes have evolved lower mass-specific BMRs. We propose that the inconsistent pattern in hepatocytes derives from the efficient delivery system to hepatocytes, combined with their intense involvement in supracellular function and anabolic activity. PMID:29540429

  1. Concerted evolution of body mass and cell size: similar patterns among species of birds (Galliformes and mammals (Rodentia

    Directory of Open Access Journals (Sweden)

    Marcin Czarnoleski

    2018-04-01

    Full Text Available Cell size plays a role in body size evolution and environmental adaptations. Addressing these roles, we studied body mass and cell size in Galliformes birds and Rodentia mammals, and collected published data on their genome sizes. In birds, we measured erythrocyte nuclei and basal metabolic rates (BMRs. In birds and mammals, larger species consistently evolved larger cells for five cell types (erythrocytes, enterocytes, chondrocytes, skin epithelial cells, and kidney proximal tubule cells and evolved smaller hepatocytes. We found no evidence that cell size differences originated through genome size changes. We conclude that the organism-wide coordination of cell size changes might be an evolutionarily conservative characteristic, and the convergent evolutionary body size and cell size changes in Galliformes and Rodentia suggest the adaptive significance of cell size. Recent theory predicts that species evolving larger cells waste less energy on tissue maintenance but have reduced capacities to deliver oxygen to mitochondria and metabolize resources. Indeed, birds with larger size of the abovementioned cell types and smaller hepatocytes have evolved lower mass-specific BMRs. We propose that the inconsistent pattern in hepatocytes derives from the efficient delivery system to hepatocytes, combined with their intense involvement in supracellular function and anabolic activity.

  2. The influence of body size on adult skeletal age estimation methods.

    Science.gov (United States)

    Merritt, Catherine E

    2015-01-01

    Accurate age estimations are essential to archaeological and forensic analyses. However, reliability for adult skeletal age estimations is poor, especially for individuals over the age of 40 years. This is the first study to show that body size influences skeletal age estimation. The İşcan et al., Lovejoy et al., Buckberry and Chamberlain, and Suchey-Brooks age methods were tested on 764 adult skeletons from the Hamann-Todd and William Bass Collections. Statures ranged from 1.30 to 1.93 m and body masses ranged from 24.0 to 99.8 kg. Transition analysis was used to evaluate the differences in the age estimations. For all four methods, the smallest individuals have the lowest ages at transition and the largest individuals have the highest ages at transition. Short and light individuals are consistently underaged, while tall and heavy individuals are consistently overaged. When femoral length and femoral head diameter are compared with the log-age model, results show the same trend as the known stature and body mass measurements. The skeletal remains of underweight individuals have fewer age markers while those of obese individuals have increased surface degeneration and osteophytic lipping. Tissue type and mechanical loading have been shown to affect bone turnover rates, and may explain the differing patterns of skeletal aging. From an archaeological perspective, the underaging of light, short individuals suggests the need to revisit the current research consensus on the young mortality rates of past populations. From a forensic perspective, understanding the influence of body size will impact efforts to identify victims of mass disasters, genocides, and homicides. © 2014 Wiley Periodicals, Inc.

  3. Vertebral Adaptations to Large Body Size in Theropod Dinosaurs.

    Directory of Open Access Journals (Sweden)

    John P Wilson

    Full Text Available Rugose projections on the anterior and posterior aspects of vertebral neural spines appear throughout Amniota and result from the mineralization of the supraspinous and interspinous ligaments via metaplasia, the process of permanent tissue-type transformation. In mammals, this metaplasia is generally pathological or stress induced, but is a normal part of development in some clades of birds. Such structures, though phylogenetically sporadic, appear throughout the fossil record of non-avian theropod dinosaurs, yet their physiological and adaptive significance has remained unexamined. Here we show novel histologic and phylogenetic evidence that neural spine projections were a physiological response to biomechanical stress in large-bodied theropod species. Metaplastic projections also appear to vary between immature and mature individuals of the same species, with immature animals either lacking them or exhibiting smaller projections, supporting the hypothesis that these structures develop through ontogeny as a result of increasing bending stress subjected to the spinal column. Metaplastic mineralization of spinal ligaments would likely affect the flexibility of the spinal column, increasing passive support for body weight. A stiff spinal column would also provide biomechanical support for the primary hip flexors and, therefore, may have played a role in locomotor efficiency and mobility in large-bodied species. This new association of interspinal ligament metaplasia in Theropoda with large body size contributes additional insight to our understanding of the diverse biomechanical coping mechanisms developed throughout Dinosauria, and stresses the significance of phylogenetic methods when testing for biological trends, evolutionary or not.

  4. Vertebral Adaptations to Large Body Size in Theropod Dinosaurs.

    Science.gov (United States)

    Wilson, John P; Woodruff, D Cary; Gardner, Jacob D; Flora, Holley M; Horner, John R; Organ, Chris L

    2016-01-01

    Rugose projections on the anterior and posterior aspects of vertebral neural spines appear throughout Amniota and result from the mineralization of the supraspinous and interspinous ligaments via metaplasia, the process of permanent tissue-type transformation. In mammals, this metaplasia is generally pathological or stress induced, but is a normal part of development in some clades of birds. Such structures, though phylogenetically sporadic, appear throughout the fossil record of non-avian theropod dinosaurs, yet their physiological and adaptive significance has remained unexamined. Here we show novel histologic and phylogenetic evidence that neural spine projections were a physiological response to biomechanical stress in large-bodied theropod species. Metaplastic projections also appear to vary between immature and mature individuals of the same species, with immature animals either lacking them or exhibiting smaller projections, supporting the hypothesis that these structures develop through ontogeny as a result of increasing bending stress subjected to the spinal column. Metaplastic mineralization of spinal ligaments would likely affect the flexibility of the spinal column, increasing passive support for body weight. A stiff spinal column would also provide biomechanical support for the primary hip flexors and, therefore, may have played a role in locomotor efficiency and mobility in large-bodied species. This new association of interspinal ligament metaplasia in Theropoda with large body size contributes additional insight to our understanding of the diverse biomechanical coping mechanisms developed throughout Dinosauria, and stresses the significance of phylogenetic methods when testing for biological trends, evolutionary or not.

  5. Ultrasonography assessment of renal size and its correlation with body mass index in adults without known renal disease

    International Nuclear Information System (INIS)

    Raza, M.; Hameed, A.; Khan, M.I.

    2012-01-01

    Many conditions affect renal size. To evaluate abnormalities in renal size, knowledge of standardised values for normal renal dimensions is essential as it shows variability in the values of normal renal size depending on body size, age and ethnicity. Ultrasound, being an easily available, non-invasive, safe and less expensive modality, is widely used for evaluation of renal dimensions and repeated follow-ups. The objectives of this study were to determine renal size by ultrasound in adults without any known renal disease, and to determine the relationship of renal size with body mass index. Methods: Study was conducted in the Department of Diagnostic Radiology, Shifa International Hospital and PIMS Islamabad. Renal size was assessed by ultrasound in 4,035 adult subjects with normal serum creatinine and without any known renal disease, between November 2002 and December 2010. Renal length, width, thickness and volume were obtained and mean renal length and volume were correlated with body mass index and other factors like age, side, gender, weight and height of the subjects. Results: Mean renal length on right side was 101.6+-8.9 mm, renal width 42.7+-7.1 mm, and parenchymal thickness 14.4+-2.9 mm. On left side, mean renal length was 102.7+-9.2 mm, width 47.6+-7.0 mm, and parenchymal thickness 15.1+-3.1 mm. Mean renal volume on right was 99.8+-37.2 cm/sup 3/ and on left was 124.4+-41.3 cm/sup 3/. Left renal size was significantly larger than right in both genders. Relationship of mean renal length was significant when correlated with age, side, gender, height and weight, and body mass index. Renal volumes also showed a similar relationship with side, gender, height and weight, and body mass index; but with age such a relationship was seen only for left kidney. Conclusion: Pakistani population has mean renal size smaller than reference values available in international literature. Renal length and volume have a direct relationship with body mass index. Mean renal

  6. Effect of gender and lean body mass on kidney size in healthy 10-year-old children

    DEFF Research Database (Denmark)

    Schmidt, I. M.; Mølgaard, C.; Main, K. M.

    2001-01-01

    predictor of kidney volume was lean body mass, overruling height, weight, and surface area. When total kidney volume was related to lean body mass as a ratio, the gender difference in kidney size was no longer significant. A strong negative correlation was found between fat body mass and kidney volume...

  7. Patient size and x-ray transmission in body CT.

    Science.gov (United States)

    Ogden, Kent; Huda, Walter; Scalzetti, Ernest M; Roskopf, Marsha L

    2004-04-01

    Physical characteristics were obtained for 196 patients undergoing chest and abdomen computed tomography (CT) examinations. Computed tomography sections for these patients having no evident pathology were analyzed to determine patient dimensions (AP and lateral), together with the average attenuation coefficient. Patient weights ranged from approximately 3 kg to about 120 kg. For chest CT, the mean Hounsfield unit (HU) fell from about -120 HU for newborns to about -300 HU for adults. For abdominal CT, the mean HU for children and normal-sized adults was about 20 HU, but decreased to below -50 HU for adults weighing more than 100 kg. The effective photon energy and percent energy fluence transmitted through a given patient size and composition was calculated for representative x-ray spectra at 80, 100, 120, and 140 kV tube potentials. A 70-kg adult scanned at 120 kVp transmits 2.6% of the energy fluence for chest and 0.7% for abdomen CT examinations. Reducing the patient size to 10 kg increases transmission by an order of magnitude. For 70 kg patients, effective energies in body CT range from approximately 50 keV at 80 kVp to approximately 67 keV at 140 kVp; increasing patient size from 10 to 120 kg resulted in an increase in effective photon energy of approximately 4 keV. The x-ray transmission data and effective photon energy data can be used to determine CT image noise and image contrast, respectively, and information on patient size and composition can be used to determine patient doses.

  8. Change in body size and mortality: results from the Melbourne collaborative cohort study.

    Science.gov (United States)

    Karahalios, Amalia; Simpson, Julie A; Baglietto, Laura; MacInnis, Robert J; Hodge, Allison M; Giles, Graham G; English, Dallas R

    2014-01-01

    The association between change in weight or body mass index, and mortality is widely reported, however, both measures fail to account for fat distribution. Change in waist circumference, a measure of central adiposity, in relation to mortality has not been studied extensively. We investigated the association between mortality and changes in directly measured waist circumference, hips circumference and weight from baseline (1990-1994) to wave 2 (2003-2007) in a prospective cohort study of people aged 40-69 years at baseline. Cox regression, with age as the time metric and follow-up starting at wave 2, adjusted for confounding variables, was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for change in body size in relation to mortality from all causes, cardiovascular disease and cancer. There were 1465 deaths (109 cancer, 242 cardiovascular disease) identified during an average 7.7 years of follow-up from 21 298 participants. Compared to minimal increase in body size, loss of waist circumference (HR: 1.26; 95% CI: 1.09-1.47), weight (1.80; 1.54-2.11), or hips circumference (1.35; 1.15-1.57) were associated with an increased risk of all-cause mortality, particularly for older adults. Weight loss was associated with cardiovascular disease mortality (2.40; 1.57-3.65) but change in body size was not associated with obesity-related cancer mortality. This study confirms the association between weight loss and increased mortality from all-causes for older adults. Based on evidence from observational cohort studies, weight stability may be the recommended option for most adults, especially older adults.

  9. Physical capital and the embodied nature of income inequality: gender differences in the effect of body size on workers' incomes in Canada.

    Science.gov (United States)

    Perks, Thomas

    2012-02-01

    This study assesses the effects of body size--measured using the body mass index--on the income attainment of female and male workers in Canada. Using data from a national representative sample of Canadians, multivariate analyses show that, for female workers, the body size-income relationship is negative. However, for male workers, the body size-income relationship is positive and nonlinear. Using Bourdieu's conceptualization of physical capital, and Shilling's extension of it, it is argued that these results are suggestive of the relative importance of body size to the production and continuation of gender income inequality in Canada.

  10. Season, molt, and body size influence mercury concentrations in grebes.

    Science.gov (United States)

    Hartman, C Alex; Ackerman, Joshua T; Herzog, Mark P; Eagles-Smith, Collin A

    2017-10-01

    We studied seasonal and physiological influences on mercury concentrations in western grebes (Aechmophorus occidentalis) and Clark's grebes (A. occidentalis) across 29 lakes and reservoirs in California, USA. Additionally, at three of these lakes, we conducted a time series study, in which we repeatedly sampled grebe blood mercury concentrations during the spring, summer, and early fall. Grebe blood mercury concentrations were higher among males (0.61 ± 0.12 μg/g ww) than females (0.52 ± 0.10 μg/g ww), higher among Clark's grebes (0.58 ± 0.12 μg/g ww) than western grebes (0.51 ± 0.10 μg/g ww), and exhibited a strong seasonal pattern (decreasing by 60% from spring to fall). Grebe blood THg concentrations exhibited a shallow, inverse U-shaped pattern with body size, and was lowest among the smallest and largest grebes. Further, the relationship between grebe blood mercury concentrations and wing primary feather molt exhibited a shallow U-shaped pattern, where mercury concentrations were highest among birds that had not yet begun molting, decreased approximately 24% between pre-molt and late molt, and increased approximately 19% from late molt to post-molt. Because grebes did not begin molting until mid-summer, lower grebe blood mercury concentrations observed in late summer and early fall were consistent with the onset of primary feather molt. However, because sampling date was a much stronger predictor of grebe mercury concentrations than molt, other seasonally changing environmental factors likely played a larger role than molt in the seasonal variation in grebe mercury concentrations. In the time series study, we found that seasonal trends in grebe mercury concentrations were not consistent among lakes, indicating that lake-specific variation in mercury dynamics influence the overall seasonal decline in grebe blood mercury concentrations. These results highlight the importance of accounting for sampling date, as well as ecological processes

  11. From the Cover: Environmental and biotic controls on the evolutionary history of insect body size

    Science.gov (United States)

    Clapham, Matthew E.; Karr, Jered A.

