WorldWideScience

Sample records for complex life histories

  1. Ecological Interactions in Dinosaur Communities: Influences of Small Offspring and Complex Ontogenetic Life Histories

    Science.gov (United States)

    Codron, Daryl; Carbone, Chris; Clauss, Marcus

    2013-01-01

    Because egg-laying meant that even the largest dinosaurs gave birth to very small offspring, they had to pass through multiple ontogenetic life stages to adulthood. Dinosaurs’ successors as the dominant terrestrial vertebrate life form, the mammals, give birth to live young, and have much larger offspring and less complex ontogenetic histories. The larger number of juveniles in dinosaur as compared to mammal ecosystems represents both a greater diversity of food available to predators, and competitors for similar-sized individuals of sympatric species. Models of population abundances across different-sized species of dinosaurs and mammals, based on simulated ecological life tables, are employed to investigate how differences in predation and competition pressure influenced dinosaur communities. Higher small- to medium-sized prey availability leads to a normal body mass-species richness (M-S) distribution of carnivorous dinosaurs (as found in the theropod fossil record), in contrast to the right-skewed M-S distribution of carnivorous mammals (as found living members of the order Carnivora). Higher levels of interspecific competition leads to a left-skewed M-S distribution in herbivorous dinosaurs (as found in sauropods and ornithopods), in contrast to the normal M-S distribution of large herbivorous mammals. Thus, our models suggest that differences in reproductive strategy, and consequently ontogeny, explain observed differences in community structure between dinosaur and mammal faunas. Models also show that the largest dinosaurian predators could have subsisted on similar-sized prey by including younger life stages of the largest herbivore species, but that large predators likely avoided prey much smaller than themselves because, despite predicted higher abundances of smaller than larger-bodied prey, contributions of small prey to biomass intake would be insufficient to satisfy meat requirements. A lack of large carnivores feeding on small prey exists in mammals

  2. Ecological interactions in dinosaur communities: influences of small offspring and complex ontogenetic life histories.

    Science.gov (United States)

    Codron, Daryl; Carbone, Chris; Clauss, Marcus

    2013-01-01

    Because egg-laying meant that even the largest dinosaurs gave birth to very small offspring, they had to pass through multiple ontogenetic life stages to adulthood. Dinosaurs' successors as the dominant terrestrial vertebrate life form, the mammals, give birth to live young, and have much larger offspring and less complex ontogenetic histories. The larger number of juveniles in dinosaur as compared to mammal ecosystems represents both a greater diversity of food available to predators, and competitors for similar-sized individuals of sympatric species. Models of population abundances across different-sized species of dinosaurs and mammals, based on simulated ecological life tables, are employed to investigate how differences in predation and competition pressure influenced dinosaur communities. Higher small- to medium-sized prey availability leads to a normal body mass-species richness (M-S) distribution of carnivorous dinosaurs (as found in the theropod fossil record), in contrast to the right-skewed M-S distribution of carnivorous mammals (as found living members of the order Carnivora). Higher levels of interspecific competition leads to a left-skewed M-S distribution in herbivorous dinosaurs (as found in sauropods and ornithopods), in contrast to the normal M-S distribution of large herbivorous mammals. Thus, our models suggest that differences in reproductive strategy, and consequently ontogeny, explain observed differences in community structure between dinosaur and mammal faunas. Models also show that the largest dinosaurian predators could have subsisted on similar-sized prey by including younger life stages of the largest herbivore species, but that large predators likely avoided prey much smaller than themselves because, despite predicted higher abundances of smaller than larger-bodied prey, contributions of small prey to biomass intake would be insufficient to satisfy meat requirements. A lack of large carnivores feeding on small prey exists in mammals

  3. Ecological interactions in dinosaur communities: influences of small offspring and complex ontogenetic life histories.

    Directory of Open Access Journals (Sweden)

    Daryl Codron

    Full Text Available Because egg-laying meant that even the largest dinosaurs gave birth to very small offspring, they had to pass through multiple ontogenetic life stages to adulthood. Dinosaurs' successors as the dominant terrestrial vertebrate life form, the mammals, give birth to live young, and have much larger offspring and less complex ontogenetic histories. The larger number of juveniles in dinosaur as compared to mammal ecosystems represents both a greater diversity of food available to predators, and competitors for similar-sized individuals of sympatric species. Models of population abundances across different-sized species of dinosaurs and mammals, based on simulated ecological life tables, are employed to investigate how differences in predation and competition pressure influenced dinosaur communities. Higher small- to medium-sized prey availability leads to a normal body mass-species richness (M-S distribution of carnivorous dinosaurs (as found in the theropod fossil record, in contrast to the right-skewed M-S distribution of carnivorous mammals (as found living members of the order Carnivora. Higher levels of interspecific competition leads to a left-skewed M-S distribution in herbivorous dinosaurs (as found in sauropods and ornithopods, in contrast to the normal M-S distribution of large herbivorous mammals. Thus, our models suggest that differences in reproductive strategy, and consequently ontogeny, explain observed differences in community structure between dinosaur and mammal faunas. Models also show that the largest dinosaurian predators could have subsisted on similar-sized prey by including younger life stages of the largest herbivore species, but that large predators likely avoided prey much smaller than themselves because, despite predicted higher abundances of smaller than larger-bodied prey, contributions of small prey to biomass intake would be insufficient to satisfy meat requirements. A lack of large carnivores feeding on small prey

  4. Life History Approach

    DEFF Research Database (Denmark)

    Olesen, Henning Salling

    2015-01-01

    of the social and the psychic, both in the interpretation procedure and in some main theoretical understandings of language, body and mind. My article will present the reflections on the use of life history based methodology in learning and education research as a kind of learning story of research work....... as in everyday life. Life histories represent lived lives past, present and anticipated future. As such they are interpretations of individuals’ experiences of the way in which societal dynamics take place in the individual body and mind, either by the individual him/herself or by another biographer. The Life...... History approach was developing from interpreting autobiographical and later certain other forms of language interactive material as moments of life history, i.e. it is basically a hermeneutic approach. Talking about a psycho-societal approach indicates the ambition of attacking the dichotomy...

  5. Potential responses to climate change in organisms with complex life histories: evolution and plasticity in Pacific salmon.

    Science.gov (United States)

    Crozier, L G; Hendry, A P; Lawson, P W; Quinn, T P; Mantua, N J; Battin, J; Shaw, R G; Huey, R B

    2008-05-01

    Salmon life histories are finely tuned to local environmental conditions, which are intimately linked to climate. We summarize the likely impacts of climate change on the physical environment of salmon in the Pacific Northwest and discuss the potential evolutionary consequences of these changes, with particular reference to Columbia River Basin spring/summer Chinook (Oncorhynchus tshawytscha) and sockeye (Oncorhynchus nerka) salmon. We discuss the possible evolutionary responses in migration and spawning date egg and juvenile growth and development rates, thermal tolerance, and disease resistance. We know little about ocean migration pathways, so cannot confidently suggest the potential changes in this life stage. Climate change might produce conflicting selection pressures in different life stages, which will interact with plastic (i.e. nongenetic) changes in various ways. To clarify these interactions, we present a conceptual model of how changing environmental conditions shift phenotypic optima and, through plastic responses, phenotype distributions, affecting the force of selection. Our predictions are tentative because we lack data on the strength of selection, heritability, and ecological and genetic linkages among many of the traits discussed here. Despite the challenges involved in experimental manipulation of species with complex life histories, such research is essential for full appreciation of the biological effects of climate change.

  6. Life-history interviews

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine

    2010-01-01

    My first encounter with life history research was during my Ph.D. research. This concerned a multi-method study of nomadic mobility in Senegal. One method stood out as yielding the most interesting and in-depth data: life story interviews using a time line. I made interviews with the head...... of a time line for making life story interviews. I decided that the lack of authoritative literature should not omit me from teaching my students how to make a time line interview. After an introduction, they had to use the tool for making an interview each other concerning their learning journey to DPU...... for conducting life history research. While I also consider time line interviews useful for other types of research, that story will have to wait for another paper....

  7. Life History and Identity

    Science.gov (United States)

    Tierney, William G.

    2013-01-01

    This article uses the life history method to chronicle the challenges of a low-income, first-generation student en route to college. The paper addresses three questions: how Manuel navigates college and related topics such as roommates, family, and money; how he creates social networks; and how he works with adults such as teachers and…

  8. Potential responses to climate change in organisms with complex life histories: evolution and plasticity in Pacific salmon

    Science.gov (United States)

    L.G. Crozier; A.P. Hendry; P.W. Lawson; T.P. Quinn; N.J. Mantua; J. Battin; R.G. Shaw; R.B. Huey

    2008-01-01

    Salmon life histories are finely tuned to local environmental conditions, which are intimately linked to climate. We summarize the likely impacts of climate change on the physical environment of salmon in the Pacific Northwest and discuss the potential evolutionary consequences of these changes, with particular reference to Columbia River Basin spring/summer Chinook (...

  9. Complex life histories of fishes revealed through natural information storage devices: case studies of diadromous events as recorded by otoliths

    International Nuclear Information System (INIS)

    Elfman, M.; Limburg, K.E.; Kristiansson, P.; Svedaeng, H.; Westin, L.; Wickstroem, H.; Malmqvist, K.; Pallon, J.

    2000-01-01

    Diadromous fishes - species that move across salinity gradients as part of their life repertoire - form a major part of coastal and inland fisheries. Conventional mark-recapture techniques have long been used to track their movements, but give incomplete information at best. On the other hand, otoliths (ear-stones) of fishes can provide a complete record of major life history events, as reflected both in their microstructure and elemental composition. Strontium, which substitutes for calcium in the aragonite matrix of otoliths, is a powerful tracer of salinity histories in many migratory fishes. We measured Sr and Ca with a nuclear microprobe (PIXE) and show examples (eel, Anguilla anguilla; brown trout, Salmo trutta; American shad, Alosa sapidissima) of how the technique has solved several mysteries within fisheries biology

  10. Potential responses to climate change in organisms with complex life histories: evolution and plasticity in Pacific salmon

    OpenAIRE

    Crozier, L G; Hendry, A P; Lawson, P W; Quinn, T P; Mantua, N J; Battin, J; Shaw, R G; Huey, R B

    2008-01-01

    Salmon life histories are finely tuned to local environmental conditions, which are intimately linked to climate. We summarize the likely impacts of climate change on the physical environment of salmon in the Pacific Northwest and discuss the potential evolutionary consequences of these changes, with particular reference to Columbia River Basin spring/summer Chinook (Oncorhynchus tshawytscha) and sockeye (Oncorhynchus nerka) salmon. We discuss the possible evolutionary responses in migration ...

  11. The complex early life history of a marine estuarine-opportunist fish species, Solea turbynei (Soleidae from temperate South Africa

    Directory of Open Access Journals (Sweden)

    Nadine A. Strydom

    2015-06-01

    Full Text Available The early life history stages and ecology of Solea turbynei, a marine estuarine-opportunist species, is described from nursery areas in Algoa Bay, South Africa. Early life history stages were collected over multiple years from known nursery habitats using plankton, fyke and larval seine nets. The larvae are described using morphometric measurements, meristic counts and pigmentation based on 29 individuals. Solea turbynei is differentiated from other Soleidae by the small size at flexion (3-4 mm, low myomere count and presence of two characteristic blotches of pigment on the dorsal fin. This species has a unique early life history strategy in that the larvae progressively span nearshore, surf zone and estuarine habitats with ontogeny. Abundance of preflexion stages peaks in summer in nearshore waters, indicative of peak spawning period but preflexion larvae are present throughout the year, indicating protracted spawning by adults. At flexion stage, larvae utilize surf zones where metamorphosis and settlement takes place. Early juveniles migrate into the sandy lower reaches of estuaries, after which fish take up residency to adulthood. Warm water is important for larval growth and survival in the nearshore, while turbidity shows a positive relationship with recruitment into estuarine nurseries.

  12. Human Life History Strategies

    Directory of Open Access Journals (Sweden)

    Kristine J. Chua

    2016-12-01

    Full Text Available Human life history (LH strategies are theoretically regulated by developmental exposure to environmental cues that ancestrally predicted LH-relevant world states (e.g., risk of morbidity–mortality. Recent modeling work has raised the question of whether the association of childhood family factors with adult LH variation arises via (i direct sampling of external environmental cues during development and/or (ii calibration of LH strategies to internal somatic condition (i.e., health, which itself reflects exposure to variably favorable environments. The present research tested between these possibilities through three online surveys involving a total of over 26,000 participants. Participants completed questionnaires assessing components of self-reported environmental harshness (i.e., socioeconomic status, family neglect, and neighborhood crime, health status, and various LH-related psychological and behavioral phenotypes (e.g., mating strategies, paranoia, and anxiety, modeled as a unidimensional latent variable. Structural equation models suggested that exposure to harsh ecologies had direct effects on latent LH strategy as well as indirect effects on latent LH strategy mediated via health status. These findings suggest that human LH strategies may be calibrated to both external and internal cues and that such calibrational effects manifest in a wide range of psychological and behavioral phenotypes.

  13. Experience and Life History. Roskilde University Life History Project Paper.

    Science.gov (United States)

    Salling Olesen, Henning

    The Life History Project at Denmark's Roskilde University is a 5-year research project that was initiated in 1998 to examine learning and participation in adult and continuing education from a life history perspective. The project was designed to build on a broad range of qualitative interview studies and case studies into learning processes. The…

  14. Complex interplay of body condition, life history, and prevailing environment shapes immune defenses of garter snakes in the wild.

    Science.gov (United States)

    Palacios, Maria G; Cunnick, Joan E; Bronikowski, Anne M

    2013-01-01

    The immunocompetence "pace-of-life" hypothesis proposes that fast-living organisms should invest more in innate immune defenses and less in adaptive defenses compared to slow-living ones. We found some support for this hypothesis in two life-history ecotypes of the snake Thamnophis elegans; fast-living individuals show higher levels of innate immunity compared to slow-living ones. Here, we optimized a lymphocyte proliferation assay to assess the complementary prediction that slow-living snakes should in turn show stronger adaptive defenses. We also assessed the "environmental" hypothesis that predicts that slow-living snakes should show lower levels of immune defenses (both innate and adaptive) given the harsher environment they live in. Proliferation of B- and T-lymphocytes of free-living individuals was on average higher in fast-living than slow-living snakes, opposing the pace-of-life hypothesis and supporting the environmental hypothesis. Bactericidal capacity of plasma, an index of innate immunity, did not differ between fast-living and slow-living snakes in this study, contrasting the previously documented pattern and highlighting the importance of annual environmental conditions as determinants of immune profiles of free-living animals. Our results do not negate a link between life history and immunity, as indicated by ecotype-specific relationships between lymphocyte proliferation and body condition, but suggest more subtle nuances than those currently proposed.

  15. Life Complexity and Diversity

    Indian Academy of Sciences (India)

    It is as if the stage is cleared from time to time to make for fresh beginnings, with major bouts of extinction. Humans are amongst the most complex products of evolution having in turn populated the world with ever growing numbers of complex artefacts. These artefacts are now threatening to overwhelm the diversity of life.

  16. Life history types and strategies

    DEFF Research Database (Denmark)

    Boel, Mikkel

    strategies and types in migratory freshwater fish, using brown trout and alewife as study organisms. Firstly, we investigated underlying mechanisms of resident and migratory life history strategies of salmonids, using indicators for nutritional status, stress, tissue damage and smoltification. Secondly......, A and Post, D.M. Life history differences in alewives (Alosa pseudoharengus) alter the ontogenetic trajectory of juvenile largemouth (Micropterus salmoides) (manuscript) MS III Boel, M. & Koed, A. Habitat specific avian predation on brown trout (Salmo trutta) (manuscript) MS IV Boel, M., Aarestrup, K., Koed......, A., Baktoft, H. and Skov, C.. Field based evaluation of the effect of 23 mm passive integrated transponder (PIT) tags on the length-mass relationship in wild juvenile brown trout (Salmo trutta) (submitted manuscript: Fisheries Management and Ecology) The thesis was focused on the life history...

  17. Life Complexity and Diversity

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 12. Life Complexity and Diversity Whither Diversity. Madhav Gadgil. Series Article Volume 1 Issue 12 December 1996 pp 17-25. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/12/0017-0025 ...

  18. Life: Complexity and Diversity

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 4. Life : Complexity and Diversity Growing Larger. Madhav Gadgil. Series Article Volume 1 Issue 4 April 1996 pp 15-22. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/04/0015-0022 ...

  19. Life History Trade-offs

    NARCIS (Netherlands)

    Smallegange, I.M.; Kliman, R.M.

    2016-01-01

    Trade-offs play a central role in life history theory. This article explains why they exist, how they arise, how they can be measured, and briefly discusses their evolution. Three important trade-offs are discussed in detail: the trade-off between current reproduction and survival, between current

  20. Dynamic heterogeneity in life histories

    DEFF Research Database (Denmark)

    Tuljapurkar, Shripad; Steiner, Uli; Orzack, Steven Hecht

    2009-01-01

    describes the persistence of reproductive success during the life of an individual. Trajectories of reproductive stage determine survivorship, and we analyse the variance in lifespan within and between trajectories of reproductive stage. We show how stage-structured models can be used to predict realized......Longitudinal data on natural populations have been analysed using multistage models in which survival depends on reproductive stage, and individuals change stages according to a Markov chain. These models are special cases of stage-structured population models. We show that stage-structured models...... generate dynamic heterogeneity: life-history differences produced by stochastic stratum dynamics. We characterize dynamic heterogeneity in a range of species across taxa by properties of the Markov chain: the entropy, which describes the extent of heterogeneity, and the subdominant eigenvalue, which...

  1. Life: Complexity and Diversity

    Indian Academy of Sciences (India)

    This promotes a con- tinual increase in the diversity of life over evolutionary time. Ways of Life. Decomposing, photosynthesizing and feeding on other organ- isms are three ... As living organisms have adopted these newer ways of life and invaded an .... honeyguide flies in stages towards the hive with the badger following it ...

  2. Life: Complexity and Diversity

    Indian Academy of Sciences (India)

    His fascination for the diversity of life has prompted him to study a whole range of life forms from paper wasps to anchovies, mynas to elephants, goldenrods to bamboos. Figure 1 ... nucleic acids,for assembling proteins and in tum a whole range of ... balloons; as flying lizards gliding from tree to tree and birds flying fr~m the ...

  3. Life: Complexity and Diversity

    Indian Academy of Sciences (India)

    Research, Bangalore. His fascination for the .... largest being an egg of the ostrich, largely loaded with stored food. So, to achieve larger sizes .... viruses and fungi. Packing Species. The diversity of living organisms has exploded, hand in hand with the evolving complexity of their interactions in communi- ties. In the dance ...

  4. Globalization and Life History Research: Fragments of a Life Foretold

    Science.gov (United States)

    Tierney, William G.

    2010-01-01

    The goal of this paper is to understand, by way of a life history of one low-income working-class youth, how globalization impacts the working class in a developing nation. The concept of globalization and the method of life history seem diametrically opposed. Globalization is an idea about large social forces that impact the economic and material…

  5. Evolutionary biology and life histories

    Directory of Open Access Journals (Sweden)

    Brown, C. R.

    2004-06-01

    Full Text Available The demographic processes that drive the spread of populations through environments and in turn determine the abundance of organisms are the same demographic processes that drive the spread of genes through populations and in turn determine gene frequencies and fitness. Conceptually, marked similarities exist in the dynamic processes underlying population ecology and those underlying evolutionary biology. Central to an understanding of both disciplines is life history and its component demographic rates, such as survival, fecundity, and age of first breeding, and biologists from both fields have a vested interest in good analytical machinery for the estimation and analysis of these demographic rates. In the EURING conferences, we have been striving since the mid 1980s to promote a quantitative understanding of demographic rates through interdisciplinary collaboration between ecologists and statisticians. From the ecological side, the principal impetus has come from population biology, and in particular from wildlife biology, but the importance of good quantitative insights into demographic processes has long been recognized by a number of evolutionary biologists (e.g., Nichols & Kendall, 1995; Clobert, 1995; Cooch et al., 2002. In organizing this session, we have aimed to create a forum for those committed to gaining the best possible understanding of evolutionary processes through the application of modern quantitative methods for the collection and interpretation of data on marked animal populations. Here we present a short overview of the material presented in the session on evolutionary biology and life histories. In a plenary talk, Brown & Brown (2004 explored how mark–recapture methods have allowed a better understanding of the evolution of group–living and alternative reproductive tactics in colonial cliff swallows (Petrochelidon pyrrhonota. By estimating the number of transient birds passing through colonies of different sizes, they

  6. Population momentum across vertebrate life histories

    Science.gov (United States)

    Koons, D.N.; Grand, J.B.; Arnold, J.M.

    2006-01-01

    Population abundance is critically important in conservation, management, and demographic theory. Thus, to better understand how perturbations to the life history affect long-term population size, we examined population momentum for four vertebrate classes with different life history strategies. In a series of demographic experiments we show that population momentum generally has a larger effect on long-term population size for organisms with long generation times than for organisms with short generation times. However, patterns between population momentum and generation time varied across taxonomic groups and according to the life history parameter that was changed. Our findings indicate that momentum may be an especially important aspect of population dynamics for long-lived vertebrates, and deserves greater attention in life history studies. Further, we discuss the importance of population momentum in natural resource management, pest control, and conservation arenas. ?? 2006 Elsevier B.V. All rights reserved.

  7. Bluefin Tuna Life History (1972-1979)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Catch and size data for animals from which a collection of fish parts were done for life history studies. These samples will be used in comparison studies with more...

  8. The Early History of Life

    Science.gov (United States)

    Nisbet, E. G.; Fowler, C. M. R.

    2003-12-01

    The youth of the Earth is strange to us. Many of the most fundamental constraints on life may have been different, especially the oxidation state of the surface. Should we suddenly land on its Hadean or early Archean surface by some sci-fi accident, we would not recognize our home. Above, the sky may have been green or some other unworldly color, and above that the weak young Sun might have been unrecognizable to someone trying to identify it from its spectrum. Below, seismology would show a hot, comparatively low-viscosity interior, possibly with a magma ocean in the deeper part of the upper mantle (Drake and Righter, 2002; Nisbet and Walker, 1982), and a core that, though present, was perhaps rather smaller than today. The continents may have been small islands in an icy sea, mostly frozen with some leads of open water, ( Sleep et al., 2001). Into these icy oceans, huge protruding Hawaii-like volcanoes would have poured out vast far-spreading floods of komatiite lavas in immense eruptions that may have created sudden local hypercane storms to disrupt the nearby icebergs. And meteorites would rain down.Or perhaps it was not so strange, nor so violent. The child is father to the man; young Earth was mother to Old Earth. Earth had hydrogen, silicate rock below and on the surface abundant carbon, which her ancient self retains today. Moreover, Earth was oxygen-rich, as today. Today, a tiny part of the oxygen is free, as air; then the oxygen would have been in the mantle while the surface oxygen was used to handcuff the hydrogen as dihydrogen monoxide. Oxygen dihydride is dense, unlikely to fly off to space, and at the poles, rock-forming. Of all the geochemical features that make Earth unique, the initial degassing (Genesis 2 : b) and then the sustained presence of liquid water is the defining oddity of this planet. Early Earth probably also kept much of its carbon, nitrogen, and sulfur as oxide or hydride. And, after the most cataclysmic events had passed, ˜4.5 Ga

  9. Life history, sin, and disease.

    Science.gov (United States)

    Eibach, Ulrich

    2006-08-01

    On the basis of experiences in pastoral hospital care, the relationship between disease, sin, and guilt in the life of patients is explored. Against the disregard of this subject in medicine, and even in most of pastoral care, it is argued that patients' interest requires that their hidden or manifest questions be addressed, rather than their being exposed to efforts at "helping" through mere attempts at "debt clearance." Only by openly confronting sin and guilt can the patient be taken seriously in his role as subject of his disease. Theological and anthropological background considerations revealing the essence of sin as a disruption or even destruction of the Divine gift of life in its realization through a lived relationship to God and other humans are offered as evidence for this claim.

  10. Dynamic heterogeneity and life histories

    DEFF Research Database (Denmark)

    Tuljapurkar, Shripad; Steiner, Uli

    2010-01-01

    of dynamic models of observable phenotypes of individuals. Phenotypic change in turn determines variation among individuals in their fitness components over the life course. We refer to this dynamic accumulation of fitness differences as dynamic heterogeneity and illustrate it for an animal population...... in which longitudinal data are studied using multistate capture-mark-recapture models. Although our approach can be applied to any characteristic, for our empirical example we use reproduction as the phenotypic character to define stages. We indicate how our stage-structured model describes the nature...... of the variation among individual characteristics that is generated by dynamic heterogeneity. We conclude by discussing our ongoing and planned work on animals and humans. We also discuss the connections between our work and recent work on human mortality, disability and health, and life course theory....

  11. Multistate analysis of life histories with R

    CERN Document Server

    Willekens, Frans

    2014-01-01

    This book provides an introduction to multistate event history analysis. It is an extension of survival analysis, in which a single terminal event (endpoint) is considered and the time-to-event is studied. Multistate models focus on life histories or trajectories, conceptualized as sequences of states and sequences of transitions between states. Life histories are modeled as realizations of continuous-time Markov processes. The model parameters, transition rates, are estimated from data on event counts and populations at risk, using the statistical theory of counting processes. The Comprehensive R Network Archive (CRAN) includes several packages for multistate modeling. This book is about Biograph. The package is designed to (a) enhance exploratory analysis of life histories and (b) make multistate modeling accessible. The package incorporates utilities that connect to several packages for multistate modeling, including survival, eha, Epi, mvna, etm, mstate, msm, and TraMineR for sequence analysis. The book ...

  12. The evolution of complex life

    Science.gov (United States)

    Billingham, J.

    1985-01-01

    The emergence of complex living organisms in the context of evolutionary biology, planetary environments, and space events is investigated. The application of data on biological evolution, climatology, and the chemical and physical environments of the earth's surface, to explain the development of extraterrestrial life is described and an example is provided. The possibility of extraplanetary disturbances such as, meteorite and comet bombardments, and supernova explosions, causing the elimination of preexisting life and allowing advanced life development is analyzed. The possible existence of different life cycles (genetic and reproductive strategies) on other planets is studied. The GAIA hypothesis (Lovelock, 1979) which states living things modify the global environment to their own advantage is examined. The improved identification of habitable planetary environments and the possible existence of a form of extraterrestrial intelligent life is discussed.

  13. Lemur Biorhythms and Life History Evolution.

    Directory of Open Access Journals (Sweden)

    Russell T Hogg

    Full Text Available Skeletal histology supports the hypothesis that primate life histories are regulated by a neuroendocrine rhythm, the Havers-Halberg Oscillation (HHO. Interestingly, subfossil lemurs are outliers in HHO scaling relationships that have been discovered for haplorhine primates and other mammals. We present new data to determine whether these species represent the general lemur or strepsirrhine condition and to inform models about neuroendocrine-mediated life history evolution. We gathered the largest sample to date of HHO data from histological sections of primate teeth (including the subfossil lemurs to assess the relationship of these chronobiological measures with life history-related variables including body mass, brain size, age at first female reproduction, and activity level. For anthropoids, these variables show strong correlations with HHO conforming to predictions, though body mass and endocranial volume are strongly correlated with HHO periodicity in this group. However, lemurs (possibly excepting Daubentonia do not follow this pattern and show markedly less variability in HHO periodicity and lower correlation coefficients and slopes. Moreover, body mass is uncorrelated, and brain size and activity levels are more strongly correlated with HHO periodicity in these animals. We argue that lemurs evolved this pattern due to selection for risk-averse life histories driven by the unpredictability of the environment in Madagascar. These results reinforce the idea that HHO influences life history evolution differently in response to specific ecological selection regimes.

  14. Life History Theory and Exploitative Strategies

    Directory of Open Access Journals (Sweden)

    Joshua J. Reynolds

    2016-07-01

    Full Text Available Exploitative strategies involve depriving others of resources while enhancing one’s own. Life history theory suggests that there are individual differences (life history strategy and environmental characteristics (life history contingencies [LHCs] that influence the use of exploitative strategies. However, past work manipulating LHCs has found mixed evidence for the influence of this information on exploitative behavior. We present three studies that help clarify the effects of this type of information. Results indicated that younger individuals are most sensitive to LHC information. We also found, contrary to predictions, that communicating slow LHC information (i.e., high population density, intraspecific competition, and resource scarcity increased rather than decreased the temptation to engage in exploitative behavior. Limitations and future directions are discussed.

  15. Educating Feminists: Life Histories and Pedagogy.

    Science.gov (United States)

    Middleton, Sue

    This book explores philosophical differences between feminist teacher-educators of the post-World War II generations and their students, who have experienced the restructured schools and recessionary environment of the "New Right." The volume reaches across boundaries and cultures with a life-history approach to women's studies, giving dimension…

  16. Life History Strategy and Disordered Eating Behavior

    Directory of Open Access Journals (Sweden)

    Catherine Salmon

    2009-10-01

    Full Text Available A sample of female undergraduates completed a packet of questionnaires consisting of the Arizona Life History Battery, a modified version of the Eating Disorders Inventory, the Behavioral Regulation scales from the Behavior Rating Inventory of Executive Function, and two measures of Female Intrasexual Competitiveness that distinguished between competition for mates and competition for status. As predicted, Executive Functions completely mediated the relation between Slow Life History Strategy and Disordered Eating Behavior. Surprisingly, however, the relation between Female Intrasexual Competitiveness (competition for mates and competition for status and Disordered Eating Behavior was completely spurious, with executive functions serving as a common cause underlying the inhibition of both Disordered Eating Behavior and Female Intrasexual Competitiveness. The protective function of Slow Life History Strategy with respect to Disordered Eating Behavior apparently resides in a higher degree of Behavioral Regulation, a type of Executive Function. The enhanced Behavioral Regulation or self-control, of individuals with a Slow Life History Strategy is also protective against hazardously escalated levels of Female Intrasexual Competitiveness.

  17. Planetary Atmospheres and Evolution of Complex Life

    Science.gov (United States)

    Catling, D.

    2014-04-01

    Let us define "complex life" as actively mobile organisms exceeding tens of centimeter size scale with specialized, differentiated anatomy comparable to advanced metazoans. Such organisms on any planet will need considerable energy for growth and metabolism, and an atmosphere is likely to play a key role. The history of life on Earth suggests that there were at least two major hurdles to overcome before complex life developed. The first was biological. Large, three-dimensional multicellular animals and plants are made only of eukaryotic cells, which are the only type that can develop into a large, diverse range of cell types unlike the cells of microbes. Exactly how eukaryotes allow 3D multicellularity and how they originated are matters of debate. But the internal structure and bigger and more modular genomes of eukaryotes are important factors. The second obstacle for complex life was having sufficient free, diatomic oxygen (O2). Aerobic metabolism provides about an order of magnitude more energy for a given intake of food than anaerobic metabolism, so anaerobes don't grow multicellular beyond filaments because of prohibitive growth efficiencies. A precursor to a 2.4 Ga rise of oxygen was the evolution of water-splitting, oxygen-producing photosynthesis. But although the atmosphere became oxidizing at 2.4 Ga, sufficient atmospheric O2 did not occur until about 0.6 Ga. Earth-system factors were involved including planetary outgassing (as affected by size and composition), hydrogen escape, and processing of organic carbon. An atmosphere rich in O2 provides the largest feasible energy source per electron transfer in the Periodic Table, which suggests that O2 would be important for complex life on exoplanets. But plentiful O2 is unusual in a planetary atmosphere because O2 is easily consumed in chemical reactions with reducing gases or surface materials. Even with aerobic metabolism, the partial pressure of O2 (pO2) must exceed 10^3 Pa to allow organisms that rely on

  18. The life trajectories modality of oral history

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Gonçalves

    2007-05-01

    Full Text Available This article seeks to explore the potential of qualitative research. It presents the life trajectory modality of the oral history method, to discuss the possibility of its utilization in scientific research in the Social Work profession. The epistemological foundations of oral history are discussed to establish its scientific character. The life trajectories modality is presented as a historic and social construction that utilizes different interview techniques to give voice to previously invisible subjects, indicating the principal phases of the methodological procedures used in this approach. The conclusions highlight the importance of the construction of this model and its projection as a research proposal that implies a process of understanding and analyzing the social universes that are contextualized and interconnected, considering the realities of the life trajectories of the subjects studied.

  19. Parasitism shaping host life-history evolution

    DEFF Research Database (Denmark)

    Fredensborg, Brian Lund; Poulin, R

    2006-01-01

    1. Variation in life-history strategies among conspecific populations indicates the action of local selective pressures; recently, parasitism has been suggested as one of these local forces. 2. Effects of trematode infections on reproductive effort, juvenile growth, size at maturity and susceptib......1. Variation in life-history strategies among conspecific populations indicates the action of local selective pressures; recently, parasitism has been suggested as one of these local forces. 2. Effects of trematode infections on reproductive effort, juvenile growth, size at maturity...... and susceptibility were investigated among different natural populations of the marine gastropod Zeacumantus subcarinatus, Sowerby 1855. 3. Reproductive effort was not higher in uninfected snails from populations experiencing a high trematode prevalence, but females from high prevalence populations produced...... to the same infection pressure in the field. 7. Our results strongly indicate that Z. subcarinatus adapt to trematodes by reaching maturity early, thereby maximizing their chance of reproducing in populations experiencing a high prevalence of infection by castrating trematodes....

  20. Evolutionary assembly rules for fish life histories

    DEFF Research Database (Denmark)

    Charnov, E.L.; Gislason, Henrik; Pope, J.G.

    2012-01-01

    length along the growth trajectory within the species. We then interpret K in terms of the VBGE in mass , and show that the previous equation is itself equivalent to a -1/3 power function rule between M and the mass at first reproduction (W α); this new -1/3 power function emerges directly from the life...... history that maximizes Darwinian fitness in non-growing populations. We merge this M, W α power function with other power functions to produce general across-species scaling rules for yearly reproductive allocation, reproductive effort and age at first reproduction in fish. We then suggest a new way...

  1. Oxidative stress and life histories : Unresolved issues and current needs

    NARCIS (Netherlands)

    Speakman, John R.; Blount, Jonathan D.; Bronikowski, Anne M.; Buffenstein, Rochelle; Isaksson, Caroline; Kirkwood, Tom B. L.; Monaghan, Pat; Ozanne, Susan E.; Beaulieu, Michael; Briga, Michael; Carr, Sarah K.; Christensen, Louise L.; Cocheme, Helena M.; Cram, Dominic L.; Dantzer, Ben; Harper, Jim M.; Jurk, Diana; King, Annette; Noguera, Jose C.; Salin, Karine; Sild, Elin; Simons, Mirre J. P.; Smith, Shona; Stier, Antoine; Tobler, Michael; Vitikainen, Emma; Peaker, Malcolm; Selman, Colin

    2015-01-01

    Life-history theory concerns the trade-offs that mold the patterns of investment by animals between reproduction, growth, and survival. It is widely recognized that physiology plays a role in the mediation of life-history trade-offs, but the details remain obscure. As life-history theory concerns

  2. Agency and Female Teachers' Career Decisions: A Life History Study of 40 Women

    Science.gov (United States)

    Smith, Joan

    2011-01-01

    This article reports on some of the findings of a wider, life history study on the factors affecting the career decisions of 40 female secondary school teachers in England. By using life history interviews, it was possible to gain rich and nuanced insights into the complexity of factors influencing women's career decisions. While acknowledging the…

  3. Life history and the male mutation bias.

    Science.gov (United States)

    Bartosch-Härlid, Anna; Berlin, Sofia; Smith, Nick G C; Møller, Anders P; Ellegren, Hans

    2003-10-01

    If DNA replication is a major cause of mutation, then those life-history characters, which are expected to affect the number of male germline cell divisions, should also affect the male to female mutation bias (alpha(m)). We tested this hypothesis by comparing several clades of bird species, which show variation both in suitable life-history characters (generation time as measured by age at first breeding and sexual selection as measured by frequency of extrapair paternity) and in alpha(m), which was estimated by comparing Z-linked and W-linked substitution rates in gametologous introns. Alpha(m) differences between clades were found to positively covary with both generation time and sexual selection, as expected if DNA replication causes mutation. The effects of extrapair paternity frequency on alpha(m) suggests that increased levels of sexual selection cause higher mutation rates, which offers an interesting solution to the paradox of the loss of genetic variance associated with strong directional sexual selection. We also used relative rate tests to examine whether the observed differences in alpha(m) between clades were due to differences in W-linked or Z-linked substitution rates. In one case, a significant difference in alpha(m) between two clades was shown to be due to W-linked rates and not Z-linked rates, a result that suggests that mutation rates are not determined by replication alone.

  4. Predicting life-history adaptations to pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Maltby, L. [Univ. of Sheffield (United Kingdom). Dept. of Animal and Plant Sciences

    1995-12-31

    Animals may adapt to pollutant stress so that individuals from polluted environments are less susceptible than those from unpolluted environments. In addition to such direct adaptations, animals may respond to pollutant stress by life-history modifications; so-called indirect adaptations. This paper will demonstrate how, by combining life-history theory and toxicological data, it is possible to predict stress-induced alterations in reproductive output and offspring size. Pollutant-induced alterations in age-specific survival in favor of adults and reductions in juvenile growth, conditions are predicted to select for reduced investment in reproduction and the allocation of this investment into fewer, larger offspring. Field observations on the freshwater crustaceans, Asellus aquaticus and Gammarus pulex, support these predictions. Females from metal-polluted sites had lower investment in reproduction and produced larger offspring than females of the same species from unpolluted sites. Moreover, interpopulation differences in reproductive biology persisted in laboratory cultures indicating that they had a genetic basis and were therefore due to adaptation rather than acclimation. The general applicability of this approach will be considered.

  5. Parasitism shaping host life-history evolution

    DEFF Research Database (Denmark)

    Fredensborg, Brian Lund; Poulin, R

    2006-01-01

    1. Variation in life-history strategies among conspecific populations indicates the action of local selective pressures; recently, parasitism has been suggested as one of these local forces. 2. Effects of trematode infections on reproductive effort, juvenile growth, size at maturity and susceptib......1. Variation in life-history strategies among conspecific populations indicates the action of local selective pressures; recently, parasitism has been suggested as one of these local forces. 2. Effects of trematode infections on reproductive effort, juvenile growth, size at maturity...... and susceptibility were investigated among different natural populations of the marine gastropod Zeacumantus subcarinatus, Sowerby 1855. 3. Reproductive effort was not higher in uninfected snails from populations experiencing a high trematode prevalence, but females from high prevalence populations produced...... significantly larger offspring compared with their conspecifics from other populations. 4. Juvenile growth rate was significantly higher in laboratory-raised snails originating from females in a high prevalence population compared with other populations. 5. Size at maturity, determined by the appearance...

  6. Biograph. A package in R to explore life history data and to enchance multistate modelling of life histories

    NARCIS (Netherlands)

    Willekens, F.J.C.

    2011-01-01

    Biograph: Explore life histories Biograph is designed to facilitate the descriptive and statistical analysis of life histories. It follows a multistate perspective on the life course and conceptualizes the life course as a sequence of states and transitions between states (events). Transitions are

  7. Otolith output - Project to study alternative life history types of fall Chinook based on otoliths

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The life-history complexity of Snake River fall Chinook salmon has hindered efforts to manage the ESU. In particular, the existence of an overwintering behavior in a...

  8. Procrastination as a Fast Life History Strategy

    Directory of Open Access Journals (Sweden)

    Bin-Bin Chen

    2016-02-01

    Full Text Available Research has revealed that procrastination—the purposive delay of an intended course of action—is a maladaptive behavior. However, by drawing on an evolutionary life history (LF approach, the present study proposes that procrastination may be an adaptive fast LF strategy characterized by prioritizing immediate benefits with little regard to long-term consequences. A total of 199 undergraduate students completed measures of procrastination and future orientation and the Mini-K scale, which measures the slow LF strategy. Structural equation modeling revealed that, as predicted, procrastination was negatively associated with a slow LF strategy both directly and indirectly through the mediation of future orientation. These results define the fast LF origin of procrastination.

  9. Dynamic heterogeneity and life history variability in the kittiwake

    DEFF Research Database (Denmark)

    Steiner, Uli; Tuljapurkar, Shripad; Orzack, Steven Hecht

    2010-01-01

    1. Understanding the evolution of life histories requires an assessment of the process that generates variation in life histories. Within-population heterogeneity of life histories can be dynamically generated by stochastic variation of reproduction and survival or be generated by individual...... differences that are fixed at birth. 2. We show for the kittiwake that dynamic heterogeneity is a sufficient explanation of observed variation of life histories. 3. The total heterogeneity in life histories has a small contribution from reproductive stage dynamics and a large contribution from survival...... differences. We quantify the diversity in life histories by metrics computed from the generating stochastic process. 4. We show how dynamic heterogeneity can be used as a null model and also how it can lead to positive associations between reproduction and survival across the life span. 5. We believe our...

  10. Applying Movement Ecology to Marine Animals with Complex Life Cycles

    Science.gov (United States)

    Allen, Richard M.; Metaxas, Anna; Snelgrove, Paul V. R.

    2018-01-01

    Marine animals with complex life cycles may move passively or actively for fertilization, dispersal, predator avoidance, resource acquisition, and migration, and over scales from micrometers to thousands of kilometers. This diversity has catalyzed idiosyncratic and unfocused research, creating unsound paradigms regarding the role of movement in ecology and evolution. The emerging movement ecology paradigm offers a framework to consolidate movement research independent of taxon, life-history stage, scale, or discipline. This review applies the framework to movement among life-history stages in marine animals with complex life cycles to consolidate marine movement research and offer insights for scientists working in aquatic and terrestrial realms. Irrespective of data collection or simulation strategy, breaking each life-history stage down into the fundamental units of movement allows each unit to be studied independently or interactively with other units. Understanding these underlying mechanisms of movement within each life-history stage can then be used to construct lifetime movement paths. These paths can allow further investigation of the relative contributions and interdependencies of steps and phases across a lifetime and how these paths influence larger research topics, such as population-level movements.

  11. Life history evolution in social insects : A female perspective

    NARCIS (Netherlands)

    Negroni, Matteo Antoine; Jongepier, Evelien; Feldmeyer, Barbara; Kramer, Boris H.; Foitzik, Susanne

    2016-01-01

    Social insects are known for their unusual life histories with fecund, long-lived queens and sterile, short-lived workers. We review ultimate factors underlying variation in life history strategies in female social insects, whose social life reshapes common trade-offs, such as the one between

  12. Life history determines genetic structure and evolutionary potential of host-parasite interactions.

    Science.gov (United States)

    Barrett, Luke G; Thrall, Peter H; Burdon, Jeremy J; Linde, Celeste C

    2008-12-01

    Measures of population genetic structure and diversity of disease-causing organisms are commonly used to draw inferences regarding their evolutionary history and potential to generate new variation in traits that determine interactions with their hosts. Parasite species exhibit a range of population structures and life-history strategies, including different transmission modes, life-cycle complexity, off-host survival mechanisms and dispersal ability. These are important determinants of the frequency and predictability of interactions with host species. Yet the complex causal relationships between spatial structure, life history and the evolutionary dynamics of parasite populations are not well understood. We demonstrate that a clear picture of the evolutionary potential of parasitic organisms and their demographic and evolutionary histories can only come from understanding the role of life history and spatial structure in influencing population dynamics and epidemiological patterns.

  13. Invader population speeds up life history during colonization

    OpenAIRE

    Amundsen, Per-Arne; Salonen, Erno; Niva, Teuvo; Gjelland, Karl Øystein; Præbel, Kim; Sandlund, Odd Terje; Knudsen, Rune; Bøhn, Thomas

    2012-01-01

    We explore the long-term developments in population biology and life history during the invasion and establishment of the fish species vendace Coregonus albula in a subarctic watercourse by comparing life-history traits and molecular genetic estimates between the source and the colonist population. The two populations exhibited highly contrasting life-history strategies. Relative to the source population, the colonist population was characterized by slower somatic growth rates, earlier sexual...

  14. Variability in the developmental life history of the genus Gorilla.

    Science.gov (United States)

    Stoinski, Tara S; Perdue, Bonnie; Breuer, Thomas; Hoff, Michael P

    2013-10-01

    Life history is influenced by factors both intrinsic (e.g., body and relative brain size) and extrinsic (e.g., diet, environmental instability) to organisms. In this study, we examine the prediction that energetic risk influences the life history of gorillas. Recent comparisons suggest that the more frugivorous western lowland gorilla shows increased infant dependence, and thus a slower life history, than the primarily folivorous mountain gorilla to buffer against the risk of starvation during periods of food unpredictability. We further tested this hypothesis by incorporating additional life history data from wild western lowland gorillas and captive western lowland gorillas with the assumption that the latter live under ecological conditions of energetic risk that more closely resemble those of mountain gorillas and thus should show faster life histories than wild members of the species. Overall, we found captive western lowland and wild mountain gorillas to have faster developmental life histories than wild western lowland gorillas, weaning their infants approximately a year earlier and thus reducing interbirth intervals by a year. These results provide support that energetic risk plays an important role in determining gorilla life history. Unlike previous assertions, gorillas do not have substantially faster life histories, at least at the genus level, than other great apes. This calls for a re-evaluation of theories concerning comparative ape life history and evolution and highlights the need for data from additional populations that vary in energetic risk. Copyright © 2013 Wiley Periodicals, Inc.

  15. Demography and life history of Thomas Langurs (Presbytis thomasi)

    NARCIS (Netherlands)

    Wich, S.A.; Steenbeek, R.; Sterck, E.H.M.; Korstjens, A.H.; Willems, E.P.; Schaik, C.P. van

    2007-01-01

    Life history data from wild primate populations are necessary to explain variation in primate social systems and explain differences between primates and other mammals. Here we report life history data from a 12.5-year study on wild Thomas langurs. Mean age at first reproduction was 5.4 years and

  16. Interrupting Life History: The Evolution of Relationship within Research

    Science.gov (United States)

    Hallett, Ronald E.

    2013-01-01

    In this paper the author explores how relationships are defined within the context of constructing a life history. The life history of Benjamin, a homeless young man transitioning to adulthood, is used to illustrate how difficult it is to define the parameters of the research environment. During an "ethically important moment" in the…

  17. Life-history parameters of white stumpnose Rhabdosargus ...

    African Journals Online (AJOL)

    Age-at-50% maturity was 2+ for females and 1+ for males, and size-at-50% maturity was 222 mm (fork length) for females and 194 mm for males. It is necessary to use area-specific growth and life-history parameters for the assessment of the stock status of white stumpnose in South Arica. Keywords: growth; life history; ...

  18. Inadvertent Exemplars: Life History Portraits of Two Socially Just Principals

    Science.gov (United States)

    Scanlan, Martin

    2012-01-01

    This study creates life history portraits of two White middle-class native-English-speaking principals demonstrating commitments to social justice in their work in public elementary schools serving disproportionately high populations of students who are marginalized by poverty, race, and linguistic heritage. Through self-reported life histories of…

  19. Elevational trends in life histories: revising the pace-of-life framework.

    Science.gov (United States)

    Hille, Sabine M; Cooper, Caren B

    2015-02-01

    Life-history traits in birds, such as lifespan, age at maturity, and rate of reproduction, vary across environments and in combinations imposed by trade-offs and limitations of physiological mechanisms. A plethora of studies have described the diversity of traits and hypothesized selection pressures shaping components of the survival-reproduction trade-off. Life-history variation appears to fall along a slow-fast continuum, with slow pace characterized by higher investment in survival over reproduction and fast pace characterized by higher investment in reproduction over survival. The Pace-of-Life Syndrome (POLS) is a framework to describe the slow-fast axis of variation in life-history traits and physiological traits. The POLS corresponds to latitudinal gradients, with tropical birds exhibiting a slow pace of life. We examined four possible ways that the traits of high-elevation birds might correspond to the POLS continuum: (i) rapid pace, (ii) tropical slow pace, (iii) novel elevational pace, or (iv) constrained pace. Recent studies reveal that birds breeding at high elevations in temperate zones exhibit a combination of traits creating a unique elevational pace of life with a central trade-off similar to a slow pace but physiological trade-offs more similar to a fast pace. A paucity of studies prevents consideration of the possibility of a constrained pace of life. We propose extending the POLS framework to include trait variation of elevational clines to help to investigate complexity in global geographic patterns. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

  20. Life history determines genetic structure and evolutionary potential of host–parasite interactions

    OpenAIRE

    Barrett, Luke G.; Thrall, Peter H.; Burdon, Jeremy J.; Linde, Celeste C.

    2008-01-01

    Measures of population genetic structure and diversity of disease-causing organisms are commonly used to draw inferences regarding their evolutionary history and potential to generate new variation in traits that determine interactions with their hosts. Parasite species exhibit a range of population structures and life-history strategies, including different transmission modes, life-cycle complexity, off-host survival mechanisms and dispersal ability. These are important determinants of the f...

  1. Metabolite changes during the life history of Porphyra haitanensis.

    Science.gov (United States)

    Wang, X; Zhao, P; Luo, Q; Yan, X; Xu, J; Chen, J; Chen, H

    2015-05-01

    Plant metabolomics is essentially the comprehensive analysis of complex metabolites of plant extracts. Metabolic fingerprinting is an important part of plant metabolomics research. In this study, metabolic fingerprinting of different stages of the life history of the red alga Porphyra haitanensis was performed. The stages included conchocelis filaments, sporangial branchlets, conchosporangia, discharged conchospores and conchosporangial branchlets after conchospore discharge. Metabolite extracts were analysed with ultra-performance liquid chromatography coupled with electrospray ionisation quadrupole-time of flight mass spectrometry. Analyses profiles were subjected to principal components analysis and orthogonal projection to latent structures discriminant analysis using the SIMCA-P software for biomarker selection and identification. Based on the MS/MS spectra and data from the literature, potential biomarkers, mainly of phosphatidylcholine and lysophosphatidylcholine, were identified. Identification of these biomarkers suggested that plasma membrane phospholipids underwent major changes during the life history of P. haitanensis. The levels of phosphatidylcholine and lysophosphatidylcholine increased in sporangial branchlets and decreased in discharged conchospores. Moreover, levels of sphingaine (d18:0) decreased in sporangial branchlets and increased in discharged conchospores, which indicates that membrane lipids were increasingly synthesised as energy storage in sporangial branchlets, while energy was consumed in sporangial branchlets to discharged conchospores. A metabolomic study of different growth phases of P. haitanensis will enhance our understanding of its physiology and ecology. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  2. Zimbabwean history: becoming complex | Moore | African ...

    African Journals Online (AJOL)

    Review of Brian Raftopoulos and Alois Mlambo, eds. Becoming Zimbabwe: A History from the Pre-Colonial Period to 2008. Harare and Johannesburg: Weaver and Jacana, 2009 pp. v-xxxiv, 260. ISBN: 978-1-77922-083-7. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD ...

  3. Oxidative stress and life histories: unresolved issues and current needs.

    Science.gov (United States)

    Speakman, John R; Blount, Jonathan D; Bronikowski, Anne M; Buffenstein, Rochelle; Isaksson, Caroline; Kirkwood, Tom B L; Monaghan, Pat; Ozanne, Susan E; Beaulieu, Michaël; Briga, Michael; Carr, Sarah K; Christensen, Louise L; Cochemé, Helena M; Cram, Dominic L; Dantzer, Ben; Harper, Jim M; Jurk, Diana; King, Annette; Noguera, Jose C; Salin, Karine; Sild, Elin; Simons, Mirre J P; Smith, Shona; Stier, Antoine; Tobler, Michael; Vitikainen, Emma; Peaker, Malcolm; Selman, Colin

    2015-12-01

    Life-history theory concerns the trade-offs that mold the patterns of investment by animals between reproduction, growth, and survival. It is widely recognized that physiology plays a role in the mediation of life-history trade-offs, but the details remain obscure. As life-history theory concerns aspects of investment in the soma that influence survival, understanding the physiological basis of life histories is related, but not identical, to understanding the process of aging. One idea from the field of aging that has gained considerable traction in the area of life histories is that life-history trade-offs may be mediated by free radical production and oxidative stress. We outline here developments in this field and summarize a number of important unresolved issues that may guide future research efforts. The issues are as follows. First, different tissues and macromolecular targets of oxidative stress respond differently during reproduction. The functional significance of these changes, however, remains uncertain. Consequently there is a need for studies that link oxidative stress measurements to functional outcomes, such as survival. Second, measurements of oxidative stress are often highly invasive or terminal. Terminal studies of oxidative stress in wild animals, where detailed life-history information is available, cannot generally be performed without compromising the aims of the studies that generated the life-history data. There is a need therefore for novel non-invasive measurements of multi-tissue oxidative stress. Third, laboratory studies provide unrivaled opportunities for experimental manipulation but may fail to expose the physiology underpinning life-history effects, because of the benign laboratory environment. Fourth, the idea that oxidative stress might underlie life-history trade-offs does not make specific enough predictions that are amenable to testing. Moreover, there is a paucity of good alternative theoretical models on which contrasting

  4. Temperature, food quality and life history traits of herbivorous insects.

    Science.gov (United States)

    Clissold, Fiona J; Simpson, Stephen J

    2015-10-01

    Population dynamics of herbivorous insects are strongly influenced by temperature and host plant quality; an interaction generally thought to be mediated via effects of temperature on metabolic rate and altered energy requirements. However, recent research suggests the relationship between nutrition, temperature, host plant quality and life history traits that influence insect fitness are more complex than appreciated to date. In the laboratory, rates of development are most strongly influenced by temperature, while growth, body composition, and reproductive output are greatly affected by nutrition, notably the uptake of protein and carbohydrate. However, individual outcomes and consequently population responses in the field are not readily predicted from data on ambient temperatures and host plant chemical composition. The relative amounts of protein and carbohydrate gained from a host plant depends on complex interactions between plant cell structure and leaf chemistry, combined with plasticity in feeding behaviour, microclimate selection, digestive and assimilative physiology. For example, grasshoppers can exploit the temperature dependence of host plant quality to maintain nutritional homeostasis. Consequently, understanding environmental interactions such as leaf defences and patterns of foraging, and predicting the effects of climate change on insect populations, will be complex. Copyright © 2015. Published by Elsevier Inc.

  5. Life: An Introduction to Complex Systems Biology

    CERN Document Server

    Kaneko, Kunihiko

    2006-01-01

    What is life? Has molecular biology given us a satisfactory answer to this question? And if not, why, and how to carry on from there? This book examines life not from the reductionist point of view, but rather asks the question: what are the universal properties of living systems and how can one construct from there a phenomenological theory of life that leads naturally to complex processes such as reproductive cellular systems, evolution and differentiation? The presentation has been deliberately kept fairly non-technical so as to address a broad spectrum of students and researchers from the natural sciences and informatics.

  6. Variation in adult life history and stress resistance across five ...

    Indian Academy of Sciences (India)

    Unknown

    Dry weight at eclosion, adult lifespan, lifetime fecundity, lipid and carbohydrate content at eclosion, and starvation and desiccation ... Keywords. life-history evolution; lifespan; fecundity; starvation; desiccation; lipid; glycogen; sexual dimorphism; laboratory ...... Rapid loss of stress resistance in Drosophila melanogaster.

  7. Extending Life Concepts to Complex Systems

    Directory of Open Access Journals (Sweden)

    Jean Le Fur

    2013-01-01

    Full Text Available There is still no consensus definition of complex systems. This article explores, as a heuristic approach, the possibility of using notions associated with life as transversal concepts for defining complex systems. This approach is developed within a general classification of systems, with complex systems considered as a general ‘living things’ category and living organisms as a specialised class within this category. Concepts associated with life are first explored in the context of complex systems: birth, death and lifetime, adaptation, ontogeny and growth, reproduction. Thereafter, a refutation approach is used to test the proposed classification against a set of diverse systems, including a reference case, edge cases and immaterial complex systems. The summary of this analysis is then used to generate a definition of complex systems, based on the proposal, and within the background of cybernetics, complex adaptive systems and biology. Using notions such as ‘birth’ or ‘lifespan’ as transversal concepts may be of heuristic value for the generic characterization of complex systems, opening up new lines of research for improving their definition.

  8. Variations in morphological and life-history traits under extreme ...

    Indian Academy of Sciences (India)

    Madhsudhan

    The genetic variations for all the quantitative and life-history traits were higher at ... variation in quantitative traits has important evolutionary ..... Mean ± SE and phenotypic variance (s2) of morphometric and life-history traits in D. ananassae reared at different temperatures. 18°C. 25°C. 32°C. Trait. Sex. Mean ± SE s2. Mean ± ...

  9. Life-history evolution: understanding the proximate mechanisms

    Indian Academy of Sciences (India)

    history evolution, I was required to write a term paper for a course on 'Advanced evolutionary biol- ogy'. Having worked in the laboratory for about six months and read through numerous papers on life-history evolution,. I was convinced that ...

  10. Life stress and family history for depression: the moderating role of past depressive episodes.

    Science.gov (United States)

    Monroe, Scott M; Slavich, George M; Gotlib, Ian H

    2014-02-01

    Three of the most consistently reported and powerful predictors of depression are a recent major life event, a positive family history for depression, and a personal history of past depressive episodes. Little research, however, has evaluated the inter-relations among these predictors in depressed samples. Such information is descriptively valuable and potentially etiologically informative. In the present article we summarize the existing literature and test four predictions in a sample of 62 clinically depressed individuals: (1) participants who experienced a major life event prior to onset would be less likely than participants who did not experience a major life event to have a positive family history for depression; (2) participants with a recent major life event would have fewer lifetime episodes of depression than would participants without; (3) participants with a positive family history for depression would have more lifetime episodes of depression than would participants with a negative family history for depression; and (4) we would obtain a 3-way interaction in which participants with a positive family history and without a major life event would have the most lifetime episodes, whereas participants with a negative family history and a major life event would have the fewest lifetime episodes. The first three predictions were confirmed, and the fourth prediction partially confirmed. These novel findings begin to elucidate the complex relations among these three prominent risk factors for depression, and point to avenues of research that may help illuminate the origins of depressive episodes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Life· Complexity and Diversity

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 1. Life: Complexity and Diversity A World in Flux. Madhav Gadgil. Series Article Volume 1 Issue 1 January 1996 pp 14-19. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/01/0014-0019 ...

  12. Life· Complexity and Diversity

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 8. Life: Complexity and Diversity - Scales of Diversity. Madhav Gadgil. Series Article Volume 1 Issue 8 August 1996 pp 16-21. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/08/0016-0021 ...

  13. Preadult life history variation determines adult transcriptome expression.

    Science.gov (United States)

    Etges, William J; de Oliveira, Cássia; Rajpurohit, Subhash; Gibbs, Allen G

    2016-02-01

    Preadult determinants of adult fitness and behaviour have been documented in a variety of organisms with complex life cycles, but little is known about expression patterns of genes underlying these adult traits. We explored the effects of differences in egg-to-adult development time on adult transcriptome and cuticular hydrocarbon variation in order to understand the nature of the genetic correlation between preadult development time and premating isolation between populations of Drosophila mojavensis reared in different host cactus environments. Transcriptome variation was analysed separately in flies reared on each host and revealed that hundreds of genes in adults were differentially expressed (FDR P pitaya agria cactus, longer preadult development times caused increased expression of genes in adults enriched for ribosome production, protein metabolism, chromatin remodelling and regulation of alternate splicing and transcription. Baja California flies reared on organ pipe cactus showed fewer differentially expressed genes in adults due to longer preadult development time, but these were enriched for ATP synthesis and the TCA cycle. Mainland flies reared on organ pipe cactus with shorter development times showed increased transcription of genes enriched for mitochondria and energy production, protein synthesis and glucose metabolism: adults with longer development times had increased expression of genes enriched for adult life span, cuticle proteins and ion binding, although most differentially expressed genes were unannotated. Differences due to population, sex, mating status and their interactions were also assessed. Adult cuticular hydrocarbon profiles also showed shifts due to egg-to-adult development time and were influenced by population and mating status. These results help to explain why preadult life history variation determines subsequent expression of the adult transcriptome along with traits involved with reproductive isolation and revealed previously

  14. Seedling architecture and life history evolution in pines

    Science.gov (United States)

    Steven H. Strauss; F. Thomas Ledig

    1985-01-01

    Much of the work on life history evolution in plants has dealt with allocation of reproductive effort (Abrahamson 1975; Abrahamson and Gadgil 1973; Gaines et al. 1974; McNaughton 1975; Oka 1976; Stearns 1976, 1977, 1980; Newell and Tramer 1978; Primack 1979). The juvenile period, however, occupies a major and critical portion of the life cycle of many species....

  15. Heterogeneity of life histories in a nonhuman primate population

    DEFF Research Database (Denmark)

    Hernández Pacheco, Raisa; Steiner, Uli

    2014-01-01

    Identifying the sources of variation in life histories, whether fixed (heritable) and/or dynamic differences, remains a fundamental task to address in order to understand the meaning and significance of phenotypic variation within populations. To test whether the variation among individual life...

  16. Life history theory predicts fish assemblage response to hydrologic regimes.

    Science.gov (United States)

    Mims, Meryl C; Olden, Julian D

    2012-01-01

    The hydrologic regime is regarded as the primary driver of freshwater ecosystems, structuring the physical habitat template, providing connectivity, framing biotic interactions, and ultimately selecting for specific life histories of aquatic organisms. In the present study, we tested ecological theory predicting directional relationships between major dimensions of the flow regime and life history composition of fish assemblages in perennial free-flowing rivers throughout the continental United States. Using long-term discharge records and fish trait and survey data for 109 stream locations, we found that 11 out of 18 relationships (61%) tested between the three life history strategies (opportunistic, periodic, and equilibrium) and six hydrologic metrics (two each describing flow variability, predictability, and seasonality) were statistically significant (P history strategies, with 82% of all significant relationships observed supporting predictions from life history theory. Specifically, we found that (1) opportunistic strategists were positively related to measures of flow variability and negatively related to predictability and seasonality, (2) periodic strategists were positively related to high flow seasonality and negatively related to variability, and (3) the equilibrium strategists were negatively related to flow variability and positively related to predictability. Our study provides important empirical evidence illustrating the value of using life history theory to understand both the patterns and processes by which fish assemblage structure is shaped by adaptation to natural regimes of variability, predictability, and seasonality of critical flow events over broad biogeographic scales.

  17. Life History Trade-Offs Modulate the Speed of Senescence

    DEFF Research Database (Denmark)

    Salguero-Gómez, Roberto; Jones, Owen

    2017-01-01

    The vast amount of scientific attention attracted by ageing research is, to a large extent, due to humanity’s desire to prolong life span and ‘health span’. Still, from a purely ecological and evolutionary point of view, the fact that such a large diversity of longevities exists is extremely...... examined how key life-history traits such as mean life expectancy, generation time and the length of life lived before maturity correlate with this measure of senescence, finding that iteroparous, slow-growing species are more likely to senesce slowly and thus attain long mature life spans. We further...

  18. A life-history theory perspective on obesity.

    Science.gov (United States)

    Dittmann, Andrea G; Maner, Jon K

    2017-01-01

    We extend Nettle et al.'s insurance hypothesis (IH) argument, drawing upon life-history theory (LHT), a developmental evolutionary perspective that documents downstream consequences of early-life exposure to unpredictable environments. We discuss novel evidence consistent with both IH and LHT, suggesting that early-life exposure to unpredictable environments is associated with reduced engagement in weight management behaviors and a greater probability of adulthood obesity.

  19. Life history migrations of adult Yellowstone Cutthroat Trout in the upper Yellowstone River

    Science.gov (United States)

    Ertel, Brian D.; McMahon, Thomas E.; Koel, Todd M.; Gresswell, Robert E.; Burckhardt, Jason

    2017-01-01

    Knowledge of salmonid life history types at the watershed scale is increasingly recognized as a cornerstone for effective management. In this study, we used radiotelemetry to characterize the life history movements of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri in the upper Yellowstone River, an extensive tributary that composes nearly half of the drainage area of Yellowstone Lake. In Yellowstone Lake, Yellowstone Cutthroat Trout have precipitously declined over the past 2 decades primarily due to predation from introduced Lake Trout Salvelinus namaycush. Radio tags were implanted in 152 Yellowstone Cutthroat Trout, and their movements monitored over 3 years. Ninety-six percent of tagged trout exhibited a lacustrine–adfluvial life history, migrating upstream a mean distance of 42.6 km to spawn, spending an average of 24 d in the Yellowstone River before returning to Yellowstone Lake. Once in the lake, complex postspawning movements were observed. Only 4% of radio-tagged trout exhibited a fluvial or fluvial–adfluvial life history. Low prevalence of fluvial and fluvial–adfluvial life histories was unexpected given the large size of the upper river drainage. Study results improve understanding of life history diversity in potamodromous salmonids inhabiting relatively undisturbed watersheds and provide a baseline for monitoring Yellowstone Cutthroat Trout response to management actions in Yellowstone Lake.

  20. Nutrition shapes life-history evolution across species.

    Science.gov (United States)

    Swanson, Eli M; Espeset, Anne; Mikati, Ihab; Bolduc, Isaac; Kulhanek, Robert; White, William A; Kenzie, Susan; Snell-Rood, Emilie C

    2016-07-13

    Nutrition is a key component of life-history theory, yet we know little about how diet quality shapes life-history evolution across species. Here, we test whether quantitative measures of nutrition are linked to life-history evolution across 96 species of butterflies representing over 50 independent diet shifts. We find that butterflies feeding on high nitrogen host plants as larvae are more fecund, but their eggs are smaller relative to their body size. Nitrogen and sodium content of host plants are also both positively related to eye size. Some of these relationships show pronounced lineage-specific effects. Testis size is not related to nutrition. Additionally, the evolutionary timing of diet shifts is not important, suggesting that nutrition affects life histories regardless of the length of time a species has been adapting to its diet. Our results suggest that, at least for some lineages, species with higher nutrient diets can invest in a range of fitness-related traits like fecundity and eye size while allocating less to each egg as offspring have access to a richer diet. These results have important implications for the evolution of life histories in the face of anthropogenic changes in nutrient availability. © 2016 The Author(s).

  1. Life-History Patterns of Lizards of the World.

    Science.gov (United States)

    Mesquita, Daniel O; Costa, Gabriel C; Colli, Guarino R; Costa, Taís B; Shepard, Donald B; Vitt, Laurie J; Pianka, Eric R

    2016-06-01

    Identification of mechanisms that promote variation in life-history traits is critical to understand the evolution of divergent reproductive strategies. Here we compiled a large life-history data set (674 lizard populations, representing 297 species from 263 sites globally) to test a number of hypotheses regarding the evolution of life-history traits in lizards. We found significant phylogenetic signal in most life-history traits, although phylogenetic signal was not particularly high. Climatic variables influenced the evolution of many traits, with clutch frequency being positively related to precipitation and clutches of tropical lizards being smaller than those of temperate species. This result supports the hypothesis that in tropical and less seasonal climates, many lizards tend to reproduce repeatedly throughout the season, producing smaller clutches during each reproductive episode. Our analysis also supported the hypothesis that viviparity has evolved in lizards as a response to cooler climates. Finally, we also found that variation in trait values explained by clade membership is unevenly distributed among lizard clades, with basal clades and a few younger clades showing the most variation. Our global analyses are largely consistent with life-history theory and previous results based on smaller and scattered data sets, suggesting that these patterns are remarkably consistent across geographic and taxonomic scales.

  2. The Power of Life Histories: Moving Readers to Greater Acts of Empathy through Literature and Memoir

    Science.gov (United States)

    Lee, Valarie G.; Madden, Marjorie E.

    2016-01-01

    This paper argues that narratives, specifically literature and memoir, offer a way to build empathy and understanding by moving readers to deeper levels of text interpretation and critique. The paper examines a new literacy framework, Life Histories, that uses talk, collaboration, writing, and performance to understand the complex relationships…

  3. The ecology of life history evolution : genes, individuals and populations

    OpenAIRE

    Visser, M.E.

    2013-01-01

    Natural selection shapes the life histories of organisms. The ecological interactions of these organisms with their biotic and abiotic environment shape the selection pressure on their phenotypes while their genetics determine how fast this selection leads to adaptation to their environment. The field of ecological genetics studies the response to natural selection in the wild and thus plays a key role in our understanding of the adaptive capacity of life, essential to understand how a changi...

  4. Planetary biology--paleontological, geological, and molecular histories of life.

    Science.gov (United States)

    Benner, Steven A; Caraco, M Daniel; Thomson, J Michael; Gaucher, Eric A

    2002-05-03

    The history of life on Earth is chronicled in the geological strata, the fossil record, and the genomes of contemporary organisms. When examined together, these records help identify metabolic and regulatory pathways, annotate protein sequences, and identify animal models to develop new drugs, among other features of scientific and biomedical interest. Together, planetary analysis of genome and proteome databases is providing an enhanced understanding of how life interacts with the biosphere and adapts to global change.

  5. Early life history and habitat ecology of estuarine fishes: responses to natural and human induced change

    Directory of Open Access Journals (Sweden)

    Kenneth Able

    2015-12-01

    Full Text Available Our understanding of the early life history of fishes and their habitats has proceeded from basic natural history to ecology, but we often need to return to natural history to address deficiencies in conceptual and quantitative models of ecosystems. This understanding is further limited by the complex life history of fishes and the lack of appreciation of shifting baselines in estuaries. These inadequacies are especially evident when we try to address the effects of human influences, e.g. fishing, urbanization, and climate change. Often our baselines are inadequate or inaccurate. Our work has detected these along the coasts of the U.S. in extensive time series of larval fish ingress into estuaries, studies of the effects of urbanization, and responses to catastrophes such as the BP oil spill. Long-term monitoring, especially, continues to provide critical insights

  6. Life-History and Developmental Antecedents of Female Vocational Preferences.

    Science.gov (United States)

    Reichel, Laura S.; Muchinsky, Paul M.

    1995-01-01

    A group of 296 female undergraduates completed the Strong Interest Inventory, Biographical Questionnaire, Bem Sex-Role Inventory, and Self-Esteem Inventory. Life history was a better predictor of vocational interests than either sex-role orientation or self-esteem. The only significant exception was that Femininity correlated with interest in…

  7. Plant life history and above–belowground interactions

    NARCIS (Netherlands)

    Deyn, de Gerlinde

    2017-01-01

    The importance of above–belowground interactions for plant growth and community dynamics became clear in the last decades, whereas the numerous studies on plant life history improved our knowledge on eco-evolutionary dynamics. However, surprisingly few studies have linked both research fields

  8. Can understanding squid life-history strategies and recruitment ...

    African Journals Online (AJOL)

    Current views of the links between life-history strategies and recruitment processes in fish are contrasted with the pattern emerging for squid. A general perspective is that the roles of space and time are reversed in the two groups, suggesting that management strategies also should differ. The space/time reversal appears to ...

  9. Book Review: Evolutionary Ecology of Birds: Life Histories, Mating ...

    African Journals Online (AJOL)

    Abstract. Book Title: Evolutionary Ecology of Birds: Life Histories, Mating Systems and Extinction. Book Authors: P.M. Bennett & I.P.F. Owens. Oxford University. Press. 2002. Pp. 272. Price £24.95 (paperback). ISBN 0 19 851089 6.

  10. The ecology of life history evolution : genes, individuals and populations

    NARCIS (Netherlands)

    Visser, M.E.

    2013-01-01

    Natural selection shapes the life histories of organisms. The ecological interactions of these organisms with their biotic and abiotic environment shape the selection pressure on their phenotypes while their genetics determine how fast this selection leads to adaptation to their environment. The

  11. A Brief History of Family Life Education in Romania

    Science.gov (United States)

    Momanu, Mariana; Popa, Nicoleta Laura; Samoila, Magda-Elena

    2018-01-01

    Starting from the state of conceptual diversity, semantic ambiguity, and poor connection of family life education practices to current policies and theoretical models in Romania, our study aims at understanding the underlying meanings of these issues by recourse to the history of approaches in the field. To this purpose, we carried out a…

  12. Life history traits of Bathyclarias nyasensis (Siluroidei) in Lake Malawi

    African Journals Online (AJOL)

    Life history traits, including age, growth, reproduction and diet of Bathyclarias nyasensis from Lake Malawi were studied between December 1996 and November 1998. Owing to reabsorp tion of pectoral spines with increasing fish size, and the relatively low number of spines that could be aged reliably, only otoliths were ...

  13. The life-history of Sphacelaria furcigera Kutz. (Phaeophyceae)

    NARCIS (Netherlands)

    Hoek, van den C.; Flinterman, A.

    1968-01-01

    Cultural and caryological investigations on Sphacelaria furcigera from Hoek van Holland give evidence of a slightly heteromorphic diplohaplontic life-history in this species. A relatively slender (13.5—31 μ) haploid gametophytic phase alternates with a more robust (19—41 μ) diploid sporophytic

  14. Comparison of the population structure and life-history parameters ...

    African Journals Online (AJOL)

    Blacktail seabream Diplodus capensis were sampled from proximate (10 km apart) exploited and unexploited areas in southern Angola to compare their population structures and life-history parameters. Females dominated the larger size and older age classes in the unexploited area. In the exploited area the length and ...

  15. Variations in morphological and life-history traits under extreme ...

    Indian Academy of Sciences (India)

    C than at 32°C in D. ananassae. The genetic variations for all the quantitative and life-history traits were higher at low temperature. Variation in sexual traits was more pronounced as compared with other morphometric traits, which shows that ...

  16. Bringing history to life: simulating landmark experiments in psychology.

    Science.gov (United States)

    Boynton, David M; Smith, Laurence D

    2006-05-01

    The course in history of psychology can be challenging for students, many of whom enter it with little background in history and faced with unfamiliar names and concepts. The sheer volume of material can encourage passive memorization unless efforts are made to increase student involvement. As part of a trend toward experiential history, historians of science have begun to supplement their lectures with demonstrations of classic physics experiments as a way to bring the history of science to life. Here, the authors report on computer simulations of five landmark experiments from early experimental psychology in the areas of reaction time, span of attention, and apparent motion. The simulations are designed not only to permit hands-on replication of historically important results but also to reproduce the experimental procedures closely enough that students can gain a feel for the nature of early research and the psychological processes being studied.

  17. Ecological and evolutionary consequences of linked life-history stages in the sea.

    Science.gov (United States)

    Marshall, Dustin J; Morgan, Steven G

    2011-09-27

    Naturalists and scientists have been captivated by the diversity of marine larval forms since they were discovered following the advent of the microscope. Because they often bear little resemblance to adults, larvae were identified initially as new life forms, classified into different groups based on the similarity of their body plans and given new names that are still with us today. The radically different body plans and lifestyles of marine larvae and adults have led most investigators historically to study the two phases of complex life cycles in isolation. More recently, important ecological insights have sprung from taking a holistic view of marine life cycles. Meanwhile, the evolutionary (phenotypic and genetic) links among life-history phases remain less appreciated. In this review, our objective is to evaluate the evolutionary links within marine life cycles, and explore their ecological and evolutionary consequences. We provide a brief overview of marine life histories, discuss the phenotypic and genetic links between the two phases of the life cycle and pose challenges to advance our understanding of the evolutionary constraints acting on marine life histories. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Telling Modernization: Three Voices. Life History, Gender and the Discourse of Modernization. Roskilde University Life History Project Paper.