    2012-07-01

    Giant insects, with wingspans as large as 70 cm, ruled the Carboniferous and Permian skies. Gigantism has been linked to hyperoxic conditions because oxygen concentration is a key physiological control on body size, particularly in groups like flying insects that have high metabolic oxygen demands. Here we show, using a dataset of more than 10,500 fossil insect wing lengths, that size tracked atmospheric oxygen concentrations only for the first 150 Myr of insect evolution. The data are best explained by a model relating maximum size to atmospheric environmental oxygen concentration (pO2) until the end of the Jurassic, and then at constant sizes, independent of oxygen fluctuations, during the Cretaceous and, at a smaller size, the Cenozoic. Maximum insect size decreased even as atmospheric pO2 rose in the Early Cretaceous following the evolution and radiation of early birds, particularly as birds acquired adaptations that allowed more agile flight. A further decrease in maximum size during the Cenozoic may relate to the evolution of bats, the Cretaceous mass extinction, or further specialization of flying birds. The decoupling of insect size and atmospheric pO2 coincident with the radiation of birds suggests that biotic interactions, such as predation and competition, superseded oxygen as the most important constraint on maximum body size of the largest insects.

  12. Cryptic lineage diversity, body size divergence, and sympatry in a species complex of Australian lizards (Gehyra).

    Science.gov (United States)

    Moritz, Craig C; Pratt, Renae C; Bank, Sarah; Bourke, Gayleen; Bragg, Jason G; Doughty, Paul; Keogh, J Scott; Laver, Rebecca J; Potter, Sally; Teasdale, Luisa C; Tedeschi, Leonardo G; Oliver, Paul M

    2018-01-01

    Understanding the joint evolutionary and ecological underpinnings of sympatry among close relatives remains a key challenge in biology. This problem can be addressed through joint phylogenomic and phenotypic analysis of complexes of closely related lineages within, and across, species and hence representing the speciation continuum. For a complex of tropical geckos from northern Australia-Gehyra nana and close relatives-we combine mtDNA phylogeography, exon-capture sequencing, and morphological data to resolve independently evolving lineages and infer their divergence history and patterns of morphological evolution. Gehyra nana is found to include nine divergent lineages and is paraphyletic with four other species from the Kimberley region of north-west Australia. Across these 13 taxa, 12 of which are restricted to rocky habitats, several lineages overlap geographically, including on the diverse Kimberley islands. Morphological evolution is dominated by body size shifts, and both body size and shape have evolved gradually across the group. However, larger body size shifts are observed among overlapping taxa than among closely related parapatric lineages of G. nana, and sympatric lineages are more divergent than expected at random. Whether elevated body size differences among sympatric lineages are due to ecological sorting or character displacement remains to be determined. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  13. Body size and hosts of Triatoma infestans populations affect the size of bloodmeal contents and female fecundity in rural northwestern Argentina.

    Science.gov (United States)

    Gürtler, Ricardo E; Fernández, María Del Pilar; Cecere, María Carla; Cohen, Joel E

    2017-12-01

    Human sleeping quarters (domiciles) and chicken coops are key source habitats of Triatoma infestans-the principal vector of the infection that causes Chagas disease-in rural communities in northern Argentina. Here we investigated the links among individual bug bloodmeal contents (BMC, mg), female fecundity, body length (L, mm), host blood sources and habitats. We tested whether L, habitat and host blood conferred relative fitness advantages using generalized linear mixed-effects models and a multimodel inference approach with model averaging. The data analyzed include 769 late-stage triatomines collected in 120 sites from six habitats in 87 houses in Figueroa, Santiago del Estero, during austral spring. L correlated positively with other body-size surrogates and was modified by habitat type, bug stage and recent feeding. Bugs from chicken coops were significantly larger than pig-corral and kitchen bugs. The best-fitting model of log BMC included habitat, a recent feeding, bug stage, log Lc (mean-centered log L) and all two-way interactions including log Lc. Human- and chicken-fed bugs had significantly larger BMC than bugs fed on other hosts whereas goat-fed bugs ranked last, in consistency with average blood-feeding rates. Fecundity was maximal in chicken-fed bugs from chicken coops, submaximal in human- and pig-fed bugs, and minimal in goat-fed bugs. This study is the first to reveal the allometric effects of body-size surrogates on BMC and female fecundity in a large set of triatomine populations occupying multiple habitats, and discloses the links between body size, microsite temperatures and various fitness components that affect the risks of transmission of Trypanosoma cruzi.

  14. Body size and hosts of Triatoma infestans populations affect the size of bloodmeal contents and female fecundity in rural northwestern Argentina.

    Directory of Open Access Journals (Sweden)

    Ricardo E Gürtler

    2017-12-01

    Full Text Available Human sleeping quarters (domiciles and chicken coops are key source habitats of Triatoma infestans-the principal vector of the infection that causes Chagas disease-in rural communities in northern Argentina. Here we investigated the links among individual bug bloodmeal contents (BMC, mg, female fecundity, body length (L, mm, host blood sources and habitats. We tested whether L, habitat and host blood conferred relative fitness advantages using generalized linear mixed-effects models and a multimodel inference approach with model averaging. The data analyzed include 769 late-stage triatomines collected in 120 sites from six habitats in 87 houses in Figueroa, Santiago del Estero, during austral spring. L correlated positively with other body-size surrogates and was modified by habitat type, bug stage and recent feeding. Bugs from chicken coops were significantly larger than pig-corral and kitchen bugs. The best-fitting model of log BMC included habitat, a recent feeding, bug stage, log Lc (mean-centered log L and all two-way interactions including log Lc. Human- and chicken-fed bugs had significantly larger BMC than bugs fed on other hosts whereas goat-fed bugs ranked last, in consistency with average blood-feeding rates. Fecundity was maximal in chicken-fed bugs from chicken coops, submaximal in human- and pig-fed bugs, and minimal in goat-fed bugs. This study is the first to reveal the allometric effects of body-size surrogates on BMC and female fecundity in a large set of triatomine populations occupying multiple habitats, and discloses the links between body size, microsite temperatures and various fitness components that affect the risks of transmission of Trypanosoma cruzi.

  15. Huntingtin gene repeat size variations affect risk of lifetime depression.

    Science.gov (United States)

    Gardiner, Sarah L; van Belzen, Martine J; Boogaard, Merel W; van Roon-Mom, Willeke M C; Rozing, Maarten P; van Hemert, Albert M; Smit, Johannes H; Beekman, Aartjan T F; van Grootheest, Gerard; Schoevers, Robert A; Oude Voshaar, Richard C; Roos, Raymund A C; Comijs, Hannie C; Penninx, Brenda W J H; van der Mast, Roos C; Aziz, N Ahmad

    2017-12-11

    Huntington disease (HD) is a severe neuropsychiatric disorder caused by a cytosine-adenine-guanine (CAG) repeat expansion in the HTT gene. Although HD is frequently complicated by depression, it is still unknown to what extent common HTT CAG repeat size variations in the normal range could affect depression risk in the general population. Using binary logistic regression, we assessed the association between HTT CAG repeat size and depression risk in two well-characterized Dutch cohorts─the Netherlands Study of Depression and Anxiety and the Netherlands Study of Depression in Older Persons─including 2165 depressed and 1058 non-depressed persons. In both cohorts, separately as well as combined, there was a significant non-linear association between the risk of lifetime depression and HTT CAG repeat size in which both relatively short and relatively large alleles were associated with an increased risk of depression (β = -0.292 and β = 0.006 for the linear and the quadratic term, respectively; both P < 0.01 after adjustment for the effects of sex, age, and education level). The odds of lifetime depression were lowest in persons with a HTT CAG repeat size of 21 (odds ratio: 0.71, 95% confidence interval: 0.52 to 0.98) compared to the average odds in the total cohort. In conclusion, lifetime depression risk was higher with both relatively short and relatively large HTT CAG repeat sizes in the normal range. Our study provides important proof-of-principle that repeat polymorphisms can act as hitherto unappreciated but complex genetic modifiers of depression.

  16. Mammalian collection on Noah's Ark: the effects of beauty, brain and body size.

    Directory of Open Access Journals (Sweden)

    Daniel Frynta

    Full Text Available The importance of today's zoological gardens as the so-called "Noah's Ark" grows as the natural habitat of many species quickly diminishes. Their potential to shelter a large amount of individuals from many species gives us the opportunity to reintroduce a species that disappeared in nature. However, the selection of animals to be kept in zoos worldwide is highly selective and depends on human decisions driven by both ecological criteria such as population size or vulnerability and audience-driven criteria such as aesthetic preferences. Thus we focused our study on the most commonly kept and bred animal class, the mammals, and we asked which factors affect various aspects of the mammalian collection of zoos. We analyzed the presence/absence, population size, and frequency per species of each of the 123 mammalian families kept in the worldwide zoo collection. Our aim was to explain these data using the human-perceived attractiveness of mammalian families, their body weight, relative brain size and species richness of the family. In agreement with various previous studies, we found that the body size and the attractiveness of mammals significantly affect all studied components of the mammalian collection of zoos. There is a higher probability of the large and attractive families to be kept. Once kept, these animals are presented in larger numbers in more zoos. On the contrary, the relative mean brain size only affects the primary selection whether to keep the family or not. It does not affect the zoo population size or the number of zoos that keep the family.

  17. Associations between age, body size and nephron number with individual glomerular volumes in urban West African males.

    Science.gov (United States)

    McNamara, Bridgette J; Diouf, Boucar; Hughson, Michael D; Hoy, Wendy E; Bertram, John F

    2009-05-01

    Glomerulomegaly has been associated with an increased risk of renal disease. Few reports have investigated the heterogeneity of glomerular size within kidneys and associated risk factors. This study measured the individual glomerular volume (IGV) of 720 non-sclerotic glomeruli in kidneys of adult West African males, and investigated associations of IGV with age, total glomerular (nephron) number and body surface area (BSA). IGVs were determined in the kidneys of 24 Senegalese males from two age groups (12 subjects aged 20- 30 years and 12 subjects aged 50-70 years). Subjects were randomly chosen at autopsies performed at Le Dantec Hospital in Dakar. Volumes of 30 glomeruli per subject were determined using the disector/Cavalieri stereological method. IGVs ranged from 1.31 x 10(6) microm3 to 12.40 x 10(6) microm3 (a 9.4-fold variation). IGV varied up to 5.3-fold within single kidneys. The trimmed range of IGV within subjects (10th to 90th percentile of IGV) was directly correlated with median glomerular size. The mean and standard deviation (SD) of IGV did not differ significantly between age groups or between subjects with higher (> or =1.78 m2) and lower BSA (IGV was significantly and directly correlated with BSA. Kidneys with less than 1 million nephrons had significantly larger mean IGV than kidneys with more than 1 million nephrons, and the trimmed range of IGVs within subjects was inversely correlated with total glomerular number. There was a considerable variation in IGV within kidneys of Senegalese males at autopsy. The heterogeneity of IGV was increased in association with low nephron number and increased BSA, with more pronounced effects in older subjects.

  18. Professional hazards? The impact of models' body size on advertising effectiveness and women's body-focused anxiety in professions that do and do not emphasize the cultural ideal of thinness.

    Science.gov (United States)

    Dittmar, Helga; Howard, Sarah

    2004-12-01

    Previous experimental research indicates that the use of average-size women models in advertising prevents the well-documented negative effect of thin models on women's body image, while such adverts are perceived as equally effective (Halliwell & Dittmar, 2004). The current study extends this work by: (a) seeking to replicate the finding of no difference in advertising effectiveness between average-size and thin models (b) examining level of ideal-body internalization as an individual, internal factor that moderates women's vulnerability to thin media models, in the context of (c) comparing women in professions that differ radically in their focus on, and promotion of, the sociocultural ideal of thinness for women--employees in fashion advertising (n = 75) and teachers in secondary schools (n = 75). Adverts showing thin, average-size and no models were perceived as equally effective. High internalizers in both groups of women felt worse about their body image after exposure to thin models compared to other images. Profession affected responses to average-size models. Teachers reported significantly less body-focused anxiety after seeing average-size models compared to no models, while there was no difference for fashion advertisers. This suggests that women in professional environments with less focus on appearance-related ideals can experience increased body-esteem when exposed to average-size models, whereas women in appearance-focused professions report no such relief.

  19. The extended Price equation quantifies species selection on mammalian body size across the Palaeocene/Eocene Thermal Maximum.

    Science.gov (United States)

    Rankin, Brian D; Fox, Jeremy W; Barrón-Ortiz, Christian R; Chew, Amy E; Holroyd, Patricia A; Ludtke, Joshua A; Yang, Xingkai; Theodor, Jessica M

    2015-08-07

    Species selection, covariation of species' traits with their net diversification rates, is an important component of macroevolution. Most studies have relied on indirect evidence for its operation and have not quantified its strength relative to other macroevolutionary forces. We use an extension of the Price equation to quantify the mechanisms of body size macroevolution in mammals from the latest Palaeocene and earliest Eocene of the Bighorn and Clarks Fork Basins of Wyoming. Dwarfing of mammalian taxa across the Palaeocene/Eocene Thermal Maximum (PETM), an intense, brief warming event that occurred at approximately 56 Ma, has been suggested to reflect anagenetic change and the immigration of small bodied-mammals, but might also be attributable to species selection. Using previously reconstructed ancestor-descendant relationships, we partitioned change in mean mammalian body size into three distinct mechanisms: species selection operating on resident mammals, anagenetic change within resident mammalian lineages and change due to immigrants. The remarkable decrease in mean body size across the warming event occurred through anagenetic change and immigration. Species selection also was strong across the PETM but, intriguingly, favoured larger-bodied species, implying some unknown mechanism(s) by which warming events affect macroevolution. © 2015 The Author(s).

  20. Human fertility variation, size-related obstetrical performance and the evolution of sexual stature dimorphism

    OpenAIRE

    Guégan, Jean-François; Teriokhin, A.T.; Thomas, F.

    2000-01-01

    In several animal species, change in sexual size dimorphism is a correlated response to selection on fecundity. In humans, different hypotheses have been proposed to explain the variation of sexual dimorphism in stature, but no consensus has yet emerged. In this paper, we evaluate from a theoretical and an empirical point of view the hypothesis that the extent of sexual dimorphism in human populations results from the interaction between fertility and size-related obstetric complications. We ...

  1. Circadian variation of EEG power spectra in NREM and REM sleep in humans: dissociation from body temperature

    Science.gov (United States)

    Dijk, D. J.

    1999-01-01

    In humans, EEG power spectra in REM and NREM sleep, as well as characteristics of sleep spindles such as their duration, amplitude, frequency and incidence, vary with circadian phase. Recently it has been hypothesized that circadian variations in EEG spectra in humans are caused by variations in brain or body temperature and may not represent phenomena relevant to sleep regulatory processes. To test this directly, a further analysis of EEG power spectra - collected in a forced desynchrony protocol in which sleep episodes were scheduled to a 28-h period while the rhythms of body temperature and plasma melatonin were oscillating at their near 24-h period - was carried out. EEG power spectra were computed for NREM and REM sleep occurring between 90-120 and 270-300 degrees of the circadian melatonin rhythm, i.e. just after the clearance of melatonin from plasma in the 'morning' and just after the 'evening' increase in melatonin secretion. Average body temperatures during scheduled sleep at these two circadian phases were identical (36.72 degrees C). Despite identical body temperatures, the power spectra in NREM sleep were very different at these two circadian phases. EEG activity in the low frequency spindle range was significantly and markedly enhanced after the evening increase in plasma melatonin as compared to the morning phase. For REM sleep, significant differences in power spectra during these two circadian phases, in particular in the alpha range, were also observed. The results confirm that EEG power spectra in NREM and REM sleep vary with circadian phase, suggesting that the direct contribution of temperature to the circadian variation in EEG power spectra is absent or only minor, and are at variance with the hypothesis that circadian variations in EEG power spectra are caused by variations in temperature.

  2. German and English Bodies: No Evidence for Cross-Linguistic Differences in Preferred Orthographic Grain Size

    Directory of Open Access Journals (Sweden)

    Xenia Schmalz

    2017-03-01

    Full Text Available Previous studies have found that words and nonwords with many body neighbours (i.e., words with the same orthographic body, e.g., 'cat, brat, at' are read faster than items with fewer body neighbours. This body-N effect has been explored in the context of cross-linguistic differences in reading where it has been reported that the size of the effect differs as a function of orthographic depth: readers of English, a deep orthography, show stronger facilitation than readers of German, a shallow orthography. Such findings support the psycholinguistic grain size theory, which proposes that readers of English rely on large orthographic units to reduce ambiguity of print-to-speech correspondences in their orthography. Here we re-examine the evidence for this pattern and find that there is no reliable evidence for such a cross-linguistic difference. Re-analysis of a key study (Ziegler et al., 2001, analysis of data from the English Lexicon Project (Balota et al., 2007, and a large-scale analysis of nine new experiments all support this conclusion. Using Bayesian analysis techniques, we find little evidence of the body-N effect in most tasks and conditions. Where we do find evidence for a body-N effect (lexical decision for nonwords, we find evidence against an interaction with language.

  3. Monte Carlo modelling of a-Si EPID response: The effect of spectral variations with field size and position

    International Nuclear Information System (INIS)

    Parent, Laure; Seco, Joao; Evans, Phil M.; Fielding, Andrew; Dance, David R.

    2006-01-01

    This study focused on predicting the electronic portal imaging device (EPID) image of intensity modulated radiation treatment (IMRT) fields in the absence of attenuation material in the beam with Monte Carlo methods. As IMRT treatments consist of a series of segments of various sizes that are not always delivered on the central axis, large spectral variations may be observed between the segments. The effect of these spectral variations on the EPID response was studied with fields of various sizes and off-axis positions. A detailed description of the EPID was implemented in a Monte Carlo model. The EPID model was validated by comparing the EPID output factors for field sizes between 1x1 and 26x26 cm 2 at the isocenter. The Monte Carlo simulations agreed with the measurements to within 1.5%. The Monte Carlo model succeeded in predicting the EPID response at the center of the fields of various sizes and offsets to within 1% of the measurements. Large variations (up to 29%) of the EPID response were observed between the various offsets. The EPID response increased with field size and with field offset for most cases. The Monte Carlo model was then used to predict the image of a simple test IMRT field delivered on the beam axis and with an offset. A variation of EPID response up to 28% was found between the on- and off-axis delivery. Finally, two clinical IMRT fields were simulated and compared to the measurements. For all IMRT fields, simulations and measurements agreed within 3%--0.2 cm for 98% of the pixels. The spectral variations were quantified by extracting from the spectra at the center of the fields the total photon yield (Y total ), the photon yield below 1 MeV (Y low ), and the percentage of photons below 1 MeV (P low ). For the studied cases, a correlation was shown between the EPID response variation and Y total , Y low , and P low

  4. Grain-to-grain variations in NbC particle size distributions in an austenitic stainless steel

    International Nuclear Information System (INIS)

    Barlow, C.Y.; Ralph, B.; Silverman, B.; Jones, A.R.

    1979-01-01

    Quantitative information has been obtained concerning the size distributions of NbC precipitate particles in different grains in a deformed and aged austenitic stainless steel specimen. The precipitate size distributions obtained differ from one grain to another. The average disparity measured between the mean precipitate sizes was a function of the distance between the grains compared. The results obtained are considered in terms of differences in precipitation behaviour due to variations in the levels of plastic strain in constituent grains of the deformed specimen. (author)

  5. DNA methylation patterns in cord blood DNA and body size in childhood.

    Directory of Open Access Journals (Sweden)

    Caroline L Relton

    Full Text Available Epigenetic markings acquired in early life may have phenotypic consequences later in development through their role in transcriptional regulation with relevance to the developmental origins of diseases including obesity. The goal of this study was to investigate whether DNA methylation levels at birth are associated with body size later in childhood.A study design involving two birth cohorts was used to conduct transcription profiling followed by DNA methylation analysis in peripheral blood. Gene expression analysis was undertaken in 24 individuals whose biological samples and clinical data were collected at a mean ± standard deviation (SD age of 12.35 (0.95 years, the upper and lower tertiles of body mass index (BMI were compared with a mean (SD BMI difference of 9.86 (2.37 kg/m(2. This generated a panel of differentially expressed genes for DNA methylation analysis which was then undertaken in cord blood DNA in 178 individuals with body composition data prospectively collected at a mean (SD age of 9.83 (0.23 years. Twenty-nine differentially expressed genes (>1.2-fold and p<10(-4 were analysed to determine DNA methylation levels at 1-3 sites per gene. Five genes were unmethylated and DNA methylation in the remaining 24 genes was analysed using linear regression with bootstrapping. Methylation in 9 of the 24 (37.5% genes studied was associated with at least one index of body composition (BMI, fat mass, lean mass, height at age 9 years, although only one of these associations remained after correction for multiple testing (ALPL with height, p(Corrected = 0.017.DNA methylation patterns in cord blood show some association with altered gene expression, body size and composition in childhood. The observed relationship is correlative and despite suggestion of a mechanistic epigenetic link between in utero life and later phenotype, further investigation is required to establish causality.

  6. Effect of directional selection for body size on fluctuating asymmetry in certain morphological traits in Drosophila ananassae.

    Science.gov (United States)

    Vishalakshi, C; Singh, B N

    2009-06-01

    Variation in the subtle differences between the right and left sides of bilateral characters or fluctuating asymmetry (FA) has been considered as an indicator of an organism's ability to cope with genetic and environmental stresses during development. However, due to inconsistency in the results of empirical studies, the relationship between FA and stress has been the subject of intense debate. In this study, we investigated whether stress caused by artificial bidirectional selection for body size has any effect on the levels of FA of different morphological traits in Drosophila ananassae. The realised heritability (h2) was higher in low-line females and high-line males, which suggests an asymmetrical response to selection for body size. Further, the levels of FA were compared across 10 generations of selection in different selection lines in both sexes for sternopleural bristle number, wing length, wing-to-thorax ratio, sex combtooth number and ovariole number. The levels of FA differed significantly among generations and selection lines but did not change markedly with directional selection. However, the levels of FA were higher in the G10 generation (at the end of selection) than G0 (at the start of selection) but lower than the G5 generation in different selection lines, suggesting that the levels of FA are not affected by the inbreeding generated during the course of selection. Also, the levels of FA in the hybrids of high and low lines were signifi cantly lower than the parental selection lines, suggesting that FA is influenced by hybridisation. These results are discussed in the framework of the literature available on FA and its relationship with stress.

  7. Seasonal and particle size-dependent variations in gas/particle partitioning of PCDD/Fs

    International Nuclear Information System (INIS)

    Lee, Se-Jin; Ale, Debaki; Chang, Yoon-Seok; Oh, Jeong-Eun; Shin, Sun Kyoung

    2008-01-01

    This study monitored particle size-dependent variations in atmospheric polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Two gas/particle partitioning models, the subcooled liquid vapor pressure (P L 0 ) and the octanol-air partition coefficient (K OA ) model, were applied to each particle sizes. The regression coefficients of each fraction against the gas/particle partition coefficient (K P ) were similar for separated particles within the same sample set but differed for particles collected during different periods. Gas/particle partitioning calculated from the integral of fractions was similar to that of size-segregated particles and previously measured bulk values. Despite the different behaviors and production mechanisms of atmospheric particles of different sizes, PCDD/F partitioning of each size range was controlled by meteorological conditions such as atmospheric temperature, O 3 and UV, which reflects no source related with certain particle size ranges but mixed urban sources within this city. Our observations emphasize that when assessing environmental and health effects, the movement of PCDD/Fs in air should be considered in conjunction with particle size in addition to the bulk aerosol. - Gas/particle partitioning of atmospheric PCDD/Fs for different particle sizes reflects the impacts of emitters of different size ranges

  8. Egg incubation effects generate positive correlations between size, speed and learning ability in young lizards.

    Science.gov (United States)

    Amiel, Joshua Johnstone; Lindström, Tom; Shine, Richard

    2014-03-01

    Previous studies have suggested that body size and locomotor performance are targets of Darwinian selection in reptiles. However, much of the variation in these traits may derive from phenotypically plastic responses to incubation temperature, rather than from underlying genetic variation. Intriguingly, incubation temperature may also influence cognitive traits such as learning ability. Therefore, we might expect correlations between a reptile's size, locomotor speed and learning ability either due to selection on all of these traits or due to environmental effects during egg incubation. In the present study, we incubated lizard eggs (Scincidae: Bassiana duperreyi) under 'hot' and 'cold' thermal regimes and then assessed differences in hatchling body size, running speed and learning ability. We measured learning ability using a Y-maze and a food reward. We found high correlations between size, speed and learning ability, using two different metrics to quantify learning (time to solution, and directness of route), and showed that environmental effects (incubation temperature) cause these correlations. If widespread, such correlations challenge any simple interpretation of fitness advantages due to body size or speed within a population; for example, survivors may be larger and faster than nonsurvivors because of differences in learning ability, not because of their size or speed.

  9. Body size, blood feeding activity, and fecundity of Psorophora howardii, Psorophora ciliata, and Psorophora ferox (Diptera: Culicidae).

    Science.gov (United States)

    Zhu, Lin; Fulcher, Ali; Hossain, Tanjim; Davidson, Claudia; Beier, John C; Xue, Rui-De

    2014-03-01

    Field-collected female Psorophora howardii (Coquillett), Psorophora ciliate (F.), and Psorophora ferox (Humboltd) mosquitoes were tested in laboratory conditions to measure body size, blood engorgement duration, bloodmeal size, fecundity, and egg morphology. Mean bloodmeal size was significantly different among the three species of mosquitoes, whereas there was no difference in blood engorgement duration. Mean body weights and wing lengths of Ps. howardii and Ps. ciliata were significantly greater than Ps.ferox. Seven days after bloodmeals, oviposition rates for Ps. howardii, Ps. ciliata, and Ps.ferox were 18.8, 56.2, and 0%, respectively. The mean number of total eggs produced per female for the three species was 59, 81, and 73, respectively. Mean egg lengths of Ps. howardii and Ps. ciliata were significantly greater than Ps.ferox, and egg diameters for each of the three species were significantly different from one another. Length per diameter ratios of Ps. howardii and Ps. ciliata were significantly smaller than Ps. ferox. Bloodmeal size was positively related to body weight, but not related to blood engorgement duration, and the total egg number was positively related to bloodmeal size.

  10. Seasonal body size reductions with warming covary with major body size gradients in arthropod species

    DEFF Research Database (Denmark)

    Horne, Curtis R.; Hirst, Andrew G.; Atkinson, David

    2017-01-01

    experience different developmental conditions. Yet, unlike other size patterns, these common seasonal temperature–size gradients have never been collectively analysed. We undertake the largest analysis to date of seasonal temperature-size gradients in multivoltine arthropods, including 102 aquatic...... and terrestrial species from 71 global locations. Adult size declines in warmer seasons in 86% of the species examined. Aquatic species show approximately 2.5-fold greater reduction in size per °C of warming than terrestrial species, supporting the hypothesis that greater oxygen limitation in water than in air...

  11. Genome size variation and incidence of polyploidy in Scrophulariaceae sensu lato from the Iberian Peninsula.

    Science.gov (United States)

    Castro, Mariana; Castro, Sílvia; Loureiro, João

    2012-01-01

    In the last decade, genomic studies using DNA markers have strongly influenced the current phylogeny of angiosperms. Genome size and ploidy level have contributed to this discussion, being considered important characters in biosystematics, ecology and population biology. Despite the recent increase in studies related to genome size evolution and polyploidy incidence, only a few are available for Scrophulariaceae. In this context, we assessed the value of genome size, mostly as a taxonomic marker, and the role of polyploidy as a process of genesis and maintenance of plant diversity in Scrophulariaceae sensu lato in the Iberian Peninsula. Large-scale analyses of genome size and ploidy-level variation across the Iberian Peninsula were performed using flow cytometry. One hundred and sixty-two populations of 59 distinct taxa were analysed. A bibliographic review on chromosome counts was also performed. From the 59 sampled taxa, 51 represent first estimates of genome size. The majority of the Scrophulariaceae species presented very small to small genome sizes (2C ≤ 7.0 pg). Furthermore, in most of the analysed genera it was possible to use this character to separate several taxa, independently if these genera were homoploid or heteroploid. Also, some genome-related phenomena were detected, such as intraspecific variation of genome size in some genera and the possible occurrence of dysploidy in Verbascum spp. With respect to polyploidy, despite a few new DNA ploidy levels having been detected in Veronica, no multiple cytotypes have been found in any taxa. This work contributed with important basic scientific knowledge on genome size and polyploid incidence in the Scrophulariaceae, providing important background information for subsequent studies, with several perspectives for future studies being opened.

  12. Examining predator–prey body size, trophic level and body mass across marine and terrestrial mammals

    Science.gov (United States)

    Tucker, Marlee A.; Rogers, Tracey L.