    Science.gov (United States)

    Anderson, Linda

    The relationship between life history, gender, and the discourse of modernization was examined from the perspective of a researcher with extensive experience performing evaluations about modernization within human services in Denmark. Three stories about site-based management in two human service institutionsa youth center and a boarding school…

  19. Towards cancer-aware life-history modelling.

    Science.gov (United States)

    Kokko, Hanna; Hochberg, Michael E

    2015-07-19

    Studies of body size evolution, and life-history theory in general, are conducted without taking into account cancer as a factor that can end an organism's reproductive lifespan. This reflects a tacit assumption that predation, parasitism and starvation are of overriding importance in the wild. We argue here that even if deaths directly attributable to cancer are a rarity in studies of natural populations, it remains incorrect to infer that cancer has not been of importance in shaping observed life histories. We present first steps towards a cancer-aware life-history theory, by quantifying the decrease in the length of the expected reproductively active lifespan that follows from an attempt to grow larger than conspecific competitors. If all else is equal, a larger organism is more likely to develop cancer, but, importantly, many factors are unlikely to be equal. Variations in extrinsic mortality as well as in the pace of life--larger organisms are often near the slow end of the fast-slow life-history continuum--can make realized cancer incidences more equal across species than what would be observed in the absence of adaptive responses to cancer risk (alleviating the so-called Peto's paradox). We also discuss reasons why patterns across species can differ from within-species predictions. Even if natural selection diminishes cancer susceptibility differences between species, within-species differences can remain. In many sexually dimorphic cases, we predict males to be more cancer-prone than females, forming an understudied component of sexual conflict.

  20. Life history parameters of narwhals (Monodon monoceros) from Greenland

    DEFF Research Database (Denmark)

    Garde, Eva; Hansen, Steen H; Ditlevsen, Susanne

    2015-01-01

    Life history parameters for narwhals (Monodon monoceros) were estimated based on age estimates from aspartic acid racemization of eye lens nuclei. Eyes, reproductive organs, and measures of body lengths were collected from 282 narwhals in East and West Greenland in the years 1993, 2004, and 2007...... assessed based on data from reproductive organs and was estimated to be 8–9 years for females and 12–20 years for males. Pregnancy rates for East and West Greenland were estimated to be 0.38–0.42 and 0.38, respectively. Maximum life span expectancy was found to be approximately 100 years. A population...

  1. Industrial energy use and the human life history.

    Science.gov (United States)

    Burger, Oskar; Delong, John P; Hamilton, Marcus J

    2011-01-01

    The demographic rates of most organisms are supported by the consumption of food energy, which is used to produce new biomass and fuel physiological processes. Unlike other species, modern humans use 'extra-metabolic' energy sources acquired independent of physiology, which also influence demographics. We ask whether the amount of extra-metabolic energy added to the energy budget affects demographic and life history traits in a predictable way. Currently it is not known how human demographics respond to energy use, and we characterize this response using an allometric approach. All of the human life history traits we examine are significant functions of per capita energy use across industrialized populations. We find a continuum of traits from those that respond strongly to the amount of extra-metabolic energy used, to those that respond with shallow slopes. We also show that the differences in plasticity across traits can drive the net reproductive rate to below-replacement levels.

  2. Dissecting molecular stress networks: identifying nodes of divergence between life-history phenotypes.

    Science.gov (United States)

    Schwartz, Tonia S; Bronikowski, Anne M

    2013-02-01

    The complex molecular network that underlies physiological stress response is comprised of nodes (proteins, metabolites, mRNAs, etc.) whose connections span cells, tissues and organs. Variable nodes are points in the network upon which natural selection may act. Thus, identifying variable nodes will reveal how this molecular stress network may evolve among populations in different habitats and how it might impact life-history evolution. Here, we use physiological and genetic assays to test whether laboratory-born juveniles from natural populations of garter snakes (Thamnophis elegans), which have diverged in their life-history phenotypes, vary concomitantly at candidate nodes of the stress response network, (i) under unstressed conditions and (ii) in response to an induced stress. We found that two common measures of stress (plasma corticosterone and liver gene expression of heat shock proteins) increased under stress in both life-history phenotypes. In contrast, the phenotypes diverged at four nodes both under unstressed conditions and in response to stress: circulating levels of reactive oxygen species (superoxide, H(2)O(2)); liver gene expression of GPX1 and erythrocyte DNA damage. Additionally, allele frequencies for SOD2 diverge from neutral markers, suggesting diversifying selection on SOD2 alleles. This study supports the hypothesis that these life-history phenotypes have diverged at the molecular level in how they respond to stress, particularly in nodes regulating oxidative stress. Furthermore, the differences between the life-history phenotypes were more pronounced in females. We discuss the responses to stress in the context of the associated life-history phenotype and the evolutionary pressures thought to be responsible for divergence between the phenotypes. © 2012 Blackwell Publishing Ltd.

  3. Sleep-Wake State Tradeoffs, Impulsivity and Life History Theory

    Directory of Open Access Journals (Sweden)

    Alissa A. Miller

    2012-04-01

    Full Text Available Evolutionary ecological theory predicts that sleep-wake state tradeoffs may be related to local environmental conditions and should therefore correlate to alterations in behavioral life history strategies. It was predicted that firefighters who slept more and reported better quality sleep on average would exhibit lower impulsivity inclinations related to slower life history trajectories. UPPS impulsivity scores and self-reported sleep averages were analyzed and indicated a negative association between sleep variables and urgency and a positive association with premeditation. Perseverance, and in some cases premeditation, however, disclosed an unpredicted marginally significant positive association between increased and emergency nighttime waking-related sleep deprivation. Sensation seeking was not associated with sleep variables, but was strongly associated with number of biological children. This research contributes to understanding the implications of human sleep across ecological and behavioral contexts and implies further research is necessary for constructing evolutionarily oriented measures of impulsivity inclination and its meaning in the context of life history strategies.

  4. Bioinvasion Triggers Rapid Evolution of Life Histories in Freshwater Snails.

    Science.gov (United States)

    Chapuis, Elodie; Lamy, Thomas; Pointier, Jean-Pierre; Juillet, Nicolas; Ségard, Adeline; Jarne, Philippe; David, Patrice

    2017-11-01

    Biological invasions offer interesting situations for observing how novel interactions between closely related, formerly allopatric species may trigger phenotypic evolution in situ. Assuming that successful invaders are usually filtered to be competitively dominant, invasive and native species may follow different trajectories. Natives may evolve traits that minimize the negative impact of competition, while trait shifts in invasives should mostly reflect expansion dynamics, through selection for colonization ability and transiently enhanced mutation load at the colonization front. These ideas were tested through a large-scale common-garden experiment measuring life-history traits in two closely related snail species, one invasive and one native, co-occurring in a network of freshwater ponds in Guadeloupe. We looked for evidence of recent evolution by comparing uninvaded or recently invaded sites with long-invaded ones. The native species adopted a life history favoring rapid population growth (i.e., increased fecundity, earlier reproduction, and increased juvenile survival) that may increase its prospects of coexistence with the more competitive invader. We discuss why these effects are more likely to result from genetic change than from maternal effects. The invader exhibited slightly decreased overall performances in recently colonized sites, consistent with a moderate expansion load resulting from local founder effects. Our study highlights a rare example of rapid life-history evolution following invasion.

  5. The life-history basis of behavioural innovations.

    Science.gov (United States)

    Sol, Daniel; Sayol, Ferran; Ducatez, Simon; Lefebvre, Louis

    2016-03-19

    The evolutionary origin of innovativeness remains puzzling because innovating means responding to novel or unusual problems and hence is unlikely to be selected by itself. A plausible alternative is considering innovativeness as a co-opted product of traits that have evolved for other functions yet together predispose individuals to solve problems by adopting novel behaviours. However, this raises the question of why these adaptations should evolve together in an animal. Here, we develop the argument that the adaptations enabling animals to innovate evolve together because they are jointly part of a life-history strategy for coping with environmental changes. In support of this claim, we present comparative evidence showing that in birds, (i) innovative propensity is linked to life histories that prioritize future over current reproduction, (ii) the link is in part explained by differences in brain size, and (iii) innovative propensity and life-history traits may evolve together in generalist species that frequently expose themselves to novel or unusual conditions. Combined with previous evidence, these findings suggest that innovativeness is not a specialized adaptation but more likely part of a broader general adaptive system to cope with changes in the environment. © 2016 The Author(s).

  6. Contrasting life histories in neighbouring populations of a large mammal.

    Science.gov (United States)

    Mason, Tom H E; Chirichella, Roberta; Richards, Shane A; Stephens, Philip A; Willis, Stephen G; Apollonio, Marco

    2011-01-01

    A fundamental life history question is how individuals should allocate resources to reproduction optimally over time (reproductive allocation). The reproductive restraint hypothesis predicts that reproductive effort (RE; the allocation of resources to current reproduction) should peak at prime-age, whilst the terminal investment hypothesis predicts that individuals should continue to invest more resources in reproduction throughout life, owing to an ever-decreasing residual reproductive value. There is evidence supporting both hypotheses in the scientific literature. We used an uncommonly large, 38 year dataset on Alpine chamois (Rupicapra rupicapra) shot at various times during the rutting period to test these two hypotheses. We assumed that body mass loss in rutting males was strongly related to RE and, using a process-based approach, modelled how male relative mass loss rates varied with age. For different regions of our study area, we provide evidence consistent with different hypotheses for reproductive allocation. In sites where RE declined in older age, this appears to be strongly linked to declining body condition in old males. In this species, terminal investment may only occur in areas with lower rates of body mass senescence. Our results show that patterns of reproductive allocation may be more plastic than previously thought. It appears that there is a continuum from downturns in RE at old age to terminal investment that can be manifest, even across adjacent populations. Our work identifies uncertainty in the relationship between reproductive restraint and a lack of competitive ability in older life (driven by body mass senescence); both could explain a decline in RE in old age and may be hard to disentangle in empirical data. We discuss a number of environmental and anthropogenic factors which could influence reproductive life histories, underlining that life history patterns should not be generalised across different populations.

  7. Contrasting life histories in neighbouring populations of a large mammal.

    Directory of Open Access Journals (Sweden)

    Tom H E Mason

    Full Text Available A fundamental life history question is how individuals should allocate resources to reproduction optimally over time (reproductive allocation. The reproductive restraint hypothesis predicts that reproductive effort (RE; the allocation of resources to current reproduction should peak at prime-age, whilst the terminal investment hypothesis predicts that individuals should continue to invest more resources in reproduction throughout life, owing to an ever-decreasing residual reproductive value. There is evidence supporting both hypotheses in the scientific literature.We used an uncommonly large, 38 year dataset on Alpine chamois (Rupicapra rupicapra shot at various times during the rutting period to test these two hypotheses. We assumed that body mass loss in rutting males was strongly related to RE and, using a process-based approach, modelled how male relative mass loss rates varied with age. For different regions of our study area, we provide evidence consistent with different hypotheses for reproductive allocation. In sites where RE declined in older age, this appears to be strongly linked to declining body condition in old males. In this species, terminal investment may only occur in areas with lower rates of body mass senescence.Our results show that patterns of reproductive allocation may be more plastic than previously thought. It appears that there is a continuum from downturns in RE at old age to terminal investment that can be manifest, even across adjacent populations. Our work identifies uncertainty in the relationship between reproductive restraint and a lack of competitive ability in older life (driven by body mass senescence; both could explain a decline in RE in old age and may be hard to disentangle in empirical data. We discuss a number of environmental and anthropogenic factors which could influence reproductive life histories, underlining that life history patterns should not be generalised across different populations.

  8. The Surprising History of Claims for Life on the Sun

    Science.gov (United States)

    Crowe, Michael J.

    2011-11-01

    Because astronomers are now convinced that it is impossible for life, especially intelligent life, to exist on the Sun and stars, it might be assumed that astronomers have always held this view. This paper shows that throughout most of the history of astronomy, some intellectuals, including a number of well-known astronomers, have advocated the existence of intelligent life on our Sun and thereby on stars. Among the more prominent figures discussed are Nicolas of Cusa, Giordano Bruno, William Whiston, Johann Bode, Roger Boscovich, William Herschel, Auguste Comte, Carl Gauss, Thomas Dick, John Herschel, and François Arago. One point in preparing this paper is to show differences between the astronomy of the past and that of the present.

  9. Life history and bioeconomy of the house mouse.

    Science.gov (United States)

    Berry, R J; Bronson, F H

    1992-11-01

    1. More is known about the western European house mouse, Mus (musculus) domesticus than any other non-human mammal. If laboratory and field information is combined, an extremely valuable understanding of the species' bioeconomy could be obtained. 2. The seven stages of mouse life-history are surveyed (up to birth, nest life, sex life, social structure, population statics and stability, senescence, and death), and the interactions between the changing phenotype and the environment are described. 3. These interactions can be used to build up a model of the opportunities and compromises which result in the fitness of individual mice. It is not yet possible to quantify such a model, but this should in principle be achievable.

  10. The history of life and death: a 'spiritual' history from invisible matter to prolongation of life.

    Science.gov (United States)

    Gemelli, Benedino

    2012-01-01

    Over a long period of time, particularly from the nineteenth century on, Francis Bacon's philosophy has been interpreted as centred on the Novum organum and focused on the role that a well-organized method may play in securing a reliable knowledge of nature. In fact, if we examine Bacon's oeuvre as a whole, including some recent manuscript findings (De vijs mortis), we can safely argue that the issues addressed in the Novum organum represent only a part of Bacon's agenda, and not even the most important ones. By contrast, it is apparent that, from the very beginning of his investigations, he emphasized the central role of medicine, the need to establish new approaches in the study of the vital functions and the importance of promoting new discoveries in the medical field, not so much to find a cure for the many illnesses that plagued mankind as to prolong human life. In this sense, Historia vitae et mortis plays a central role in Bacon's programme to extend human knowledge and power, for, in his opinion, human beings could recover their lost ability to live a long and healthy life by embarking on careful investigations of nature. Far from being a purely descriptive or abstract exercise, Bacon's historia can therefore be seen as an operative tool to attain some of mankind's basic aims.

  11. The contribution of developmental experience vs. condition to life history, trait variation, and individual differences

    OpenAIRE

    DiRienzo, Nicholas; Montiglio, Pierre-Olivier

    2016-01-01

    Developmental experience, for example food abundance during juvenile stages, is known to affect life history and behaviour. However, the life history and behavioural consequences of developmental experience have rarely been studied in concert. As a result it is still unclear whether developmental experience affects behaviour through changes in life history, or independently of it.The effect of developmental experience on life history and behaviour may also be masked or affected by individual ...

  12. Life-history strategy determines constraints on immune function.

    Science.gov (United States)

    Parker, Benjamin J; Barribeau, Seth M; Laughton, Alice M; Griffin, Lynn H; Gerardo, Nicole M

    2017-05-01

    Determining the factors governing investment in immunity is critical to understanding host-pathogen ecological and evolutionary dynamics. Studies often consider disease resistance in the context of life-history theory, with the expectation that investment in immunity will be optimized in anticipation of disease risk. Immunity, however, is constrained by context-dependent fitness costs. How the costs of immunity vary across life-history strategies has yet to be considered. Pea aphids are typically unwinged but produce winged offspring in response to high population densities and deteriorating conditions. This is an example of polyphenism, a strategy used by many organisms to adjust to environmental cues. The goal of this study was to examine the relationship between the fitness costs of immunity, pathogen resistance and the strength of an immune response across aphid morphs that differ in life-history strategy but are genetically identical. We measured fecundity of winged and unwinged aphids challenged with a heat-inactivated fungal pathogen, and found that immune costs are limited to winged aphids. We hypothesized that these costs reflect stronger investment in immunity in anticipation of higher disease risk, and that winged aphids would be more resistant due to a stronger immune response. However, producing wings is energetically expensive. This guided an alternative hypothesis - that investing resources into wings could lead to a reduced capacity to resist infection. We measured survival and pathogen load after live fungal infection, and we characterized the aphid immune response to fungi by measuring immune cell concentration and gene expression. We found that winged aphids are less resistant and mount a weaker immune response than unwinged aphids, demonstrating that winged aphids pay higher costs for a less effective immune response. Our results show that polyphenism is an understudied factor influencing the expression of immune costs. More generally, our work

  13. "Ant" and "grasshopper" life-history strategies in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Aymé Spor

    Full Text Available From the evolutionary and ecological points of view, it is essential to distinguish between the genetic and environmental components of the variability of life-history traits and of their trade-offs. Among the factors affecting this variability, the resource uptake rate deserves particular attention, because it depends on both the environment and the genetic background of the individuals. In order to unravel the bases of the life-history strategies in yeast, we grew a collection of twelve strains of Saccharomyces cerevisiae from different industrial and geographical origins in three culture media differing for their glucose content. Using a population dynamics model to fit the change of population size over time, we estimated the intrinsic growth rate (r, the carrying capacity (K, the mean cell size and the glucose consumption rate per cell. The life-history traits, as well as the glucose consumption rate, displayed large genetic and plastic variability and genetic-by-environment interactions. Within each medium, growth rate and carrying capacity were not correlated, but a marked trade-off between these traits was observed over the media, with high K and low r in the glucose rich medium and low K and high r in the other media. The cell size was tightly negatively correlated to carrying capacity in all conditions. The resource consumption rate appeared to be a clear-cut determinant of both the carrying capacity and the cell size in all media, since it accounted for 37% to 84% of the variation of those traits. In a given medium, the strains that consume glucose at high rate have large cell size and low carrying capacity, while the strains that consume glucose at low rate have small cell size but high carrying capacity. These two contrasted behaviors may be metaphorically defined as "ant" and "grasshopper" strategies of resource utilization. Interestingly, a strain may be "ant" in one medium and "grasshopper" in another. These life-history

  14. A psycho-societal approach to life histories

    DEFF Research Database (Denmark)

    Olesen, Henning Salling

    2016-01-01

    particularly interested in the relations between the culturally mediated and the sensory/bodily aspects of experience processes because this is the boundary zones of knowledge and seat of the dynamics of learning. My psycho-societal approach was developing from interpreting autobiographical and later certain...... other forms of language interactive material as moments of life history, i.e. it is basically a hermeneutic approach. Talking about a psycho-societal approach indicates the ambition of attacking the dichotomy of the social and the psychic, both in the interpretation procedure and in some main...

  15. The life history of Pygidiopsis macrostomum Travassos, 1928 (Digenea: Heterophyidae

    Directory of Open Access Journals (Sweden)

    Susana Balmant Emerique Simões

    2009-02-01

    Full Text Available The life history of the trematode Pygidiopsis macrostomum Travassos, 1928 is described for the first time. Rediae and cercariae were obtained from naturally infected snails Heleobia australis (d´Orbigny, a new first intermediate host. Metacercariae were found encysted in the mesenteries of three naturally infected guppies, Phalloptychus januarius (Hensel, Jenynsia multidentata (Jenyns (new host records and Poecilia vivipara Bloch and Schneider. Experimental infections were successfully completed in the intermediate hosts H. australis and Poe. vivipara reared in the laboratory and hamsters Mesocricetus auratus Waterhouse were utilised as a definitive host.

  16. Life history of the Harlequin ladybird, Harmonia axyridis; a global meta-analysis

    NARCIS (Netherlands)

    Raak-van den Berg, C.L.; Hemerik, A.; Werf, van der W.; Jong, de P.W.; Lenteren, van J.C.

    2017-01-01

    Data collected en used for a meta analysis on life history data of H. axyridis. And the resulting 20 best models for each life history characteristic. Published in the paper: Life history of the Harlequin ladybird, Harmonia axyridis; a global meta-analysis.

  17. Robin's Story: Life History of an Exemplary American Female Physical Education Teacher

    Science.gov (United States)

    Cazers, Gunars; Curtner-Smith, Matthew D.

    2017-01-01

    Purpose: The purpose was to construct the life history of Robin, an exemplary female physical educator, to hear her voice, and to explore ways in which she experienced marginalization. Few life histories of exemplary physical educators have been recounted. Method: Robin's life history was investigated in light of the theory of occupational…

  18. Atom and life - History of a research issued from nuclear

    International Nuclear Information System (INIS)

    Griset, Pascal; Picard, Jean-Francois

    2015-01-01

    As many examples illustrate the commitment of the French CEA in biology (development of medical imagery technologies, of the first prion test for the detection of the Creutzfeldt-Jakob disease), this book proposes an insight into those specific researches in life sciences performed within this institution initially devoted to nuclear sciences. This history comprises researches performed in Fontenay aux Roses at the initiative of Frederic Joliot on basic physiological processes, the development of a scientific library in Saclay where physicists, chemists and biologists worked together, the building of a medical department within the Saclay hospital, research activities in Grenoble, the regrouping of biology laboratories, the increasingly important mission of the Life Sciences Directorate within the CEA in four domains (radiobiology and radio-pathology, protein engineering and structural biology, medical imagery and pharmacology, eco-physiology and vegetal ecosystems). This research field is now characterized by its international dimension

  19. Impaired Perinatal Growth and Longevity: A Life History Perspective

    Directory of Open Access Journals (Sweden)

    Deborah M. Sloboda

    2009-01-01

    Full Text Available Life history theory proposes that early-life cues induce highly integrated responses in traits associated with energy partitioning, maturation, reproduction, and aging such that the individual phenotype is adaptively more appropriate to the anticipated environment. Thus, maternal and/or neonatally derived nutritional or endocrine cues suggesting a threatening environment may favour early growth and reproduction over investment in tissue reserve and repair capacity. These may directly affect longevity, as well as prioritise insulin resistance and capacity for fat storage, thereby increasing susceptibility to metabolic dysfunction and obesity. These shifts in developmental trajectory are associated with long-term expression changes in specific genes, some of which may be underpinned by epigenetic processes. This normative process of developmental plasticity may prove to be maladaptive in human environments in transition towards low extrinsic mortality and energy-dense nutrition, leading to the development of an inappropriate phenotype with decreased potential for longevity and/or increased susceptibility to metabolic disease.

  20. Learning in Life History - psycho-societal interpretation of biographies

    DEFF Research Database (Denmark)

    Olesen, Henning Salling

    2008-01-01

    of subjectivity and experience, derived from European critical theory, are briefly introduced with respect to their intellectual background. Based on examples from the author’s research into the professional learning, the article outlines the implications of these concepts in relation to an understanding...... of emotional aspects of learning in everyday life and to an understanding of knowledge. The pivotal role of language use and language socialisation is explained in brief, and a psychodynamic complement to a language game concept of language use is developed.......Taking its point of departure from some critical remarks about some of the most important recent theorizing of learning, this article presents an alternative framework for theorizing learning as a subjective process in a social and societal context, based on life history research. The key concepts...

  1. Theorizing Learning in Life History - a psycho-societal approach

    DEFF Research Database (Denmark)

    Olesen, Henning Salling

    2007-01-01

    derived from European critical theory, subjectivity and experience, are briefly introduced with a view to their intellectual background. The chapter elaborates the implication of these concepts in relation to the understanding of emotional aspects of learning in everyday life and in relation...... to the understanding of knowledge, based on examples from the author's research into professional learning (general practitioners). The pivotal role of language use and language socialisation is explained in brief, developing a psychodynamic complement to a language game concept of language use.......  Taking it's point of departure in some critical remarks to some of the most important recent theorizing of learning, this article presents an alternative framework for theorizing learning as a subjective process in a social and societal context, based in life history research. Key concepts...

  2. Contributions of endocrinology to the migration life history of birds.

    Science.gov (United States)

    Cornelius, J M; Boswell, T; Jenni-Eiermann, S; Breuner, C W; Ramenofsky, M

    2013-09-01

    Migration is a key life cycle stage in nearly 2000 species of birds and is a greatly appreciated phenomenon in both cultural and academic arenas. Despite a long research tradition concerning many aspects of migration, investigations of hormonal contributions to migratory physiology and behavior are more limited and represent a comparatively young research field. We review advances in our understanding of the hormonal mechanisms of migration with particular emphasis on the sub-stages of the migration life history: development, departure, flight and arrival. These sub-stages vary widely in their behavioral, ecological and physiological contexts and, as such, should be given appropriate individual consideration. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Life-history interviews of aging gay men.

    Science.gov (United States)

    Kimmel, D C

    Homosexual men and women have seldom been studied by gerontologists and almost nothing is known about the lifestyles, pattern of development through the adult years, and the effect of homosexuality on aging. Fourteen gay men, ranging in age from fifty-five to eighty-one, were interviewed about their life history and experiences of aging as gay men. Three of the respondents had long-term relationships that lasted up to forty years; two had experienced the death of a lover and had begun a new long-term relationship; four had been married to women and two had children (one unmarried man adopted a son and is now a grandfather). The wide diversity of their patterns of aging, the presence of positive aspects of gay aging, and the high life satisfaction of many of the respondents contradict the stereotype of the lonely, isolated old gay man.

  4. Movements of Blue Sharks (Prionace glauca) across Their Life History

    Science.gov (United States)

    Vandeperre, Frederic; Aires-da-Silva, Alexandre; Fontes, Jorge; Santos, Marco; Serrão Santos, Ricardo; Afonso, Pedro

    2014-01-01

    Spatial structuring and segregation by sex and size is considered to be an intrinsic attribute of shark populations. These spatial patterns remain poorly understood, particularly for oceanic species such as blue shark (Prionace glauca), despite its importance for the management and conservation of this highly migratory species. This study presents the results of a long-term electronic tagging experiment to investigate the migratory patterns of blue shark, to elucidate how these patterns change across its life history and to assess the existence of a nursery area in the central North Atlantic. Blue sharks belonging to different life stages (n = 34) were tracked for periods up to 952 days during which they moved extensively (up to an estimated 28.139 km), occupying large parts of the oceanic basin. Notwithstanding a large individual variability, there were pronounced differences in movements and space use across the species' life history. The study provides strong evidence for the existence of a discrete central North Atlantic nursery, where juveniles can reside for up to at least 2 years. In contrast with previously described nurseries of coastal and semi-pelagic sharks, this oceanic nursery is comparatively vast and open suggesting that shelter from predators is not its main function. Subsequently, male and female blue sharks spatially segregate. Females engage in seasonal latitudinal migrations until approaching maturity, when they undergo an ontogenic habitat shift towards tropical latitudes. In contrast, juvenile males generally expanded their range southward and apparently displayed a higher degree of behavioural polymorphism. These results provide important insights into the spatial ecology of pelagic sharks, with implications for the sustainable management of this heavily exploited shark, especially in the central North Atlantic where the presence of a nursery and the seasonal overlap and alternation of different life stages coincides with a high fishing

  5. Life-history stages of the jellyfish Aurelia aurita - towards a demographic understanding of jellyfish blooms

    DEFF Research Database (Denmark)

    Goldstein, Josephine

    2017-01-01

    species involved in mass occurrence have been covered in previous studies, providing important insight into diverse life stage-specific adaptation strategies to changing environmental conditions. Quantification of the demographic rates that characterize different life-history stages however has remained...... scarce and patchy, although may unravel the basic principles underlying jellyfish blooms. In this thesis, vital rates for all life stages of the common jellyfish Aurelia aurita (Scyphozoa, Cnidaria) are documented, which allows pointing out important mechanisms that drive the population dynamics......Jellyfish blooms are conspicuous demographic events that have received increasing attention by the public and the scientific community over the last decades due to their negative impact on fisheries, tourism and other human industries. Several aspects of the complex life cycles of the jellyfish...

  6. Life history, immunity, Peto's paradox and tumours in birds.

    Science.gov (United States)

    Møller, A P; Erritzøe, J; Soler, J J

    2017-05-01

    Cancer and tumours may evolve in response to life-history trade-offs between growth and duration of development on one hand, and between growth and maintenance of immune function on the other. Here, we tested whether (i) bird species with slow developmental rates for their body size experience low incidence of tumours because slow development allows for detection of rapid proliferation of cell lineages. We also test whether (ii) species with stronger immune response during development are more efficient at detecting tumour cells and hence suffer lower incidence of tumours. Finally, we tested Peto's paradox, that there is a positive relationship between tumour incidence and body mass. We used information on developmental rates and body mass from the literature and of tumour incidence (8468 birds) and size of the bursa of Fabricius for 7659 birds brought to a taxidermist in Denmark. We found evidence of the expected negative relationship between incidence of tumours and developmental rates and immunity after controlling for the positive association between tumour incidence and body size. These results suggest that evolution has modified the incidence of tumours in response to life history and that Peto's paradox may be explained by covariation between body mass, developmental rates and immunity. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  7. Life-history evolution and mitogenomic phylogeny of caecilian amphibians.

    Science.gov (United States)

    San Mauro, Diego; Gower, David J; Müller, Hendrik; Loader, Simon P; Zardoya, Rafael; Nussbaum, Ronald A; Wilkinson, Mark

    2014-04-01

    We analyze mitochondrial genomes to reconstruct a robust phylogenetic framework for caecilian amphibians and use this to investigate life-history evolution within the group. Our study comprises 45 caecilian mitochondrial genomes (19 of them newly reported), representing all families and 27 of 32 currently recognized genera, including some for which molecular data had never been reported. Support for all relationships in the inferred phylogenetic tree is high to maximal, and topology tests reject all investigated alternatives, indicating an exceptionally robust molecular phylogenetic framework of caecilian evolution consistent with current morphology-based supraspecific classification. We used the mitogenomic phylogenetic framework to infer ancestral character states and to assess correlation among three life-history traits (free-living larvae, viviparity, specialized pre-adult or vernal teeth), each of which occurs only in some caecilian species. Our results provide evidence that an ancestor of the Seychelles caecilians abandoned direct development and re-evolved a free-living larval stage. This study yields insights into the concurrent evolution of direct development and of vernal teeth in an ancestor of Teresomata that likely gave rise to skin-feeding (maternal dermatophagy) behavior and subsequently enabled evolution of viviparity, with skin feeding possibly a homologous precursor of oviduct feeding in viviparous caecilians. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Life History Strategy and Young Adult Substance Use

    Directory of Open Access Journals (Sweden)

    George B. Richardson

    2014-04-01

    Full Text Available This study tested whether life history strategy (LHS and its intergenerational transmission could explain young adult use of common psychoactive substances. We tested a sequential structural equation model using data from the National Longitudinal Survey of Youth. During young adulthood, fast LHS explained 61% of the variance in overall liability for substance use. Faster parent LHS predicted poorer health and lesser alcohol use, greater neuroticism and cigarette smoking, but did not predict fast LHS or overall liability for substance use among young adults. Young adult neuroticism was independent of substance use controlling for fast LHS. The surprising finding of independence between parent and child LHS casts some uncertainty upon the identity of the parent and child LHS variables. Fast LHS may be the primary driver of young adult use of common psychoactive substances. However, it is possible that the young adult fast LHS variable is better defined as young adult mating competition. We discuss our findings in depth, chart out some intriguing new directions for life history research that may clarify the dimensionality of LHS and its mediation of the intergenerational transmission of substance use, and discuss implications for substance abuse prevention and treatment.

  9. Life-history patterns of fishes in the Hellenic Seas

    Directory of Open Access Journals (Sweden)

    K. I. Stergiou

    2000-01-01

    Full Text Available The available quantitative information (age, growth, maturation and mortality for 103 fish stocks in Hellenic Seas was analysed here in the context of life-history theory and compared with similar information from other areas of the world.

    The results showed that the fish species and stocks inhabiting Hellenic waters are generally small in size, have low longevity, mature at an early age and size, and probably suffer high adult mortality rates. Such a pattern most probably is an adaptation to the synergetic combination of highly oligotrophic conditions and high subtropical temperatures prevailing in Hellenic waters and is consistent with life-history theory.

    Finally, the auximetric grid was used to compare the growth of four species, each represented by more than six stocks. The results revealed that the growth spaces occupied by the four species reflect their strikingly different feeding habits, especially with respect to the size of prey and the relative importance of fish prey to their diet.

  10. Population-specific life histories contribute to metapopulation viability

    Science.gov (United States)

    Halsey, Samniqueka J.; Bell, Timothy J.; McEachern, A. Kathryn; Pavlovic, Noel B.

    2016-01-01

    Restoration efforts can be improved by understanding how variations in life-history traits occur within populations of the same species living in different environments. This can be done by first understanding the demographic responses of natural occurring populations. Population viability analysis continues to be useful to species management and conservation with sensitivity analysis aiding in the understanding of population dynamics. In this study, using life-table response experiments and elasticity analyses, we investigated how population-specific life-history demographic responses contributed to the metapopulation viability of the Federally threatened Pitcher's thistle (Cirsium pitcheri). Specifically, we tested the following hypotheses: (1) Subpopulations occupying different environments within a metapopulation have independent demographic responses and (2) advancing succession results in a shift from a demographic response focused on growth and fecundity to one dominated by stasis. Our results showed that reintroductions had a positive contribution to the metapopulation growth rate as compared to native populations which had a negative contribution. We found no difference in succession on the contribution to metapopulation viability. In addition, we identified distinct population-specific contributions to metapopulation viability and were able to associate specific life-history demographic responses. For example, the positive impact of Miller High Dunes population on the metapopulation growth rate resulted from high growth contributions, whereas increased time of plant in stasis for the State Park Big Blowout population resulted in negative contributions. A greater understanding of how separate populations respond in their corresponding environment may ultimately lead to more effective management strategies aimed at reducing extinction risk. We propose the continued use of sensitivity analyses to evaluate population-specific demographic influences on

  11. Using Plants to Explore the Nature & Structural Complexity of Life

    Science.gov (United States)

    Howard, Ava R.

    2014-01-01

    Use of real specimens brings the study of biology to life. This activity brings easily acquired plant specimens into the classroom to tackle common alternative conceptions regarding life, size, complexity, the nature of science, and plants as multicellular organisms. The activity occurs after a discussion of the characteristics of life and engages…

  12. Palliative care for the homeless: complex lifes, complex care.

    NARCIS (Netherlands)

    Veer, A. de; Stringer, B.; Meijel, B. van; Verkaik, R.; Francke, A.

    2017-01-01

    Background: Homeless people often encounter multiple problems and have a shorter life- expectancy. Little is known about how palliative care for this group is organized and can be improved. Aim: To explore and describe aspects of the palliative care for homeless people in The Netherlands from the

  13. Niche partitioning in sympatric Gorilla and Pan from Cameroon: implications for life history strategies and for reconstructing the evolution of hominin life history.

    Science.gov (United States)

    Macho, Gabriele A; Lee-Thorp, Julia A

    2014-01-01

    Factors influencing the hominoid life histories are poorly understood, and little is known about how ecological conditions modulate the pace of their development. Yet our limited understanding of these interactions underpins life history interpretations in extinct hominins. Here we determined the synchronisation of dental mineralization/eruption with brain size in a 20th century museum collection of sympatric Gorilla gorilla and Pan troglodytes from Central Cameroon. Using δ13C and δ15N of individuals' hair, we assessed whether and how differences in diet and habitat use may have impacted on ape development. The results show that, overall, gorilla hair δ13C and δ15N values are more variable than those of chimpanzees, and that gorillas are consistently lower in δ13C and δ15N compared to chimpanzees. Within a restricted, isotopically-constrained area, gorilla brain development appears delayed relative to dental mineralization/eruption [or dental development is accelerated relative to brains]: only about 87.8% of adult brain size is attained by the time first permanent molars come into occlusion, whereas it is 92.3% in chimpanzees. Even when M1s are already in full functional occlusion, gorilla brains lag behind those of chimpanzee (91% versus 96.4%), relative to tooth development. Both bootstrap analyses and stable isotope results confirm that these results are unlikely due to sampling error. Rather, δ15N values imply that gorillas are not fully weaned (physiologically mature) until well after M1 are in full functional occlusion. In chimpanzees the transition from infant to adult feeding appears (a) more gradual and (b) earlier relative to somatic development. Taken together, the findings are consistent with life history theory that predicts delayed development when non-density dependent mortality is low, i.e. in closed habitats, and with the "risk aversion" hypothesis for frugivorous species as a means to avert starvation. Furthermore, the results highlight

  14. Complex regional pain syndromes (CRPS type 1 validating case histories

    Directory of Open Access Journals (Sweden)

    P. Berger

    2003-01-01

    Full Text Available The treatment of patients with complex regional pain syndrome (CRPS type 1 is challenging and unpredictable as the condition presents with vascular and neuropathic symptoms after nil or even minor injury to a peripheral nerve. The condition is one of a pain and motor dysfunction. The pathophysiology is not well understood and the relief of symptoms may change from being sympathetically mediated to sympathetically independent during  the course of the disease. At any stage physiotherapy has been advocated as the corner stone and most important aspect of treatment in the rehabilitation of these individuals but unfortunately it has been difficult to execute when pain is exacerbated due to allodynia (unbearable to touch or move and hyperalgesia. Best results have been obtained if the patients are recognised and treated in the early or acute phase and it has been found that through careful assessment and analysis these patients can be recognised by previous events that have occurred in their initial case history. The treatment in the acute stage with physiotherapy modalities such as electrical stimulation and acupuncture will produce an early cessation of the symptoms and prevention of the disease developing into the fully blown CRPS type 1 with irreversible and possibly atrophic consequences. Case histories have been presented that illustrate these important aspects and demonstrate  the value of early and the appropriate physiotherapy that may be more successful than other pharmacological and physical interventions in this disease.

  15. Adapting data collection methods in the Australian Life Histories and Health Survey: a retrospective life course study.