    2014-01-01

    Predator–prey relationships and trophic levels are indicators of community structure, and are important for monitoring ecosystem changes. Mammals colonized the marine environment on seven separate occasions, which resulted in differences in species' physiology, morphology and behaviour. It is likely that these changes have had a major effect upon predator–prey relationships and trophic position; however, the effect of environment is yet to be clarified. We compiled a dataset, based on the literature, to explore the relationship between body mass, trophic level and predator–prey ratio across terrestrial (n = 51) and marine (n = 56) mammals. We did not find the expected positive relationship between trophic level and body mass, but we did find that marine carnivores sit 1.3 trophic levels higher than terrestrial carnivores. Also, marine mammals are largely carnivorous and have significantly larger predator–prey ratios compared with their terrestrial counterparts. We propose that primary productivity, and its availability, is important for mammalian trophic structure and body size. Also, energy flow and community structure in the marine environment are influenced by differences in energy efficiency and increased food web stability. Enhancing our knowledge of feeding ecology in mammals has the potential to provide insights into the structure and functioning of marine and terrestrial communities. PMID:25377460

  13. The thermal environment of the nest affects body and cell size in the solitary red mason bee (Osmia bicornis L.).

    Science.gov (United States)

    Kierat, Justyna; Szentgyörgyi, Hajnalka; Czarnoleski, Marcin; Woyciechowski, Michał

    2017-08-01

    Many ectotherms grow larger at lower temperatures than at higher temperatures. This pattern, known as the temperature-size rule, is often accompanied by plastic changes in cell size, which can mechanistically explain the thermal dependence of body size. However, the theory predicts that thermal plasticity in cell size has adaptive value for ectotherms because there are different optimal cell-membrane-to-cell-volume ratios at different temperatures. At high temperatures, the demand for oxygen is high; therefore, a large membrane surface of small cells is beneficial because it allows high rates of oxygen transport into the cell. The metabolic costs of maintaining membranes become more important at low temperatures than at high temperatures, which favours large cells. In a field experiment, we manipulated the thermal conditions inside nests of the red mason bee, a solitary bee that does not regulate the temperature in its nests and whose larvae develop under ambient conditions. We assessed the effect of temperature on body mass and ommatidia size (our proxy of cell size). The body and cell sizes decreased in response to a higher mean temperature and greater temperature fluctuations. This finding is in accordance with predictions of the temperature-size rule and optimal cell size theory and suggests that both the mean temperature and the magnitude of temperature fluctuations are important for determining body and cell sizes. Additionally, we observed that males of the red mason bee tend to have larger ommatidia in relation to their body mass than females, which might play an important role during mating flight. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Schwinger variational principle in the nuclear two-body problem and multichannel theory

    International Nuclear Information System (INIS)

    Zubarev, A.L.; Podkopaev, A.P.

    1978-01-01

    The aim of the investigation is to study the Schwinger variational principle in the nuclear two-body problem and the multichannel theory. An approach is proposed to problems of the potential scattering based on the substitution of the exact potential operator V by the finite rank operator Vsup((n)) with which the dynamic equations are solved exactly. The functionals obtained for observed values coincide with corresponding expressions derived by the Schwinger variational principle with the set of test functions. The determination of the Schwinger variational principle is given. The method is given for finding amplitude of the double-particle scattering with the potential Vsup((n)). The corresponding amplitudes are constructed within the framework of the multichannel potential model. Interpolation formula for determining amplitude, which describes with high accuracy a process of elastic scattering for any energies, is obtained. On the basis of the above method high-energy amplitude may be obtained within the range of small and large scattering angles

  15. In Depth Characterization of Repetitive DNA in 23 Plant Genomes Reveals Sources of Genome Size Variation in the Legume Tribe Fabeae.

    Science.gov (United States)

    Macas, Jiří; Novák, Petr; Pellicer, Jaume; Čížková, Jana; Koblížková, Andrea; Neumann, Pavel; Fuková, Iva; Doležel, Jaroslav; Kelly, Laura J; Leitch, Ilia J

    2015-01-01

    The differential accumulation and elimination of repetitive DNA are key drivers of genome size variation in flowering plants, yet there have been few studies which have analysed how different types of repeats in related species contribute to genome size evolution within a phylogenetic context. This question is addressed here by conducting large-scale comparative analysis of repeats in 23 species from four genera of the monophyletic legume tribe Fabeae, representing a 7.6-fold variation in genome size. Phylogenetic analysis and genome size reconstruction revealed that this diversity arose from genome size expansions and contractions in different lineages during the evolution of Fabeae. Employing a combination of low-pass genome sequencing with novel bioinformatic approaches resulted in identification and quantification of repeats making up 55-83% of the investigated genomes. In turn, this enabled an analysis of how each major repeat type contributed to the genome size variation encountered. Differential accumulation of repetitive DNA was found to account for 85% of the genome size differences between the species, and most (57%) of this variation was found to be driven by a single lineage of Ty3/gypsy LTR-retrotransposons, the Ogre elements. Although the amounts of several other lineages of LTR-retrotransposons and the total amount of satellite DNA were also positively correlated with genome size, their contributions to genome size variation were much smaller (up to 6%). Repeat analysis within a phylogenetic framework also revealed profound differences in the extent of sequence conservation between different repeat types across Fabeae. In addition to these findings, the study has provided a proof of concept for the approach combining recent developments in sequencing and bioinformatics to perform comparative analyses of repetitive DNAs in a large number of non-model species without the need to assemble their genomes.

  16. In Depth Characterization of Repetitive DNA in 23 Plant Genomes Reveals Sources of Genome Size Variation in the Legume Tribe Fabeae.

    Directory of Open Access Journals (Sweden)

    Jiří Macas

    Full Text Available The differential accumulation and elimination of repetitive DNA are key drivers of genome size variation in flowering plants, yet there have been few studies which have analysed how different types of repeats in related species contribute to genome size evolution within a phylogenetic context. This question is addressed here by conducting large-scale comparative analysis of repeats in 23 species from four genera of the monophyletic legume tribe Fabeae, representing a 7.6-fold variation in genome size. Phylogenetic analysis and genome size reconstruction revealed that this diversity arose from genome size expansions and contractions in different lineages during the evolution of Fabeae. Employing a combination of low-pass genome sequencing with novel bioinformatic approaches resulted in identification and quantification of repeats making up 55-83% of the investigated genomes. In turn, this enabled an analysis of how each major repeat type contributed to the genome size variation encountered. Differential accumulation of repetitive DNA was found to account for 85% of the genome size differences between the species, and most (57% of this variation was found to be driven by a single lineage of Ty3/gypsy LTR-retrotransposons, the Ogre elements. Although the amounts of several other lineages of LTR-retrotransposons and the total amount of satellite DNA were also positively correlated with genome size, their contributions to genome size variation were much smaller (up to 6%. Repeat analysis within a phylogenetic framework also revealed profound differences in the extent of sequence conservation between different repeat types across Fabeae. In addition to these findings, the study has provided a proof of concept for the approach combining recent developments in sequencing and bioinformatics to perform comparative analyses of repetitive DNAs in a large number of non-model species without the need to assemble their genomes.

  17. Variation in salmonid life histories: patterns and perspectives.

    Science.gov (United States)

    Mary F. Willson

    1997-01-01

    Salmonid fishes differ in degree of anadromy, age of maturation, frequency of reproduction, body size and fecundity, sexual dimorphism, breeding season, morphology, and, to a lesser degree, parental care. Patterns of variation and their possible significance for ecology and evolution and for resource management are the focus of this review.

  18. Body size distributions of the pale grass blue butterfly in Japan: Size rules and the status of the Fukushima population

    Science.gov (United States)

    Taira, Wataru; Iwasaki, Mayo; Otaki, Joji M.

    2015-01-01

    The body size of the pale grass blue butterfly, Zizeeria maha, has been used as an environmental indicator of radioactive pollution caused by the Fukushima nuclear accident. However, geographical and temporal size distributions in Japan and temperature effects on size have not been established in this species. Here, we examined the geographical, temporal, and temperature-dependent changes of the forewing size of Z. maha argia in Japan. Butterflies collected in 2012 and 2013 from multiple prefectures throughout Japan demonstrated an inverse relationship of latitude and forewing size, which is the reverse of Bergmann’s cline. The Fukushima population was significantly larger than the Aomori and Miyagi populations and exhibited no difference from most of the other prefectural populations. When monitored at a single geographic locality every other month, forewing sizes were the largest in April and the smallest in August. Rearing larvae at a constant temperature demonstrated that forewing size followed the temperature-size rule. Therefore, the converse Bergmann’s rule and the temperature-size rule coexist in this multivoltine species. Our study establishes this species as a useful environmental indicator and supports the idea that the size reduction observed only in Fukushima Prefecture in 2011 was caused by the environmental stress of radioactive pollution. PMID:26197998

  19. Ideal Body Size as a Mediator for the Gender-Specific Association between Socioeconomic Status and Body Mass Index: Evidence from an Upper-Middle-Income Country in the African Region

    Science.gov (United States)

    Yepes, Maryam; Maurer, Jürgen; Stringhini, Silvia; Viswanathan, Barathi; Gedeon, Jude; Bovet, Pascal

    2016-01-01

    Background: While obesity continues to rise globally, the associations between body size, gender, and socioeconomic status (SES) seem to vary in different populations, and little is known on the contribution of perceived ideal body size in the social disparity of obesity in African countries. Purpose: We examined the gender and socioeconomic…

  20. Distribution coefficients for Pb+2 and Cr+6 with variation in soil particle size

    International Nuclear Information System (INIS)

    Singhal, R.K.; Preetha, J.; Gurg, R.P.

    2003-01-01

    Simulated experiments were conducted in the laboratory to evaluate the impact of soil particle size on the distribution coefficient (K d ) for soil - water system for Pb as Pb +2 and Cr as Cr +6 . The variation in particle size leads to variation in mineralogical and organic carbon (OC) contents which in turn lead to variation in cation exchange capacity (CEC). The conditions were kept as close to that of the natural environment during the spiking of the soil. The spiked soil is fractionated in seven different fractions between 500 - 355 μm and 105 - > 75 μm contains relatively higher percentage of OC than the other fractions. The CEC of different fractions of the soil is determined by ammonium acetate method. Higher CEC was observed for particle in the range of 105 - > 75 μm. The analysis of Pb and Cr was carried out using Atomic Absorption Spectrometer after the complete destruction f the soil matrix. Among the various fractions, the K d values are higher for 75μm for Pb +2 and Cr +6 and their ranges are 4.3-9.6 x 10 5 ml/gm and 2.1-24.8 x 10 6 ml/gm, respectively. (author)

  1. Impact of Glucose Tolerance Status, Sex, and Body Size on Glucose Absorption Patterns During OGTTs

    DEFF Research Database (Denmark)

    Faerch, K.; Pacini, G.; Nolan, J. J.

    2013-01-01

    OBJECTIVEWe studied whether patterns of glucose absorption during oral glucose tolerance tests (OGTTs) were abnormal in individuals with impaired glucose regulation and whether they were related to sex and body size (height and fat-free mass). We also examined how well differences in insulin......, reflected the differences for these parameters between those with normal and impaired glucose regulation as measured by gold-standard tests.CONCLUSIONSGlucose absorption patterns during an OGTT are significantly related to plasma glucose levels and body size, which should be taken into account when.......RESULTSMore rapid glucose absorption (P 0.036) and reduced late glucose absorption (P 0.039) were observed in the i-IFG group relative to NGT and i-IGT groups. Women with i-IGT had a lower early glucose absorption than did men with i-IGT (P = 0.041); however, this difference did not persist when differences in body...

  2. Effect of litter size on the variation in birth and weaning weights of Landrace piglets

    Directory of Open Access Journals (Sweden)

    Camila Duarte Prazeres

    2016-03-01

    Full Text Available The objective of this study was to evaluate the effect of the size class of the litter at birth on the variation in birth and weaning weights and on the survival rate of piglets from birth to weaning. For this purpose, records of individual weight at birth and weaning of piglets obtained from a database of 295 Landrace litters born between 2000 and 2010 on a pig farm in the western region of the State of Paraná were used. The litters were classified as small (up to 7 piglets, medium (8 to 13 piglets, and large (> 14 piglets according to the total number of piglets born. The data were analyzed considering the effects of the year of sow mating and size class of the litter at birth. The correlations between mean weight and variance in litter weight and size were higher for medium and large litters. The size class of the litter significantly influenced the mean weight of piglets at birth and weaning and the variance in birth weight. Piglets born in medium and large litters weighed less and exhibited greater birth weight variation and a lower survival rate until weaning than piglets born in small litters.

  3. Multi-decadal variation in size of juvenile Summer Flounder (Paralichthys dentatus) in Chesapeake Bay

    Science.gov (United States)

    Nys, Lauren N.; Fabrizio, Mary C.; Tuckey, Troy D.

    2016-01-01

    During the last quarter-century, management of Summer Flounder Paralichthys dentatus along the Atlantic coast resulted in significant increases in abundance such that rebuilding targets were recently achieved. Although spawning stock biomass is high, recruitment of young-of-the-year (YOY) Summer Flounder remains variable. Chesapeake Bay is one of the principal nursery areas for this species, but processes such as growth and survival that affect production of YOY Summer Flounder in this estuary have not been explored. Here, we investigated the relationship between abundance and size of Summer Flounder recruits from the 1988 to 2012 year classes in Chesapeake Bay. We also considered the effects of environmental factors on fish size because conditions in the bay vary spatially during the time that fish occupy nursery areas. To describe variations in Summer Flounder size, we used monthly length observations from 13,018 YOY fish captured by bottom trawl from the lower Chesapeake Bay and the James, York, and Rappahannock river subestuaries where Summer Flounder are commonly observed. We applied a generalized additive model to describe spatial, temporal, and environmental effects on observed fish size; we also considered the density of Summer Flounder and an index of productivity as factors in the model. Summer Flounder in Chesapeake Bay exhibited density-dependent and spatially related variations in mean length: larger fish were found mostly in the Bay and smaller fish in the subestuaries. Additionally, low ( 26 °C) temperatures and low salinities (indicating that individuals found in these environments were typically smaller than conspecifics inhabiting areas of moderate temperatures and higher salinities. Variable nursery habitat conditions in temperate estuaries affect fish size and, subsequently, may influence production of Summer Flounder year classes through effects on maturation and survival. As water temperatures in the mid-Atlantic region continue to increase

  4. Body Image and Body Type Preferences in St. Kitts, Caribbean: A Cross-Cultural Comparison with U.S. Samples regarding Attitudes towards Muscularity, Body Fat, and Breast Size

    Directory of Open Access Journals (Sweden)

    Peter B. Gray

    2012-07-01

    Full Text Available We investigated body image in St. Kitts, a Caribbean island where tourism, international media, and relatively high levels of body fat are common. Participants were men and women recruited from St. Kitts (n = 39 and, for comparison, U.S. samples from universities (n = 618 and the Internet (n = 438. Participants were shown computer generated images varying in apparent body fat level and muscularity or breast size and they indicated their body type preferences and attitudes. Overall, there were only modest differences in body type preferences between St. Kitts and the Internet sample, with the St. Kitts participants being somewhat more likely to value heavier women. Notably, however, men and women from St. Kitts were more likely to idealize smaller breasts than participants in the U.S. samples. Attitudes regarding muscularity were generally similar across samples. This study provides one of the few investigations of body preferences in the Caribbean.