    Science.gov (United States)

    Kendig, Hal; Byles, Julie E; O'Loughlin, Kate; Nazroo, James Y; Mishra, Gita; Noone, Jack; Loh, Vanessa; Forder, Peta M

    2014-03-24

    Ideally, life course data are collected prospectively through an ongoing longitudinal study. We report adaptive multimethod fieldwork procedures that gathered life history data by mail survey and telephone interview, comparable with the face-to-face methods employed in the English Longitudinal Study on Ageing (ELSA). The Australian Life Histories and Health (LHH) Survey was a substudy of the Australian 45 and Up Study, with data collection methods modified from the ELSA Study. A self-complete questionnaire and life history calendar were completed by the participants, followed by a computer-assisted telephone interview recording key life events. The LHH survey developed and tested procedures and instruments that gathered rich life history data within an ongoing Australian longitudinal survey on ageing. Data collection proved to be economical. The use of a self-complete questionnaire in conjunction with a life history calendar and coordinated computer-assisted telephone interview was successful in collecting retrospective life course information, in terms of being thorough, practical and efficient. This study has a diverse collection of data covering the life course, starting with early life experiences and continuing with socioeconomic and health exposures and outcomes during adult life. Mail and telephone methodology can accurately and economically add a life history dimension to an ongoing longitudinal survey. The method is particularly valuable for surveying widely dispersed populations. The results will facilitate understanding of the social determinants of health by gathering data on earlier life exposures as well as comparative data across geographical and societal contexts.

  16. Dynamics and life histories of northern ungulates in changing environments

    Science.gov (United States)

    Hendrichsen, D. K.

    2011-12-01

    Regional climate and local weather conditions can profoundly influence life history parameters (growth, survival, fecundity) and population dynamics in northern ungulates (Post and Stenseth 1999, Coulson et al. 2001). The influence is both direct, for example through reduced growth or survival (Aanes et al. 2000, Tyler et al. 2008), and indirect, for example through changes in resource distribution, phenology and quality, changes which subsequently influence consumer dynamics (Post et al. 2008). By comparing and contrasting data from three spatially independent populations of ungulates, I discuss how variation in local weather parameters and vegetation growth influence spatial and temporal dynamics through changes in life history parameters and/or behavioural dynamics. The data originate from long term (11-15 years) monitoring data from three populations of ungulates in one subarctic and two high Arctic sites; semi-domesticated reindeer (Rangifer tarandus tarandus) in northern Norway, Svalbard reindeer (R. t. platyrhynchus) on Spitsbergen and muskoxen (Ovibos moschatus) in Northeast Greenland. The results show that juvenile animals can be particularly vulnerable to changes in their environment, and that this is mirrored to different degrees in the spatio-temporal dynamics of the three populations. Adverse weather conditions, acting either directly or mediated through access to and quality of vegetation, experienced by young early in life, or even by their dams during pregnancy, can lead to reduced growth, lower survival and reduced reproductive performance later in life. The influence of current climatic variation, and the predictions of how local weather conditions may change over time, differs between the three sites, resulting in potentially different responses in the three populations. Aanes R, Saether BE and Øritsland NA. 2000. Fluctuations of an introduced population of Svalbard reindeer: the effects of density dependence and climatic variation. Ecography

  17. Life History Strategy and the HEXACO Personality Dimensions

    Directory of Open Access Journals (Sweden)

    Joseph H. Manson

    2015-01-01

    Full Text Available Although several studies have linked Life History Strategy (LHS variation with variation in the Five Factor Model personality dimensions, no published research has explored the relationship of LHS to the HEXACO personality dimensions. The theoretically expected relationship of the HEXACO Emotionality factor to LHS is unclear. The results of two studies (N = 641 demonstrated that LHS indicators form part of a factor along with HEXACO Extraversion, Agreeableness, Conscientiousness, and (marginally Honesty-Humility. People higher on these dimensions pursue a slower LHS. Neither Openness nor Emotionality was associated with this factor. Holding LHS constant, social involvement with kin was consistently predicted by higher Emotionality and was not consistently predicted by any other HEXACO factor. These results support a view of Emotionality as part of an LHS-independent personality dimension that influences the provision and receipt of kin altruism.

  18. How Life History Can Sway the Fixation Probability of Mutants

    Science.gov (United States)

    Li, Xiang-Yi; Kurokawa, Shun; Giaimo, Stefano; Traulsen, Arne

    2016-01-01

    In this work, we study the effects of demographic structure on evolutionary dynamics when selection acts on reproduction, survival, or both. In contrast to the previously discovered pattern that the fixation probability of a neutral mutant decreases while the population becomes younger, we show that a mutant with a constant selective advantage may have a maximum or a minimum of the fixation probability in populations with an intermediate fraction of young individuals. This highlights the importance of life history and demographic structure in studying evolutionary dynamics. We also illustrate the fundamental differences between selection on reproduction and selection on survival when age structure is present. In addition, we evaluate the relative importance of size and structure of the population in determining the fixation probability of the mutant. Our work lays the foundation for also studying density- and frequency-dependent effects in populations when demographic structures cannot be neglected. PMID:27129737

  19. Life-history tradeoffs and reproductive cycles in Spotted Owls

    Science.gov (United States)

    Stoelting, Ricka E.; Gutierrez, R.J.; Kendall, William L.; Peery, M. Zachariah

    2015-01-01

    The study of tradeoffs among life-history traits has long been key to understanding the evolution of life-history strategies. However, more recently, evolutionary ecologists have realized that reproductive costs have the potential to influence population dynamics. Here, we tested for costs of reproduction in the California Spotted Owl (Strix occidentalis occidentalis), and assessed whether costs of reproduction in year t − 1 on reproduction in year t could be responsible for regionally synchronized biennial cycles in reproductive output. Logistic regression analysis and multistate mark–recapture models with state uncertainty revealed that breeding reduced the likelihood of reproducing in the subsequent year by 16% to 38%, but had no influence on subsequent survival. We also found that costs of reproduction in year t − 1 were correlated with climatic conditions in year t, with evidence of higher costs during the dry phase of the El Niño–Southern Oscillation. Using a simulation-based population model, we showed that strong reproductive costs had the potential to create biennial cycles in population-level reproductive output; however, estimated costs of reproduction appeared to be too small to explain patterns observed in Spotted Owls. In the absence of strong reproductive costs, we hypothesize that observed natural cycles in the reproductive output of Spotted Owls are related to as-yet-unmeasured, regionally concordant fluctuations in environmental conditions or prey resources. Despite theoretical evidence for demographic effects, our analyses illustrate that linking tradeoffs to actual changes in population processes will be challenging because of the potential confounding effects of individual and environmental variation.

  20. Life history strategy influences parasite responses to habitat fragmentation.

    Science.gov (United States)

    Froeschke, Götz; van der Mescht, Luther; McGeoch, Melodie; Matthee, Sonja

    2013-12-01

    Anthropogenic habitat use is a major threat to biodiversity and is known to increase the abundance of generalist host species such as rodents, which are regarded as potential disease carriers. Parasites have an intimate relationship with their host and the surrounding environment and it is expected that habitat fragmentation will affect parasite infestation levels. We investigated the effect of habitat fragmentation on the ecto- and endoparasitic burdens of a broad niche small mammal, Rhabdomys pumilio, in the Western Cape Province, South Africa. Our aim was to look at the effects of fragmentation on different parasite species with diverse life history characteristics and to determine whether general patterns can be found. Sampling took place within pristine lowland (Fynbos/Renosterveld) areas and at fragmented sites surrounded and isolated by agricultural activities. All arthropod ectoparasites and available gastrointestinal endoparasites were identified. We used conditional autoregressive models to investigate the effects of habitat fragmentation on parasite species richness and abundance of all recovered parasites. Host density and body size were larger in the fragments. Combined ecto- as well as combined endoparasite taxa showed higher parasite species richness in fragmented sites. Parasite abundance was generally higher in the case of R. pumilio individuals in fragmented habitats but it appears that parasites that are more permanently associated with the host's body and those that are host-specific show the opposite trend. Parasite life history is an important factor that needs to be considered when predicting the effects of habitat fragmentation on parasite and pathogen transmission. Copyright © 2013 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  1. Reproductive and Life History Parameters of Wild Female Macaca assamensis

    Science.gov (United States)

    Schülke, Oliver; Heistermann, Michael; Ostner, Julia

    2010-01-01

    Information on basic reproductive parameters and life-history traits is crucial for the understanding of primate evolution, ecology, social behavior, and reproductive strategies. Here, we report 4 yr of data on reproductive and life-history traits for wild female Assamese macaques (Macaca assamensis) at Phu Khieo Wildlife Sanctuary, northeastern Thailand. During 2 consecutive reproductive seasons, we investigated reproductive behavior and sexual swelling size in 16 females and collected 1832 fecal samples. Using enzyme immunoassays, we measured fecal estrogen and progesterone metabolites to assess ovarian activity and timing of ovulation and to ascertain conceptions and pregnancies. Timing of reproduction was strictly seasonal (births: April–July, 86% in April–June, 4 yr, n = 29; conceptions: October–February, 65% in December–January, 2 yr, n = 17). Females showed no cyclic ovarian activity outside the mating season and conceived in their first or second cycle (mean: 1.2 cycles to conception, n = 13). Gestation length was on average 164.2 d (range: 158–170, n = 10), and females had their first infant at an age of 5 yr (n = 4). Interbirth intervals were bimodally distributed, with females giving birth on average every 13.9 or 23.2 mo. Shorter interbirth intervals were linked to early parturition within the birth season. Most females displayed subcaudal sexual swellings which, however, did not reliably indicate female reproductive status or fertility. Overall, our results fall within the range of findings reported for other macaque species. These results thus add to the growing body of information available for wild macaques, facilitating comparative studies for a better understanding of interspecific differences in social and reproductive patterns. PMID:20651906

  2. Evolution, human-microbe interactions, and life history plasticity.

    Science.gov (United States)

    Rook, Graham; Bäckhed, Fredrik; Levin, Bruce R; McFall-Ngai, Margaret J; McLean, Angela R

    2017-07-29

    A bacterium was once a component of the ancestor of all eukaryotic cells, and much of the human genome originated in microorganisms. Today, all vertebrates harbour large communities of microorganisms (microbiota), particularly in the gut, and at least 20% of the small molecules in human blood are products of the microbiota. Changing human lifestyles and medical practices are disturbing the content and diversity of the microbiota, while simultaneously reducing our exposures to the so-called old infections and to organisms from the natural environment with which human beings co-evolved. Meanwhile, population growth is increasing the exposure of human beings to novel pathogens, particularly the crowd infections that were not part of our evolutionary history. Thus some microbes have co-evolved with human beings and play crucial roles in our physiology and metabolism, whereas others are entirely intrusive. Human metabolism is therefore a tug-of-war between managing beneficial microbes, excluding detrimental ones, and channelling as much energy as is available into other essential functions (eg, growth, maintenance, reproduction). This tug-of-war shapes the passage of each individual through life history decision nodes (eg, how fast to grow, when to mature, and how long to live). Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Amphibian terrestrial habitat selection and movement patterns vary with annual life-history period

    Science.gov (United States)

    Groff, Luke A.; Calhoun, Aram J.K.; Loftin, Cynthia S.

    2017-01-01

    Identification of essential habitat is a fundamental component of amphibian conservation; however, species with complex life histories frequently move among habitats. To better understand dynamic habitat use, we evaluated Wood Frog (Lithobates sylvaticus (LeConte, 1825)) habitat selection and movement patterns during the spring migration and foraging periods and described the spatiotemporal variability of habitats used during all annual life-history periods. We radio-tracked 71 frogs in Maine during 2011–2013 and evaluated spring migration, foraging activity center (FAC), and within-FAC habitat selection. Telemetered frogs spent the greatest percentage of each field season in hibernacula (≥54.4%), followed by FACs (≥25.5%), migration habitat (≥16.9%), and breeding sites (≥4.5%). FACs ranged 49 – 1 335 m2 (568.0 ± 493.4 m2) and annual home ranges spanned 1 413 – 32 165 m2 (11 780.6 ± 12 506.1 m2). During spring migration, Wood Frogs exhibited different movement patterns (e.g., turn angles), selected different habitat features, and selected habitat features less consistently than while occupying FACs, indicating that the migration and foraging periods are ecologically distinct. Habitat-use studies that do not discriminate among annual life-history periods may obscure true ecological relationships and fail to identify essential habitat necessary for sustaining amphibian populations.

  4. Multi-state models: metapopulation and life history analyses

    Directory of Open Access Journals (Sweden)

    Arnason, A. N.

    2004-06-01

    Full Text Available Multi–state models are designed to describe populations that move among a fixed set of categorical states. The obvious application is to population interchange among geographic locations such as breeding sites or feeding areas (e.g., Hestbeck et al., 1991; Blums et al., 2003; Cam et al., 2004 but they are increasingly used to address important questions of evolutionary biology and life history strategies (Nichols & Kendall, 1995. In these applications, the states include life history stages such as breeding states. The multi–state models, by permitting estimation of stage–specific survival and transition rates, can help assess trade–offs between life history mechanisms (e.g. Yoccoz et al., 2000. These trade–offs are also important in meta–population analyses where, for example, the pre–and post–breeding rates of transfer among sub–populations can be analysed in terms of target colony distance, density, and other covariates (e.g., Lebreton et al. 2003; Breton et al., in review. Further examples of the use of multi–state models in analysing dispersal and life–history trade–offs can be found in the session on Migration and Dispersal. In this session, we concentrate on applications that did not involve dispersal. These applications fall in two main categories: those that address life history questions using stage categories, and a more technical use of multi–state models to address problems arising from the violation of mark–recapture assumptions leading to the potential for seriously biased predictions or misleading insights from the models. Our plenary paper, by William Kendall (Kendall, 2004, gives an overview of the use of Multi–state Mark–Recapture (MSMR models to address two such violations. The first is the occurrence of unobservable states that can arise, for example, from temporary emigration or by incomplete sampling coverage of a target population. Such states can also occur for life history reasons, such

  5. Counterfactuals and history: Contingency and convergence in histories of science and life.

    Science.gov (United States)

    Hesketh, Ian

    2016-08-01

    This article examines a series of recent histories of science that have attempted to consider how science may have developed in slightly altered historical realities. These works have, moreover, been influenced by debates in evolutionary science about the opposing forces of contingency and convergence in regard to Stephen Jay Gould's notion of "replaying life's tape." The article argues that while the historians under analysis seem to embrace contingency in order to present their counterfactual narratives, for the sake of historical plausibility they are forced to accept a fairly weak role for contingency in shaping the development of science. It is therefore argued that Simon Conway Morris's theory of evolutionary convergence comes closer to describing the restrained counterfactual worlds imagined by these historians of science than does contingency. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Adapting data collection methods in the Australian Life Histories and Health Survey: a retrospective life course study

    OpenAIRE

    Kendig, Hal; Byles, Julie E; O'Loughlin, Kate; Nazroo, James Y; Mishra, Gita; Noone, Jack; Loh, Vanessa; Forder, Peta M

    2014-01-01

    Objective Ideally, life course data are collected prospectively through an ongoing longitudinal study. We report adaptive multimethod fieldwork procedures that gathered life history data by mail survey and telephone interview, comparable with the face-to-face methods employed in the English Longitudinal Study on Ageing (ELSA). Design The Australian Life Histories and Health (LHH) Survey was a substudy of the Australian 45 and Up Study, with data collection methods modified from the ELSA Study...

  7. Circumstantial evidence of life history events in loricate choanoflagellates

    DEFF Research Database (Denmark)

    Thomsen, Helge Abildhauge; Østergaard, Jette Buch

    2017-01-01

    Sex is found in all major eukaryotic groups of organisms. It has been known for some time that the choanoflagellates also possess the genes involved in meiosis and a full sexual cycle was also recently accounted for in Salpingoeca rosetta. With reference to the loricate choanoflagellates the curr......Sex is found in all major eukaryotic groups of organisms. It has been known for some time that the choanoflagellates also possess the genes involved in meiosis and a full sexual cycle was also recently accounted for in Salpingoeca rosetta. With reference to the loricate choanoflagellates...... the current status is that only circumstantial evidence, from wild material of Bicosta spinifera, exists in favour of documenting division patterns that go beyond plain asexual division, and that has the potential to represent stages in a sexual life cycle. Here we present further evidence from wild material...... documenting possible morphotype changes that might similarly indicate the existence of complex life cycles. In this particular case, it revolves around the existence of so-called ‘combination loricas’ (i.e. two loricas that occur physically united), representing consistent species combinations from the genera...

  8. The Dark Triad Traits from a Life History Perspective in Six Countries

    Directory of Open Access Journals (Sweden)

    Peter K. Jonason

    2017-08-01

    Full Text Available Work on the Dark Triad traits has benefited from the use of a life history framework but it has been limited to primarily Western samples and indirect assessments of life history strategies. Here, we examine how the Dark Triad traits (i.e., psychopathy, Machiavellianism, and narcissism relate to two measures of individual differences in life history strategies. In Study 1 (N = 937, we replicated prior observed links between life history strategies, as measured by the Mini-K, and the Dark Triad traits using samples recruited from three countries. In Study 2 (N = 1032, we measured life history strategies using the Consideration of Future Consequences Scale and correlated it with the Dark Triad traits in samples recruited from three additional countries. While there was some variability across participants’ sex and country, the results were generally consistent in that psychopathy and (to a lesser extent Machiavellianism were related to faster life history strategies and narcissism was related to slower life history strategies. These results add cross-cultural data and the use of two measures of life history speed to understand the Dark Triad traits from a life history perspective.

  9. Life history of Manataria maculata (Lepidoptera: Satyrinae from Costa Rica

    Directory of Open Access Journals (Sweden)

    L. Ricardo Murillo

    2003-06-01

    Full Text Available The life history and early stages of the satyrine butterfly Manataria maculata are described and illustrated from Costa Rica. Eggs are laid on Lasiacis sp. (Panicoideae, a new non-bamboo host plant for the genus Manataria. The larval stage varied from 23 to 28 days, and the pupal duration was approximately 12 days when reared on Bambusa vulgaris and Guadua angustifolia in captivity at 23-24°C.Se describe e ilustran los estadios tempranos y la historia natura de Manataria maculata (Hopffer, 1874 de Costa Rica. Los huevos fueron encontrados en Lasiacis sp. (Panicoideae, una nueva planta hospedera para el género Manataria, y que no es un bambú. El estadio larval varió desde 23 a 28 días y el estadio pupal, aproximadamente 12 días cuando es criado con Bambusa vulgaris y Guadua angustifolia bajo condiciones de cautiverio a 23-24°C.

  10. Life history dictates fluorosis risk in a small mammal community

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, D.P.; Faulkner, B.; Lochmiller, R.L.; Qualls, C.W. Jr.; McBee, K. [Oklahoma State Univ., Stillwater, OK (United States)

    1995-12-31

    Dental lesions, due to fluorosis, previously have been reported in wild, male cotton rats (Sigmodon hispidus) on an abandoned oil refinery located at the Oklahoma Refining Company in Cyril, Oklahoma. This study was expanded to include examinations of the fulvous harvest mouse (Reithrodontomys fulvescens), house mouse (Mus musculus), prairie vole (Microtus ochrogaster), plains pocket gopher (Geomys bursarius), least shrew (Cryptotis parva), shorttailed shrew (Blarina brevicauda), and deer mouse (Peromyscus spp.) at this same site. A sample of each species was collected form the contaminated refining site and a reference site with no known contamination. The authors grossly scored dentition of lower and upper incisors, microscopically examined cellular aberrations in ameloblasts and ondontoblasts, and quantified femur fluoride levels. Alterations in the lower and upper incisors were common in prairie voles, whose incisors possessed striations and erosion of the enamel and appeared chalky white. Incisors of animals taken from the reference site were normal. Patterns in occurrence of fluorosis and degree of enamel erosion was examined relative to the life history characteristics of the species.

  11. Evolution of reproductive life histories in island birds worldwide.

    Science.gov (United States)

    Covas, Rita

    2012-04-22

    Island environments typically share characteristics such as impoverished biotas and less-seasonal climates, which should be conducive to specific adaptations by organisms. However, with the exception of morphological studies, broad-scale tests of patterns of adaptation on islands are rare. Here, I examine reproductive patterns in island birds worldwide. Reproductive life histories are influenced by latitude, which could affect the response to insularity; therefore, I additionally test this hypothesis. Island colonizers showed mostly bi-parental care, but there was a significant increase in cooperative breeding on islands. Additionally, I found support for previous suggestions of reduced fecundity, longer developmental periods and increased investment in young on islands. However, clutch size increased with latitude at a rate nearly five times faster on the mainland than on the islands revealing a substantially stronger effect of insularity at higher latitudes. Latitude and insularity may also interact to determine egg volume and incubation periods, but these effects were less clear. Analyses of reproductive success did not support an effect of reduced nest predation as a driver of reproductive change, but this requires further study. The effect of latitude detected here suggests that the evolutionary changes associated with insularity relate to environmental stability and improved adult survival.

  12. A Course on Humanistic Creativity in Later Life: Literature Review, Case Histories, and Recommendations.

    Science.gov (United States)

    Nuessel, Frank; Van Stewart, Arthur; Cedeno, Aristofanes

    2001-01-01

    Presents case histories of late-life creativity in literature (May Sarton), painting (Marcel Duchamp), music (Leos Janacek), dance (Martha Graham), and theatre (Jessica Tandy). Offers suggestions for a course on humanistic creativity in later life. (Contains 74 references.) (SK)

  13. Environmental effects on growth, reproduction, and life-history traits of loggerhead turtles

    NARCIS (Netherlands)

    Marn, Nina; Jusup, Marko; Legović, Tarzan; Kooijman, S. A.L.M.; Klanjšček, Tin

    2017-01-01

    Understanding the relationship between the environmental conditions and life-history traits (such as growth, reproduction, and size at specific life stages) is important for understanding the population dynamics of a species and for constructing adaptable, relevant, and efficient conservation

  14. Migration of steelhead - Genetic basis of migratory tendency and life history plasticity in Oncorhynchus mykiss

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Steelhead and rainbow trout are the same species. However, their life histories diverge - with steelhead undertaking an anadromous life cycle whereas rainbow trout...

  15. Complex history as a source of planning problems: Old Belgrade fairground

    Directory of Open Access Journals (Sweden)

    Vukotić-Lazar Marta

    2006-01-01

    Full Text Available The Old Belgrade Fairground complex is the large area in the center of Belgrade that is completely isolated from other parts of Belgrade: it is one of the most devastated city areas, populated by poor inhabitants, often by those from the marginal groups, burdened with tragic history and it represents one of hardest problems for planners to solve. It is situated on the left bank of the Sava River between two bridges and downtown New Belgrade. Opposite to it, the Sava Amphitheatre slopes down the Belgrade Ridge towards the river. The complex was built in the thirties of the 20th century across the River Sava in the area that was an unpopulated swamp - Belgrade was situated on the right Sava bank. It was meant to be modern extension of oriental city, which could represent the western tendencies of the young state (Kingdom of Yugoslavia and its capital. Modern and monumental complex of exhibition and commercial pavilions was built, and started its life with national and international fairs and exhibitions. World War 2 changed its destiny: German occupation forces transformed the complex into the concentration camp, where thousands of people were tortured and killed. After the war, new republican government, both communist and antifascist, had double frustration regarding this space: it’s tragic (during the War and "capitalist" (before the War past, so complex that was absolutely ignored in the period of the postwar renewal, and the result is described at the beginning of this text. This paper discusses the possibility to conciliate historical roles of the complex, and to realize it’s potentials in the modern world. Facts of the complex’s history are presented in the first part of the paper. Further on, these facts are analyzed in the context of contemporary city development of Belgrade in particular but globally, too.. Finally, some guidelines for crossing the gap between this area and the rest of the city are presented in the third part of

  16. Life history theory and breast cancer risk: methodological and theoretical challenges: Response to "Is estrogen receptor negative breast cancer risk associated with a fast life history strategy?".

    Science.gov (United States)

    Aktipis, Athena

    2016-01-01

    In a meta-analysis published by myself and co-authors, we report differences in the life history risk factors for estrogen receptor negative (ER-) and estrogen receptor positive (ER+) breast cancers. Our meta-analysis did not find the association of ER- breast cancer risk with fast life history characteristics that Hidaka and Boddy suggest in their response to our article. There are a number of possible explanations for the differences between their conclusions and the conclusions we drew from our meta-analysis, including limitations of our meta-analysis and methodological challenges in measuring and categorizing estrogen receptor status. These challenges, along with the association of ER+ breast cancer with slow life history characteristics, may make it challenging to find a clear signal of ER- breast cancer with fast life history characteristics, even if that relationship does exist. The contradictory results regarding breast cancer risk and life history characteristics illustrate a more general challenge in evolutionary medicine: often different sub-theories in evolutionary biology make contradictory predictions about disease risk. In this case, life history models predict that breast cancer risk should increase with faster life history characteristics, while the evolutionary mismatch hypothesis predicts that breast cancer risk should increase with delayed reproduction. Whether life history tradeoffs contribute to ER- breast cancer is still an open question, but current models and several lines of evidence suggest that it is a possibility. © The Author(s) 2016. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health.

  17. Oxygen: Key for Life but Enemy of the History of Life.

    Science.gov (United States)

    Best, M.

    2004-05-01

    a complex of environmental gradients, with oxygen and other essential parameters varying among environments. As a function of physiological limits, environments vary in the density and diversity of biota that they contain. Biological remains are part of the resources of an ecosystem with tissues as sources of organic carbon, skeletons as potential substrates and eventually as chemical ions (particularly in marine settings). So, the more healthy the community, the more they are busy recycling and obliterating any record of previous generations/communities. Similarly, for carbonate burial, regions of the highest carbonate production are likely also regions of the highest carbonate recycling. Lest this be taken as an excuse to dismiss the fossil record as biased, we would no more think of doing so than with historical or archeological records, despite the fact that those preferentially record histories of the victors, the wealthy, and the literate. Just as we look beyond well preserved accounts of life at a monastery for clues of life in urban medieval Europe, so should we look beyond well preserved fossils to glean what paleo-biological and environmental clues we can from less than beautifully preserved fossils and the sediments that contain them.

  18. Life histories of microalgal species causing harmful blooms: Haploids, diploids and the relevance of benthic stages.

    Science.gov (United States)

    Figueroa, Rosa Isabel; Estrada, Marta; Garcés, Esther

    2018-03-01

    In coastal and offshore waters, Harmful Algal Blooms (HABs) currently threaten the well-being of coastal countries. These events, which can be localized or involve wide-ranging areas, pose risks to human health, marine ecosystems, and economic resources, such as tourism, fisheries, and aquaculture. Dynamics of HABs vary from one site to another, depending on the hydrographic and ecological conditions. The challenge in investigating HABs is that they are caused by organisms from multiple algal classes, each with its own unique features, including different life histories. The complete algal life cycle has been determined in life cycles of bloom-forming species is essential in developing preventative measures. The knowledge obtained thus far has confirmed the complexity of the algal life cycle, which is composed of discrete life stages whose morphology, ecological niche (plankton/benthos), function, and lifespan vary. The factors that trigger transitions between the different stages in nature are mostly unknown, but it is clear that an understanding of this process provides the key to effectively forecasting bloom recurrence, maintenance, and decline. Planktonic stages constitute an ephemeral phase of the life cycle of most species whereas resistant, benthic stages enable a species to withstand adverse conditions for prolonged periods, thus providing dormant reservoirs for eventual blooms and facilitating organismal dispersal. Here we review current knowledge of the life cycle strategies of major groups of HAB producers in marine and brackish waters. Rather than providing a comprehensive discussion, the objective was to highlight several of the research milestones that have changed our understanding of the plasticity and frequency of the different life cycle stages as well as the transitions between them. We also discuss the relevance of benthic and planktonic forms and their implications for HAB dynamics. Copyright © 2018. Published by Elsevier B.V.

  19. The simple life: on the benefits of low self-complexity.

    Science.gov (United States)

    McConnell, Allen R; Strain, Laura M; Brown, Christina M; Rydell, Robert J

    2009-07-01

    This article examines the spillover amplification hypothesis, which proposes that because people lower in self-complexity experience stronger responses to life events they will show relatively better well-being in the presence of positive factors (e.g., better social support) and relatively poorer well-being in the presence of negative factors (e.g., a history of negative experiences). Across three studies, support for spillover amplification was found. Specifically, people lower in self-complexity revealed greater self-esteem, less depression, and fewer illnesses when they had greater social support (Study 1) and more desirable personality characteristics (Study 2), yet they had poorer well-being if they had a history of many negative life events (Study 3). Thus, how one's self-concept is represented in memory moderates the relationship between many well-established factors and well-being.

  20. Life history plasticity and population regulation in sea otters

    Science.gov (United States)

    Monson, Daniel H.; Estes, James A.; Bodkin, James L.; Siniff, Donald B.

    2000-01-01

    We contrasted body condition, and age-specific reproduction and mortality between a growing population of sea otters (Enhydralutris) at Kodiak Island and a high-density near-equilibrium population at Amchitka Island, Alaska. We obtained data from marked individuals, population surveys, and collections of beach-cast carcasses. Mass:length ratios indicated that females (but not males) captured in 1992 at Amchitka were in poorer condition than those captured at Kodiak in 1986–1987. In 1993, the condition of females at Amchitka improved in apparent response to two factors: (1) an episodic influx of Pacific smooth lumpsuckers, Aptocyclus ventricocus, from the epi-pelagic zone, which otters consumed; and (2) an increase in the otters’ benthic invertebrate prey resulting from declining otter numbers. Reproductive rates varied with age (0.37 [CI=0.21 to 0.53] births female−1 yr−1 for 2–3-yr-olds, and 0.83 [CI=0.69 to 0.90] for females ≥4 yr old), and were similar at both areas. Weaning success (pups surviving to ≥120 d), in contrast, was almost 50% lower at Amchitka than at Kodiak and for females ≥4 yr of age was 0.52 (CI=0.38 to 0.66) vs 0.94 (CI=0.75 to 0.99), respectively. Sixty-two percent of the preweaning pup losses at Amchitka occurred within a month of parturition and 79% within two months. Postweaning survival was also low at Amchitka as only 18% of instrumented pups were known to be alive one year after mother-pup separation. Adult survival rates appeared similar at Amchitka and Kodiak. Factors affecting survival early in life thus are a primary demographic mechanism of population regulation in sea otters. By maintaining uniformly high reproductive rates over time and limiting investment in any particular reproductive event, sea otters can take advantage of unpredictable environmental changes favorable to pup survival. This strategy is consistent with predictions of “bet-hedging” life history models.

  1. Niche partitioning in sympatric Gorilla and Pan from Cameroon: implications for life history strategies and for reconstructing the evolution of hominin life history.

    Directory of Open Access Journals (Sweden)

    Gabriele A Macho

    Full Text Available Factors influencing the hominoid life histories are poorly understood, and little is known about how ecological conditions modulate the pace of their development. Yet our limited understanding of these interactions underpins life history interpretations in extinct hominins. Here we determined the synchronisation of dental mineralization/eruption with brain size in a 20th century museum collection of sympatric Gorilla gorilla and Pan troglodytes from Central Cameroon. Using δ13C and δ15N of individuals' hair, we assessed whether and how differences in diet and habitat use may have impacted on ape development. The results show that, overall, gorilla hair δ13C and δ15N values are more variable than those of chimpanzees, and that gorillas are consistently lower in δ13C and δ15N compared to chimpanzees. Within a restricted, isotopically-constrained area, gorilla brain development appears delayed relative to dental mineralization/eruption [or dental development is accelerated relative to brains]: only about 87.8% of adult brain size is attained by the time first permanent molars come into occlusion, whereas it is 92.3% in chimpanzees. Even when M1s are already in full functional occlusion, gorilla brains lag behind those of chimpanzee (91% versus 96.4%, relative to tooth development. Both bootstrap analyses and stable isotope results confirm that these results are unlikely due to sampling error. Rather, δ15N values imply that gorillas are not fully weaned (physiologically mature until well after M1 are in full functional occlusion. In chimpanzees the transition from infant to adult feeding appears (a more gradual and (b earlier relative to somatic development. Taken together, the findings are consistent with life history theory that predicts delayed development when non-density dependent mortality is low, i.e. in closed habitats, and with the "risk aversion" hypothesis for frugivorous species as a means to avert starvation. Furthermore, the

  2. Love Styles in the Context of Life History Theory

    Directory of Open Access Journals (Sweden)

    Marzec Magdalena

    2017-06-01

    Full Text Available The evolutionary function of love is to create a strong bond between the partners with reproduction in view. In order to achieve this goal, humans use various sexual/reproductive strategies, which have evolved due to specific reproductive benefits. The use of particular strategies depends on many factors but one of the most important is early childhood experiences, on which life history theory (LHT focuses. John Lee (1973 identified 6 basic love styles: eros, ludus, storge, pragma, agape, and mania. Our goal was to check whether love styles may be treated as sexual/reproductive strategies in the context of LHT - slow or fast strategy. In our study (N = 177 we found that people who prefer the slow reproductive strategy are inclined to show passionate, pragmatic and friendly love, and those who prefer the fast strategy, treated love as a game. A low level of environmental stress in childhood results in preferring eros, storge and agape love styles, belonging to the slow strategy, and a high one results in preferring ludus, which belongs to the fast strategy. People representing eros, storge or pragma styles have restricted sociosexual orientation so they prefer long-term relationships, whereas those with the ludus style are people with unrestricted orientation, preferring short-term relationships. Besides, storge, agape and pragma seem to determine preferring qualities connected with parental effort in one’s partner, mania - with mating effort, and eros - with both kinds of effort. No correlation was found between the love style and the number of children.

  3. Integration of manatee life-history data and population modeling

    Science.gov (United States)

    Eberhardt, L.L.; O'Shea, Thomas J.; O'Shea, Thomas J.; Ackerman, B.B.; Percival, H. Franklin

    1995-01-01

    Aerial counts and the number of deaths have been a major focus of attention in attempts to understand the population status of the Florida manatee (Trichechus manatus latirostris). Uncertainties associated with these data have made interpretation difficult. However, knowledge of manatee life-history attributes increased and now permits the development of a population model. We describe a provisional model based on the classical approach of Lotka. Parameters in the model are based on data from'other papers in this volume and draw primarily on observations from the Crystal River, Blue Spring, and Adantic Coast areas. The model estimates X (the finite rate ofincrease) at each study area, and application ofthe delta method provides estimates of variance components and partial derivatives ofX with respectto key input parameters (reproduction, adult survival, and early survival). In some study areas, only approximations of some parameters are available. Estimates of X and coefficients of variation (in parentheses) of manatees were 1.07 (0.009) in the Crystal River, 1.06 (0.012) at Blue Spring, and 1.01 (0.012) on the Atlantic Coast. Changing adult survival has a major effect on X. Early-age survival has the smallest effect. Bootstrap comparisons of population growth estimates from trend counts in the Crystal River and at Blue Spring and the reproduction and survival data suggest that the higher, observed rates from counts are probably not due to chance. Bootstrapping for variance estimates based on reproduction and survival data from manatees at Blue Spring and in the Crystal River provided estimates of X, adult survival, and rates of reproduction that were similar to those obtained by other methods. Our estimates are preliminary and suggestimprovements for future data collection and analysis. However, results support efforts to reduce mortality as the most effective means to promote the increased growth necessary for the eventual recovery of the Florida manatee

  4. Application of Diversity Indices to Quantify Early Life-History Diversity for Chinook Salmon

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Sather, Nichole K.; Skalski, John R.; Teel, David

    2014-03-01

    We developed an index of early life history diversity (ELHD) for Pacific salmon (Oncorhynchus spp.) Early life history diversity is the variation in morphological and behavioral traits expressed within and among populations by individual juvenile salmon during their downstream migration. A standard quantitative method does not exist for this prominent concept in salmon biology.

  5. Revolutionaries, wanderers, converts, and compliants: Life histories of extreme right activists

    NARCIS (Netherlands)

    Linden, A.; Klandermans, P.G.

    2007-01-01

    Life-history interviews were conducted with thirty-six extreme right activists in the Netherlands (1996-1998). Becoming an activist was a matter of continuity, of conversion, or of compliance. Continuity denotes life histories wherein movement membership and participation are a natural consequence

  6. Life History Theory and Social Deviance: The Mediating Role of Executive Function

    Science.gov (United States)

    Wenner, C. J.; Bianchi, J.; Figueredo, A. J.; Rushton, J. Philippe; Jacobs, W. J.

    2013-01-01

    The present work examined predicted relations among Life History strategies, Executive Functions, socially antagonistic attitudes, socially antagonistic behaviors, and general intelligence. Life History (LH) theory predicts that Executive Functions and socially antagonistic attitudes and behaviors underpin an interrelated and coherent set of…

  7. Consilience and Life History Theory: From Genes to Brain to Reproductive Strategy

    Science.gov (United States)

    Figueredo, Aurelio Jose; Vasquez, Geneva; Brumbach, Barbara H.; Schneider, Stephanie M. R.; Sefcek, Jon A.; Tal, Ilanit R.; Hill, Dawn; Wenner, Christopher J.; Jacobs, W. Jake

    2006-01-01

    We describe an integrated theory of individual differences that traces the behavioral development of life history from genes to brain to reproductive strategy. We provide evidence that a single common factor, the K-Factor, underpins a variety of life-history parameters, including an assortment of sexual, reproductive, parental, familial, and…

  8. What have two decades of laboratory life-history evolution studies ...

    Indian Academy of Sciences (India)

    A series of laboratory selection experiments on Drosophila melanogaster over the past two decades has provided insights into the specifics of life-history tradeoffs in the species and greatly refined our understanding of how ecology and genetics interact in life-history evolution. Much of what has been learnt from these ...

  9. Life History of the Red-legged Thrush (Mimocichla plumbea ardosiacea) in Puerto Rico

    NARCIS (Netherlands)

    Rolle, Francis J.

    1963-01-01

    To the ornithologist the West Indies offer an assortment of field problems. In an area where it is unlikely that new species of birds will be discovered, and where the life histories of only a handful of birds are known, concentrated study of individual life histories becomes of prime importance.

  10. Explaining density-dependent regulation in earthworm populations using life-history analysis

    NARCIS (Netherlands)

    Kammenga, J.E.; Spurgeon, D.J.; Svendsen, C.; Weeks, J.M.