  5. SU-D-BRE-03: Dosimetric Impact of In-Air Spot Size Variations for Commissioning a Room-Matched Beam Model for Pencil Beam Scanning Proton Therapy

    International Nuclear Information System (INIS)

    Zhang, Y; Giebeler, A; Mascia, A; Piskulich, F; Perles, L; Lepage, R; Dong, L

    2014-01-01

    Purpose: To quantitatively evaluate dosimetric consequence of spot size variations and validate beam-matching criteria for commissioning a pencil beam model for multiple treatment rooms. Methods: A planning study was first conducted by simulating spot size variations to systematically evaluate dosimetric impact of spot size variations in selected cases, which was used to establish the in-air spot size tolerance for beam matching specifications. A beam model in treatment planning system was created using in-air spot profiles acquired in one treatment room. These spot profiles were also acquired from another treatment room for assessing the actual spot size variations between the two treatment rooms. We created twenty five test plans with targets of different sizes at different depths, and performed dose measurement along the entrance, proximal and distal target regions. The absolute doses at those locations were measured using ionization chambers at both treatment rooms, and were compared against the calculated doses by the beam model. Fifteen additional patient plans were also measured and included in our validation. Results: The beam model is relatively insensitive to spot size variations. With an average of less than 15% measured in-air spot size variations between two treatment rooms, the average dose difference was −0.15% with a standard deviation of 0.40% for 55 measurement points within target region; but the differences increased to 1.4%±1.1% in the entrance regions, which are more affected by in-air spot size variations. Overall, our single-room based beam model in the treatment planning system agreed with measurements in both rooms < 0.5% within the target region. For fifteen patient cases, the agreement was within 1%. Conclusion: We have demonstrated that dosimetrically equivalent machines can be established when in-air spot size variations are within 15% between the two treatment rooms

  6. Time budgets of Snow Geese Chen caerulescens and Ross's Geese Chen rossii in mixed flocks: Implications of body size, ambient temperature and family associations

    Science.gov (United States)

    Jonsson, J.E.; Afton, A.D.

    2009-01-01

    Body size affects foraging and forage intake rates directly via energetic processes and indirectly through interactions with social status and social behaviour. Ambient temperature has a relatively greater effect on the energetics of smaller species, which also generally are more vulnerable to predator attacks than are larger species. We examined variability in an index of intake rates and an index of alertness in Lesser Snow Geese Chen caerulescens caerulescens and Ross's Geese Chen rossii wintering in southwest Louisiana. Specifically we examined variation in these response variables that could be attributed to species, age, family size and ambient temperature. We hypothesized that the smaller Ross's Geese would spend relatively more time feeding, exhibit relatively higher peck rates, spend more time alert or raise their heads up from feeding more frequently, and would respond to declining temperatures by increasing their proportion of time spent feeding. As predicted, we found that Ross's Geese spent more time feeding than did Snow Geese and had slightly higher peck rates than Snow Geese in one of two winters. Ross's Geese spent more time alert than did Snow Geese in one winter, but alert rates differed by family size, independent of species, in contrast to our prediction. In one winter, time spent foraging and walking was inversely related to average daily temperature, but both varied independently of species. Effects of age and family size on time budgets were generally independent of species and in accordance with previous studies. We conclude that body size is a key variable influencing time spent feeding in Ross's Geese, which may require a high time spent feeding at the expense of other activities. ?? 2008 The Authors.

  7. Geographical variation and sexual differences of body length and age composition in Rana temporaria: the ontogenetic development and phenotypic trends

    Directory of Open Access Journals (Sweden)

    Lyapkov Sergey

    2012-06-01

    Full Text Available The analysis of literature data on the mean values of age and body length of adult individuals of widespread species Rana temporaria from about 70 spatially separated populations, including our published data, was conducted. The evident trend in population mean age increase with the decrease of the of activity season length was revealed as well as the absence of that trend in the mean body length, with the maximal mean value in body length being near central part of the range. Our explanation of non-linear trend in the mean values of body length does not contradict other models of geographic variability explaining the correspondence and discrepance with the Bergman rule. In addition our explanation corresponds to the revealed features of interpopulation variation in growth rate. The revealed trend of variation in the mean body length is resulted from both growth rate decrease and mean age increase with the decrease in the length of activity season. The relatively low mean values of body length in populations from south and southern-west borders of the range are explained not only by low mean age but by lower growth rate despite high length of activity season. The interpopulation variation in body length is determined not only by body length but by age composition differences both between and within population. Therefore, the direction and intensity of sexual differences have not distinct trends, and the correspondence to Rensch rule (in contrast to Bergman rule is rarely observed.

  8. Body size distribution in ground beetles (Coleoptera: Carabidae) as a possible monitoring method of environmental impacts of transgenic maize

    DEFF Research Database (Denmark)

    Grumo, Davide di; Lövei, Gabor L.

    2015-01-01

    Despite the obligatory post-market environmental monitoring of genetically modified (GM) crops in Europe, there are no available standards on methods. Our aim was to examine the suitability of using changes in carabid body size distribution as a possible monitoring method. The sampling was carried...... informative Lorenz asymmetry coefficients. A total of 6339 carabids belonging to 38 species were captured and indentified. The analysis detected a shift in size distribution between months but no important differences in the assemblages in Bt vs. non-Bt maize plots were found. We concluded that an increasing...... body size trend from spring to autumn was evident, and the use of a multilevel analysis was important to correctly interpret the body size distribution. Therefore, the proposed methods are indeed sensitive to subtle changes in the structure of the carabid assemblages, and they have the potential...

  9. The art of being small : brain-body size scaling in minute parasitic wasps

    NARCIS (Netherlands)

    Woude, van der Emma

    2017-01-01

    Haller’s rule states that small animals have relatively larger brains than large animals. This brain-body size relationship may enable small animals to maintain similar levels of brain performance as large animals. However, it also causes small animals to spend an exceptionally large proportion

  10. Examining predator-prey body size, trophic level and body mass across marine and terrestrial mammals.

    Science.gov (United States)

    Tucker, Marlee A; Rogers, Tracey L

    2014-12-22

    Predator-prey relationships and trophic levels are indicators of community structure, and are important for monitoring ecosystem changes. Mammals colonized the marine environment on seven separate occasions, which resulted in differences in species' physiology, morphology and behaviour. It is likely that these changes have had a major effect upon predator-prey relationships and trophic position; however, the effect of environment is yet to be clarified. We compiled a dataset, based on the literature, to explore the relationship between body mass, trophic level and predator-prey ratio across terrestrial (n = 51) and marine (n = 56) mammals. We did not find the expected positive relationship between trophic level and body mass, but we did find that marine carnivores sit 1.3 trophic levels higher than terrestrial carnivores. Also, marine mammals are largely carnivorous and have significantly larger predator-prey ratios compared with their terrestrial counterparts. We propose that primary productivity, and its availability, is important for mammalian trophic structure and body size. Also, energy flow and community structure in the marine environment are influenced by differences in energy efficiency and increased food web stability. Enhancing our knowledge of feeding ecology in mammals has the potential to provide insights into the structure and functioning of marine and terrestrial communities. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  11. Lower limits of ornithischian dinosaur body size inferred from a new Upper Jurassic heterodontosaurid from North America

    Science.gov (United States)

    Butler, Richard J.; Galton, Peter M.; Porro, Laura B.; Chiappe, Luis M.; Henderson, Donald M.; Erickson, Gregory M.

    2010-01-01

    The extremes of dinosaur body size have long fascinated scientists. The smallest (dinosaurs are carnivorous saurischian theropods, and similarly diminutive herbivorous or omnivorous ornithischians (the other major group of dinosaurs) are unknown. We report a new ornithischian dinosaur, Fruitadens haagarorum, from the Late Jurassic of western North America that rivals the smallest theropods in size. The largest specimens of Fruitadens represent young adults in their fifth year of development and are estimated at just 65–75 cm in total body length and 0.5–0.75 kg body mass. They are thus the smallest known ornithischians. Fruitadens is a late-surviving member of the basal dinosaur clade Heterodontosauridae, and is the first member of this clade to be described from North America. The craniodental anatomy and diminutive body size of Fruitadens suggest that this taxon was an ecological generalist with an omnivorous diet, thus providing new insights into morphological and palaeoecological diversity within Dinosauria. Late-surviving (Late Jurassic and Early Cretaceous) heterodontosaurids are smaller and less ecologically specialized than Early (Late Triassic and Early Jurassic) heterodontosaurids, and this ecological generalization may account in part for the remarkable 100-million-year-long longevity of the clade. PMID:19846460

  12. Birth mass is the key to understanding the negative correlation between lifespan and body size in dogs.

    Science.gov (United States)

    Fan, Rong; Olbricht, Gayla; Baker, Xavior; Hou, Chen

    2016-12-08

    Larger dog breeds live shorter than the smaller ones, opposite of the mass-lifespan relationship observed across mammalian species. Here we use data from 90 dog breeds and a theoretical model based on the first principles of energy conservation and life history tradeoffs to explain the negative correlation between longevity and body size in dogs. We found that the birth/adult mass ratio of dogs scales negatively with adult size, which is different than the weak interspecific scaling in mammals. Using the model, we show that this ratio, as an index of energy required for growth, is the key to understanding why the lifespan of dogs scales negatively with body size. The model also predicts that the difference in mass-specific lifetime metabolic energy usage between dog breeds is proportional to the difference in birth/adult mass ratio. Empirical data on lifespan, body mass, and metabolic scaling law of dogs strongly supports this prediction.

  13. Tensor-optimized antisymmetrized molecular dynamics as a successive variational method in nuclear many-body system

    Energy Technology Data Exchange (ETDEWEB)

    Myo, Takayuki, E-mail: takayuki.myo@oit.ac.jp [General Education, Faculty of Engineering, Osaka Institute of Technology, Osaka 535-8585 (Japan); Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki 567-0047 (Japan); Toki, Hiroshi [Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki 567-0047 (Japan); Ikeda, Kiyomi [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Horiuchi, Hisashi [Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki 567-0047 (Japan); Suhara, Tadahiro [Matsue College of Technology, Matsue 690-8518 (Japan)

    2017-06-10

    We study the tensor-optimized antisymmetrized molecular dynamics (TOAMD) as a successive variational method in many-body systems with strong interaction for nuclei. In TOAMD, the correlation functions for the tensor force and the short-range repulsion and their multiples are operated to the AMD state as the variational wave function. The total wave function is expressed as the sum of all the components and the variational space can be increased successively with the multiple correlation functions to achieve convergence. All the necessary matrix elements of many-body operators, consisting of the multiple correlation functions and the Hamiltonian, are expressed analytically using the Gaussian integral formula. In this paper we show the results of TOAMD with up to the double products of the correlation functions for the s-shell nuclei, {sup 3}H and {sup 4}He, using the nucleon–nucleon interaction AV8′. It is found that the energies and Hamiltonian components of two nuclei converge rapidly with respect to the multiple of correlation functions. This result indicates the efficiency of TOAMD for the power series expansion in terms of the tensor and short-range correlation functions.

  14. Clinical correlation of radiological spinal stenosis after standardization for vertebral body size

    International Nuclear Information System (INIS)

    Athiviraham, A.; Yen, D.; Scott, C.; Soboleski, D.

    2007-01-01

    Aim: To determine the relationship between the degree of radiographic lumbar spinal stenosis, adjusted with an internal control for vertebral body size, and disability from lumbar stenosis. Materials and methods: one hundred and twenty-three consecutive patients with clinical and radiological confirmation of neural impingement secondary to lumbar stenosis were enrolled prospectively. Thecal sac anteroposterior (AP) diameter (TSD) and cross-sectional area (CSA), and vertebral body AP dimension (VBD) were determined. These parameters were then correlated with patients' symptoms using the modified Roland-Morris questionnaire (RMQ) disability score. Results: No statistically significant inverse correlation was found between the TSD and RMQ score (p = 0.433), between the CSA and RMQ score (p = 0.124), or between the TSD:VBD ratio and RMQ score (p = 0.109). There was a significant positive correlation between the CSA:VBD ratio and RMQ score (p = .036), and therefore, there was no statistical support for an inverse relationship between the two. There was a significant difference in mean RMQ scores when the patients were divided into those with CSA greater than or equal to 70 mm 2 and those less than 70 mm 2 , with T = -2.104 and p = 0.038. Conclusion: The degree of radiographic lumbar spinal stenosis, even with the use of an internal control of vertebral body size and standardized disability questionnaires, does not correlate with clinical symptoms. However, patients with more severe stenosis below a CSA critical threshold of 70 mm 2 , have significantly greater functional disability

  15. Body size and the rate of spread of invasive ladybird beetles in North America

    Czech Academy of Sciences Publication Activity Database

    Hemptinne, J. L.; Magro, A.; Evans, E.W.; Dixon, Anthony F. G.

    2012-01-01

    Roč. 14, č. 3 (2012), s. 595-605 ISSN 1387-3547 Institutional support: RVO:67179843 Keywords : Invasiveness * Body size * Reproductive rate * Coccinella septempunctata * Harmonia axyridis Subject RIV: EH - Ecology , Behaviour Impact factor: 2.509, year: 2012

  16. A critical evaluation of the insect body size model and causes of metamorphosis in solitary bees

    Science.gov (United States)

    The insect body size model posits that adult size is determined by growth rate and the duration of growth during the larval stage of development. Within the model, growth rate is regulated by many mechanistic elements that are influenced by both internal and external factors. However, the duration o...