    2003-01-01

    At present there is little knowledge about how density regulates population growth rate and to what extent this is determined by life-history patterns. We compared density dependent population consequences in the Nicholsonian sense based oil experimental observations and life-history modeling for

  11. Mapping phenotypic plasticity and genotype-environment interactions affecting life-history traits in Caenorhabditis elegans

    NARCIS (Netherlands)

    Gutteling, E.W.; Riksen, J.A.G.; Bakker, J.; Kammenga, J.E.

    2007-01-01

    Phenotypic plasticity and genotype-environment interactions (GEI) play an important role in the evolution of life histories. Knowledge of the molecular genetic basis of plasticity and GEI provides insight into the underlying mechanisms of life-history changes in different environments. We used a

  12. Life History and Collective Memory as Methodological Strategies: Studying Teacher Professionalism

    Science.gov (United States)

    Goodson, Ivor; Choi, Pik Lin

    2008-01-01

    The life history method, which achieved a prominent position in the Chicago tradition of sociological research in the early 1920s, has been widely adopted for educational inquiries since the 1980s. The power of the life history method in illuminating subjective teacher experiences in social historical contexts has made it "probably the only…

  13. Hormonal correlates of male life history stages in wild white-faced capuchin monkeys (Cebus capucinus).

    Science.gov (United States)

    Jack, Katharine M; Schoof, Valérie A M; Sheller, Claire R; Rich, Catherine I; Klingelhofer, Peter P; Ziegler, Toni E; Fedigan, Linda

    2014-01-01

    Much attention has been paid to hormonal variation in relation to male dominance status and reproductive seasonality, but we know relatively little about how hormones vary across life history stages. Here we examine fecal testosterone (fT), dihydrotestosterone (fDHT), and glucocorticoid (fGC) profiles across male life history stages in wild white-faced capuchins (Cebus capucinus). Study subjects included 37 males residing in three habituated social groups in the Área de Conservacíon Guanacaste, Costa Rica. Male life history stages included infant (0 to Life history stage was a significant predictor of fT; levels were low throughout the infant and juvenile phases, doubled in subadult and subordinate adults, and were highest for alpha males. Life history stage was not a significant predictor of fDHT, fDHT:fT, or fGC levels. Puberty in white-faced capuchins appears to begin in earnest during the subadult male phase, indicated by the first significant rise in fT. Given their high fT levels and exaggerated secondary sexual characteristics, we argue that alpha adult males represent a distinctive life history stage not experienced by all male capuchins. This study is the first to physiologically validate observable male life history stages using patterns of hormone excretion in wild Neotropical primates, with evidence for a strong association between fT levels and life history stage. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Early-life immune activation increases song complexity and alters phenotypic associations between sexual ornaments.

    Science.gov (United States)

    Merrill, Loren; Naylor, Madeleine F; Dalimonte, Merria; McLaughlin, Sean; Stewart, Tara E; Grindstaff, Jennifer L

    2017-12-01

    Early-life adversity can have long-lasting effects on physiological, behavioural, cognitive, and somatic processes. Consequently, these effects may alter an organism's life-history strategy and reproductive tactics.In response to early-life immune activation, we quantified levels of the acute phase protein haptoglobin (Hp) during development in male zebra finches ( Taeniopygia guttata ). Then, we examined the long-term impacts of early-life immune activation on an important static sexual signal, song complexity, as well as effects of early-life immune activation on the relationship between song complexity and a dynamic sexual signal, beak colouration. Finally, we performed mate-choice trials to determine if male early-life experience impacted female preference.Challenge with keyhole limpet hemocyanin (KLH) resulted in increased song complexity compared to lipopolysaccharide (LPS) treatment or the control. Hp levels were inversely correlated with song complexity. Moreover, KLH-treatment resulted in negative associations between the two sexual signals (beak colouration and song complexity). Females demonstrated some preference for KLH-treated males over controls and for control males over LPS-treated males in mate choice trials.Developmental immune activation has variable effects on the expression of secondary sexual traits in adulthood, including enhancing the expression of some traits. Because developmental levels of Hp and adult song complexity were correlated, future studies should explore a potential role for exposure to inflammation during development on song learning.Early-life adversity may differentially impact static versus dynamic signals. The use of phenotypic correlations can be a powerful tool for examining the impact of early-life experience on the associations among different traits, including sexual signals.

  15. Corticosterone profiles in northern cardinals (Cardinalis cardinalis): Do levels vary through life history stages?

    Science.gov (United States)

    Duckworth, Benjamin M; Jawor, Jodie M

    2018-04-17

    As animals move through life history stages, energy requirements for each stage will vary. Both daily and annual variation in the glucocoriticoid hormones (specifically corticosterone, or CORT, in birds) helps provide the variable energy needed through life history stages. In many bird species, CORT is higher in the breeding season when energy demands can be quite high and is often lower in the non-breeding season. Additionally, CORT has a role to play in the response to stressful stimuli and the level to which CORT is elevated following stressful events can vary through the annual cycle as well. Here we report on baseline and stress-induced CORT levels in both sexes of northern cardinals, Cardinalis cardinalis, a non-migrating, year-round territorial species across life history stages. Corticosterone is overall higher in the non-breeding season than the breeding season in both sexes. Males tend to have higher levels of stress-induced CORT than females, although the observed patterns are complex. Our findings differ from one of the more common profile reported in songbirds where breeding season CORT tends to be higher than non-breeding levels. A strong influence may be the prolonged breeding season seen in cardinals; lower levels of CORT during breeding may guard against adverse maternal effects, interruptions in breeding behaviors, or egg production. Additional investigation of species with similar ecologies to northern cardinals, and more populations of cardinals, may show that annual glucocorticoid profiles are more labile than previously appreciated. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Selection on a Subunit of the NURF Chromatin Remodeler Modifies Life History Traits in a Domesticated Strain of Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Edward E Large

    2016-07-01

    Full Text Available Evolutionary life history theory seeks to explain how reproductive and survival traits are shaped by selection through allocations of an individual's resources to competing life functions. Although life-history traits evolve rapidly, little is known about the genetic and cellular mechanisms that control and couple these tradeoffs. Here, we find that two laboratory-adapted strains of C. elegans descended from a single common ancestor that lived in the 1950s have differences in a number of life-history traits, including reproductive timing, lifespan, dauer formation, growth rate, and offspring number. We identified a quantitative trait locus (QTL of large effect that controls 24%-75% of the total trait variance in reproductive timing at various timepoints. Using CRISPR/Cas9-induced genome editing, we show this QTL is due in part to a 60 bp deletion in the 3' end of the nurf-1 gene, which is orthologous to the human gene encoding the BPTF component of the NURF chromatin remodeling complex. Besides reproduction, nurf-1 also regulates growth rate, lifespan, and dauer formation. The fitness consequences of this deletion are environment specific-it increases fitness in the growth conditions where it was fixed but decreases fitness in alternative laboratory growth conditions. We propose that chromatin remodeling, acting through nurf-1, is a pleiotropic regulator of life history trade-offs underlying the evolution of multiple traits across different species.

  17. Human evolution, life history theory, and the end of biological reproduction.

    Science.gov (United States)

    Last, Cadell

    2014-01-01

    Throughout primate history there have been three major life history transitions towards increasingly delayed sexual maturation and biological reproduction, as well as towards extended life expectancy. Monkeys reproduce later and live longer than do prosimians, apes reproduce later and live longer than do monkeys, and humans reproduce later and live longer than do apes. These life history transitions are connected to increased encephalization. During the last life history transition from apes to humans, increased encephalization co-evolved with increased dependence on cultural knowledge for energy acquisition. This led to a dramatic pressure for more energy investment in growth over current biological reproduction. Since the industrial revolution socioeconomic development has led to even more energy being devoted to growth over current biological reproduction. I propose that this is the beginning of an ongoing fourth major primate life history transition towards completely delayed biological reproduction and an extension of the evolved human life expectancy. I argue that the only fundamental difference between this primate life history transition and previous life history transitions is that this transition is being driven solely by cultural evolution, which may suggest some deeper evolutionary transition away from biological evolution is already in the process of occurring.

  18. The cooperative economy of food: Its effect on human life history and physiology.

    Science.gov (United States)

    Kramer, Karen L

    2018-04-06

    The human diet has undergone substantial modifications since the emergence of modern humans and varies considerably in today's traditional societies. Despite these changes and cross-cultural differences, the human diet can be characterized by several common elements. These include diverse, high quality foods, technological complexity to acquire and process food, and the establishment of home bases for storage, processing and consumption. Together these aspects of the human diet challenge any one individual to independently meet all of his or her daily caloric needs. Humans solve this challenge through food sharing, labor exchange and the division of labor. The cooperative nature of the human diet is associated with downstream effects on our life history and physiology. This paper overviews the constellation of traits that likely led to a cooperative economy of food, and draws on ethnographic examples to illustrate its effects on human life history and physiology. Two detailed examples using body composition, time allocation and food acquisition data show how cooperation among Savanna Pumé hunter-gatherers affects activity levels, sexual dimorphism in body fat, maturational pace and age at first birth. Copyright © 2018. Published by Elsevier Inc.

  19. Life History Consequences of the Facultative Expression of a Dispersal Life Stage in the Phoretic Bulb Mite (Rhizoglyphus robini.

    Directory of Open Access Journals (Sweden)

    Jacques A Deere

    Full Text Available Life history traits play an important role in population dynamics and correlate, both positively and negatively, with dispersal in a wide range of taxa. Most invertebrate studies on trade-offs between life history traits and dispersal have focused on dispersal via flight, yet much less is known about how life history trade-offs influence species that disperse by other means. In this study, we identify effects of investing in dispersal morphology (dispersal expression on life history traits in the male dimorphic bulb mite (Rhizoglyphus robini. This species has a facultative juvenile life stage (deutonymph during which individuals can disperse by phoresy. Further, adult males are either fighters (which kill other mites or benign scramblers. Here, in an experiment, we investigate the effects of investing in dispersal on size at maturity, sex and male morph ratio, and female lifetime reproductive success. We show that life history traits correlate negatively with the expression of the dispersal stage. Remarkably, all males that expressed the dispersal life stage developed into competitive fighters and none into scramblers. This suggests that alternative, male reproductive strategies and dispersal should not be viewed in isolation but considered concurrently.

  20. Life history variation in Barents Sea fish: implications for sensitivity to fishing in a changing environment.

    Science.gov (United States)

    Wiedmann, Magnus A; Primicerio, Raul; Dolgov, Andrey; Ottesen, Camilla A M; Aschan, Michaela

    2014-09-01

    Under exploitation and environmental change, it is essential to assess the sensitivity and vulnerability of marine ecosystems to such stress. A species' response to stress depends on its life history. Sensitivity to harvesting is related to the life history "fast-slow" continuum, where "slow" species (i.e., large, long lived, and late maturing) are expected to be more sensitive to fishing than "fast" ones. We analyze life history traits variation for all common fish species in the Barents Sea and rank fishes along fast-slow gradients obtained by ordination analyses. In addition, we integrate species' fast-slow ranks with ecosystem survey data for the period 2004-2009, to assess life history variation at the community level in space and time. Arctic fishes were smaller, had shorter life spans, earlier maturation, larger offspring, and lower fecundity than boreal ones. Arctic fishes could thus be considered faster than the boreal species, even when body size was corrected for. Phylogenetically related species possessed similar life histories. Early in the study period, we found a strong spatial gradient, where members of fish assemblages in the southwestern Barents Sea displayed slower life histories than in the northeast. However, in later, warmer years, the gradient weakened caused by a northward movement of boreal species. As a consequence, the northeast experienced increasing proportions of slower fish species. This study is a step toward integrating life history traits in ecosystem-based areal management. On the basis of life history traits, we assess the fish sensitivity to fishing, at the species and community level. We show that climate warming promotes a borealization of fish assemblages in the northeast, associated with slower life histories in that area. The biology of Arctic species is still poorly known, and boreal species that now establish in the Arctic are fishery sensitive, which calls for cautious ecosystem management of these areas.

  1. Life history strategies of fish species and biodiversity in eastern USA streams

    Science.gov (United States)

    Meador, Michael R.; Brown, Larry M.

    2015-01-01

    Predictive models have been used to determine fish species that occur less frequently than expected (decreasers) and those that occur more frequently than expected (increasers) in streams in the eastern U.S. Coupling life history traits with 51 decreaser and 38 increaser fish species provided the opportunity to examine potential mechanisms associated with predicted changes in fish species distributions in eastern streams. We assigned six life history traits – fecundity, longevity, maturation age, maximum total length, parental care, and spawning season duration – to each fish species. Decreaser species were significantly smaller in size and shorter-lived with reduced fecundity and shorter spawning seasons compared to increaser species. Cluster analysis of traits revealed correspondence with a life history model defining equilibrium (low fecundity, high parental care), opportunistic (early maturation, low parental care), and periodic (late maturation, high fecundity, low parental care) end-point strategies. Nearly 50 % of decreaser species were associated with an intermediate opportunistic-periodic strategy, suggesting that abiotic factors such as habitat specialization and streamflow alteration may serve as important influences on life history traits and strategies of decreaser species. In contrast, the percent of increaser species among life history strategy groups ranged from 21 to 32 %, suggesting that life history strategies of increaser species were more diverse than those of decreaser species. This study highlights the utility of linking life history theory to biodiversity to better understand mechanisms that contribute to fish species distributions in the eastern U.S.

  2. Comparative effect of carotenoid complex from golden neo-life ...

    African Journals Online (AJOL)

    Summary: The immunomodulatory effect of Carotenoid complex from Golden Neo-Life Dynamite (GNLD) and carrot extracted Carotenoid was assessed using 24 albino Wistar rats. The rats were assigned to 4 groups of 6 rats each consisting of group 1(control group treated with distilled water), group 2 (treated with olive oil) ...

  3. NARRATIVE: A short history of my life in science A short history of my life in science

    Science.gov (United States)

    Manson, Joseph R.

    2010-08-01

    I was certainly surprised, and felt extremely honored, when Salvador Miret-Artés suggested that he would like to organize this festschrift. Before that day I never anticipated that such an honor would come to me. I would like to thank Salvador for the large amount of time and work he has expended in organizing this special issue, the Editors of Journal of Physics: Condensed Matter for making it possible, and also the contributing authors for their efforts. My family home was outside of Petersburg, Virginia in Dinwiddie County in an area that was, during my youth, largely occupied by small farms. This is a region rich in American history and our earliest ancestors on both sides of the family settled in this area, beginning in the decade after the first Virginia settlement in Jamestown. My father was an engineer and my mother was a former school teacher, and their parents were small business owners. From earliest memories I recall being interested in finding out how things worked and especially learning about the wonders of nature. These interests were fostered by my parents who encouraged such investigations during long walks, visits to friends and relatives, and trips to museums. However, my earliest memory of wanting to become a scientist is associated with a Christmas gift of a chemistry set when I was about ten years old. I was absolutely fascinated by the amazing results that could be achieved with simple chemical reactions and realized then that I wanted to do something in life that would be associated with science. The gift of that small chemistry set developed over the next few years into a serious interest in chemistry, and throughout my junior high-school years I spent nearly all the money I earned doing odd jobs for neighbors on small laboratory equipment and chemical supplies, eventually taking over our old abandoned chicken house and turning it into a small chemistry lab. I remember being somewhat frustrated at the limits, mainly financial, that kept

  4. Source, Method, and Surmise: Quality of Life in History

    Science.gov (United States)

    Jordan, Thomas E.

    2009-01-01

    The purpose of the essay is to demonstrate that study of quality of life can explore eras before our own. There are caches of social data as early as the seventeenth century, and there were people who attempted to formulate social circumstances close to today's concepts of quality of life. Data from England and Ireland are presented and analyzed.

  5. The cosmic zoo complex life on many worlds

    CERN Document Server

    Schulze-Makuch, Dirk

    2017-01-01

    Are humans a galactic oddity, or will complex life with human abilities develop on planets with environments that remain habitable for long enough? In a clear, jargon-free style, two leading researchers in the burgeoning field of astrobiology critically examine the major evolutionary steps that led us from the distant origins of life to the technologically advanced species we are today. Are the key events that took life from simple cells to astronauts unique occurrences that would be unlikely to occur on other planets? By focusing on what life does - it's functional abilities - rather than specific biochemistry or anatomy, the authors provide plausible answers to this question. Systematically exploring the various pathways that led to the complex biosphere we experience on planet Earth, they show that most of the steps along that path are likely to occur on any world hosting life, with only two exceptions: One is the origin of life itself – if this is a highly improbable event, then we live in a rather “e...

  6. Daily life historyasmodern direction of urban history of Englandof High Middle Ages

    OpenAIRE

    O. S. Okhrimenko

    2014-01-01

    Historiographical review of recent research is an important aspect of the scientific study of the problems of medieval urban history of England. In 2000s there was marked the beginning of years of studying the history of everyday of medieval towns. The most important works in this field are the studies of Professor C. Dyer. Studying the history of everyday life of the city the researcher has identified as «standards of living». One of the modern directions of the history of everyday life ...

  7. Skagit River coho salmon life history model—Users’ guide

    Science.gov (United States)

    Woodward, Andrea; Kirby, Grant; Morris, Scott

    2017-09-29

    Natural resource management is conducted in the context of multiple anthropogenic stressors and is further challenged owing to changing climate. Experiments to determine the effects of climate change on complex ecological systems are nearly impossible. However, using a simulation model to synthesize current understanding of key ecological processes through the life cycle of a fish population can provide a platform for exploring potential effects of and management responses to changing conditions. Potential climate-change scenarios can be imposed, responses can be observed, and the effectiveness of potential actions can be evaluated. This approach is limited owing to future conditions likely deviating in range and timing from conditions used to create the model so that the model is expected to become obsolete. In the meantime, however, the modeling process explicitly states assumptions, clarifies information gaps, and provides a means to better understand which relationships are robust and which are vulnerable to changing climate by observing whether and why model output diverges from actual observations through time. The purpose of the model described herein is to provide such a decision-support tool regarding coho (Oncorhynchus kisutch) salmon for the Sauk-Suiattle Indian Tribe of Washington State.The Skagit coho salmon model is implemented in a system dynamics format and has three primary stocks—(1) predicted smolts, (2) realized smolts, and (3) escapement. “Predicted smolts” are the number of smolts expected based on the number of spawners in any year and the Ricker production curve. Pink salmon (Oncorhynchus gorbuscha) return to the Skagit River in odd years, and when they overlap with juvenile rearing coho salmon, coho smolt production is substantially higher than in non-pink years. Therefore, the model uses alternative Ricker equations to predict smolts depending on whether their juvenile year was a pink or non-pink year. The stock “realized smolts

  8. Dynamics of body time, social time and life history at adolescence

    Science.gov (United States)

    Worthman, Carol M.; Trang, Kathy

    2018-02-01

    Recent opposing trends towards earlier physical maturation and later social maturation present a conundrum of apparent biological-social mismatch. Here we use life history analysis from evolutionary ecology to identify forces that drive these shifts. Together with findings in developmental science, our life history analysis indicates that adolescence is a distinctive period for biological embedding of culture. Ethnographic evidence shows that mass education is a novel feature of the globalizing cultural configurations of adolescence, which are driven by transformations in labour, livelihood and lifestyle. Evaluation of the life history trade-offs and sociocultural ecologies that are experienced by adolescents may offer a practical basis for enhancing their development.

  9. The relationship between religion, illness and death in life histories of family members of children with life-threatening diseases.

    Science.gov (United States)

    Bousso, Regina Szylit; Serafim, Taís de Souza; Misko, Maira Deguer

    2010-01-01

    This qualitative study aimed to get to know the relationship between the experiences of families of children with a life-threatening disease and their religion, illness and life histories. The methodological framework was based on Oral History. The data were collected through interviews and the participants were nine families from six different religions who had lived the experience of having a child with a life-threatening disease. The interviews, held with one or two family members, were transcribed, textualized and, through their analysis, the Vital Tone was elaborated, representing the moral synthesis of each narrative. Three dimensions of spirituality were related to illness and death in their life histories: a Higher Being with a healing power; Development and Maintenance of a Connection with God and Faith Encouraging Optimism. The narratives demonstrated the family's search to attribute meanings to their experiences, based on their religious beliefs.

  10. Daily life historyasmodern direction of urban history of Englandof High Middle Ages

    Directory of Open Access Journals (Sweden)

    O. S. Okhrimenko

    2014-07-01

    Full Text Available Historiographical review of recent research is an important aspect of the scientific study of the problems of medieval urban history of England. In 2000s there was marked the beginning of years of studying the history of everyday of medieval towns. The most important works in this field are the studies of Professor C. Dyer. Studying the history of everyday life of the city the researcher has identified as «standards of living». One of the modern directions of the history of everyday life is a history of food. There is the significant research of Professor M. Carlin on the history of English feasting of urban residents of the Middle Ages. In the article Fast food and urban living standards in medieval England, she looked anew at the narrative sources XII-XIV centuries. Another area of daily life history is a history of clothes (fashion. L. A. Wilson in his work De novo modo: The birth of fashion in the Middle Ages analyzes comprehensively the written, visual, and archaeological evidence. Modern interpretations of medieval hygiene (including sanitation of medieval towns related to research in the area of a history body. Its appointed destination for British urban sources dealing D. Jorgensen, D. Keene, U. Ewert, G. Geltner, J. Lee etc. They revised the traditional view medievalists of the nineteenth century. At the present period the historiography of medieval towns of England are mostly social history. Towards the history of everyday life there is a tendency to positive characteristics of urban life in the English Middle Ages. Contemporary scholars refer to the current trends in the world. Active urbanization processes forced researchers to seek appeal of such a way of life in previous centuries, particularly in the Middle Ages. The key features of everyday modern city (commercialization, fast food, fashion, high standards of hygiene etc. historians find their roots in the past.

  11. Lack of Ecological and Life History Context Can Create the Illusion of Social Interactions in Dictyostelium discoideum.

    Science.gov (United States)

    Martínez-García, Ricardo; Tarnita, Corina E

    2016-12-01

    Studies of social microbes often focus on one fitness component (reproductive success within the social complex), with little information about or attention to other stages of the life cycle or the ecological context. This can lead to paradoxical results. The life cycle of the social amoeba Dictyostelium discoideum includes a multicellular stage in which not necessarily clonal amoebae aggregate upon starvation to form a possibly chimeric (genetically heterogeneous) fruiting body made of dead stalk cells and spores. The lab-measured reproductive skew in the spores of chimeras indicates strong social antagonism that should result in low genotypic diversity, which is inconsistent with observations from nature. Two studies have suggested that this inconsistency stems from the one-dimensional assessment of fitness (spore production) and that the solution lies in tradeoffs between multiple life-history traits, e.g.: spore size versus viability; and spore-formation (via aggregation) versus staying vegetative (as non-aggregated cells). We develop an ecologically-grounded, socially-neutral model (i.e. no social interactions between genotypes) for the life cycle of social amoebae in which we theoretically explore multiple non-social life-history traits, tradeoffs and tradeoff-implementing mechanisms. We find that spore production comes at the expense of time to complete aggregation, and, depending on the experimental setup, spore size and viability. Furthermore, experimental results regarding apparent social interactions within chimeric mixes can be qualitatively recapitulated under this neutral hypothesis, without needing to invoke social interactions. This allows for simple potential resolutions to the previously paradoxical results. We conclude that the complexities of life histories, including social behavior and multicellularity, can only be understood in the appropriate multidimensional ecological context, when considering all stages of the life cycle.

  12. Late-life and life history predictors of older adults' high-risk alcohol consumption and drinking problems.

    Science.gov (United States)

    Moos, Rudolf H; Schutte, Kathleen K; Brennan, Penny L; Moos, Bernice S

    2010-04-01

    This prospective, longitudinal study focused on late-life and life history predictors of high-risk alcohol consumption and drinking problems during a 20-year interval as adults matured from age 55-65 to 75-85. A sample of older community residents (N=719) who had consumed alcohol in the past year or shortly before was surveyed at baseline and 10 and 20 years later. At each contact point, participants completed an inventory that assessed their alcohol consumption, drinking problems, and personal and life context factors. Participants also provided information about their life history of drinking and help-seeking. Older adults who, at baseline, had more friends who approved of drinking, relied on substances for tension reduction, and had more financial resources were more likely to engage in high-risk alcohol consumption and to incur drinking problems at 10- and 20-year follow-ups. With respect to life history factors, drinking problems by age 50 were associated with a higher likelihood of late-life high-risk alcohol consumption and drinking problems; having tried to cut down on drinking and participation in Alcoholics Anonymous were associated with a lower likelihood of high-risk consumption and problems. Specific late-life and life history factors can identify older adults likely to engage in excessive alcohol consumption 10 and 20 years later. Targeted screening that considers current alcohol consumption and life context, and history of drinking problems and help-seeking, could help identify older adults at higher risk for excessive or problematic drinking. Published by Elsevier Ireland Ltd.

  13. Notes on the life history of Acraea encedon l. (Lepidoptera ...

    African Journals Online (AJOL)

    The life cycle of Acraea encedon (Lepidoptera: Acraeidae) was completed in 40.3 + 2.64 days at a mean daily temperature of 27.91 + 0.440C and relative humidity of 84.8 + 2.62%. The duration of the developmental period of the different life stages of the insect are: embryonic development, 7.5 + 0.54 days; 1st instar, 10.4 + ...

  14. Chum and pink salmon genetics - Genetic and life history variation of southern chum and pink salmon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The distribution of genetic and life history variation in chum (Oncorhynchus keta) and pink (O. gorbuscha) salmon in their southern range in North America is key to...

  15. COPEPOD REPRODUCTIVE STRATEGIES: LIFE-HISTORY THEORY, PHYLOGENETIC PATTERN AND INVASION OF INLAND WATERS. (R824771)

    Science.gov (United States)

    AbstractLife-history theory predicts that different reproductive strategies should evolve in environments that differ in resource availability, mortality, seasonality, and in spatial or temporal variation. Within a population, the predicted optimal strategy is driven ...

  16. Disparate relatives: Life histories vary more in genera occupying intermediate environments

    Czech Academy of Sciences Publication Activity Database

    Hermant, M.; Hennion, F.; Bartish, Igor V.; Yugel, B.; Prinzing, A.

    2012-01-01

    Roč. 14, č. 4 (2012), s. 283-301 ISSN 1433-8319 Institutional support: RVO:67985939 Keywords : life- history traits * dated phylogeny * regional trait variability Subject RIV: EF - Botanics Impact factor: 4.158, year: 2012

  17. Snake River fall Chinook reproductive success - Juvenile life history changes in Snake River fall Chinook salmon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This population historically migrated as subyearling smolts, but in recent years, the yearling life history has become more common. Environmental conditions...

  18. CLASH's life history foundations [commentary on Van Lange et al., 2017

    NARCIS (Netherlands)

    Frankenhuis, W.E.; Fenneman, J.; Gelder, J.L. van; Godoy, I.

    2017-01-01

    We recommend extending CLASH by incorporating two evolutionary accounts of the shift toward fast life histories under harsh, unpredictable conditions. These accounts, if integrated with CLASH, make different predictions about the distributions of aggression and violence within and between societies.

  19. The complex biogeographic history of a widespread tropical tree species.

    Science.gov (United States)

    Dick, Christopher W; Heuertz, Myriam

    2008-11-01

    Many tropical forest tree species have broad geographic ranges, and fossil records indicate that population disjunctions in some species were established millions of years ago. Here we relate biogeographic history to patterns of population differentiation, mutational and demographic processes in the widespread rainforest tree Symphonia globulifera using ribosomal (ITS) and chloroplast DNA sequences and nuclear microsatellite (nSSR) loci. Fossil records document sweepstakes dispersal origins of Neotropical S. globulifera populations from Africa during the Miocene. Despite historical long-distance gene flow, nSSR differentiation across 13 populations from Costa Rica, Panama, Ecuador (east and west of Andes) and French Guiana was pronounced (F(ST)= 0.14, R(ST)= 0.39, P F(ST)) to the divergences between cis- and trans-Andean populations. Both DNA sequence and nSSR data reflect contrasting demographic histories in lower Mesoamerica and Amazonia. Amazon populations show weak phylogeographic structure and deviation from drift-mutation equilibrium indicating recent population expansion. In Mesoamerica, genetic drift was strong and contributed to marked differentiation among populations. The genetic structure of S. globulifera contains fingerprints of drift-dispersal processes and phylogeographic footprints of geological uplifts and sweepstakes dispersal.

  20. Can sexual selection drive female life histories? A comparative study on Galliform birds

    OpenAIRE

    Kolm, N.; Stein, R. W.; Mooers, A. O.; Verspoor, J. J.; Cunningham, E. J. A.

    2007-01-01

    Sexual selection has been identified as a major evolutionary force shaping male life history traits but its impact on female life history evolution is less clear. Here we examine the impact of sexual selection on three key female traits (body size, egg size and clutch size) in Galliform birds. Using comparative independent contrast analyses and directional DISCRETE analyses, based on published data and a new genera-level supertree phylogeny of Galliform birds, we investigated how sexual selec...

  1. Life history and population genetic structure of sea stars from the family Asterinidae

    OpenAIRE

    Keever, Carson C

    2010-01-01

    Life history can influence population genetic variation by altering patterns of gamete union and dispersal. Sea stars from the family Asterinidae have evolved similar life histories multiple times in parallel including planktonic feeding larvae, planktonic non-feeding larvae, development in benthic egg masses, and viviparity. In this thesis I first examine the population genetic structure of a widespread planktotrophic asterinid sea star from the East Pacific (Patiria miniata). I use mitoc...

  2. Responses to a warming world: Integrating life history, immune investment, and pathogen resistance in a model insect species.

    Science.gov (United States)

    Laughton, Alice M; O'Connor, Cian O; Knell, Robert J

    2017-11-01

    Environmental temperature has important effects on the physiology and life history of ectothermic animals, including investment in the immune system and the infectious capacity of pathogens. Numerous studies have examined individual components of these complex systems, but little is known about how they integrate when animals are exposed to different temperatures. Here, we use the Indian meal moth ( Plodia interpunctella ) to understand how immune investment and disease resistance react and potentially trade-off with other life-history traits. We recorded life-history (development time, survival, fecundity, and body size) and immunity (hemocyte counts, phenoloxidase activity) measures and tested resistance to bacterial ( E. coli ) and viral ( Plodia interpunctella granulosis virus) infection at five temperatures (20-30°C). While development time, lifespan, and size decreased with temperature as expected, moths exhibited different reproductive strategies in response to small changes in temperature. At cooler temperatures, oviposition rates were low but tended to increase toward the end of life, whereas warmer temperatures promoted initially high oviposition rates that rapidly declined after the first few days of adult life. Although warmer temperatures were associated with strong investment in early reproduction, there was no evidence of an associated trade-off with immune investment. Phenoloxidase activity increased most at cooler temperatures before plateauing, while hemocyte counts increased linearly with temperature. Resistance to bacterial challenge displayed a complex pattern, whereas survival after a viral challenge increased with rearing temperature. These results demonstrate that different immune system components and different pathogens can respond in distinct ways to changes in temperature. Overall, these data highlight the scope for significant changes in immunity, disease resistance, and host-parasite population dynamics to arise from small

  3. Work-life balance: history, costs, and budgeting for balance.

    Science.gov (United States)

    Raja, Siva; Stein, Sharon L

    2014-06-01

    The concept and difficulties of work-life balance are not unique to surgeons, but professional responsibilities make maintaining a work-life balance difficult. Consequences of being exclusively career focused include burn out, physical, and mental ailments. In addition, physician burn out may hinder optimal patient care and incur significant costs on health care in general. Assessing current uses of time, allocating goals catered to an individual surgeon, and continual self-assessment may help balance time, and ideally will help prevent burn out.

  4. Copepod reproductive strategies: life-history theory, phylogenetic pattern and invasion of inland waters

    Science.gov (United States)

    Hairston, Nelson G.; Bohonak, Andrew J.

    1998-06-01

    Life-history theory predicts that different reproductive strategies should evolve in environments that differ in resource availability, mortality, seasonality, and in spatial or temporal variation. Within a population, the predicted optimal strategy is driven by tradeoffs that are mediated by the environment in which the organisms live. At the same time, phylogenetic history may circumscribe natural selection by dictating the range of phenotypes upon which selection can act, or by limiting the range of environments encountered. Comparisons of life-history patterns in related organisms provide a powerful tool for understanding both the nature of selection on life-history characters and the diversity of life-history patterns observed in nature. Here, we explore reproductive strategies of the Copepoda, a well defined group with many phylogenetically independent transitions from free-living to parasitic life styles, from marine to inland waters, and from active development to diapause. Most species are iteroparous annuals, and most (with the exception of some parasitic taxa) develop through a relatively restricted range of life-history stages (nauplii and copepodids, or some modification thereof). Within these bounds, we suggest that there may be a causal relationship between the success of numerous copepod taxa in inland waters and the prevalence of either diapause or parasitism within these groups. We hypothesize that inland waters are more variable spatially and temporally than marine habitats, and accordingly, we interpret diapause and parasitism as mechanisms for coping with environmental variance.

  5. Complex regional pain syndromes (CRPS) type 1 validating case histories

    OpenAIRE

    P. Berger

    2003-01-01

    The treatment of patients with complex regional pain syndrome (CRPS) type 1 is challenging and unpredictable as the condition presents with vascular and neuropathic symptoms after nil or even minor injury to a peripheral nerve. The condition is one of a pain and motor dysfunction. The pathophysiology is not well understood and the relief of symptoms may change from being sympathetically mediated to sympathetically independent during  the course of the disease. At any stage physiotherapy has b...

  6. The Tsimane Health and Life History Project: Integrating anthropology and biomedicine.

    Science.gov (United States)

    Gurven, Michael; Stieglitz, Jonathan; Trumble, Benjamin; Blackwell, Aaron D; Beheim, Bret; Davis, Helen; Hooper, Paul; Kaplan, Hillard

    2017-04-01

    The Tsimane Health and Life History Project, an integrated bio-behavioral study of the human life course, is designed to test competing hypotheses of human life-history evolution. One aim is to understand the bidirectional connections between life history and social behavior in a high-fertility, kin-based context lacking amenities of modern urban life (e.g. sanitation, banks, electricity). Another aim is to understand how a high pathogen burden influences health and well-being during development and adulthood. A third aim addresses how modernization shapes human life histories and sociality. Here we outline the project's goals, history, and main findings since its inception in 2002. We reflect on the implications of current findings and highlight the need for more coordinated ethnographic and biomedical study of contemporary nonindustrial populations to address broad questions that can situate evolutionary anthropology in a key position within the social and life sciences. © 2017 The Authors Evolutionary Anthropology: Issues, News, and Reviews Published by Wiley Periodicals, Inc.

  7. Jellyfish life histories: role of polyps in forming and maintaining scyphomedusa populations.

    Science.gov (United States)

    Lucas, Cathy H; Graham, William M; Widmer, Chad

    2012-01-01

    Large population fluctuations of jellyfish occur over a variety of temporal scales, from weekly to seasonal, inter-annual and even decadal, with some regions of the world reported to be experiencing persistent seasonal bloom events. Recent jellyfish research has focussed on understanding the causes and consequences of these population changes, with the vast majority of studies considering the effect of changing environmental variables only on the pelagic medusa. But many of the bloom-forming species are members of the Scyphozoa with complex metagenic life cycles consisting of a sexually reproducing pelagic medusa and asexually reproducing benthic polyp. Recruitment success during the juvenile (planula, polyp and ephyrae) stages of the life cycle can have a major effect on the abundance of the adult (medusa) population, but until very recently, little was known about the ecology of the polyp or scyphistoma phase of the scyphozoan life cycle. The aim of this review is to synthesise the current state of knowledge of polyp ecology by examining (1) the recruitment and metamorphosis of planulae larvae into polyps, (2) survival and longevity of polyps, (3) expansion of polyp populations via asexual propagation and (4) strobilation and recruitment of ephyrae (juvenile medusae). Where possible, comparisons are made with the life histories of other bentho-pelagic marine invertebrates so that further inferences can be made. Differences between tropical and temperate species are highlighted and related to climate change, and populations of the same species (in particular Aurelia aurita) inhabiting different habitats within its geographic range are compared. The roles that polyps play in ensuring the long-term survival of jellyfish populations as well as in the formation of bloom populations are considered, and recommendations for future research are presented. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Using Age-Based Life History Data to Investigate the Life Cycle and Vulnerability of Octopus cyanea

    Science.gov (United States)

    Herwig, Jade N.; Depczynski, Martial; Roberts, John D.; Semmens, Jayson M.; Gagliano, Monica; Heyward, Andrew J.

    2012-01-01

    Octopus cyanea is taken as an unregulated, recreationally fished species from the intertidal reefs of Ningaloo, Western Australia. Yet despite its exploitation and importance in many artisanal fisheries throughout the world, little is known about its life history, ecology and vulnerability. We used stylet increment analysis to age a wild O. cyanea population for the first time and gonad histology to examine their reproductive characteristics. O. cyanea conforms to many cephalopod life history generalisations having rapid, non-asymptotic growth, a short life-span and high levels of mortality. Males were found to mature at much younger ages and sizes than females with reproductive activity concentrated in the spring and summer months. The female dominated sex-ratios in association with female brooding behaviours also suggest that larger conspicuous females may be more prone to capture and suggests that this intertidal octopus population has the potential to be negatively impacted in an unregulated fishery. Size at age and maturity comparisons between our temperate bordering population and lower latitude Tanzanian and Hawaiian populations indicated stark differences in growth rates that correlate with water temperatures. The variability in life history traits between global populations suggests that management of O. cyanea populations should be tailored to each unique set of life history characteristics and that stylet increment analysis may provide the integrity needed to accurately assess this. PMID:22912898

  9. Using age-based life history data to investigate the life cycle and vulnerability of Octopus cyanea.

    Directory of Open Access Journals (Sweden)

    Jade N Herwig

    Full Text Available Octopus cyanea is taken as an unregulated, recreationally fished species from the intertidal reefs of Ningaloo, Western Australia. Yet despite its exploitation and importance in many artisanal fisheries throughout the world, little is known about its life history, ecology and vulnerability. We used stylet increment analysis to age a wild O. cyanea population for the first time and gonad histology to examine their reproductive characteristics. O. cyanea conforms to many cephalopod life history generalisations having rapid, non-asymptotic growth, a short life-span and high levels of mortality. Males were found to mature at much younger ages and sizes than females with reproductive activity concentrated in the spring and summer months. The female dominated sex-ratios in association with female brooding behaviours also suggest that larger conspicuous females may be more prone to capture and suggests that this intertidal octopus population has the potential to be negatively impacted in an unregulated fishery. Size at age and maturity comparisons between our temperate bordering population and lower latitude Tanzanian and Hawaiian populations indicated stark differences in growth rates that correlate with water temperatures. The variability in life history traits between global populations suggests that management of O. cyanea populations should be tailored to each unique set of life history characteristics and that stylet increment analysis may provide the integrity needed to accurately assess this.