  17. New successive variational method of tensor-optimized antisymmetrized molecular dynamics for nuclear many-body systems

    Science.gov (United States)

    Myo, Takayuki; Toki, Hiroshi; Ikeda, Kiyomi; Horiuchi, Hisashi; Suhara, Tadahiro

    2017-07-01

    We recently proposed a new variational theory of “tensor-optimized antisymmetrized molecular dynamics” (TOAMD), which treats the strong interaction explicitly for finite nuclei [T. Myo et al., Prog. Theor. Exp. Phys. 2015, 073D02 (2015)]. In TOAMD, the correlation functions for the tensor force and the short-range repulsion and their multiple products are successively operated to the AMD state. The correlated Hamiltonian is expanded into many-body operators by using the cluster expansion and all the resulting operators are taken into account in the calculation without any truncation. We show detailed results for TOAMD with the nucleon-nucleon interaction AV8‧ for s-shell nuclei. The binding energy and the Hamiltonian components are successively converged to exact values of the few-body calculations. We also apply TOAMD to the Malfliet-Tjon central potential having a strong short-range repulsion. TOAMD can treat the short-range correlation and provided accurate energies of s-shell nuclei, reproducing the results of few-body calculations. It turns out that the numerical accuracy of TOAMD with double products of the correlation functions is beyond the variational Monte Carlo method with Jastrow's product-type correlation functions.

  18. A six decades long follow-up on body size in adolescents from Zagreb, Croatia (1951-2010).

    Science.gov (United States)

    Zajc Petranović, Matea; Tomas, Željka; Smolej Narančić, Nina; Škarić-Jurić, Tatjana; Veček, Andrea; Miličić, Jasna

    2014-03-01

    Most studies analysing the influence of socioeconomic deterioration on body size focus on the impact of food shortages and diseases on the growth in early childhood. To evaluate how socioeconomic conditions influence the growth during the adolescence, we tracked the body size of 15-19 year-olds over the last sixty years covering the socialist period (1951-1990), the war (1991-1995) and the transition to capitalistic economy. This study of Zagreb, Croatia, adolescent population provides information on the secular trend in height, weight and Body Mass Index (BMI) and examines their relation with Real Gross Domestic Product. From 1951 to 2010 the girls' height approximately increased by 6.2cm and weight by 6.8kg, while the boys' height increased by 12.2cm and weight by 17.3kg. Prior to 1991 mean BMI in girls was higher than in boys, but from 1991 on, the interrelation between the sexes has been opposite, possibly mirroring the cultural trends that started in mid-1970s and reflecting higher sensitivity of boys to the socioeconomic changes. In conclusion, the secular trend in body size over the investigated period reflects the positive economic trends interrupted by the war. The recent increase in BMI corresponds to the country's economic recovery and indicates the "nutrition transition". Copyright © 2013 Elsevier B.V. All rights reserved.

  19. The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study

    NARCIS (Netherlands)

    T.W. Winkler (Thomas W.); A.E. Justice (Anne); M.J. Graff (Maud J.L.); Barata, L. (Llilda); M.F. Feitosa (Mary Furlan); Chu, S. (Su); J. Czajkowski (Jacek); T. Esko (Tõnu); M. Fall (Magnus); T.O. Kilpeläinen (Tuomas); Y. Lu (Yingchang); R. Mägi (Reedik); E. Mihailov (Evelin); T.H. Pers (Tune); Rüeger, S. (Sina); A. Teumer (Alexander); G.B. Ehret (Georg); T. Ferreira (Teresa); N.L. Heard-Costa (Nancy); J. Karjalainen (Juha); V. Lagou (Vasiliki); A. Mahajan (Anubha); Neinast, M.D. (Michael D.); I. Prokopenko (Inga); J. Simino (Jeannette); T.M. Teslovich (Tanya M.); R. Jansen; H.J. Westra (Harm-Jan); C.C. White (Charles); D. Absher (Devin); T.S. Ahluwalia (Tarunveer Singh); S. Ahmad (Shafqat); E. Albrecht (Eva); A.C. Alves (Alexessander Couto); Bragg-Gresham, J.L. (Jennifer L.); A.J. de Craen (Anton); J.C. Bis (Joshua); A. Bonnefond (Amélie); G. Boucher (Gabrielle); G. Cadby (Gemma); Y.-C. Cheng (Yu-Ching); Chiang, C.W. (Charleston W K); G. Delgado; A. Demirkan (Ayşe); N. Dueker (Nicole); N. Eklund (Niina); G. Eiriksdottir (Gudny); J. Eriksson (Joel); B. Feenstra (Bjarke); K. Fischer (Krista); F. Frau (Francesca); T.E. Galesloot (Tessel); F. Geller (Frank); A. Goel (Anuj); M. Gorski (Mathias); T.B. Grammer (Tanja); S. Gustafsson (Stefan); Haitjema, S. (Saskia); J.J. Hottenga (Jouke Jan); J.E. Huffman (Jennifer); A.U. Jackson (Anne); K.B. Jacobs (Kevin); A. Johansson (Åsa); M. Kaakinen (Marika); M.E. Kleber (Marcus); J. Lahti (Jari); I.M. Leach (Irene Mateo); Lehne, B. (Benjamin); Liu, Y. (Youfang); K.S. Lo; M. Lorentzon (Mattias); J. Luan (Jian'An); P.A. Madden (Pamela); M. Mangino (Massimo); B. McKnight (Barbara); Medina-Gomez, C. (Carolina); K.L. Monda (Keri); M.E. Montasser (May E.); G. Müller (Gabriele); M. Müller-Nurasyid (Martina); I.M. Nolte (Ilja); Panoutsopoulou, K. (Kalliope); L. Pascoe (Laura); L. Paternoster (Lavinia); N.W. Rayner (Nigel William); F. Renström (Frida); Rizzi, F. (Federica); L.M. Rose (Lynda); Ryan, K.A. (Kathy A.); P. Salo (Perttu); S. Sanna (Serena); H. Scharnagl (Hubert); Shi, J. (Jianxin); A.V. Smith (Albert Vernon); L. Southam (Lorraine); A. Stancáková (Alena); V. Steinthorsdottir (Valgerdur); R.J. Strawbridge (Rona); Sung, Y.J. (Yun Ju); I. Tachmazidou (Ioanna); T. Tanaka (Toshiko); G. Thorleifsson (Gudmar); S. Trompet (Stella); N. Pervjakova (Natalia); J.P. Tyrer (Jonathan); L. Vandenput (Liesbeth); S.W. Van Der Laan (Sander W.); N. van der Velde (Nathalie); J. van Setten (Jessica); J.V. van Vliet-Ostaptchouk (Jana); N. Verweij (Niek); E. Vlachopoulou (Efthymia); L. Waite (Lindsay); S.R. Wang (Sophie); Z. Wang (Zhaoming); S.H. Wild (Sarah); C. Willenborg (Christina); J.F. Wilson (James); A. Wong (Andrew); Yang, J. (Jian); L. Yengo (Loic); L.M. Yerges-Armstrong (Laura); Yu, L. (Lei); W. Zhang (Weihua); Zhao, J.H. (Jing Hua); E.A. Andersson (Ehm Astrid); S.J.L. Bakker (Stephan); D. Baldassarre (Damiano); Banasik, K. (Karina); Barcella, M. (Matteo); Barlassina, C. (Cristina); C. Bellis (Claire); P. Benaglio (Paola); J. Blangero (John); M. Blüher (Matthias); Bonnet, F. (Fabrice); L.L. Bonnycastle (Lori); H.A. Boyd (Heather); M. Bruinenberg (M.); Buchman, A.S. (Aron S.); H. Campbell (Harry); Y.D. Chen (Y.); P.S. Chines (Peter); S. Claudi-Boehm (Simone); J.W. Cole (John W.); F.S. Collins (Francis); E.J.C. de Geus (Eco); L.C.P.G.M. de Groot (Lisette); M. Dimitriou (Maria); J. Duan (Jubao); S. Enroth (Stefan); E. Eury (Elodie); A.-E. Farmaki (Aliki-Eleni); N.G. Forouhi (Nita); N. Friedrich (Nele); P.V. Gejman (Pablo); B. Gigante (Bruna); N. Glorioso (Nicola); A. Go (Attie); R.F. Gottesman (Rebecca); J. Gräßler (Jürgen); H. Grallert (Harald); N. Grarup (Niels); Gu, Y.-M. (Yu-Mei); L. Broer (Linda); A.C. Ham (Annelies); T. Hansen (T.); T.B. Harris (Tamara); C.A. Hartman (Catharina A.); Hassinen, M. (Maija); N. Hastie (Nick); A.T. Hattersley (Andrew); A.C. Heath (Andrew); A.K. Henders (Anjali); D.G. Hernandez (Dena); H.L. Hillege (Hans); O.L. Holmen (Oddgeir); G.K. Hovingh (Kees); J. Hui (Jennie); Husemoen, L.L. (Lise L.); Hutri-Kähönen, N. (Nina); P.G. Hysi (Pirro); T. Illig (Thomas); P.L. de Jager (Philip); S. Jalilzadeh (Shapour); T. Jorgensen (Torben); J.W. Jukema (Jan Wouter); Juonala, M. (Markus); S. Kanoni (Stavroula); M. Karaleftheri (Maria); K.T. Khaw; L. Kinnunen (Leena); T. Kittner (Thomas); W. Koenig (Wolfgang); I. Kolcic (Ivana); P. Kovacs (Peter); Krarup, N.T. (Nikolaj T.); W. Kratzer (Wolfgang); Krüger, J. (Janine); Kuh, D. (Diana); M. Kumari (Meena); T. Kyriakou (Theodosios); C. Langenberg (Claudia); L. Lannfelt (Lars); C. Lanzani (Chiara); V. Lotay (Vaneet); L.J. Launer (Lenore); K. Leander (Karin); J. Lindström (Jaana); A. Linneberg (Allan); Liu, Y.-P. (Yan-Ping); S. Lobbens (Stéphane); R.N. Luben (Robert); V. Lyssenko (Valeriya); S. Männistö (Satu); P.K. Magnusson (Patrik); W.L. McArdle (Wendy); C. Menni (Cristina); S. Merger (Sigrun); L. Milani (Lili); Montgomery, G.W. (Grant W.); A.P. Morris (Andrew); N. Narisu (Narisu); M. Nelis (Mari); K.K. Ong (Ken); A. Palotie (Aarno); L. Perusse (Louis); I. Pichler (Irene); M.G. Pilia (Maria Grazia); A. Pouta (Anneli); Rheinberger, M. (Myriam); Ribel-Madsen, R. (Rasmus); Richards, M. (Marcus); K.M. Rice (Kenneth); T.K. Rice (Treva K.); C. Rivolta (Carlo); V. Salomaa (Veikko); A.R. Sanders (Alan); M.A. Sarzynski (Mark A.); S. Scholtens (Salome); R.A. Scott (Robert); W.R. Scott (William R.); S. Sebert (Sylvain); S. Sengupta (Sebanti); B. Sennblad (Bengt); T. Seufferlein (Thomas); A. Silveira (Angela); P.E. Slagboom (Eline); J.H. Smit (Jan); T. Sparsø (Thomas); K. Stirrups (Kathy); R.P. Stolk (Ronald); H.M. Stringham (Heather); Swertz, M.A. (Morris A.); A.J. Swift (Amy); A.C. Syvänen; S.-T. Tan (Sian-Tsung); B. Thorand (Barbara); A. Tönjes (Anke); Tremblay, A. (Angelo); E. Tsafantakis (Emmanouil); P.J. van der Most (Peter); U. Völker (Uwe); M.-C. Vohl (Marie-Claude); J.M. Vonk (Judith); M. Waldenberger (Melanie); Walker, R.W. (Ryan W.); R. Wennauer (Roman); E. Widen; G.A.H.M. Willemsen (Gonneke); T. Wilsgaard (Tom); A.F. Wright (Alan); M.C. Zillikens (Carola); S. Van Dijk (Suzanne); N.M. van Schoor (Natasja); F.W. Asselbergs (Folkert); P.I.W. de Bakker (Paul); J.S. Beckmann (Jacques); J.P. Beilby (John); D.A. Bennett (David A.); R.N. Bergman (Richard); S.M. Bergmann (Sven); C.A. Böger (Carsten); B.O. Boehm (Bernhard); E.A. Boerwinkle (Eric); D.I. Boomsma (Dorret); S.R. Bornstein (Stefan); E.P. Bottinger (Erwin); C. Bouchard (Claude); J.C. Chambers (John); S.J. Chanock (Stephen); D.I. Chasman (Daniel); F. Cucca (Francesco); D. Cusi (Daniele); G.V. Dedoussis (George); J. Erdmann (Jeanette); K. Hagen (Knut); D. Evans; U. de Faire (Ulf); M. Farrall (Martin); L. Ferrucci (Luigi); I. Ford (Ian); L. Franke (Lude); P.W. Franks (Paul); P. Froguel (Philippe); R.T. Gansevoort (Ron); C. Gieger (Christian); H. Grönberg (Henrik); V. Gudnason (Vilmundur); U. Gyllensten (Ulf); P. Hall (Per); A. Hamsten (Anders); P. van der Harst (Pim); C. Hayward (Caroline); M. Heliovaara (Markku); C. Hengstenberg (Christian); A.A. Hicks (Andrew); A. Hingorani (Aroon); A. Hofman (Albert); Hu, F. (Frank); H.V. Huikuri (Heikki); K. Hveem (Kristian); A. James (Alan); Jordan, J.M. (Joanne M.); A. Jula (Antti); M. Kähönen (Mika); E. Kajantie (Eero); S. Kathiresan (Sekar); L.A.L.M. Kiemeney (Bart); M. Kivimaki (Mika); P. Knekt; H. Koistinen (Heikki); J.S. Kooner (Jaspal S.); S. Koskinen (Seppo); J. Kuusisto (Johanna); W. Maerz (Winfried); N.G. Martin (Nicholas); M. Laakso (Markku); T.A. Lakka (Timo); T. Lehtimäki (Terho); G. Lettre (Guillaume); D.F. Levinson (Douglas); W.H.L. Kao (Wen); M.L. Lokki; Mäntyselkä, P. (Pekka); M. Melbye (Mads); A. Metspalu (Andres); B.D. Mitchell (Braxton); F.L. Moll (Frans); J.C. Murray (Jeffrey); A.W. Musk (Arthur); M.S. Nieminen (Markku); I. Njølstad (Inger); C. Ohlsson (Claes); A.J. Oldehinkel (Albertine); B.A. Oostra (Ben); C. Palmer (Cameron); J.S. Pankow (James); G. Pasterkamp (Gerard); N.L. Pedersen (Nancy); O. Pedersen (Oluf); B.W.J.H. Penninx (Brenda); M. Perola (Markus); A. Peters (Annette); O. Polasek (Ozren); P.P. Pramstaller (Peter Paul); Psaty, B.M. (Bruce M.); Qi, L. (Lu); T. Quertermous (Thomas); Raitakari, O.T. (Olli T.); T. Rankinen (Tuomo); R. Rauramaa (Rainer); P.M. Ridker (Paul); J.D. Rioux (John); F. Rivadeneira Ramirez (Fernando); J.I. Rotter (Jerome I.); I. Rudan (Igor); H.M. den Ruijter (Hester ); J. Saltevo (Juha); N. Sattar (Naveed); Schunkert, H. (Heribert); P.E.H. Schwarz (Peter); A.R. Shuldiner (Alan); J. Sinisalo (Juha); H. Snieder (Harold); T.I.A. Sørensen (Thorkild); T.D. Spector (Timothy); Staessen, J.A. (Jan A.); Stefania, B. (Bandinelli); U. Thorsteinsdottir (Unnur); M. Stumvoll (Michael); J.-C. Tardif (Jean-Claude); E. Tremoli (Elena); J. Tuomilehto (Jaakko); A.G. Uitterlinden (André); M. Uusitupa (Matti); A.L.M. Verbeek; S.H.H.M. Vermeulen (Sita); J. Viikari (Jorma); Vitart, V. (Veronique); H. Völzke (Henry); P. Vollenweider (Peter); G. Waeber (Gérard); M. Walker (Mark); H. Wallaschofski (Henri); N.J. Wareham (Nick); H. Watkins (Hugh); E. Zeggini (Eleftheria); A. Chakravarti (Aravinda); Clegg, D.J. (Deborah J.); L.A. Cupples (Adrienne); P. Gordon-Larsen (Penny); C.E. Jaquish (Cashell); D.C. Rao (Dabeeru C.); Abecasis, G.R. (Goncalo R.); T.L. Assimes (Themistocles); I.E. Barroso (Inês); S.I. Berndt (Sonja); M. Boehnke (Michael); P. Deloukas (Panagiotis); C.S. Fox (Caroline); L. Groop (Leif); D. Hunter (David); E. Ingelsson (Erik); R.C. Kaplan (Robert); McCarthy, M.I. (Mark I.); K.L. Mohlke (Karen); J.R. O´Connell; Schlessinger, D. (David); D.P. Strachan (David); J-A. Zwart (John-Anker); C.M. van Duijn (Cornelia); J.N. Hirschhorn (Joel); C.M. Lindgren (Cecilia M.); I.M. Heid (Iris); K.E. North (Kari); I.B. Borecki (Ingrid); Z. Kutalik (Zoltán); R.J.F. Loos (Ruth)

    2015-01-01

    textabstractGenome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ

  20. Genome size evolution at the speciation level: the cryptic species complex Brachionus plicatilis (Rotifera).

    Science.gov (United States)

    Stelzer, Claus-Peter; Riss, Simone; Stadler, Peter

    2011-04-07

    Studies on genome size variation in animals are rarely done at lower taxonomic levels, e.g., slightly above/below the species level. Yet, such variation might provide important clues on the tempo and mode of genome size evolution. In this study we used the flow-cytometry method to study the evolution of genome size in the rotifer Brachionus plicatilis, a cryptic species complex consisting of at least 14 closely related species. We found an unexpectedly high variation in this species complex, with genome sizes ranging approximately seven-fold (haploid '1C' genome sizes: 0.056-0.416 pg). Most of this variation (67%) could be ascribed to the major clades of the species complex, i.e. clades that are well separated according to most species definitions. However, we also found substantial variation (32%) at lower taxonomic levels--within and among genealogical species--and, interestingly, among species pairs that are not completely reproductively isolated. In one genealogical species, called B. 'Austria', we found greatly enlarged genome sizes that could roughly be approximated as multiples of the genomes of its closest relatives, which suggests that whole-genome duplications have occurred early during separation of this lineage. Overall, genome size was significantly correlated to egg size and body size, even though the latter became non-significant after controlling for phylogenetic non-independence. Our study suggests that substantial genome size variation can build up early during speciation, potentially even among isolated populations. An alternative, but not mutually exclusive interpretation might be that reproductive isolation tends to build up unusually slow in this species complex.

  1. Size, rarity and charisma: valuing African wildlife trophies.

    Directory of Open Access Journals (Sweden)

    Paul J Johnson

    Full Text Available We explore variation in the prices paid by recreational hunters of trophy animals in Africa and its possible causes, including perceived rarity. Previous work has raised the possibility that extinction can result if demand rises fast enough as a species becomes rarer. We attempt to disentangle this from other inter-correlated influences affecting price. Species with larger body sizes and larger trophies were more valuable. Value increased less steeply as a function of size for bovids than for felids and the effect was consistent across countries. Power laws, ubiquitous in physical and social systems, described the trends. The exponent was approximately 0.4 for bovids, compared with approximately 1.0 for felids. Rarity (as indexed by IUCN score influenced the value of bovid trophies - price was higher for species in categories denoting higher global threat. There was substantial variation in price among and within families not explained by either size or rarity. This may be attributable to a 'charisma' effect, which seems likely to be a general attribute of human perceptions of wildlife. Species where prices were higher than predicted by size or rarity are ranked high in published accounts of desirability by hunters. We conclude that the valuation of these species is explicable to a large extent by body size and perceived rarity, and that differences in valuation between taxonomic groups are related to less easily quantified 'charisma' effects. These findings are relevant for conservationists considering the threat status of species exploited in open access markets, and where license quotas are adjusted in response to changes in perceived rarity.

  2. Reproductive success in a natural population of male three-spined stickleback Gasterosteus aculeatus: effects of nuptial colour, parasites and body size.

    Science.gov (United States)

    Sparkes, T C; Rush, V; Kopp, D A; Foster, S A

    2013-05-01

    The effects of nuptial colour, parasites and body size on reproductive success were examined in a natural population of three-spined stickleback Gasterosteus aculeatus. Reproductive males were collected, with the contents of their nests, during the embryo-guarding stage from Lynne Lake (Cook Inlet, Alaska, U.S.A.), and nuptial colour, infection status and body size were recorded. Regression analysis revealed that male body size was the only predictor, of those measured, of reproductive success in nature. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

  3. BODY SIZE AND HAREM SIZE IN MALE RED-WINGED BLACKBIRDS: MANIPULATING SELECTION WITH SEX-SPECIFIC FEEDERS.

    Science.gov (United States)

    Rohwer, Sievert; Langston, Nancy; Gori, Dave

    1996-10-01

    We experimentally manipulated the strength of selection in the field on red-winged blackbirds (Agelaius phoeniceus) to test hypotheses about contrasting selective forces that favor either large or small males in sexually size dimorphic birds. Selander (1972) argued that sexual selection favors larger males, while survival selection eventually stabilizes male size because larger males do not survive as well as smaller males during harsh winters. Searcy (1979a) proposed instead that sexual selection may be self limiting: male size might be stabilized not by overwinter mortality, but by breeding-season sexual selection that favors smaller males. Under conditions of energetic stress, smaller males should be able to display more and thus achieve higher reproductive success. Using feeders that provisioned males or females but not both, we produced conditions that mimicked the extremes of natural conditions. We found experimental support for the hypothesis that when food is abundant, sexual selection favors larger males. But even under conditions of severe energetic stress, smaller males did not gain larger harems, as the self-limiting hypothesis predicted. Larger males were more energetically stressed than smaller males, but in ways that affected their future reproductive output rather than their current reproductive performance. Stressed males that returned had smaller wings and tails than those that did not return; among returning stressed males, relative harem sizes were inversely related to wing and tail length. Thus, male body size may be stabilized not by survival costs during the non-breeding season, nor by energetic costs during the breeding season, but by costs of future reproduction that larger males pay for their increased breeding-season effort. © 1996 The Society for the Study of Evolution.

  4. Anemia and Iron Status Among Different Body Size Phenotypes in Chinese Adult Population: a Nation-Wide, Health and Nutrition Survey.

    Science.gov (United States)

    Li, Jiang; Xiao, Cheng; Yang, Hui; Zhou, Yun; Wang, Rui; Cao, Yongtong

    2017-12-09

    Previous studies have shown that there is a controversial relationship between iron homeostasis and obesity. This study aims to explore the relationship of anemia and iron status with different body size phenotypes in adult Chinese population. Using information on iron status-related parameters and lifestyle data from 8462 participants of the 2009 wave of China Health and Nutrition Survey (2009 CHNS), we performed multivariable logistic regression analyses to estimate the odds ratios (ORs) for the risk of anemia and iron parameters according to different body size phenotypes. Participants with higher body mass index (BMI) had a lower anemia prevalence with significant trends in both metabolic status groups (P different metabolic status groups and in different body size phenotypes, respectively. The ORs for higher ferritin and transferrin increased across different body size phenotypes in both genders, and for sTfR/log ferritin index decreased (P < 0.01 for trend). This association was still statistically significant after adjustment for multiple confounders. We found an inverse association of BMI levels with the prevalence of anemia and strong association of serum ferritin and transferrin with higher risk of obesity or overweight in both metabolic status groups.

  5. Association between body size and blood pressure in children from different ethnic origins

    NARCIS (Netherlands)

    LA de Hoog, Marieke; van Eijsden, Manon; Stronks, Karien; Gemke, Reinoud J. B. J.; Vrijkotte, Tanja G. M.

    2012-01-01

    Objective: To assess associations between body size and blood pressure in children (5-6 years) from different ethnic origins. Method: Five ethnic groups of the ABCD cohort were examined: Dutch (n=1 923), Turkish (n=99), Moroccan (n=187), Black-African (n=67) and Black-Caribbean (n=121). Data on

  6. Variation in clutch size in relation to nest size in birds.

    Science.gov (United States)

    Møller, Anders P; Adriaensen, Frank; Artemyev, Alexandr; Bańbura, Jerzy; Barba, Emilio; Biard, Clotilde; Blondel, Jacques; Bouslama, Zihad; Bouvier, Jean-Charles; Camprodon, Jordi; Cecere, Francesco; Charmantier, Anne; Charter, Motti; Cichoń, Mariusz; Cusimano, Camillo; Czeszczewik, Dorota; Demeyrier, Virginie; Doligez, Blandine; Doutrelant, Claire; Dubiec, Anna; Eens, Marcel; Eeva, Tapio; Faivre, Bruno; Ferns, Peter N; Forsman, Jukka T; García-Del-Rey, Eduardo; Goldshtein, Aya; Goodenough, Anne E; Gosler, Andrew G; Góźdź, Iga; Grégoire, Arnaud; Gustafsson, Lars; Hartley, Ian R; Heeb, Philipp; Hinsley, Shelley A; Isenmann, Paul; Jacob, Staffan; Järvinen, Antero; Juškaitis, Rimvydas; Korpimäki, Erkki; Krams, Indrikis; Laaksonen, Toni; Leclercq, Bernard; Lehikoinen, Esa; Loukola, Olli; Lundberg, Arne; Mainwaring, Mark C; Mänd, Raivo; Massa, Bruno; Mazgajski, Tomasz D; Merino, Santiago; Mitrus, Cezary; Mönkkönen, Mikko; Morales-Fernaz, Judith; Morin, Xavier; Nager, Ruedi G; Nilsson, Jan-Åke; Nilsson, Sven G; Norte, Ana C; Orell, Markku; Perret, Philippe; Pimentel, Carla S; Pinxten, Rianne; Priedniece, Ilze; Quidoz, Marie-Claude; Remeš, Vladimir; Richner, Heinz; Robles, Hugo; Rytkönen, Seppo; Senar, Juan Carlos; Seppänen, Janne T; da Silva, Luís P; Slagsvold, Tore; Solonen, Tapio; Sorace, Alberto; Stenning, Martyn J; Török, János; Tryjanowski, Piotr; van Noordwijk, Arie J; von Numers, Mikael; Walankiewicz, Wiesław; Lambrechts, Marcel M

    2014-09-01

    Nests are structures built to support and protect eggs and/or offspring from predators, parasites, and adverse weather conditions. Nests are mainly constructed prior to egg laying, meaning that parent birds must make decisions about nest site choice and nest building behavior before the start of egg-laying. Parent birds should be selected to choose nest sites and to build optimally sized nests, yet our current understanding of clutch size-nest size relationships is limited to small-scale studies performed over short time periods. Here, we quantified the relationship between clutch size and nest size, using an exhaustive database of 116 slope estimates based on 17,472 nests of 21 species of hole and non-hole-nesting birds. There was a significant, positive relationship between clutch size and the base area of the nest box or the nest, and this relationship did not differ significantly between open nesting and hole-nesting species. The slope of the relationship showed significant intraspecific and interspecific heterogeneity among four species of secondary hole-nesting species, but also among all 116 slope estimates. The estimated relationship between clutch size and nest box base area in study sites with more than a single size of nest box was not significantly different from the relationship using studies with only a single size of nest box. The slope of the relationship between clutch size and nest base area in different species of birds was significantly negatively related to minimum base area, and less so to maximum base area in a given study. These findings are consistent with the hypothesis that bird species have a general reaction norm reflecting the relationship between nest size and clutch size. Further, they suggest that scientists may influence the clutch size decisions of hole-nesting birds through the provisioning of nest boxes of varying sizes.

  7. Small body size and extreme cortical bone remodeling indicate phyletic dwarfism in Magyarosaurus dacus (Sauropoda: Titanosauria).

    Science.gov (United States)

    Stein, Koen; Csiki, Zoltan; Rogers, Kristina Curry; Weishampel, David B; Redelstorff, Ragna; Carballido, Jose L; Sander, P Martin

    2010-05-18

    Sauropods were the largest terrestrial tetrapods (>10(5) kg) in Earth's history and grew at rates that rival those of extant mammals. Magyarosaurus dacus, a titanosaurian sauropod from the Upper Cretaceous (Maastrichtian) of Romania, is known exclusively from small individuals (dwarfism (phyletic nanism) in dinosaurs, but a recent study suggested that the small Romanian titanosaurs actually represent juveniles of a larger-bodied taxon. Here we present strong histological evidence that M. dacus was indeed a dwarf (phyletic nanoid). Bone histological analysis of an ontogenetic series of Magyarosaurus limb bones indicates that even the smallest Magyarosaurus specimens exhibit a bone microstructure identical to fully mature or old individuals of other sauropod taxa. Comparison of histologies with large-bodied sauropods suggests that Magyarosaurus had an extremely reduced growth rate, but had retained high basal metabolic rates typical for sauropods. The uniquely decreased growth rate and diminutive body size in Magyarosaurus were adaptations to life on a Cretaceous island and show that sauropod dinosaurs were not exempt from general ecological principles limiting body size.