  10. Mammalian life histories: their evolution and molecular-genetic mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Sacher, G.A.

    1978-01-01

    Survival curves for various species of mammals are discussed and a table is presented to show recorded maximum life spans of about 30 species of mammals. The range of longevities is from one year for shrews and moles up to more than 80 years for the fin whale. The constitutional correlates of longevity are discussed with regard to body size, brain weight,metabolic rates, and body temperature. It is concluded that longevity evolved as a positive trait, associated with the evolution of large body size and brain size. Life table data for man, the thorough-bred horse, beagle dogs, and the laboratory rodents, Mus musculus and Peromyscus leucopus are discussed. The data show a pattern of exponential increase of death rate with age. A laboratory model using Mus musculus and Peromyscus leucopus for the study of the longevity-assurance mechanisms is described. (HLW)

  11. Analysis of Life Histories: A State Space Approach

    Directory of Open Access Journals (Sweden)

    Rajulton, Fernando

    2001-01-01

    Full Text Available EnglishThe computer package LIFEHIST written by the author, is meant for analyzinglife histories through a state-space approach. Basic ideas on which the various programs have beenbuilt are described in this paper in a non-mathematical language. Users can use various programs formultistate analyses based on Markov and semi-Markov frameworks and sequences of transitions implied inlife histories. The package is under constant revision and programs for using a few specific modelsthe author thinks will be useful for analyzing longitudinal data will be incorporated in the nearfuture.FrenchLe système d'ordinateur LIFEHIST écrit par l'auteur est établi pour analyser desévénements au cours de la vie par une approche qui tient compte des états aucours du temps. Les idées fondamentales à la base des divers programmes dumodule sont décrites dans un langage non-mathématique. Le systèmeLIFEHIST peut être utilisé pour des analyses Markov et semi-Markov desséquences d’événements au cours de la vie. Le module est sous révisionconstante, et des programmes que l’auteur compte ajouter pour l'usage dedonnées longitudinales sont décrit.

  12. Fast-slow continuum and reproductive strategies structure plant life-history variation worldwide

    DEFF Research Database (Denmark)

    Salguero-Gómez, Roberto; Jones, Owen R; Jongejans, Eelke

    2016-01-01

    The identification of patterns in life-history strategies across the tree of life is essential to our prediction of population persistence, extinction, and diversification. Plants exhibit a wide range of patterns of longevity, growth, and reproduction, but the general determinants of this enormous...

  13. Fast–slow continuum and reproductive strategies structure plant life-history variation worldwide

    NARCIS (Netherlands)

    Salguero-Gómez, Roberto; Jones, Owen R.; Jongejans, Eelke; Blomberg, Simon; Hodgson, D.; Zuidema, P.A.; Kroon, de Hans; Buckley, Yvonne M.

    2016-01-01

    The identification of patterns in life-history strategies across the tree of life is essential to our prediction of population persistence, extinction, and diversification. Plants exhibit a wide range of patterns of longevity, growth, and reproduction, but the general determinants of this enormous

  14. Road–side herbaceous vegetation: life history groups and habitat preferences

    Czech Academy of Sciences Publication Activity Database

    Šerá, Božena

    2010-01-01

    Roč. 58, č. 1 (2010), s. 69-79 ISSN 1505-2249 R&D Projects: GA MŠk(CZ) OC 350.002 Institutional research plan: CEZ:AV0Z60870520 Keywords : road-side vegetation * road ecology * life form * life history * habitat preference * alien species Subject RIV: EH - Ecology, Behaviour Impact factor: 0.542, year: 2010

  15. Life history strategies and biomass allocation : the population dynamics of perennial plants in a regional perspective

    NARCIS (Netherlands)

    Jongejans, E.

    2004-01-01

    This study aims to contribute to the knowledge of how plants respond to adverse influences of intensified land use. In particular, attention was paid to the ways in which life history strategies change in order to buffer environmental variation, and which important parts of the life cycle are

  16. Debkiss or the quest for the simplest generic model of animal life history.

    NARCIS (Netherlands)

    Jager, T.; Martin, B.T.; Zimmer, E.I.

    2013-01-01

    Understanding the life cycle of individual animals, and how it responds to stress, requires a model that causally links life-history traits (feeding, growth, development and reproduction). Dynamic Energy Budget (DEB) theory offers a powerful and formalised framework for building process-based models

  17. Hope Amidst Hopelessness: Life Histories of Illiterate Oraon Tribal Women in Jharkhand, India

    Science.gov (United States)

    Minz, Nijhar Jharia

    2012-01-01

    This interpretive study asked the question: "What education and literacy insights can be gained from the studies of the life stories of illiterate Oraon women in Jharkhand, India?" Life history methodology was used to gain insights into the lived experiences of illiterate women. I hoped to provide meaning and give voice to the voiceless.…

  18. Convergent and correlated evolution of major life-history traits in the angiosperm genus Leucadendron (Proteaceae).

    Science.gov (United States)

    Tonnabel, Jeanne; Mignot, Agnès; Douzery, Emmanuel J P; Rebelo, Anthony G; Schurr, Frank M; Midgley, Jeremy; Illing, Nicola; Justy, Fabienne; Orcel, Denis; Olivieri, Isabelle

    2014-10-01

    Natural selection is expected to cause convergence of life histories among taxa as well as correlated evolution of different life-history traits. Here, we quantify the extent of convergence of five key life-history traits (adult fire survival, seed storage, degree of sexual dimorphism, pollination mode, and seed-dispersal mode) and test hypotheses about their correlated evolution in the genus Leucadendron (Proteaceae) from the fire-prone South African fynbos. We reconstructed a new molecular phylogeny of this highly diverse genus that involves more taxa and molecular markers than previously. This reconstruction identifies new clades that were not detected by previous molecular study and morphological classifications. Using this new phylogeny and robust methods that account for phylogenetic uncertainty, we show that the five life-history traits studied were labile during the evolutionary history of the genus. This diversity allowed us to tackle major questions about the correlated evolution of life-history strategies. We found that species with longer seed-dispersal distances tended to evolve lower pollen-dispersal distance, that insect-pollinated species evolved decreased sexual dimorphism, and that species with a persistent soil seed-bank evolved toward reduced fire-survival ability of adults. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  19. Defoliation and bark harvesting affect life-history traits of a tropical tree

    DEFF Research Database (Denmark)

    Gaoue, Orou; Horvitz, Carol; Ticktin, Tamara

    2013-01-01

    Selectively harvesting whole individuals in managed populations (e.g. fisheries, hunting) has substantial effects on life expectancy and age at maturity. Although demographic rates of trees are impacted by recurrent harvest of plant organs (e.g. fruit, leaf, bark) known as non-timber forest...... products, the effect of such harvesting on life-history traits is less explored. Here, we investigate how different strategies of foliage and bark harvest by local people affect life expectancy and age at maturity of Khaya senegalensis across two climatic regions in West Africa. We compare elasticities....... However, there is an interactive effect of harvest on life-history traits between regions. Increasing harvesting pressure accelerates maturity and reduces life expectancy in the dry region but delays reproduction and increases life expectancy in the moist region. This indicates that stochasticity...

  20. Comparing plant life histories using elasticity analysis: the importance of life span and the number of life-cycle stages.

    Science.gov (United States)

    Enright, N J; Franco, M; Silvertown, J

    1995-09-01

    Recent studies have used transition matrix elasticity analysis to investigate the relative role of survival (L), growth (G) and fecundity (F) in determining the estimated rate of population increase for perennial plants. The relative importance of these three variables has then been used as a framework for comparing patterns of plant life history in a triangular parameter space. Here we analyse the ways in which the number of life-cycle stages chosen to describe a species (transition matrix dimensionality) might influence the interpretation of such comparisons. Because transition matrix elements describing survival ("stasis") and growth are not independent, the number of stages used to describe a species influences their relative contribution to the population growth rate. Reduction in the number of stages increases the apparent importance of stasis relative to growth, since each becomes broader and fewer individuals make the transition to the next stage per unit time period. Analysis of a test matrix for a hypothetical tree species divided into 4-32 life-cycle stages confirms this. If the number of stages were defined in relation to species longevity so that mean residence time in each stage were approximately constant, then the elasticity of G would reflect the importance of relative growth rate to λ. An alternative, and simpler, approach to ensure comparability of results between species may be to use the same number of stages regardless of species longevity. Published studies for both herbaceous and woody species have tended to use relatively few stages to describe life cycles (herbs: n=45, [Formula: see text]; woody plants: n=21, [Formula: see text]) and so approximate this approach. By using the same number of stages regardless of longevities, the position of species along the G-L side of the triangular parameter space largely reflects differences in longevity. The extent of variation in elasticity for L, G and F within and between species may also be

  1. The prevalence and natural history of complex sleep apnea.

    Science.gov (United States)

    Javaheri, Shahrokh; Smith, Jason; Chung, Eugene

    2009-06-15

    Central sleep apnea (CSA) may occasionally occur in patients with obstructive sleep apnea during titration with a continuous positive airway pressure (CPAP) device. To determine the prevalence and the natural history of CPAP-emergent CSA. This is a retrospective study of 1286 patients with a diagnosis of OSAwho underwent titration with a positive airway device during a 1-year period. Patients were seen in consultation and underwent full-night attended polysomnography followed by full-night attended CPAP titration. Four weeks after CPAP therapy, patients returned to the clinic for follow-up, and objective adherence to CPAP was recorded. In patients who had CSA on CPAP, a second full-night attended CPAP titration was recommended. Eighty-four of the 1286 patients developed a central apnea index (CAI) of 5 or greater per hour while on CPAP. The incidence of CSA varied from 3% to 10% monthly, with an overall incidence of 6.5%. Forty-two of the 84 patients returned for a second CPAP titration. In 33 patients, CSA was eliminated. In each of the remaining 9 patients, the CAI remained at 5 or greater per hour, with an average of 13 per hour. These patients characteristically had the most severe OSA, and 5 had a CAI of 5 or more per hour at baseline. Two of the 9 patients were on opioids In this large retrospective study of 1286 patients with a diagnosis of OSA, 6.5% had CPAP-emergent or persistent CSA. However, CPAP-emergent CSA was generally transitory and was eliminated within 8 weeks after CPAP therapy. The prevalence of CPAP-persistent CSA was about 1.5%. Severity of OSA, a CAI of 5 or greater per hour, and use of opioids were potential risk factors.

  2. Microbiome analysis among bats describes influences of host phylogeny, life history, physiology and geography.

    Science.gov (United States)

    Phillips, Caleb D; Phelan, Georgina; Dowd, Scot E; McDonough, Molly M; Ferguson, Adam W; Delton Hanson, J; Siles, Lizette; Ordóñez-Garza, Nicté; San Francisco, Michael; Baker, Robert J

    2012-06-01

    Metagenomic methods provide an experimental approach to inform the relationships between hosts and their microbial inhabitants. Previous studies have provided the conceptual realization that microbiomes are dynamic among hosts and the intimacy of relation between micro- and macroorganisms. Here, we present an intestinal microflora community analysis for members of the order Chiroptera and investigate the relative influence of variables in shaping observed microbiome relationships. The variables ranged from those considered to have ancient and long-term influences (host phylogeny and life history) to the relatively transient variable of host reproductive condition. In addition, collection locality data, representing the geographic variable, were included in analyses. Results indicate a complex influence of variables in shaping sample relationships in which signal for host phylogeny is recovered at broad taxonomic levels (family), whereas intrafamilial analyses disclosed various degrees of resolution for the remaining variables. Although cumulative probabilities of assignment indicated both reproductive condition and geography influenced relationships, comparison of ecological measures among groups revealed statistical differences between most variable classifications. For example, ranked ecological diversity was associated with host phylogeny (deeper coalescences among families were associated with more microfloral diversity), dietary strategy (herbivory generally retained higher diversity than carnivory) and reproductive condition (reproductively active females displayed more diverse microflora than nonreproductive conditions). Overall, the results of this study describe a complex process shaping microflora communities of wildlife species as well as provide avenues for future research that will further inform the nature of symbiosis between microflora communities and hosts. © 2012 Blackwell Publishing Ltd.

  3. Effects of maternal history of depression and early life maltreatment on children's health-related quality of life.

    Science.gov (United States)

    Dittrich, Katja; Fuchs, Anna; Bermpohl, Felix; Meyer, Justus; Führer, Daniel; Reichl, Corinna; Reck, Corinna; Kluczniok, Dorothea; Kaess, Michael; Hindi Attar, Catherine; Möhler, Eva; Bierbaum, Anna-Lena; Zietlow, Anna-Lena; Jaite, Charlotte; Winter, Sibylle Maria; Herpertz, Sabine C; Brunner, Romuald; Bödeker, Katja; Resch, Franz

    2018-01-01

    There is a well-established link between maternal depression and child mental health. Similar effects have been found for maternal history of early life maltreatment (ELM). However, studies investigating the relationship of children's quality of life and maternal depression are scarce and none have been conducted for the association with maternal ELM. The aim of the present study was to investigate the effects of maternal history of ELM and depression on children's health-related quality of life and to identify mediating factors accounting for these effects. Our study involved 194 mothers with and without history of depression and/or ELM and their children between five and 12 years. Children's health-related quality of life was assessed by maternal proxy- and child self-ratings using the KIDSCREEN. We considered maternal sensitivity and maternal parenting stress as potential mediators. We found an effect of maternal history of depression but not of maternal history of ELM on health-related quality of life. Maternal stress and sensitivity mediated the effects of maternal depression on child global health-related quality of life, as well as on the dimensions Autonomy & Parent Relation, School Environment (maternal and child rating), and Physical Wellbeing (child rating). Due to the cross-sectional design of the study, causal interpretations must be made with caution. Some scales yielded low internal consistency. Maternal impairments in areas of parenting which possibly developed during acute depression persist even after remission of acute affective symptoms. Interventions should target parenting stress and sensitivity in parents with prior depression. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Linking habitat structure to life history strategy: Insights from a Mediterranean killifish

    Science.gov (United States)

    Cavraro, Francesco; Daouti, Irini; Leonardos, Ioannis; Torricelli, Patrizia; Malavasi, Stefano

    2014-01-01

    Modern theories of life history evolution deal with finding links between environmental factors, demographic structure of animal populations and the optimal life history strategy. Small-sized teleost fish, occurring in fragmented populations under contrasting environments, have been widely used as study models to investigate these issues. In the present study, the Mediterranean killifish Aphanius fasciatus was used to investigate the relationships between some habitat features and life history strategy. We selected four sites in the Venice lagoon inhabited by this species, exhibiting different combinations of two factors: overall adult mortality, related to intertidal water coverage and a consequent higher level of predator exposure, and the level of sediment organic matter, as indicator of habitat trophic richness. Results showed that these were the two most important factors influencing demography and life history traits in the four sites. Fish from salt marshes with high predator pressure were smaller and produced a higher number of eggs, whereas bigger fish and a lower reproductive investment were found in the two closed, not tidally influenced habitats. Habitat richness was positively related with population density, but negatively related with growth rate. In particular the synergy between high resources and low predation level was found to be important in shaping peculiar life history traits. Results were discussed in the light of the interactions between selective demographic forces acting differentially on age/size classes, such as predation, and habitat trophic richness that may represent an important energetic constraint on life history traits. The importance to link habitat productivity and morphology to demographic factors for a better understanding of the evolution of life history strategy under contrasting environments was finally suggested.

  5. Life atomic a history of radioisotopes in science and medicine

    CERN Document Server

    Creager, Angela N H

    2013-01-01

    After World War II, the US Atomic Energy Commission (AEC) began mass-producing radioisotopes, sending out nearly 64,000 shipments of radioactive materials to scientists and physicians by 1955. Even as the atomic bomb became the focus of Cold War anxiety, radioisotopes represented the government's efforts to harness the power of the atom for peace-advancing medicine, domestic energy, and foreign relations.             In Life Atomic, Angela N. H. Creager tells the story of how these radioisotopes, which were simultaneously scientific tools and political icons, transformed biomedicine and ecolog

  6. Brain structural complexity and life course cognitive change.

    Science.gov (United States)

    Mustafa, Nazahah; Ahearn, Trevor S; Waiter, Gordon D; Murray, Alison D; Whalley, Lawrence J; Staff, Roger T

    2012-07-02

    Fractal measures such as fractal dimension (FD) can quantify the structural complexity of the brain. These have been used in clinical neuroscience to investigate brain development, ageing and in studies of psychiatric and neurological disorders. Here, we examined associations between the FD of white matter and cognitive changes across the life course in the absence of detectable brain disease. The FD was calculated from segmented cerebral white matter MR images in 217 subjects aged about 68years, in whom archived intelligence scores from age 11years were available. Cognitive test scores of fluid and crystallised intelligence were obtained at the time of MR imaging. Significant differences were found (intracranial volume, brain volume, white matter volume and Raven's Progressive Matrices score) between men and women at age 68years and novel associations were found between FD and measures of cognitive change over the life course from age 11 to 68years. Those with greater FD were found to have greater than expected fluid abilities at age 68years than predicted by their childhood intelligence and less cognitive decline from age 11 to 68years. These results are consistent with other reports that FD measures of cortical structural complexity increase across the early life course during maturation of the cerebral cortex and add new data to support an association between FD and cognitive ageing. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Life lines: An art history of biological research around 1800.

    Science.gov (United States)

    Bruhn, Matthias

    2011-12-01

    Around 1800, the scientific "illustrator" emerged as a new artistic profession in Europe. Artists were increasingly sought after in order to picture anatomical dissections and microscopic observations and to translate drawings into artworks for books and journals. By training and technical expertise, they introduced a particular kind of knowledge into scientific perception that also shaped the common image of nature. Illustrations of scientific publications, often undervalued as a biased interpretation of facts and subordinate to logic and description, thus convey an 'art history' of science in its own right, relevant both for the understanding of biological thought around 1800 as well as for the development of the arts and their historiography. The article is based on an analysis of botanical treatises produced for the Göttingen Society of Sciences in 1803, during an early phase of microscopic cell research, in order to determine the constitutive role of artistic knowledge and the media employed for the visualization and conceptualization of biological issues. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Life history plasticity of a tropical seabird in response to El Niño anomalies during early life.

    Directory of Open Access Journals (Sweden)

    Sergio Ancona

    Full Text Available Food shortage and other challenges associated with El Niño Southern Oscillation (ENSO experienced early in life may have long-term impacts on life history traits, but these potential impacts remain virtually unexplored. By monitoring 2556 blue-footed boobies from 11 cohorts, we showed that birds facing warm water ENSO conditions (and probably low food availability in the natal year were underweight at fledging, recruited earlier and bred less frequently, but showed no deficit in longevity or breeding success over the first 10 years. Life history impacts of ENSO were substantial when experienced in the prenatal year, the natal year, or the second year of life, and absent when experienced in the third year of life, implying that harsh conditions have greater effects when experienced earlier in life. Sexual differences in impacts depended on the age when warm water conditions were experienced: pre-natal and natal experience, respectively, induced early recruitment and influenced the relationship between age and laying date only in females, whereas second year experience reduced total breeding success only of males. Most surprising were positive transgenerational impacts in females: daughters of females that experienced ENSO conditions in their natal year showed improved breeding success. Developmental plasticity of boobies thus enables them to largely neutralize potential long-term impacts of harsh climatic conditions experienced early in life.

  9. Molecular phylogenetics of the genus Neoconocephalus (orthoptera, tettigoniidae and the evolution of temperate life histories.

    Directory of Open Access Journals (Sweden)

    Robert L Snyder

    Full Text Available BACKGROUND: The katydid genus Neoconocephalus (25+ species has a prominent acoustic communication system and occurs in large parts of the Neotropics and Nearctic. This group has been subject of numerous behavioral, physiological, and evolutionary studies of its acoustic communication system. Two distinct life histories occur in this group: The tropical life history incorporates multiple generations/year and direct egg development without environmental triggers. Temperate life history is characterized by overwintering in the egg stage, cold trigger of egg development, and one generation/year. This study reconstructs the phylogenetic relationships within the genus to (1 determine the evolutionary history of the temperate life history, and (2 to support comparative studies of evolutionary and physiological problems in this genus. METHODOLOGY/PRINCIPAL FINDINGS: We used Amplified Fragment Length Polymorphisms (AFLP, and sequences of two nuclear loci and one mitochondrial locus to reconstruct phylogenetic relationships. The analysis included 17 ingroup and two outgroup species. AFLP and mitochondrial data provided resolution at the species level while the two nuclear loci revealed only deeper nodes. The data sets were combined in a super-matrix to estimate a total evidence tree. Seven of the temperate species form a monophyletic group; however, three more temperate species were placed as siblings of tropical species. CONCLUSIONS/SIGNIFICANCE: Our analyses support the reliability of the current taxonomic treatment of the Neoconocephalus fauna of Caribbean, Central, and North America. Ancestral state reconstruction of life history traits was not conclusive, however at least four transitions between life histories occurred among our sample of species. The proposed phylogeny will strengthen conclusions from comparative work in this group.

  10. Extraordinarily rapid life-history divergence between Cryptasterina sea star species.

    Science.gov (United States)

    Puritz, Jonathan B; Keever, Carson C; Addison, Jason A; Byrne, Maria; Hart, Michael W; Grosberg, Richard K; Toonen, Robert J

    2012-10-07

    Life history plays a critical role in governing microevolutionary processes such as gene flow and adaptation, as well as macroevolutionary processes such speciation. Here, we use multilocus phylogeographic analyses to examine a speciation event involving spectacular life-history differences between sister species of sea stars. Cryptasterina hystera has evolved a suite of derived life-history traits (including internal self-fertilization and brood protection) that differ from its sister species Cryptasterina pentagona, a gonochoric broadcast spawner. We show that these species have only been reproductively isolated for approximately 6000 years (95% highest posterior density of 905-22 628), and that this life-history change may be responsible for dramatic genetic consequences, including low nucleotide diversity, zero heterozygosity and no gene flow. The rapid divergence of these species rules out some mechanisms of isolation such as adaptation to microhabitats in sympatry, or slow divergence by genetic drift during prolonged isolation. We hypothesize that the large phenotypic differences between species relative to the short divergence time suggests that the life-history differences observed may be direct responses to disruptive selection between populations. We speculate that local environmental or demographic differences at the southern range margin are possible mechanisms of selection driving one of the fastest known marine speciation events.

  11. Life-history variation of a neotropical thrush challenges food limitation theory

    Science.gov (United States)

    Ferretti, V.; Llambias, P.E.; Martin, T.E.

    2005-01-01

    Since David Lack first proposed that birds rear as many young as they can nourish, food limitation has been accepted as the primary explanation for variation in clutch size and other life-history traits in birds. The importance of food limitation in life-history variation, however, was recently questioned on theoretical grounds. Here, we show that clutch size differences between two populations of a neotropical thrush were contrary to expectations under Lack's food limitation hypothesis. Larger clutch sizes were found in a population with higher nestling starvation rate (i.e. greater food limitation). We experimentally equalized clutches between populations to verify this difference in food limitation. Our experiment confirmed greater food limitation in the population with larger mean clutch size. In addition, incubation bout length and nestling growth rate were also contrary to predictions of food limitation theory. Our results demonstrate the inability of food limitation to explain differences in several life-history traits: clutch size, incubation behaviour, parental feeding rate and nestling growth rate. These life-history traits were better explained by inter-population differences in nest predation rates. Food limitation may be less important to life history evolution in birds than suggested by traditional theory. ?? 2005 The Royal Society.

  12. Contrasting latitudinal patterns of life-history divergence in two genera of new world thrushes (Turdinae)

    Science.gov (United States)

    Boyce, Andy J.; Martin, Thomas E.

    2017-01-01

    Several long-standing hypotheses have been proposed to explain latitudinal patterns of life-history strategies. Here, we test predictions of four such hypotheses (seasonality, food limitation, nest predation and adult survival probability) by examining life-history traits and age-specific mortality rates of several species of thrushes (Turdinae) based on field studies at temperate and tropical sites and data gathered from the literature. Thrushes in the genus Catharus showed the typical pattern of slower life-history strategies in the tropics while co-occuring Turdus thrushes differed much less across latitudes. Seasonality is a broadly accepted hypothesis for latitudinal patterns, but the lack of concordance in latitudinal patterns between co-existing genera that experience the same seasonal patterns suggests seasonality cannot fully explain latitudinal trait variation in thrushes. Nest-predation also could not explain patterns based on our field data and literature data for these two genera. Total feeding rates were similar, and per-nestling feeding rates were higher at tropical latitudes in both genera, suggesting food limitation does not explain trait differences in thrushes. Latitudinal patterns of life histories in these two genera were closely associated with adult survival probability. Thus, our data suggest that environmental influences on adult survival probability may play a particularly strong role in shaping latitudinal patterns of life-history traits.

  13. Life-history evolution in guppies VIII: the demographics of density regulation in guppies (Poecilia reticulata).

    Science.gov (United States)

    Reznick, David N; Bassar, Ronald D; Travis, Joseph; Helen Rodd, F

    2012-09-01

    In prior research, we found the way guppy life histories evolve in response to living in environments with a high or low risk of predation is consistent with life-history theory that assumes no density dependence. We later found that guppies from high-predation environments experience higher mortality rates than those from low-predation environments, but the increased risk was evenly distributed across all age/size classes. Life-history theory that assumes density-independent population growth predicts that life histories will not evolve under such circumstances, yet we have shown with field introduction experiments that they do evolve. However, theory that incorporates density regulation predicts this pattern of mortality can result in the patterns of life-history evolution we had observed. Here we report on density manipulation experiments performed in populations of guppies from low-predation environments to ask whether natural populations normally experience density regulation and, if so, to characterize the short-term demographic changes that underlie density regulation. Our experiments reveal that these populations are density regulated. Decreased density resulted in higher juvenile growth, decreased juvenile mortality rates, and increased reproductive investment by adult females. Increased density causes reduced offspring size, decreased fat storage by adult females, and increased adult mortality. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  14. Fast-slow continuum and reproductive strategies structure plant life-history variation worldwide.

    Science.gov (United States)

    Salguero-Gómez, Roberto; Jones, Owen R; Jongejans, Eelke; Blomberg, Simon P; Hodgson, David J; Mbeau-Ache, Cyril; Zuidema, Pieter A; de Kroon, Hans; Buckley, Yvonne M

    2016-01-05

    The identification of patterns in life-history strategies across the tree of life is essential to our prediction of population persistence, extinction, and diversification. Plants exhibit a wide range of patterns of longevity, growth, and reproduction, but the general determinants of this enormous variation in life history are poorly understood. We use demographic data from 418 plant species in the wild, from annual herbs to supercentennial trees, to examine how growth form, habitat, and phylogenetic relationships structure plant life histories and to develop a framework to predict population performance. We show that 55% of the variation in plant life-history strategies is adequately characterized using two independent axes: the fast-slow continuum, including fast-growing, short-lived plant species at one end and slow-growing, long-lived species at the other, and a reproductive strategy axis, with highly reproductive, iteroparous species at one extreme and poorly reproductive, semelparous plants with frequent shrinkage at the other. Our findings remain consistent across major habitats and are minimally affected by plant growth form and phylogenetic ancestry, suggesting that the relative independence of the fast-slow and reproduction strategy axes is general in the plant kingdom. Our findings have similarities with how life-history strategies are structured in mammals, birds, and reptiles. The position of plant species populations in the 2D space produced by both axes predicts their rate of recovery from disturbances and population growth rate. This life-history framework may complement trait-based frameworks on leaf and wood economics; together these frameworks may allow prediction of responses of plants to anthropogenic disturbances and changing environments.

  15. The Teacher I Wish to Be: Exploring the Influence of Life Histories on Student Teacher Idealised Identities

    Science.gov (United States)

    Furlong, Catherine

    2013-01-01

    This paper examines the influence of life histories and apprenticeship of observation on the formation of student teachers' idealised identities. The life histories of 15 student teachers are decoded. Through eliciting from the student teachers the teacher they wish to be, the paper focuses on the interplay between the personal histories and ideal…

  16. Integrating the pace-of-life syndrome across species, sexes and individuals: covariation of life history and personality under pesticide exposure.

    Science.gov (United States)

    Debecker, Sara; Sanmartín-Villar, Iago; de Guinea-Luengo, Miguel; Cordero-Rivera, Adolfo; Stoks, Robby

    2016-05-01

    The pace-of-life syndrome (POLS) hypothesis integrates covariation of life-history traits along a fast-slow continuum and covariation of behavioural traits along a proactive-reactive personality continuum. Few studies have investigated these predicted life-history/personality associations among species and between sexes. Furthermore, whether and how contaminants interfere with POLS patterns remains unexplored. We tested for covariation patterns in life history and in behaviour, and for life-history/personality covariation among species, among individuals within species and between sexes. Moreover, we investigated whether pesticide exposure affects covariation between life history and behaviour and whether species and sexes with a faster POLS strategy have a higher sensitivity to pesticides. We reared larvae of four species of Ischnura damselflies in a common garden experiment with an insecticide treatment (chlorpyrifos absent/present) in the final instar. We measured four life-history traits (larval growth rate during the pesticide treatment, larval development time, adult mass and life span) and two behavioural traits (larval feeding activity and boldness, each before and after the pesticide treatment). At the individual level, life-history traits and behavioural traits aligned along a fast-slow and a proactive-reactive continuum, respectively. Species-specific differences in life history, with fast-lived species having a faster larval growth and development, a lower mass at emergence and a shorter life span, suggested that time constraints in the larval stage were predictably driving life-history evolution both in the larval stage and across metamorphosis in the adult stage. Across species, females were consistently more slow-lived than males, reflecting that a large body size and a long life span are generally more important for females. In contrast to the POLS hypothesis, there was only little evidence for the expected positive coupling between life-history

  17. Comparative life histories of fishes in the subgenus Limia (Pisces: Poeciliidae).

    Science.gov (United States)

    Cohen, S N; Regus, J U; Reynoso, Y; Mastro, T; Reznick, D N

    2015-07-01

    This study presents life-history descriptions for 12 species in the subgenus Limia, which are endemic to the Greater Antilles. All species in this study lack evidence of superfoetation, producing a single brood of offspring before developing subsequent broods. Interbrood intervals (number of days between parturition events) are also consistent with intervals of species that lack superfoetation. Maternal provisioning, characterized by matrotrophy index, is lecithotrophic). Four species exhibit potentially bi-modal size distributions of mature males. Work on other poeciliids suggests that such bimodal distributions can be caused by genetic polymorphisms in some species. Principle component analyses revealed an axis of interspecific variation in life histories that separated species with small size at maturity and the production of many, small offspring from those with large size at maturity and that produce few, large offspring. This pattern of life-history diversity occurs in many other groups of organisms. © 2015 The Fisheries Society of the British Isles.

  18. Religious People Are Trusted Because They Are Viewed as Slow Life-History Strategists.

    Science.gov (United States)

    Moon, Jordan W; Krems, Jaimie Arona; Cohen, Adam B

    2018-03-01

    Religious people are more trusted than nonreligious people. Although most theorists attribute these perceptions to the beliefs of religious targets, religious individuals also differ in behavioral ways that might cue trust. We examined whether perceivers might trust religious targets more because they heuristically associate religion with slow life-history strategies. In three experiments, we found that religious targets are viewed as slow life-history strategists and that these findings are not the result of a universally positive halo effect; that the effect of target religion on trust is significantly mediated by the target's life-history traits (i.e., perceived reproductive strategy); and that when perceivers have direct information about a target's reproductive strategy, their ratings of trust are driven primarily by his or her reproductive strategy, rather than religion. These effects operate over and above targets' belief in moralizing gods and offer a novel theoretical perspective on religion and trust.

  19. Life history diversity of Snake River finespotted cutthroat trout: managing for persistence in a rapidly changing environment

    Science.gov (United States)

    Homel, Kristen M.; Gresswell, Robert E.; Kershner, Jeffrey L.

    2015-01-01

    Over the last century, native trout have experienced dramatic population declines, particularly in larger river systems where habitats associated with different spawning life history forms have been lost through habitat degradation and fragmentation. The resulting decrease in life history diversity has affected the capacity of populations to respond to environmental variability and disturbance. Unfortunately, because few large rivers are intact enough to permit full expression of life history diversity, it is unclear what patterns of diversity should be a conservation target. In this study, radiotelemetry was used to identify spawning and migration patterns of Snake River Finespotted Cutthroat Trout Oncorhynchus clarkii behnkei in the upper Snake River. Individuals were implanted with radio tags in October 2007 and 2008, and monitored through October 2009. Radio-tagged cutthroat trout in the upper Snake River exhibited variation in spawning habitat type and location, migration distance, spawn timing, postspawning behavior, and susceptibility to mortality sources. Between May and July, Cutthroat Trout spawned in runoff-dominated tributaries, groundwater-dominated spring creeks, and side channels of the Snake River. Individuals migrated up to 101 km from tagging locations in the upper Snake River to access spawning habitats, indicating that the upper Snake River provided seasonal habitat for spawners originating throughout the watershed. Postspawning behavior also varied; by August each year, 28% of spring-creek spawners remained in their spawning location, compared with 0% of side-channel spawners and 7% of tributary spawners. These spawning and migration patterns reflect the connectivity, habitat diversity, and dynamic template of the Snake River. Ultimately, promoting life history diversity through restoration of complex habitats may provide the most opportunities for cutthroat trout persistence in an environment likely to experience increased variability from

  20. Old world versus new world: life-history alterations in a successful invader introduced across Europe.

    Science.gov (United States)

    Fox, Michael G; Copp, Gordon H

    2014-02-01

    We examined differences in pumpkinseed (Lepomis gibbosus) life-history traits between native North American and introduced European populations, and tested three life-history predictions related to the effect of temperature, growth, waterbody size, and the presence/absence of predators on native and non-native populations. Pumpkinseed populations exhibit more 'opportunistic' traits (earlier maturity, smaller size at maturity, and higher reproductive allocation) in their introduced European range than those in their native range. Predictions of life-history traits were improved when indicators of juvenile growth rate (mean length at age 2), waterbody size (surface area), and thermal regime (air temperature degree-days above 10 °C) were incorporated into models along with continental location, but European pumpkinseed populations exhibit more opportunistic life-history traits than North American populations even when these factors are accounted for. Native pumpkinseed in waterbodies containing piscivores mature later and at a larger size, and have lower gonadosomatic indices than those in waterbodies lacking piscivores, whereas there is no significant difference in the same three life-history traits between European waterbodies containing or lacking piscivores. Because congeneric competitors of the pumpkinseed are absent from Europe, the apparent absence of a predator life-history effect there could also be due to the absence of the major sunfish competitors. In either case, the evolution and maintenance of more opportunistic traits in European pumpkinseed can likely be attributed to enemy release, and this may explain the successful establishment and spread of pumpkinseed in many parts of Europe.

  1. Life-history traits predict perennial species response to fire in a desert ecosystem

    Science.gov (United States)

    Shryock, Daniel F.; DeFalco, Lesley A.; Esque, Todd C.

    2014-01-01

    The Mojave Desert of North America has become fire-prone in recent decades due to invasive annual grasses that fuel wildfires following years of high rainfall. Perennial species are poorly adapted to fire in this system, and post-fire shifts in species composition have been substantial but variable across community types. To generalize across a range of conditions, we investigated whether simple life-history traits could predict how species responded to fire. Further, we classified species into plant functional types (PFTs) based on combinations of life-history traits and evaluated whether these groups exhibited a consistent fire-response. Six life-history traits varied significantly between burned and unburned areas in short (up to 4 years) or long-term (up to 52 years) post-fire datasets, including growth form, lifespan, seed size, seed dispersal, height, and leaf longevity. Forbs and grasses consistently increased in abundance after fire, while cacti were reduced and woody species exhibited a variable response. Woody species were classified into three PFTs based on combinations of life-history traits. Species in Group 1 increased in abundance after fire and were characterized by short lifespans, small, wind-dispersed seeds, low height, and deciduous leaves. Species in Group 2 were reduced by fire and distinguished from Group 1 by longer lifespans and evergreen leaves. Group 3 species, which also decreased after fire, were characterized by long lifespans, large non-wind dispersed seeds, and taller heights. Our results show that PFTs based on life-history traits can reliably predict the responses of most species to fire in the Mojave Desert. Dominant, long-lived species of this region possess a combination of traits limiting their ability to recover, presenting a clear example of how a novel disturbance regime may shift selective environmental pressures to favor alternative life-history strategies.