  8. Body size, growth and life span: implications for the polewards range shift of Octopus tetricus in south-eastern Australia.

    Science.gov (United States)

    Ramos, Jorge E; Pecl, Gretta T; Moltschaniwskyj, Natalie A; Strugnell, Jan M; León, Rafael I; Semmens, Jayson M

    2014-01-01

    Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E) throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters.

  9. crm-1 facilitates BMP signaling to control body size in Caenorhabditis elegans.

    Science.gov (United States)

    Fung, Wong Yan; Fat, Ko Frankie Chi; Eng, Cheah Kathryn Song; Lau, Chow King

    2007-11-01

    We have identified in Caenorhabditis elegans a homologue of the vertebrate Crim1, crm-1, which encodes a putative transmembrane protein with multiple cysteine-rich (CR) domains known to have bone morphogenetic proteins (BMPs) binding activity. Using the body morphology of C. elegans as an indicator, we showed that attenuation of crm-1 activity leads to a small body phenotype reminiscent of that of BMP pathway mutants. We showed that the crm-1 loss-of-function phenotype can be rescued by constitutive supply of sma-4 activity. crm-1 can enhance BMP signaling and this activity is dependent on the presence of the DBL-1 ligand and its receptors. crm-1 is expressed in neurons at the ventral nerve cord, where the DBL-1 ligand is produced. However, ectopic expression experiments reveal that crm-1 gene products act outside the DBL-1 producing cells and function non-autonomously to facilitate dbl/sma pathway signaling to control body size.

  10. Litter size of Danish crossbred sows increased without changes in sow body dimensions over a thirteen year period

    DEFF Research Database (Denmark)

    Nielsen, S. E.; Kristensen, A. R.; Moustsen, V. Aa

    2018-01-01

    dimensions and litter size was also investigated. Depth, width, length and height were measured from 405 Danish crossbred sows in 10 different herds, classified in groups of parity 1, 2, 3, 4, 5, 6 and ≥ 7. By Linear Mixed-Effects Models with depth, width, length and height in turn as response variable......The purpose of this study was to investigate if body dimensions of Danish crossbred sows (Yorkshire x Landrace) had increased compared to a previous Danish study from 2004. In addition, and as an expected potential benefit of increased body dimensions, a potential correlation between body...... and parity and herd as explanatory variables, estimated means, 5th and 95th percentiles, minimum and maximum observation were recorded. Furthermore, a weighted index for litter size (denoted as the “litter size potential”) was used as response variable with depth, width, length, height and parity...

  11. Gut microbiome diversity influenced more by the Westernized dietary regime than the body mass index as assessed using effect size statistic.

    Science.gov (United States)

    Davis, Shannon C; Yadav, Jagjit S; Barrow, Stephanie D; Robertson, Boakai K

    2017-08-01

    Human gut microbiome dysbiosis has been associated with the onset of metabolic diseases and disorders. However, the critical factors leading to dysbiosis are poorly understood. In this study, we provide increasing evidence of the association of diet type and body mass index (BMI) and how they relatively influence the taxonomic structure of the gut microbiota with respect to the causation of gut microbiome dysbiosis. The study included randomly selected Alabama residents (n = 81), including females (n = 45) and males (n = 36). The demographics data included age (33 ± 13.3 years), height (1.7 ± 0.11 meters), and weight (82.3 ± 20.6 kg). The mean BMI was 28.3 ± 7.01, equating to an overweight BMI category. A cross-sectional case-control design encompassing the newly recognized effect size approach to bioinformatics analysis was used to analyze data from donated stool samples and accompanying nutrition surveys. We investigated the microbiome variations in the Bacteroidetes-Firmicutes ratio relative to BMI, food categories, and dietary groups at stratified abundance percentages of gut microbiota diversity than an increased BMI with an effect size of 0.16. This implied Westernized diet as a critical factor in causing dysbiosis as compared to an overweight or obese body mass index. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  12. Age-related effects of body mass on fertility and litter size in roe deer.

    Science.gov (United States)

    Flajšman, Katarina; Jerina, Klemen; Pokorny, Boštjan

    2017-01-01

    We analysed effects of females' body mass and age on reproductive capacity of European roe deer (Capreolus capreolus) in a large sample set of 1312 females (305 yearlings and 1007 adults), hunted throughout Slovenia, central Europe, in the period 2013-2015. Body mass positively affected probability of ovulation and potential litter size (number of corpora lutea), although its effect was more pronounced in yearlings than in adults. Between age groups, we found clear differences in responses of both reproductive parameters to body mass which influences primarily reproductive performance of younger, and in particular, lighter individuals: at the same body mass yearlings would at average have smaller litters than adults, and at lower body mass also young to middle-aged adults would have smaller litters than old ones. In addition, while yearlings have to reach a critical threshold body mass to attain reproductive maturity, adult females are fertile (produce ova) even at low body mass. However, at higher body mass also younger individuals shift their efforts into the reproduction, and after reaching an age-specific threshold the body mass does not have any further effects on the reproductive output of roe deer females. Increased reproductive capacity at more advanced age, combined with declining body mass suggests that old does allocate more of their resources in reproduction than in body condition.

  13. Age-related effects of body mass on fertility and litter size in roe deer.

    Directory of Open Access Journals (Sweden)

    Katarina Flajšman

    Full Text Available We analysed effects of females' body mass and age on reproductive capacity of European roe deer (Capreolus capreolus in a large sample set of 1312 females (305 yearlings and 1007 adults, hunted throughout Slovenia, central Europe, in the period 2013-2015. Body mass positively affected probability of ovulation and potential litter size (number of corpora lutea, although its effect was more pronounced in yearlings than in adults. Between age groups, we found clear differences in responses of both reproductive parameters to body mass which influences primarily reproductive performance of younger, and in particular, lighter individuals: at the same body mass yearlings would at average have smaller litters than adults, and at lower body mass also young to middle-aged adults would have smaller litters than old ones. In addition, while yearlings have to reach a critical threshold body mass to attain reproductive maturity, adult females are fertile (produce ova even at low body mass. However, at higher body mass also younger individuals shift their efforts into the reproduction, and after reaching an age-specific threshold the body mass does not have any further effects on the reproductive output of roe deer females. Increased reproductive capacity at more advanced age, combined with declining body mass suggests that old does allocate more of their resources in reproduction than in body condition.

  14. Variation of thermal parameters in two different color morphs of a diurnal poison toad, Melanophryniscus rubriventris (Anura: Bufonidae).

    Science.gov (United States)

    Sanabria, Eduardo A; Vaira, Marcos; Quiroga, Lorena B; Akmentins, Mauricio S; Pereyra, Laura C

    2014-04-01

    We study the variation in thermal parameters in two contrasting populations Yungas Redbelly Toads (Melanophryniscus rubriventris) with different discrete color phenotypes comparing field body temperatures, critical thermal maximum and heating rates. We found significant differences in field body temperatures of the different morphs. Temperatures were higher in toads with a high extent of dorsal melanization. No variation was registered in operative temperatures between the study locations at the moment of capture and processing. Critical thermal maximum of toads was positively related with the extent of dorsal melanization. Furthermore, we founded significant differences in heating rates between morphs, where individuals with a high extent of dorsal melanization showed greater heating rates than toads with lower dorsal melanization. The color pattern-thermal parameter relationship observed may influence the activity patterns and body size of individuals. Body temperature is a modulator of physiological and behavioral functions in amphibians, influencing daily and seasonal activity, locomotor performance, digestion rate and growth rate. It is possible that some growth constraints may arise due to the relationship of color pattern-metabolism allowing different morphs to attain similar sizes at different locations instead of body-size clines. Copyright © 2014. Published by Elsevier Ltd.

  15. Selection for growth rate and body size have altered the expression profiles of somatotropic axis genes in chickens

    Science.gov (United States)

    Liu, Yong; Xu, Zhiqiang; Duan, Xiaohua; Li, Qihua; Dou, Tengfei; Gu, Dahai; Rong, Hua; Wang, Kun; Li, Zhengtian; Talpur, Mir Zulqarnain; Huang, Ying; Wang, Shanrong; Yan, Shixiong; Tong, Huiquan; Zhao, Sumei; Zhao, Guiping; Su, Zhengchang; Ge, Changrong

    2018-01-01

    The growth hormone / insulin-like growth factor-1 (GH/IGF-1) pathway of the somatotropic axis is the major controller for growth rate and body size in vertebrates, but the effect of selection on the expression of GH/IGF-1 somatotropic axis genes and their association with body size and growth performance in farm animals is not fully understood. We analyzed a time series of expression profiles of GH/IGF-1 somatotropic axis genes in two chicken breeds, the Daweishan mini chickens and Wuding chickens, and the commercial Avian broilers hybrid exhibiting markedly different body sizes and growth rates. We found that growth rate and feed conversion efficiency in Daweishan mini chickens were significantly lower than those in Wuding chickens and Avian broilers. The Wuding and Daweishan mini chickens showed higher levels of plasma GH, pituitary GH mRNA but lower levels of hepatic growth hormone receptor (GHR) mRNA than in Avian broilers. Daweishan mini chickens showed significantly lower levels of plasma IGF-1, thigh muscle and hepatic IGF-1 mRNA than did Avian broilers and Wuding chickens. These results suggest that the GH part of the somatotropic axis is the main regulator of growth rate, while IGF-1 may regulate both growth rate and body weight. Selection for growth performance and body size have altered the expression profiles of somatotropic axis genes in a breed-, age-, and tissue-specific manner, and manner, and alteration of regulatory mechanisms of these genes might play an important role in the developmental characteristics of chickens. PMID:29630644

  16. GI Joe or Average Joe? The impact of average-size and muscular male fashion models on men's and women's body image and advertisement effectiveness.

    Science.gov (United States)

    Diedrichs, Phillippa C; Lee, Christina

    2010-06-01

    Increasing body size and shape diversity in media imagery may promote positive body image. While research has largely focused on female models and women's body image, men may also be affected by unrealistic images. We examined the impact of average-size and muscular male fashion models on men's and women's body image and perceived advertisement effectiveness. A sample of 330 men and 289 women viewed one of four advertisement conditions: no models, muscular, average-slim or average-large models. Men and women rated average-size models as equally effective in advertisements as muscular models. For men, exposure to average-size models was associated with more positive body image in comparison to viewing no models, but no difference was found in comparison to muscular models. Similar results were found for women. Internalisation of beauty ideals did not moderate these effects. These findings suggest that average-size male models can promote positive body image and appeal to consumers. 2010 Elsevier Ltd. All rights reserved.

  17. Total body neutron activation analysis of calcium: calibration and normalisation

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, N S.J.; Eastell, R; Ferrington, C M; Simpson, J D; Strong, J A [Western General Hospital, Edinburgh (UK); Smith, M A; Tothill, P [Royal Infirmary, Edinburgh (UK)

    1982-05-01

    An irradiation system has been designed, using a neutron beam from a cyclotron, which optimises the uniformity of activation of calcium. Induced activity is measured in a scanning, shadow-shield whole-body counter. Calibration has been effected and reproducibility assessed with three different types of phantom. Corrections were derived for variations in body height, depth and fat thickness. The coefficient of variation for repeated measurements of an anthropomorphic phantom was 1.8% for an absorbed dose equivalent of 13 mSv (1.3 rem). Measurements of total body calcium in 40 normal adults were used to derive normalisation factors which predict the normal calcium in a subject of given size and age. The coefficient of variation of normalised calcium was 6.2% in men and 6.6% in women, with the demonstration of an annual loss of 1.5% after the menopause. The narrow range should make single measurements useful for diagnostic purposes.

  18. Twin study of genetic and environmental influences on adult body size, shape and composition

    DEFF Research Database (Denmark)

    Schousboe, K.; Visscher, P.M.; Erbas, B.

    2004-01-01

    ), we determined zygosity by DNA similarity, and performed anthropometry and bioelectrical impedance analysis of body composition. The contribution to the total phenotypic variance of genetic, common environment, and individual environment was estimated in multivariate analysis using the FISHER program...... effects under the assumptions of no nonadditive effect. The pattern of age trends was inconsistent. However, when significant there was a decrease in heritability with advancing age. DISCUSSION: These findings suggest that adult body size, shape, and composition are highly heritable in both women and men...

  19. The effect of feeding position and body size on the capacity of small ...

    African Journals Online (AJOL)

    The effect of feeding position and body size on the capacity of small ruminants to reach, for food when fed through barriers. ... The barrier allowed the neck to pass through, but not the shoulders. It was hypothesized that goats would have larger reach than sheep and that for each species, horizontal reach forwards, F, ...

  20. Scale effects between body size and limb design in quadrupedal mammals.

    Science.gov (United States)

    Kilbourne, Brandon M; Hoffman, Louwrens C

    2013-01-01

    Recently the metabolic cost of swinging the limbs has been found to be much greater than previously thought, raising the possibility that limb rotational inertia influences the energetics of locomotion. Larger mammals have a lower mass-specific cost of transport than smaller mammals. The scaling of the mass-specific cost of transport is partly explained by decreasing stride frequency with increasing body size; however, it is unknown if limb rotational inertia also influences the mass-specific cost of transport. Limb length and inertial properties--limb mass, center of mass (COM) position, moment of inertia, radius of gyration, and natural frequency--were measured in 44 species of terrestrial mammals, spanning eight taxonomic orders. Limb length increases disproportionately with body mass via positive allometry (length ∝ body mass(0.40)); the positive allometry of limb length may help explain the scaling of the metabolic cost of transport. When scaled against body mass, forelimb inertial properties, apart from mass, scale with positive allometry. Fore- and hindlimb mass scale according to geometric similarity (limb mass ∝ body mass(1.0)), as do the remaining hindlimb inertial properties. The positive allometry of limb length is largely the result of absolute differences in limb inertial properties between mammalian subgroups. Though likely detrimental to locomotor costs in large mammals, scale effects in limb inertial properties appear to be concomitant with scale effects in sensorimotor control and locomotor ability in terrestrial mammals. Across mammals, the forelimb's potential for angular acceleration scales according to geometric similarity, whereas the hindlimb's potential for angular acceleration scales with positive allometry.