  2. Differential reproductive responses to stress reveal the role of life-history strategies within a species.

    Science.gov (United States)

    Schultner, J; Kitaysky, A S; Gabrielsen, G W; Hatch, S A; Bech, C

    2013-11-22

    Life-history strategies describe that 'slow'- in contrast to 'fast'-living species allocate resources cautiously towards reproduction to enhance survival. Recent evidence suggests that variation in strategies exists not only among species but also among populations of the same species. Here, we examined the effect of experimentally induced stress on resource allocation of breeding seabirds in two populations with contrasting life-history strategies: slow-living Pacific and fast-living Atlantic black-legged kittiwakes. We tested the hypothesis that reproductive responses in kittiwakes under stress reflect their life-history strategies. We predicted that in response to stress, Pacific kittiwakes reduce investment in reproduction compared with Atlantic kittiwakes. We exposed chick-rearing kittiwakes to a short-term (3-day) period of increased exogenous corticosterone (CORT), a hormone that is released during food shortages. We examined changes in baseline CORT levels, parental care and effects on offspring. We found that kittiwakes from the two populations invested differently in offspring when facing stress. In response to elevated CORT, Pacific kittiwakes reduced nest attendance and deserted offspring more readily than Atlantic kittiwakes. We observed lower chick growth, a higher stress response in offspring and lower reproductive success in response to CORT implantation in Pacific kittiwakes, whereas the opposite occurred in the Atlantic. Our findings support the hypothesis that life-history strategies predict short-term responses of individuals to stress within a species. We conclude that behaviour and physiology under stress are consistent with trade-off priorities as predicted by life-history theory. We encourage future studies to consider the pivotal role of life-history strategies when interpreting inter-population differences of animal responses to stressful environmental events.

  3. Effects of complex life cycles on genetic diversity: cyclical parthenogenesis.

    Science.gov (United States)

    Rouger, R; Reichel, K; Malrieu, F; Masson, J P; Stoeckel, S

    2016-11-01

    Neutral patterns of population genetic diversity in species with complex life cycles are difficult to anticipate. Cyclical parthenogenesis (CP), in which organisms undergo several rounds of clonal reproduction followed by a sexual event, is one such life cycle. Many species, including crop pests (aphids), human parasites (trematodes) or models used in evolutionary science (Daphnia), are cyclical parthenogens. It is therefore crucial to understand the impact of such a life cycle on neutral genetic diversity. In this paper, we describe distributions of genetic diversity under conditions of CP with various clonal phase lengths. Using a Markov chain model of CP for a single locus and individual-based simulations for two loci, our analysis first demonstrates that strong departures from full sexuality are observed after only a few generations of clonality. The convergence towards predictions made under conditions of full clonality during the clonal phase depends on the balance between mutations and genetic drift. Second, the sexual event of CP usually resets the genetic diversity at a single locus towards predictions made under full sexuality. However, this single recombination event is insufficient to reshuffle gametic phases towards full-sexuality predictions. Finally, for similar levels of clonality, CP and acyclic partial clonality (wherein a fixed proportion of individuals are clonally produced within each generation) differentially affect the distribution of genetic diversity. Overall, this work provides solid predictions of neutral genetic diversity that may serve as a null model in detecting the action of common evolutionary or demographic processes in cyclical parthenogens (for example, selection or bottlenecks).

  4. Snake River Fall Chinook Salmon Life History Investigations, Annual Report 2008.

    Energy Technology Data Exchange (ETDEWEB)

    Tiffan, Kenneth F. [U.S. Geological Survey; Connor, William P. [U.S. Fish and Wildlife Service; Bellgraph, Brian J. [Pacific Northwest National Laboratory

    2009-09-15

    This study was initiated to provide empirical data and analyses on the dam passage timing, travel rate, survival, and life history variation of fall Chinook salmon that are produced in the Clearwater River. The area of interest for this study focuses on the lower four miles of the Clearwater River and its confluence with the Snake River because this is an area where many fish delay their seaward migration. The goal of the project is to increase our understanding of the environmental and biological factors that affect juvenile life history of fall Chinook salmon in the Clearwater River. The following summaries are provided for each of the individual chapters in this report.

  5. Life history and demographic drivers of reservoir competence for three tick-borne zoonotic pathogens.

    Science.gov (United States)

    Ostfeld, Richard S; Levi, Taal; Jolles, Anna E; Martin, Lynn B; Hosseini, Parviez R; Keesing, Felicia

    2014-01-01

    Animal and plant species differ dramatically in their quality as hosts for multi-host pathogens, but the causes of this variation are poorly understood. A group of small mammals, including small rodents and shrews, are among the most competent natural reservoirs for three tick-borne zoonotic pathogens, Borrelia burgdorferi, Babesia microti, and Anaplasma phagocytophilum, in eastern North America. For a group of nine commonly-infected mammals spanning >2 orders of magnitude in body mass, we asked whether life history features or surrogates for (unknown) encounter rates with ticks, predicted reservoir competence for each pathogen. Life history features associated with a fast pace of life generally were positively correlated with reservoir competence. However, a model comparison approach revealed that host population density, as a proxy for encounter rates between hosts and pathogens, generally received more support than did life history features. The specific life history features and the importance of host population density differed somewhat between the different pathogens. We interpret these results as supporting two alternative but non-exclusive hypotheses for why ecologically widespread, synanthropic species are often the most competent reservoirs for multi-host pathogens. First, multi-host pathogens might adapt to those hosts they are most likely to experience, which are likely to be the most abundant and/or frequently bitten by tick vectors. Second, species with fast life histories might allocate less to certain immune defenses, which could increase their reservoir competence. Results suggest that of the host species that might potentially be exposed, those with comparatively high population densities, small bodies, and fast pace of life will often be keystone reservoirs that should be targeted for surveillance or management.

  6. Life history and demographic drivers of reservoir competence for three tick-borne zoonotic pathogens.

    Directory of Open Access Journals (Sweden)

    Richard S Ostfeld

    Full Text Available Animal and plant species differ dramatically in their quality as hosts for multi-host pathogens, but the causes of this variation are poorly understood. A group of small mammals, including small rodents and shrews, are among the most competent natural reservoirs for three tick-borne zoonotic pathogens, Borrelia burgdorferi, Babesia microti, and Anaplasma phagocytophilum, in eastern North America. For a group of nine commonly-infected mammals spanning >2 orders of magnitude in body mass, we asked whether life history features or surrogates for (unknown encounter rates with ticks, predicted reservoir competence for each pathogen. Life history features associated with a fast pace of life generally were positively correlated with reservoir competence. However, a model comparison approach revealed that host population density, as a proxy for encounter rates between hosts and pathogens, generally received more support than did life history features. The specific life history features and the importance of host population density differed somewhat between the different pathogens. We interpret these results as supporting two alternative but non-exclusive hypotheses for why ecologically widespread, synanthropic species are often the most competent reservoirs for multi-host pathogens. First, multi-host pathogens might adapt to those hosts they are most likely to experience, which are likely to be the most abundant and/or frequently bitten by tick vectors. Second, species with fast life histories might allocate less to certain immune defenses, which could increase their reservoir competence. Results suggest that of the host species that might potentially be exposed, those with comparatively high population densities, small bodies, and fast pace of life will often be keystone reservoirs that should be targeted for surveillance or management.

  7. Using life history narratives to educate staff members about personhood in assisted living.

    Science.gov (United States)

    Gammonley, Denise; Lester, Connie L; Fleishman, Daniel; Duran, Lloyd; Cravero, Geoffrey

    2015-01-01

    Oral life history narratives are a promising method to promote person-centered values of personhood and belonging. This project used resident oral history interviews to educate staff members in an assisted-living setting about personhood. A single group pre-post test design evaluated impacts on 37 staff members to assess their use of resident videotaped oral history interviews and impacts on their perceived knowledge of residents. Perceived knowledge of residents declined (p = .003) between pretest and posttest. Older staff members were less likely to view a video. Staff members are interested in resident oral history biographies and identify them as helpful for delivering care. Oral history methods might provide an opportunity for staff members to promote personhood by allowing them to expand their understanding of resident preferences, values, and experiences.

  8. Chaotic harmony a dialog about physics, complexity and life

    CERN Document Server

    Sanayei, Ali

    2014-01-01

    This fascinating book written by Ali Sanayei and Otto E. Rössler is not a classic scientific publication, but a vivid dialogue on science, philosophy and  the interdisciplinary intersections of science and technology with biographic elements. Chaotic Harmony: A Dialog about Physics, Complexity and Life represents a discussion between Otto Rössler and his colleague and student, focusing on the different areas of science and highlights their mutual relations. The book's concept of interdisciplinary dialogue is  unusual nowadays although it has a long tradition in science. It provides insight not only into interesting topics that are often closely linked, but also into the mind of a prominent scientist in the field of physics, chaos and complexity in general. It allows a deep look into the fascinating process of scientific development and discovery and provides a very interesting background of known and unknown facts in the areas of complex processes in physics, cosmology, biology, brains and systems in gen...

  9. Plant fertilization interacts with life history: variation in stoichiometry and performance in nettle-feeding butterflies.

    Directory of Open Access Journals (Sweden)

    Hélène Audusseau

    Full Text Available Variation in food stoichiometry affects individual performance and population dynamics, but it is also likely that species with different life histories should differ in their sensitivity to food stoichiometry. To address this question, we investigated the ability of the three nettle-feeding butterflies (Aglais urticae, Polygonia c-album, and Aglais io to respond adaptively to induced variation in plant stoichiometry in terms of larval performance. We hypothesized that variation in larval performance between plant fertilization treatments should be functionally linked to species differences in host plant specificity. We found species-specific differences in larval performance between plant fertilization treatments that could not be explained by nutrient limitation. We showed a clear evidence of a positive correlation between food stoichiometry and development time to pupal stage and pupal mass in A. urticae. The other two species showed a more complex response. Our results partly supported our prediction that host plant specificity affects larval sensitivity to food stoichiometry. However, we suggest that most of the differences observed may instead be explained by differences in voltinism (number of generations per year. We believe that the potential of some species to respond adaptively to variation in plant nutrient content needs further attention in the face of increased eutrophication due to nutrient leakage from human activities.

  10. Determination of the appropriate use of pavement surface history in the KDOT life-cycle analysis process.

    Science.gov (United States)

    2008-09-01

    The primary objective of this study was to evaluate KDOTs pavement surfacing history and recommend : whether or not the departments life-cycle cost analysis (LCCA) procedure should include a surfacing history : component, and, if so, how the LC...

  11. Corticosterone and pace of life in two life-history ecotypes of the garter snake Thamnophis elegans.

    Science.gov (United States)

    Palacios, Maria G; Sparkman, Amanda M; Bronikowski, Anne M

    2012-02-01

    Glucocorticoids are main candidates for mediating life-history trade-offs by regulating the balance between current reproduction and survival. It has been proposed that slow-living organisms should show higher stress-induced glucocorticoid levels that favor self-maintenance rather than current reproduction when compared to fast-living organisms. We tested this hypothesis in replicate populations of two ecotypes of the garter snake (Thamnophis elegans) that exhibit slow and fast pace of life strategies. We subjected free-ranging snakes to a capture-restraint protocol and compared the stress-induced corticosterone levels between slow- and fast-living snakes. We also used a five-year dataset to assess whether baseline corticosterone levels followed the same pattern as stress-induced levels in relation to pace of life. In accordance with the hypothesis, slow-living snakes showed higher stress-induced corticosterone levels than fast-living snakes. Baseline corticosterone levels showed a similar pattern with ecotype, although differences depended on the year of study. Overall, however, levels of glucocorticoids are higher in slow-living than fast-living snakes, which should favor self-maintenance and survival at the expense of current reproduction. The results of the present study are the first to relate glucocorticoid levels and pace of life in a reptilian system and contribute to our understanding of the physiological mechanisms involved in life-history evolution. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Life history tradeoffs of pathogens and the treatment principle of antibiogenesis

    Directory of Open Access Journals (Sweden)

    Rui-An Wang

    2017-09-01

    Full Text Available There are no eternal individual lives so life continues by relaying with reproduction. Consequently, lifespan and fecundity are two essential genetic traits of life. The life history tradeoffs theory holds that there is an inverse relationship between lifespan and fecundity. This paper proposes two new concepts, i.e., “lifespan of pathogens” and treatment of infections by “antibiogenesis”. The lifespan of pathogens is the time limitation of those tiny lives just as other large creatures. Notably, the lifespan of bacterium is the time interval from the cell division by which it is produced to next division by then its life ends and transforms to two new lives, or dies. Antibiogenesis means inhibiting generation of new lives. By the principle of life history tradeoffs, the lifespan of pathogens determines the speed of their proliferations and consequently the modality of infection. The treatment principle of antibiogenesis requires the duration of treatment to be determined by the lifespan of infected pathogens. The life history tradeoffs theory and the two concepts are helpful to understanding the pathobiology and shaping the clinical aspects of infectious diseases.

  13. The role of life histories and trophic interactions in population recovery.

    Science.gov (United States)

    Audzijonyte, Asta; Kuparinen, Anna

    2016-08-01

    Factors affecting population recovery from depletion are at the focus of wildlife management. Particularly, it has been debated how life-history characteristics might affect population recovery ability and productivity. Many exploited fish stocks have shown temporal changes towards earlier maturation and reduced adult body size, potentially owing to evolutionary responses to fishing. Whereas such life-history changes have been widely documented, their potential role on stock's ability to recover from exploitation often remains ignored by traditional fisheries management. We used a marine ecosystem model parameterized for Southeastern Australian ecosystem to explore how changes towards "faster" life histories might affect population per capita growth rate r. We show that for most species changes towards earlier maturation during fishing have a negative effect (3-40% decrease) on r during the recovery phase. Faster juvenile growth and earlier maturation were beneficial early in life, but smaller adult body sizes reduced the lifetime reproductive output and increased adult natural mortality. However, both at intra- and inter-specific level natural mortality and trophic position of the species were as important in determining r as species longevity and age of maturation, suggesting that r cannot be predicted from life-history traits alone. Our study highlights that factors affecting population recovery ability and productivity should be explored in a multi-species context, where both age-specific fecundity and survival schedules are addressed simultaneously. It also suggests that contemporary life-history changes in harvested species are unlikely to increase their resilience and recovery ability. © 2016 Society for Conservation Biology.

  14. Seasonal time constraints reduce genetic variation in life-history traits along a latitudinal gradient.

    Science.gov (United States)

    Sniegula, Szymon; Golab, Maria J; Drobniak, Szymon M; Johansson, Frank

    2016-01-01

    Time constraints cause strong selection on life-history traits, because populations need to complete their life cycles within a shorter time. We therefore expect lower genetic variation in these traits in high- than in low-latitude populations, since the former are more time-constrained. The aim was to estimate life-history traits and their genetic variation in an obligately univoltine damselfly along a latitudinal gradient of 2730 km. Populations were grown in the laboratory at temperatures and photoperiods simulating those at their place of origin. In a complementary experiment, individuals from the same families were grown in constant temperature and photoperiod that mimicked average conditions across the latitude. Development time and size was faster and smaller, respectively, and growth rate was higher at northern latitudes. Additive genetic variance was very low for life-history traits, and estimates for egg development time and larval growth rate showed significant decreases towards northern latitudes. The expression of genetic effects in life-history traits differed considerably when individuals were grown in constant rather than simulated and naturally variable conditions. Our results support strong selection by time constraints. They also highlight the importance of growing organisms in their native environment for correct estimates of genetic variance at their place of origin. Our results also suggest that the evolutionary potential of life-history traits is very low at northern compared to southern latitudes, but that changes in climate could alter this pattern. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

  15. Wolf in sheep's clothing: Model misspecification undermines tests of the neutral theory for life histories.

    Science.gov (United States)

    Authier, Matthieu; Aubry, Lise M; Cam, Emmanuelle

    2017-05-01

    Understanding the processes behind change in reproductive state along life-history trajectories is a salient research program in evolutionary ecology. Two processes, state dependence and heterogeneity, can drive the dynamics of change among states. Both processes can operate simultaneously, begging the difficult question of how to tease them apart in practice. The Neutral Theory for Life Histories (NTLH) holds that the bulk of variations in life-history trajectories is due to state dependence and is hence neutral: Once previous (breeding) state is taken into account, variations are mostly random. Lifetime reproductive success (LRS), the number of descendants produced over an individual's reproductive life span, has been used to infer support for NTLH in natura. Support stemmed from accurate prediction of the population-level distribution of LRS with parameters estimated from a state dependence model. We show with Monte Carlo simulations that the current reliance of NTLH on LRS prediction in a null hypothesis framework easily leads to selecting a misspecified model, biased estimates and flawed inferences. Support for the NTLH can be spurious because of a systematic positive bias in estimated state dependence when heterogeneity is present in the data but ignored in the analysis. This bias can lead to spurious positive covariance between fitness components when there is in fact an underlying trade-off. Furthermore, neutrality implied by NTLH needs a clarification because of a probable disjunction between its common understanding by evolutionary ecologists and its translation into statistical models of life-history trajectories. Irrespective of what neutrality entails, testing hypotheses about the dynamics of change among states in life histories requires a multimodel framework because state dependence and heterogeneity can easily be mistaken for each other.

  16. Phenotypic plasticity in adult life-history strategies compensates for a poor start in life in Trinidadian guppies (Poecilia reticulata).

    Science.gov (United States)

    Auer, Sonya K

    2010-12-01

    Low food availability during early growth and development can have long-term negative consequences for reproductive success. Phenotypic plasticity in adult life-history decisions may help to mitigate these potential costs, yet adult life-history responses to juvenile food conditions remain largely unexplored. I used a food-manipulation experiment with female Trinidadian guppies (Poecilia reticulata) to examine age-related changes in adult life-history responses to early food conditions, whether these responses varied across different adult food conditions, and how these responses affected overall reproductive success. Guppy females reared on low food as juveniles matured at a later age, at a smaller size, and with less energy reserves than females reared on high food as juveniles. In response to this setback, they changed their investment in growth, reproduction, and fat storage throughout the adult stage such that they were able to catch up in body size, increase their reproductive output, and restore their energy reserves to levels comparable to those of females reared on high food as juveniles. The net effect was that adult female guppies did not merely mitigate but surprisingly were able to fully compensate for the potential long-term negative effects of poor juvenile food conditions on reproductive success.

  17. A Latino Superintendent's Life History: A Re-Examination through Brown Eyes

    Science.gov (United States)

    Mota, Alma Yvette

    2017-01-01

    Research indicates Latino males are under-represented in the educational pipeline and administrative ranks of public education. Further studies attribute the Latino culture as contributing to the obstacles encountered in Latino advancement. This qualitative study was a life history of a first generation U.S. born Latino raised in a Texas-Mexico…

  18. Food effects on life history traits and seasonal dynamics of Ceriodaphnia pulchella

    NARCIS (Netherlands)

    Boersma, M.; Vijverberg, J.

    1996-01-01

    1. This paper describes the effects of differences in food quantity and quality on selected life history traits of Ceriodaphnia pulchella. Animals were fed with four concentrations of two green algae, Scenedesmus obliquus and Chlamydomonas globosa, given separately as well as in a 1:1 mixture. 2. In

  19. Intersections of Life Histories and Science Identities: The Stories of Three Preservice Elementary Teachers

    Science.gov (United States)

    Avraamidou, Lucy

    2016-01-01

    Grounded within Connelly and Clandinin's conceptualization of teachers' professional identity in terms of "stories to live by" and through a life-history lens, this multiple case study aimed to respond to the following questions: (a) How do three preservice elementary teachers view themselves as future science teachers? (b) How have the…

  20. Life history and ecology of the southern redback salamander, Plethodon serratus, in Missouri

    Science.gov (United States)

    Laura A. Herbeck

    2000-01-01

    The life history and ecology of Plethodon serratus were studied in two populations in southcentral and southeastern Missouri, USA. One population was located on private land in Perry County and the other was located in Mark Twain National Forest in Phelps County. Courtship and insemination probably occurred between December and March. Oviposition...

  1. Page 1 Structure & Life-History of C. andhraensis from Apple Snail P ...

    Indian Academy of Sciences (India)

    Structure & Life-History of C. andhraensis from Apple Snail P. globosa 28 is a wall of cells containing vesicular nuclei. The outermost layer is a tegu- ment. In younger rediae the cells of the inner layer appear cuboidal. In older and longer rediae these cells become flattened, there being considerable stretching during the ...

  2. Comparing life history characteristics of Lake Michigan’s naturalized and stocked Chinook Salmon

    Science.gov (United States)

    Kerns, Janice A; Rogers, Mark W.; Bunnell, David B.; Claramunt, Randall M.; Collingsworth, Paris D.

    2016-01-01

    Lake Michigan supports popular fisheries for Chinook Salmon Oncorhynchus tshawytscha that have been sustained by stocking since the late 1960s. Natural recruitment of Chinook Salmon in Lake Michigan has increased in the past few decades and currently contributes more than 50% of Chinook Salmon recruits. We hypothesized that selective forces differ for naturalized populations born in the wild and hatchery populations, resulting in divergent life history characteristics with implications for Chinook Salmon population production and the Lake Michigan fishery. First, we conducted a historical analysis to determine if life history characteristics changed through time as the Chinook Salmon population became increasingly naturalized. Next, we conducted a 2-year field study of naturalized and hatchery stocked Chinook Salmon spawning populations to quantify differences in fecundity, egg size, timing of spawning, and size at maturity. In general, our results did not indicate significant life history divergence between naturalized and hatchery-stocked Chinook Salmon populations in Lake Michigan. Although historical changes in adult sex ratio were correlated with the proportion of naturalized individuals, changes in weight at maturity were better explained by density-dependent factors. The field study revealed no divergence in fecundity, timing of spawning, or size at maturity, and only small differences in egg size (hatchery > naturalized). For the near future, our results suggest that the limited life history differences observed between Chinook Salmon of naturalized and hatchery origin will not lead to large differences in characteristics important to the dynamics of the population or fishery.

  3. Personal Stories: How Students' Social and Cultural Life Histories Interact with the Field of Higher Education

    Science.gov (United States)

    Stuart, Mary; Lido, Catherine; Morgan, Jessica

    2011-01-01

    Learners' biographies affect their engagement with knowledge and shape how their learning is understood. This article uses an educational life history approach to investigate how students' social and cultural educational experiences affect their engagement with their university. Qualitative evidence is presented from interviews with students with…

  4. The evolution of alternative parasitic life histories in large blue butterflies

    DEFF Research Database (Denmark)

    Als, Thomas Damm; Vila, Roger; Kandul, Nikolai P

    2004-01-01

    Large blue (Maculinea) butterflies are highly endangered throughout the Palaearctic region, and have been the focus of intense conservation research. In addition, their extraordinary parasitic lifestyles make them ideal for studies of life history evolution. Early instars consume flower buds of s...

  5. Life-history strategies in parasitoid wasps: a comparative analysis of 'ovigeny'

    NARCIS (Netherlands)

    Jervis, M.A.; Heimpel, G.E.; Ferns, P.N.; Harvey, J.A.; Kidd, N.A.C.

    2001-01-01

    1. Ecologists concerned with life-history strategies of parasitoid wasps have recently focused on interspecific variation in the fraction of the maximum potential lifetime egg complement that is mature when the female emerges into the environment. Species that have all of this complement mature upon

  6. Early life history of pomatomus saltatrix off the East coast of South Africa

    CSIR Research Space (South Africa)

    Beckley, LE

    1996-01-01

    Full Text Available Several authors have stated that southward transport of the early life-history stages of Pomatomus saltatrix also known as the elf or shad occurs by passive drift in the Agulhas Current, a strong western boundary current which flows southwards...

  7. The biology, life history and management needs of a large sciaenid ...

    African Journals Online (AJOL)

    The biology, life history and management needs of a large sciaenid fish, Argyrosomus coronus , in Angola. ... African Journal of Marine Science ... Because some Argyrosomus species are morphologically cryptic, a DNA barcoding method was used to confirm the taxonomic status of the biological samples used in this study.

  8. Geographic, genetic and life-history variability in a sex-changing fish

    Directory of Open Access Journals (Sweden)

    Chiara Benvenuto

    2015-11-01

    Full Text Available Sequential hermaphroditism, commonly referred to as sex change or sex reversal, is a striking phenomenon in mating-system evolution and the most remarkable example of sexual plasticity. Among vertebrates, it is specific to teleosts. Some fish species reproduce initially as females and then change into males (protogynous hermaphrodites or vice versa (protandrous hermaphrodites. The white sea bream, Diplodus sargus, exhibits a high degree of sexual plasticity: populations have been reported to be gonochoristic, protandrous or digynic (with primary females, derived from intersexual juveniles, and secondary females, derived from males. We analysed populations collected from eight different locations across the species distribution range (between the Mediterranean and the North-Eastern Atlantic. These populations are characterized by different degrees of connectivity, spatial demographics and life histories. Using individual-based analyses, we linked the genetic structure of each specimen with environmental heterogeneity, life-history traits and reproductive modes. Our aim is to gather a better understanding of the variation in reproductive life-history strategies in this sexually plastic species. Diplodus sargus is a valuable candidate organism to investigate sequential hermaphroditism and it also has a commercial value. The application of population genetics tools against the background of life-history theory can bring valuable insights for the management of marine resources. The geographical patterns of sex change (and of age- and size-at-sex change linked with population genetics can be pivotal for both theoretical investigations and conservation and management plans in marine areas.

  9. Response of endemic Clarias species' life-history biometrics to land ...

    African Journals Online (AJOL)

    The Mpologoma River wetland is highly negatively impacted by rice growing and yet it provides habitat to endemic Clarias species that are important to the wetland fishery. Variations in life-history biometrics of small Clarias species at various wetland sites in relation to land-use changes within the wetland were studied in ...

  10. Psychometrics and life history strategy: the structure and validity of the High K Strategy Scale.

    Science.gov (United States)

    Copping, Lee T; Campbell, Anne; Muncer, Steven

    2014-03-22

    In this paper, we critically review the conceptualization and implementation of psychological measures of life history strategy associated with Differential K theory. The High K Strategy Scale (HKSS: Giosan, 2006) was distributed to a large British sample (n = 809) with the aim of assessing its factor structure and construct validity in relation to theoretically relevant life history variables: age of puberty, age of first sexual encounter, and number of sexual partners. Exploratory and confirmatory factor analyses indicated that the HKSS in its current form did not show an adequate statistical fit to the data. Modifications to improve fit indicated four correlated factors (personal capital, environmental stability, environmental security, and social capital). Later puberty in women was positively associated with measures of the environment and personal capital. Among men, contrary to Differential K predictions but in line with female mate preferences, earlier sexual debut and more sexual partners were positively associated with more favorable environments and higher personal and social capital. We raise concerns about the use of psychometric indicators of lifestyle and personality as proxies for life history strategy when they have not been validated against objective measures derived from contemporary life history theory and when their status as causes, mediators, or correlates has not been investigated.

  11. Life-history regulation in the subtidal red alga Calliblepharis ciliata

    NARCIS (Netherlands)

    Molenaar, FJ; Venekamp, LAH; Breeman, AM

    The life-history strategy of the subtidal red alga Calliblepharis ciliata has been studied in the field and in laboratory culture. Bi-monthly observations on a C. ciliata population at Roscoff (Brittany, France) revealed a clear seasonal pattern. In April young plants appeared and grew through the

  12. Life history, population viability, and the potential for local adaptation in isolated trout populations

    Science.gov (United States)

    K. J. Carim; Y. Vindenes; L. A. Eby; C. Barfoot; L. A. Vollestad

    2017-01-01

    Habitat loss and fragmentation have caused population decline across taxa through impacts on life history diversity, dispersal patterns, and gene flow. Yet, intentional isolation of native fish populations is a frequently used management strategy to protect against negative interactions with invasive fish species. We evaluated the population viability and genetic...

  13. The devil in the details of life-history evolution: instability and ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 82; Issue 3. The devil in the details of life-history evolution: instability and reversal of genetic correlations during selection on Drosophila development. Adam K. Chippindale Anh L. Ngo Michael R. Rose. Volume 82 Issue 3 December 2003 pp 133-145 ...

  14. Ecdysteroid hormones link the juvenile environment to alternative adult life histories in a seasonal insect

    NARCIS (Netherlands)

    Oostra, V.; Mateus, A.R.A.; Burg, van den K.R.L.; Piessens, T.; Eijk, van M.; Brakefield, P.M.; Beldade, P.; Zwaan, B.J.

    2014-01-01

    Four datasets from: Ecdysteroid hormones link the juvenile environment to alternative adult life histories in a seasonal insect; by Oostra, Vicencio; Mateus, Ana Rita A.; Van der Burg, Karin R.L.; Piessens,Thomas; Van Eijk, Marleen; Brakefield, Paul M.; Beldade, Patrícia; Zwaan, Bas; as published in

  15. How resource competition shapes individual life history for nonplastic growth: Ungulates in seasonal food environments

    NARCIS (Netherlands)

    de Roos, A.M.; Galic, N.; Heesterbeek, H.

    2009-01-01

    We analyze an age-, size- and sex-structured model to investigate how the interplay between individual-level energy budget dynamics and the feedback of population grazing on resources shapes the individual life history and the dynamics of ungulate populations, living in a predator-free, seasonal

  16. Size-Dependent Interactions Inhibit Coexistence in Intraguild Predation Systems with Life-History Omnivory

    NARCIS (Netherlands)

    van de Wolfshaar, K.E.; de Roos, A.M.; Persson, L.

    2006-01-01

    Abstract: Growth in body size during ontogeny often results in changes in diet, leading to life-history omnivory. In addition, growth is often dependent on food density. Using a physiologically structured population model, we investigated the effects of these two aspects of individual growth in a

  17. Facultative anadromy in salmonids: linking habitat, individual life history decisions, and population-level consequences

    Science.gov (United States)

    Steven F. Railsback; Bret C. Harvey; Jason L. White

    2014-01-01

    Modeling and management of facultative anadromous salmonids is complicated by their ability to select anadromous or resident life histories. Conventional theory for this behavior assumes individuals select the strategy offering highest expected reproductive success but does not predict how population-level consequences such as a stream’s smolt production emerge from...

  18. Population transcriptomics of life-history variation in the genus Salmo

    DEFF Research Database (Denmark)

    Giger, T.; Excoffier, L.; Amstutz, U.

    2008-01-01

    with physiological changes that are likely to be involved in preadaptations to seawater in anadromous populations of the genus Salmo, one of which was identified to encode for nucleophosmin 1. Our findings thus provide new molecular insights into salmonid life-history variation, opening new perspectives in the study...

  19. The ecology of life history evolution : genes, individuals and populations : inaugural lecture (oratie)

    NARCIS (Netherlands)

    Visser, M.E.

    2013-01-01

    Natural selection shapes the life histories of organisms. The ecological interactions of these organisms with their biotic and abiotic environment shape the selection pressure on their phenotypes while their genetics determine how fast this selection leads to adaptation to their environment. The

  20. Life history trade-offs and relaxed selection can decrease bacterial virulence in environmental reservoirs.

    Directory of Open Access Journals (Sweden)

    Lauri Mikonranta

    Full Text Available Pathogen virulence is usually thought to evolve in reciprocal selection with the host. While this might be true for obligate pathogens, the life histories of opportunistic pathogens typically alternate between within-host and outside-host environments during the infection-transmission cycle. As a result, opportunistic pathogens are likely to experience conflicting selection pressures across different environments, and this could affect their virulence through life-history trait correlations. We studied these correlations experimentally by exposing an opportunistic bacterial pathogen Serratia marcescens to its natural protist predator Tetrahymena thermophila for 13 weeks, after which we measured changes in bacterial traits related to both anti-predator defence and virulence. We found that anti-predator adaptation (producing predator-resistant biofilm caused a correlative attenuation in virulence. Even though the direct mechanism was not found, reduction in virulence was most clearly connected to a predator-driven loss of a red bacterial pigment, prodigiosin. Moreover, life-history trait evolution was more divergent among replicate populations in the absence of predation, leading also to lowered virulence in some of the 'predator absent' selection lines. Together these findings suggest that the virulence of non-obligatory, opportunistic bacterial pathogens can decrease in environmental reservoirs through life history trade-offs, or random accumulation of mutations that impair virulence traits under relaxed selection.

  1. Octopus life history relative to age, in a multi-geared developmental fishery

    NARCIS (Netherlands)

    Leporati, S.C.; Hart, A.M.; Larsen, R.; Franken, Linda E; De Graaf, M.

    2015-01-01

    The ability to obtain broad-scale age information for an exploited octopus population enables the identification of essential life history information, such as age at maturity, recruitment pulses and seasonal effects on growth. This study uses stylet weight (reduced internal shell) as a proxy to age

  2. Bridging scales in the evolution of infectious disease life histories: application.

    Science.gov (United States)

    Mideo, Nicole; Nelson, William A; Reece, Sarah E; Bell, Andrew S; Read, Andrew F; Day, Troy

    2011-11-01

    Within- and between-host disease processes occur on the same timescales, therefore changes in the within-host dynamics of parasites, resources, and immunity can interact with changes in the epidemiological dynamics to affect evolutionary outcomes. Consequently, studies of the evolution of disease life histories, that is, infection-age-specific patterns of transmission and virulence, have been constrained by the need for a mechanistic understanding of within-host disease dynamics. In a companion paper (Day et al. 2011), we develop a novel approach that quantifies the relevant within-host aspects of disease through genetic covariance functions. Here, we demonstrate how to apply this theory to data. Using two previously published datasets from rodent malaria infections, we show how to translate experimental measures into disease life-history traits, and how to quantify the covariance in these traits. Our results show how patterns of covariance can interact with epidemiological dynamics to affect evolutionary predictions for disease life history. We also find that the selective constraints on disease life-history evolution can vary qualitatively, and that "simple" virulence-transmission trade-offs that are often the subject of experimental investigation can be obscured by trade-offs within one trait alone. Finally, we highlight the type and quality of data required for future applications. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  3. Life history comparison of two green lacewing species Chrysoperla johnsoni and Chrysoperla carnea (Neuroptera: Chrysopidae).

    Science.gov (United States)

    Amarasekare, Kaushalya G; Shearer, Peter W

    2013-10-01

    We investigated the life histories of two green lacewing species, Chrysoperla johnsoni Henry, Wells, and Pupedis from western North America, and Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) from western Europe in the laboratory. There were both similarities and differences in their life history characteristics. C. johnsoni exhibited a significantly longer developmental time for egg, first instar, and pupal stage than C. carnea. C. carnea exhibited a significantly shorter egg to adult developmental time than C. johnsoni. Except for the pupal stage, the survival of all other life history stages was not species-specific. All C. carnea pupae were able to develop into adults, whereas only 92% of adult eclosion was observed from C. johnsoni pupae. There was no difference in egg to adult survival between the two species. Adult longevity was not species- or gender-specific. Sex ratio of emerged adults was ≈50% in both species. C. johnsoni had a longer preoviposition period than C. carnea, while the oviposition period was similar for both species. C. carnea had higher lifetime fecundity and fertility than C. johnsoni, as measured by total number of eggs laid and production of fertile eggs, respectively. Egg viability did not differ between the two species. Intrinsic rates of increase (rm) for C. carnea and C. johnsoni were 0.161 and 0.132, respectively. All lacewings used in this experiment were laboratory reared under environmental conditions similar to field as possible. This is the first available information on the life history parameters of C. johnsoni.

  4. Putting all your eggs in one basket: life-history strategies, bet hedging, and diversification.

    Science.gov (United States)

    White, Andrew Edward; Li, Yexin Jessica; Griskevicius, Vladas; Neuberg, Steven L; Kenrick, Douglas T

    2013-05-01

    Diversification of resources is a strategy found everywhere from the level of microorganisms to that of giant Wall Street investment firms. We examine the functional nature of diversification using life-history theory-a framework for understanding how organisms navigate resource-allocation trade-offs. This framework suggests that diversification may be adaptive or maladaptive depending on one's life-history strategy and that these differences should be observed under conditions of threat. In three studies, we found that cues of mortality threat interact with one index of life-history strategy, childhood socioeconomic status (SES), to affect diversification. Among those from low-SES backgrounds, mortality threat increased preferences for diversification. However, among those from high-SES backgrounds, mortality threat had the opposite effect, inclining people to put all their eggs in one basket. The same interaction pattern emerged with a potential biomarker of life-history strategy, oxidative stress. These findings highlight when, and for whom, different diversification strategies can be advantageous.

  5. Life-history traits of the northwest European flora : The LEDA database

    NARCIS (Netherlands)

    Knevel, IC; Bekker, RM; Bakker, JP; Kleyer, M

    An international group of scientists is building a 'trait base', an open internet database of life-history traits of the Northwest European flora (LEDA) that can be used as a tool in planning, in nature conservation and restoration, and in other applied research. The species-trait matrix will

  6. From traits to life-history strategies: Deconstructing fish community composition across European seas

    DEFF Research Database (Denmark)

    Pécuchet, Lauréne; Lindegren, Martin; Hidalgo, Manuel

    2017-01-01

    The life history of a species is determined by trade-offs between growth, survival and reproduction to maximize fitness in a given environment. Following a theoretical model, we investigate whether the composition of marine fish communities can be understood in terms of a set of lifehistory strat...

  7. Predator-induced phenotypic plasticity in Daphnia pulex: Uncoupling morphological defenses and life history shifts

    NARCIS (Netherlands)

    Repka, S.; Pihlajamaa, K.

    1996-01-01

    Chemical cues from a predator Chaoborus sp. induce morphological defense (neck spine) and life history shifts (later reproduction, decreased fecundity but larger juvenile size) in the waterflea Daphnia pulex. These shifts have been interpreted either as costs of defense or as separate adaptation. In

  8. Behavioral and life history responses to extreme climatic conditions: Studies on a migratory songbird

    Directory of Open Access Journals (Sweden)

    A. P. Møller

    2011-06-01

    Full Text Available Behavioral responses to environmental change are the mechanisms that allow for rapid phenotypic change preventing temporary or permanent damage and hence preventing reductions in fitness. Extreme climatic events are by definition rare, although they are predicted to increase in amplitude and frequency in the coming years. However, our current knowledge about behavioral responses to such extreme events is scarce. Here I analyze two examples of the effects of extreme weather events on behavior and life history: (1 A comparison of behavior and life history during extremely warm and extremely cold years relative to normal years; and (2 a comparison of behavior before and after the extremely early snowfall in fall 1974 when numerous birds died in the Alps during September-October. Behavioral and life history responses of barn swallows Hirundo rustica to extremely cold and extremely warm years were positively correlated, with particularly large effect sizes in cold years. Extreme mortality in barn swallows during fall migration 1974 in the Alps eliminated more than 40% of the breeding population across large areas in Central and Northern Europe, and this affected first arrival date, changes in timing and extent of reproduction and changes in degree of breeding sociality supposedly as a consequence of correlated responses to selection. Finally, I provide directions for research that will allow us to better understand behavior and life history changes in response to extreme climate change [Current Zoology 57 (3: 351–362, 2011].

  9. Levels of genetic variation in trees: influence of life history characteristics

    Science.gov (United States)

    J. L Hamrick; J. B. Milton; Y. B. Linhart

    1981-01-01

    In a previous study, levels of genetic variation, as measured by isozyme analyses, were compared for 113 taxa of vascular plants. Each species was classified for 12 life history and ecological traits and three measures of genetic variation were calculated. Plants with large ranges, high fecundities, an outcrossing mode of reproduction, wind pollination, a long...

  10. Enriching the Historiography of Religious Education: Insights from Oral Life History

    Science.gov (United States)

    Doney, Jonathan; Parker, Stephen G.; Freathy, Rob

    2017-01-01

    This article seeks to exemplify the extent to which oral life history research can enrich existing historiographies of English Religious Education (RE). Findings are reported from interviews undertaken with a sample of key informants involved in designing and/or implementing significant curriculum changes in RE in the 1960s and 1970s. The…

  11. Population dynamics, life-history traits of and habitat use by two ...

    African Journals Online (AJOL)

    Population dynamics and life-history traits of two sympatric nothobranchiid killifishes, Epiplatys bifasciatus and E. spilargyreius, were studied for 24 months in an intermittent stream in the Kainji Lake Basin, Nigeria. Epiplatys bifasciatus was more abundant throughout the study period, but monthly abundance of both species ...

  12. Wood mechanics, allometry, and life-history variation in a tropical rain forest tree community

    NARCIS (Netherlands)

    Gelder, van H.A.; Poorter, L.; Sterck, F.J.

    2006-01-01

    ¿ Wood density plays a central role in the life-history variation of trees, and has important consequences for mechanical properties of wood, stem and branches, and tree architecture. ¿ Wood density, modulus of rupture, modulus of elasticity, and safety factors for buckling and bending were

  13. The influence of diurnal temperature variation on degree-day accumulation and insect life history.

    Directory of Open Access Journals (Sweden)

    Shi Chen

    Full Text Available Ectotherms, such as insects, experience non-constant temperatures in nature. Daily mean temperatures can be derived from the daily maximum and minimum temperatures. However, the converse is not true and environments with the same mean temperature can exhibit very different diurnal temperate ranges. Here we apply a degree-day model for development of the grape berry moth (Paralobesia viteana, a significant vineyard pest in the northeastern USA to investigate how different diurnal temperature range conditions can influence degree-day accumulation and, hence, insect life history. We first consider changes in diurnal temperature range independent of changes in mean temperatures. We then investigate grape berry moth life history under potential climate change conditions, increasing mean temperature via variable patterns of change to diurnal temperature range. We predict that diurnal temperature range change can substantially alter insect life history. Altering diurnal temperature range independent of the mean temperature can affect development rate and voltinism, with the magnitude of the effects dependent on whether changes occur to the daily minimum temperature (Tmin, daily maximum temperature (Tmax, or both. Allowing for an increase in mean temperature produces more marked effects on life history but, again, the patterns and magnitude depend on the nature of the change to diurnal temperature range together with the starting conditions in the local environment. The study highlights the importance of characterizing the influence of diurnal temperature range in addition to mean temperature alone.

  14. Effects of medium renewal and handling stress on life history traits in Daphnia

    NARCIS (Netherlands)

    Rousseaux, S.; Vanoverbeke, J.; Aerts, J.; Declerck, S.A.J.

    2010-01-01

    The zooplankton genus Daphnia is used as a model organism in ecological, ecotoxicological and evolutionary research. It is often used in experimental laboratory setups to examine life history traits under a variety of factors inducing stress. One type of stress, handling stress because of

  15. The Juvenile Transition: A Developmental Switch Point in Human Life History

    Science.gov (United States)

    Del Giudice, Marco; Angeleri, Romina; Manera, Valeria

    2009-01-01

    This paper presents a new perspective on the transition from early to middle childhood (i.e., human juvenility), investigated in an integrative evolutionary framework. Juvenility is a crucial life history stage, when social learning and interaction with peers become central developmental functions; here it is argued that the "juvenile transition"…

  16. Competition as a source of constraint on life history evolution in natural populations.

    Science.gov (United States)

    Wilson, A J

    2014-01-01

    Competition among individuals is central to our understanding of ecology and population dynamics. However, it could also have major implications for the evolution of resource-dependent life history traits (for example, growth, fecundity) that are important determinants of fitness in natural populations. This is because when competition occurs, the phenotype of each individual will be causally influenced by the phenotypes, and so the genotypes, of competitors. Theory tells us that indirect genetic effects arising from competitive interactions will give rise to the phenomenon of 'evolutionary environmental deterioration', and act as a source of evolutionary constraint on resource-dependent traits under natural selection. However, just how important this constraint is remains an unanswered question. This article seeks to stimulate empirical research in this area, first highlighting some patterns emerging from life history studies that are consistent with a competition-based model of evolutionary constraint, before describing several quantitative modelling strategies that could be usefully applied. A recurrent theme is that rigorous quantification of a competition's impact on life history evolution will require an understanding of the causal pathways and behavioural processes by which genetic (co)variance structures arise. Knowledge of the G-matrix among life history traits is not, in and of itself, sufficient to identify the constraints caused by competition.

  17. Becoming a Japanese Language Learner, User, and Teacher: Revelations From Life History Research

    Science.gov (United States)

    Armour, William S.

    2004-01-01

    This article discusses how Sarah Lamond, a Japanese language teacher in Sydney, Australia has juggled three of her identities: second language (L2) learner, L2 user, and L2 teacher. Data come from four interviews used to create an edited life history. These data are used to draw attention to the relationship between L2 learner and language user.…

  18. Life-history evolution in hymenopteran parasitoids the roles of host and climate

    NARCIS (Netherlands)

    Askari Seyahooei, Majeed

    2010-01-01

    In this thesis I studied the relationships between parasitoids, hosts and climate from an evolutionary point of view by using hymenopteran parasitoids as a model system. A comparative approach was used to study the variation in life-history traits of species or populations from different habitats. I

  19. Circadian clocks and life-history related traits: is pupation height ...

    Indian Academy of Sciences (India)

    Unknown

    Keywords. pupation height; pupariation; life-history evolution; circadian clocks; circadian organization; Drosophila melanogaster. .... The role of hormonal influences on the regulation of this gene is, however, not yet known. Incidentally, it is known that the eclosion rhythm in the populations used in this study entrains to.

  20. Executive Risk Propensity and Accounting Conservatism Through the Lens of Life History Theory

    DEFF Research Database (Denmark)

    Holm, Morten; Schneider, Melanie L.

    First, we intend to investigate the impact of CFO risk propensity on accounting conservatism. Second, we will examine the role of CEOs in this context. By drawing on life history theory, we propose variables reflecting executive risk propensity. Based on this, we hypothesize that CFO risk propens...

  1. What have two decades of laboratory life-history evolution studies ...

    Indian Academy of Sciences (India)

    laboratory selection; experimental evolution; lifespan; development time; competitive ability; genetic architecture. Abstract. A series of laboratory selection experiments on Drosophila melanogaster over the past two decades has provided insights into the specifics of life-history tradeoffs in the species and greatly refined our ...

  2. Disparate relatives: Life histories vary more in genera occupying intermediate environments

    NARCIS (Netherlands)

    Hermant, M.; Hennion, F.; Bartish, I.V.; Yguel, B.; Prinzing, A.

    2012-01-01

    Species within clades are commonly assumed to share similar life history traits, but within a given region some clades show much greater variability in traits than others. Are variable clades older, allowing more time for trait diversification? Or do they occupy particular environments, providing a

  3. The "Battlefield": Life Histories of Two Higher Education Staff Members of Color

    Science.gov (United States)

    Gomez, Mary Louise; Ocasio, Kelly; Lachuk, Amy Johnson; Powell, Shameka N.

    2015-01-01

    Deploying Russian philosopher M. M. Bakhtin's notions of utterances or communicative interactions, we explore the life histories of two administrators at State University, a predominantly White institution of higher education in the Midwestern United States. In particular, we explore how working with White students, peers, and supervisors demands…

  4. Life-history traits of the bluenose shiner, Pteronotropis welaka (Cypriniformes: Cyprinidae)

    Science.gov (United States)

    Carol E. Johnston; Charles L. Knight

    1999-01-01

    Life-history aspects and behavioral ecology of the bluenose shiner (Pteronotropis welaka) were investigated from May 1993 to June 1994 in a small tributary of the lower Pearl River in Marion County, MS. Samples were taken monthly or biweekly to provide information about preferred habitat, reproductive biology, and demography. Observations were made during the breeding...

  5. A description of the early life history stages of the kob, Argyrosomus ...

    African Journals Online (AJOL)

    1989-09-12

    Sep 12, 1989 ... Though larvae of kob have been recorded from the near- shore waters of Algoa Bay (Beckley 1986), little is known about the early life history stages of this species. Gilchrist. (1916) reported on unfertilized A. hololepidotus eggs from the Cape of Good Hope and Melville-Smith (1978) illustra- ted 3,3 mm and ...

  6. Life expectancy: complex measures of the length and the health related quality of life

    Directory of Open Access Journals (Sweden)

    Daniele Spizzichino

    2008-06-01

    Full Text Available

    Background: Life expectancy is one of the most frequently used indicators to assess mortality and the health of a population. It is a synthetic measure of mortality, which has the advantage of allowing for comparisons over time and between different groups, while eliminating the influence of the age structure of the population. Life expectancy has the advantage of being very easy to understand, although it needs to be interpreted within the context of the complex system of hypothesis that generates it. This is even more important for health expectancies and health gap measures, which are synthetic indicators that take into account both survival and health condition of a population.

    Methods: It is given a description of the most frequently used methods to calculate life expectancy, health expectancies and health gap measures. Measures of health expectancy are disability free life expectancy and healthy life expectancy. As health gap measures, frequently are used DALYs (Disability Adjusted Life Years.

    Discussion: There are various bodies and central government agencies that either have management data or carry out statistical systematic surveys and disability surveys. Statistically speaking, the worst aspect of this scenario is that it creates confusion and uncertainty among the end users of this data, namely the policy makers. At an international level the statistical data on disability is scarcely comparable among countries, despite huge efforts on the part of international organisations to harmonize classifications and definitions of disability.

    Results and Conclusions: There are several methods to compute life expectancy, each of these has some advantages and some disadvantages. Usually life expectancy is used also to account for the health status of population. Actually with the growing role of chronic and degenerative diseases, the increased number of

  7. Effects of complex life cycles on genetic diversity: cyclical parthenogenesis

    Science.gov (United States)

    Rouger, R; Reichel, K; Malrieu, F; Masson, J P; Stoeckel, S

    2016-01-01

    Neutral patterns of population genetic diversity in species with complex life cycles are difficult to anticipate. Cyclical parthenogenesis (CP), in which organisms undergo several rounds of clonal reproduction followed by a sexual event, is one such life cycle. Many species, including crop pests (aphids), human parasites (trematodes) or models used in evolutionary science (Daphnia), are cyclical parthenogens. It is therefore crucial to understand the impact of such a life cycle on neutral genetic diversity. In this paper, we describe distributions of genetic diversity under conditions of CP with various clonal phase lengths. Using a Markov chain model of CP for a single locus and individual-based simulations for two loci, our analysis first demonstrates that strong departures from full sexuality are observed after only a few generations of clonality. The convergence towards predictions made under conditions of full clonality during the clonal phase depends on the balance between mutations and genetic drift. Second, the sexual event of CP usually resets the genetic diversity at a single locus towards predictions made under full sexuality. However, this single recombination event is insufficient to reshuffle gametic phases towards full-sexuality predictions. Finally, for similar levels of clonality, CP and acyclic partial clonality (wherein a fixed proportion of individuals are clonally produced within each generation) differentially affect the distribution of genetic diversity. Overall, this work provides solid predictions of neutral genetic diversity that may serve as a null model in detecting the action of common evolutionary or demographic processes in cyclical parthenogens (for example, selection or bottlenecks). PMID:27436524

  8. The Boring Billion, a slingshot for Complex Life on Earth.

    Science.gov (United States)

    Mukherjee, Indrani; Large, Ross R; Corkrey, Ross; Danyushevsky, Leonid V

    2018-03-13

    The period 1800 to 800 Ma ("Boring Billion") is believed to mark a delay in the evolution of complex life, primarily due to low levels of oxygen in the atmosphere. Earlier studies highlight the remarkably flat C, Cr isotopes and low trace element trends during the so-called stasis, caused by prolonged nutrient, climatic, atmospheric and tectonic stability. In contrast, we suggest a first-order variability of bio-essential trace element availability in the oceans by combining systematic sampling of the Proterozoic rock record with sensitive geochemical analyses of marine pyrite by LA-ICP-MS technique. We also recall that several critical biological evolutionary events, such as the appearance of eukaryotes, origin of multicellularity & sexual reproduction, and the first major diversification of eukaryotes (crown group) occurred during this period. Therefore, it appears possible that the period of low nutrient trace elements (1800-1400 Ma) caused evolutionary pressures which became an essential trigger for promoting biological innovations in the eukaryotic domain. Later periods of stress-free conditions, with relatively high nutrient trace element concentration, facilitated diversification. We propose that the "Boring Billion" was a period of sequential stepwise evolution and diversification of complex eukaryotes, triggering evolutionary pathways that made possible the later rise of micro-metazoans and their macroscopic counterparts.

  9. Comparative life cycles and life histories of North American Rhabdias spp. (Nematoda: Rhabdiasidae): lungworms from snakes and anurans.

    Science.gov (United States)

    Langford, Gabriel J; Janovy, John

    2009-10-01

    The present study used experimental infections to compare the life cycles and life histories of 6 Rhabdias spp. infecting snakes and anurans. Free-living development of anuran lungworms was primarily limited to heterogonic reproduction, and females utilized matricidal endotoky exclusively, whereas snake lungworms primarily reproduced homogonically and, when heterogonic reproduction occurred, females used a combination of releasing eggs and matricidal endotoky. Infective snake lungworms survived for longer periods in fresh water compared to anuran worms. Infective anuran lungworms penetrated into the skin of frogs and toads; few infections resulted from per os infections. In contrast, snake lungworms were unable to penetrate skin; instead, infective juveniles penetrated into snake esophageal tissue during per os infections. Despite separate points of entry, anuran and snake lungworms both migrated and developed in the fascia, eventually penetrating into the body cavity of the host. Worms molted to adulthood inside the body cavity and subsequently penetrated into the host's lungs, where they fed on blood while becoming gravid. Adult lungworm survival varied among lungworm species, but, in general, snake lungworms were longer lived than anuran worms. Anuran lungworms were poorly suited for transmission via transport hosts, whereas snake lungworms were consistently capable of establishing infections using transport hosts. Overall, these observations suggest that snake and anuran lungworms have discrepant life cycles and life history strategies.

  10. LIFE HISTORIES OF GIRLS WITH EXPERIENCE OF LIFE IN THE STREETS: PERSPECTIVES TO THE INCLUSION SOCIAL PROCESS

    Directory of Open Access Journals (Sweden)

    Normalene Sena de Oliveira

    2006-04-01

    Full Text Available ABSTRACT: It is a qualitative study approaching the life histories of eight girls with living experience in the streets and their social inclusion process. The objectives of this research was to analyze the meaning of social reintegration; to identify the pedagogic actions of the institution in the process of social reintegration; to know the meaning and the impact of the social recovery for girls with life experience in the streets. The collection of data was developed by semi-structured interview, field diary and participant observation. The results showed that the rescue and the process of social inclusion of the subjects is possible starting from the educator's relationship interpersonal with these into the institution. Thus, we understand that in despite of a life history marked by the abandonment and social exclusion, the awakening of new life possibility occurs because the pedagogic actions and interrelationship empowerment among the girls and educators inserted in this reintegration social process. Key words: Homeless Youth, Social Adjustment, Public Health Nursing.

  11. Positive predictors of quality of life for postpartum mothers with a history of childhood maltreatment.

    Science.gov (United States)

    Irwin, Jessica L; Beeghly, Marjorie; Rosenblum, Katherine L; Muzik, Maria

    2016-12-01

    The postpartum period brings a host of biopsychosocial, familial, and economic changes, which may be challenging for new mothers, especially those with trauma histories. Trauma-exposed women are at heightened risk for psychiatric symptomatology and reduced quality of life. The current study sought to evaluate whether a set of hypothesized promotive factors assessed during the first 18 months postpartum (positive parenting, family cohesion, and maternal resilience) are associated with life satisfaction in this population, after controlling for income and postpartum psychiatric symptoms. Analyses were based on data collected for 266 mother-infant dyads from a longitudinal cohort study, Maternal Anxiety during the Childbearing Years (MACY), of women oversampled for childhood maltreatment history. Hierarchical linear regression was used to evaluate the study hypotheses. Consistent with prior work, greater postpartum psychiatric symptoms and less income predicted poor perceptions of life quality. In hierarchical regressions controlling for income and psychiatric symptoms, positive parenting and family cohesion predicted unique variance in mothers' positive perceptions of life quality, and resilience was predictive beyond all other factors. Factors from multiple levels of analysis (maternal, dyadic, and familial) may serve as promotive factors predicting positive perceptions of life quality among women with childhood trauma histories, even those struggling with high levels of psychiatric or economic distress.

  12. Diagnosing the dangerous demography of manta rays using life history theory

    Directory of Open Access Journals (Sweden)

    Nicholas K. Dulvy

    2014-05-01

    Full Text Available Background. The directed harvest and global trade in the gill plates of mantas, and devil rays, has led to increased fishing pressure and steep population declines in some locations. The slow life history, particularly of the manta rays, is cited as a key reason why such species have little capacity to withstand directed fisheries. Here, we place their life history and demography within the context of other sharks and rays.Methods. Despite the limited availability of data, we use life history theory and comparative analysis to estimate the intrinsic risk of extinction (as indexed by the maximum intrinsic rate of population increase rmax for a typical generic manta ray using a variant of the classic Euler–Lotka demographic model. This model requires only three traits to calculate the maximum intrinsic population growth rate rmax: von Bertalanffy growth rate, annual pup production and age at maturity. To account for the uncertainty in life history parameters, we created plausible parameter ranges and propagate these uncertainties through the model to calculate a distribution of the plausible range of rmax values.Results. The maximum population growth rate rmax of manta ray is most sensitive to the length of the reproductive cycle, and the median rmax of 0.116 year−1 95th percentile [0.089–0.139] is one of the lowest known of the 106 sharks and rays for which we have comparable demographic information.Discussion. In common with other unprotected, unmanaged, high-value large-bodied sharks and rays the combination of very low population growth rates of manta rays, combined with the high value of their gill rakers and the international nature of trade, is highly likely to lead to rapid depletion and potential local extinction unless a rapid conservation management response occurs worldwide. Furthermore, we show that it is possible to derive important insights into the demography extinction risk of data-poor species using well-established life

  13. Expression of lysozyme in the life history of the house fly (Musca domestica l.).

    Science.gov (United States)

    Nayduch, Dana; Joyner, Chester

    2013-07-01

    From egg to adult, all life history stages of house flies associate with septic environments teeming with bacteria. House fly lysozyme was first identified in the larval midgut, where it is used for digestion of microbe-rich meals because of its broad-spectrum activity against gram-positive and gram-negative bacteria as well as fungi. This study aimed to determine the temporal expression of lysozyme in the life history of house flies (from egg through adults) on both the mRNA and protein level, and to determine the tissue-specific expression of lysozyme in adult flies induced by feeding Staphylococcus aureus. From 30-min postoviposition through adulthood, all life history stages of the house fly express lysozyme on the mRNA level. In adult flies, lysozyme is expressed both locally in the alimentary canal and systemically in the fat body. Interestingly, we found that during the normal life history of flies, lysozyme protein was only detected in larval stages and older adults, likely because of ingestion of immune-stimulating levels of bacteria, not experienced during egg, pupa, and teneral adult stages. Constitutive expression on the mRNA level implies that this effector is a primary defense molecule in all stages of the house fly life history, and that a mechanism for posttranscriptional control of mature lysozyme enzyme expression may be present. Lysozyme active enzyme primarily serves both a digestive and defensive function in larval and adult flies, and may be a key player in the ability of Musca domestica L. to thrive in microbe-rich environments.

  14. The Mass-Longevity Triangle: Pareto Optimality and the Geometry of Life-History Trait Space.

    Science.gov (United States)

    Szekely, Pablo; Korem, Yael; Moran, Uri; Mayo, Avi; Alon, Uri

    2015-10-01

    When organisms need to perform multiple tasks they face a fundamental tradeoff: no phenotype can be optimal at all tasks. This situation was recently analyzed using Pareto optimality, showing that tradeoffs between tasks lead to phenotypes distributed on low dimensional polygons in trait space. The vertices of these polygons are archetypes--phenotypes optimal at a single task. This theory was applied to examples from animal morphology and gene expression. Here we ask whether Pareto optimality theory can apply to life history traits, which include longevity, fecundity and mass. To comprehensively explore the geometry of life history trait space, we analyze a dataset of life history traits of 2105 endothermic species. We find that, to a first approximation, life history traits fall on a triangle in log-mass log-longevity space. The vertices of the triangle suggest three archetypal strategies, exemplified by bats, shrews and whales, with specialists near the vertices and generalists in the middle of the triangle. To a second approximation, the data lies in a tetrahedron, whose extra vertex above the mass-longevity triangle suggests a fourth strategy related to carnivory. Each animal species can thus be placed in a coordinate system according to its distance from the archetypes, which may be useful for genome-scale comparative studies of mammalian aging and other biological aspects. We further demonstrate that Pareto optimality can explain a range of previous studies which found animal and plant phenotypes which lie in triangles in trait space. This study demonstrates the applicability of multi-objective optimization principles to understand life history traits and to infer archetypal strategies that suggest why some mammalian species live much longer than others of similar mass.

  15. The Mass-Longevity Triangle: Pareto Optimality and the Geometry of Life-History Trait Space

    Science.gov (United States)

    Szekely, Pablo; Korem, Yael; Moran, Uri; Mayo, Avi; Alon, Uri

    2015-01-01

    When organisms need to perform multiple tasks they face a fundamental tradeoff: no phenotype can be optimal at all tasks. This situation was recently analyzed using Pareto optimality, showing that tradeoffs between tasks lead to phenotypes distributed on low dimensional polygons in trait space. The vertices of these polygons are archetypes—phenotypes optimal at a single task. This theory was applied to examples from animal morphology and gene expression. Here we ask whether Pareto optimality theory can apply to life history traits, which include longevity, fecundity and mass. To comprehensively explore the geometry of life history trait space, we analyze a dataset of life history traits of 2105 endothermic species. We find that, to a first approximation, life history traits fall on a triangle in log-mass log-longevity space. The vertices of the triangle suggest three archetypal strategies, exemplified by bats, shrews and whales, with specialists near the vertices and generalists in the middle of the triangle. To a second approximation, the data lies in a tetrahedron, whose extra vertex above the mass-longevity triangle suggests a fourth strategy related to carnivory. Each animal species can thus be placed in a coordinate system according to its distance from the archetypes, which may be useful for genome-scale comparative studies of mammalian aging and other biological aspects. We further demonstrate that Pareto optimality can explain a range of previous studies which found animal and plant phenotypes which lie in triangles in trait space. This study demonstrates the applicability of multi-objective optimization principles to understand life history traits and to infer archetypal strategies that suggest why some mammalian species live much longer than others of similar mass. PMID:26465336

  16. The Mass-Longevity Triangle: Pareto Optimality and the Geometry of Life-History Trait Space.

    Directory of Open Access Journals (Sweden)

    Pablo Szekely

    2015-10-01

    Full Text Available When organisms need to perform multiple tasks they face a fundamental tradeoff: no phenotype can be optimal at all tasks. This situation was recently analyzed using Pareto optimality, showing that tradeoffs between tasks lead to phenotypes distributed on low dimensional polygons in trait space. The vertices of these polygons are archetypes--phenotypes optimal at a single task. This theory was applied to examples from animal morphology and gene expression. Here we ask whether Pareto optimality theory can apply to life history traits, which include longevity, fecundity and mass. To comprehensively explore the geometry of life history trait space, we analyze a dataset of life history traits of 2105 endothermic species. We find that, to a first approximation, life history traits fall on a triangle in log-mass log-longevity space. The vertices of the triangle suggest three archetypal strategies, exemplified by bats, shrews and whales, with specialists near the vertices and generalists in the middle of the triangle. To a second approximation, the data lies in a tetrahedron, whose extra vertex above the mass-longevity triangle suggests a fourth strategy related to carnivory. Each animal species can thus be placed in a coordinate system according to its distance from the archetypes, which may be useful for genome-scale comparative studies of mammalian aging and other biological aspects. We further demonstrate that Pareto optimality can explain a range of previous studies which found animal and plant phenotypes which lie in triangles in trait space. This study demonstrates the applicability of multi-objective optimization principles to understand life history traits and to infer archetypal strategies that suggest why some mammalian species live much longer than others of similar mass.

  17. Life history and the competitive environment: trajectories of growth, maturation, and reproductive output among chacma baboons.

    Science.gov (United States)

    Johnson, Sara E

    2003-01-01

    The social environment is a key feature influencing primate life histories. Chacma baboons (Papio hamadryas ursinus) are a female-bonded species with a strict linear dominance hierarchy. In this species, the allocation of energy to competing demands of growth and reproduction is hypothesized to vary as a function of competitive ability, which in turn increases with social rank. Since growth rate is a major component of life history models, measures of age-specific growth were used to analyze variation in life history traits across social ranks. Weights of 42 immature baboons were obtained without sedation or baiting from a troop of well-habituated chacma baboons in the Okavango Delta, Botswana. Using demographic and weight data from this wild population, five main findings emerged: 1) Weight for age and growth rate of infant and juvenile females are positively associated with maternal rank. 2) Male growth is not influenced by maternal rank. 3) Female growth shows smaller variation across feeding conditions than male growth. 4) Low-ranking adult females continue investment in offspring through prolonged lactation until they reach a weight comparable to that of high-ranking infants. 5) The benefit of rank to reproductive success shown in this study is 0.83 additional offspring. Reproductive span determined predominantly by age at maturation contributes 27-38% to the difference in expected number of offspring by rank, vs. 62-73% due to reproductive rate. These findings have major implications for understanding the role of social environment in phenotypic plasticity of life history traits, and in the evolution of primate life histories. Copyright 2003 Wiley-Liss, Inc.

  18. Evolutionary ecology of endocrine-mediated life-history variation in the garter snake Thamnophis elegans.

    Science.gov (United States)

    Sparkman, Amanda M; Vleck, Carol M; Bronikowski, Anne M

    2009-03-01

    The endocrine system plays an integral role in the regulation of key life-history traits. Insulin-like growth factor-1 (IGF-1) is a hormone that promotes growth and reproduction, and it has been implicated in the reduction of lifespan. IGF-1 is also capable of responding plastically to environmental stimuli such as resource availability and temperature. Thus pleiotropic control of life-history traits by IGF-1 could provide a mechanism for the evolution of correlated life-history traits in a new or changing environment. An ideal system in which to investigate the role of IGF-1 in life-history evolution exists in two ecotypes of the garter snake Thamnophis elegans, which derive from a single recent ancestral source but have evolved genetically divergent life-history characteristics. Snakes from meadow populations near Eagle Lake, California (USA) exhibit slower growth rates, lower annual reproductive output, and longer median adult lifespans relative to populations along the lakeshore. We hypothesized that the IGF-1 system has differentiated between these ecotypes and can account for increased growth and reproduction and reduced survival in lakeshore vs. meadow snakes. We tested for a difference in plasma IGF-1 levels in free-ranging snakes from replicate populations of each ecotype over three years. IGF-1 levels were significantly associated with adult body size, reproductive output, and season in a manner that reflects established differences in prey ecology and age/size-specific reproduction between the ecotypes. These findings are discussed in the context of theoretical expectations for a tradeoff between reproduction and lifespan that is mediated by pleiotropic endocrine mechanisms.

  19. Diagnosing the dangerous demography of manta rays using life history theory.

    Science.gov (United States)

    Dulvy, Nicholas K; Pardo, Sebastián A; Simpfendorfer, Colin A; Carlson, John K

    2014-01-01

    Background. The directed harvest and global trade in the gill plates of mantas, and devil rays, has led to increased fishing pressure and steep population declines in some locations. The slow life history, particularly of the manta rays, is cited as a key reason why such species have little capacity to withstand directed fisheries. Here, we place their life history and demography within the context of other sharks and rays. Methods. Despite the limited availability of data, we use life history theory and comparative analysis to estimate the intrinsic risk of extinction (as indexed by the maximum intrinsic rate of population increase r max) for a typical generic manta ray using a variant of the classic Euler-Lotka demographic model. This model requires only three traits to calculate the maximum intrinsic population growth rate r max: von Bertalanffy growth rate, annual pup production and age at maturity. To account for the uncertainty in life history parameters, we created plausible parameter ranges and propagate these uncertainties through the model to calculate a distribution of the plausible range of r max values. Results. The maximum population growth rate r max of manta ray is most sensitive to the length of the reproductive cycle, and the median r max of 0.116 year(-1) 95th percentile [0.089-0.139] is one of the lowest known of the 106 sharks and rays for which we have comparable demographic information. Discussion. In common with other unprotected, unmanaged, high-value large-bodied sharks and rays the combination of very low population growth rates of manta rays, combined with the high value of their gill rakers and the international nature of trade, is highly likely to lead to rapid depletion and potential local extinction unless a rapid conservation management response occurs worldwide. Furthermore, we show that it is possible to derive important insights into the demography extinction risk of data-poor species using well-established life history theory.

  20. Evolution of boldness and life-history in response to selective harvesting

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Marty, Lise; Arlinghaus, Robert

    2018-01-01

    Whether intensive harvesting alters the behavioral repertoire of exploited fishes is currently unknown, but plausible. We extend a fish life-history model to account for boldness as a personality trait that affects foraging intensity, which affects energy intake and risk from predation and fishing...... gear. We systematically investigate life-history and behavioral trait evolution along the boldness–timidity axis in response to the full range of common selectivity and exploitation patterns in fisheries. In agreement with previous studies, we find that any type of harvesting selects for fast life...... individuals common to passive gears, whether in combination with selection on size or not. Altered behavior caused by intensive harvesting should be commonplace in nature, which can have far-reaching ecological, evolutionary, and managerial impacts. Evolution of timidity is expected to strongly erode...

  1. The Societal Impact of Extraterrestrial Life: The Relevance of History and the Social Sciences

    Science.gov (United States)

    Dick, Steven J.

    This chapter reviews past studies on the societal impact of extraterrestrial life and offers four related ways in which history is relevant to the subject: the history of impact thus far, analogical reasoning, impact studies in other areas of science and technology, and studies on the nature of discovery and exploration. We focus particularly on the promise and peril of analogical arguments, since they are by necessity widespread in the field. This chapter also summarizes the relevance of the social sciences, particularly anthropology and sociology, and concludes by taking a closer look at the possible impact of the discovery of extraterrestrial life on theology and philosophy. In undertaking this study we emphasize three bedrock principles: (1) we cannot predict the future; (2) society is not monolithic, implying many impacts depending on religion, culture and worldview; (3) the impact of any discovery of extraterrestrial life is scenario-dependent.

  2. Understanding Life : The Evolutionary Dynamics of Complexity and Semiosis

    Science.gov (United States)

    Loeckenhoff, Helmut K.

    2010-11-01

    Post-Renaissance sciences created different cultures. To establish an epistemological base, Physics were separated from the Mental domain. Consciousness was excluded from science. Life Sciences were left in between e.g. LaMettrie's `man—machine' (1748) and 'vitalism' [e.g. Bergson 4]. Causative thinking versus intuitive arguing limited strictly comprehensive concepts. First ethology established a potential shared base for science, proclaiming the `biology paradigm' in the middle of the 20th century. Initially procured by Cybernetics and Systems sciences, `constructivist' models prepared a new view on human perception and thus also of scientific `objectivity when introducing the `observer'. In sequel Computer sciences triggered the ICT revolution. In turn ICT helped to develop Chaos and Complexity sciences, Non-linear Mathematics and its spin-offs in the formal sciences [Spencer-Brown 49] as e.g. (proto-)logics. Models of life systems, as e.g. Anticipatory Systems, integrated epistemology with mathematics and Anticipatory Computing [Dubois 11, 12, 13, 14] connecting them with Semiotics. Seminal ideas laid in the turn of the 19th to the 20th century [J. v. Uexküll 53] detected the co-action and co-evolvement of environments and life systems. Bio-Semiotics ascribed purpose, intent and meaning as essential qualities of life. The concepts of Systems Biology and Qualitative Research enriched and develop also anthropologies and humanities. Brain research added models of (higher) consciousness. An avant-garde is contemplating a science including consciousness as one additional base. New insights from the extended qualitative approach led to re-conciliation of basic assumptions of scientific inquiry, creating the `epistemological turn'. Paradigmatically, resting on macro- micro- and recently on nano-biology, evolution biology sired fresh scripts of evolution [W. Wieser 60,61]. Its results tie to hypotheses describing the emergence of language, of the human mind and of

  3. Early days in complex dynamics a history of complex dynamics in one variable during 1906-1942

    CERN Document Server

    Alexander, Daniel S; Rosa, Alessandro

    2011-01-01

    The theory of complex dynamics, whose roots lie in 19th-century studies of the iteration of complex function conducted by Kœnigs, Schröder, and others, flourished remarkably during the first half of the 20th century, when many of the central ideas and techniques of the subject developed. This book by Alexander, Iavernaro, and Rosa paints a robust picture of the field of complex dynamics between 1906 and 1942 through detailed discussions of the work of Fatou, Julia, Siegel, and several others. A recurrent theme of the authors' treatment is the center problem in complex dynamics. They present its complete history during this period and, in so doing, bring out analogies between complex dynamics and the study of differential equations, in particular, the problem of stability in Hamiltonian systems. Among these analogies are the use of iteration and problems involving small divisors which the authors examine in the work of Poincaré and others, linking them to complex dynamics, principally via the work of Samuel...

  4. Early Childhood Education Teachers: Life History, Life Course, and the Problem of Family-Work Balance

    Science.gov (United States)

    Bullough, Robert V., Jr.

    2016-01-01

    In contrast to the wider education literature, rather little is known about the lives of early childhood education (ECE) teachers and the impact of those lives on their practice. Drawing on surveys completed by Head Start assistant and lead teachers, teacher lifelines, and interviews, and through the lens of life-course theory, the author portrays…

  5. From Suns to Life: A Chronological Approach to the History of Life on Earth

    CERN Document Server

    Gargaud, Muriel; López-García, Purificación; Martin, Hervé; Montmerle, Thierry; Pascal, Robert; Reisse, Jacques

    2006-01-01

    This review emerged from several interdisciplinary meetings and schools gathering a group of astronomers, geologists, biologists, and chemists, attempting to share their specialized knowledge around a common question: how did life emerge on Earth? Their ultimate goal was to provide some kind of answer as a prerequisite to an even more demanding question: is life universal? The resulting state-of-the-art articles were written by twenty-five scientists telling a not-so linear story, but on the contrary, highlighting problems, gaps, and controversies. Needless to say, this approach yielded no definitive answers to both questions. However, by adopting a chronological approach to the question of the emergence of life on Earth, the only place where we know for sure that life exists; it was possible to break down this question into several sub-topics that can be addressed by the different disciplines. The main chapters of this review present the formation and evolution of the solar system (3); the building of a habi...

  6. From Molecules to Life: Quantifying the Complexity of Chemical and Biological Systems in the Universe.

    Science.gov (United States)

    Böttcher, Thomas

    2018-01-01

    Life is a complex phenomenon and much research has been devoted to both understanding its origins from prebiotic chemistry and discovering life beyond Earth. Yet, it has remained elusive how to quantify this complexity and how to compare chemical and biological units on one common scale. Here, a mathematical description of molecular complexity was applied allowing to quantitatively assess complexity of chemical structures. This in combination with the orthogonal measure of information complexity resulted in a two-dimensional complexity space ranging over the entire spectrum from molecules to organisms. Entities with a certain level of information complexity directly require a functionally complex mechanism for their production or replication and are hence indicative for life-like systems. In order to describe entities combining molecular and information complexity, the term biogenic unit was introduced. Exemplified biogenic unit complexities were calculated for ribozymes, protein enzymes, multimeric protein complexes, and even an entire virus particle. Complexities of prokaryotic and eukaryotic cells, as well as multicellular organisms, were estimated. Thereby distinct evolutionary stages in complexity space were identified. The here developed approach to compare the complexity of biogenic units allows for the first time to address the gradual characteristics of prebiotic and life-like systems without the need for a definition of life. This operational concept may guide our search for life in the Universe, and it may direct the investigations of prebiotic trajectories that lead towards the evolution of complexity at the origins of life.

  7. GENOMIC BASIS OF AGING AND LIFE HISTORY EVOLUTION IN DROSOPHILA MELANOGASTER

    Science.gov (United States)

    Remolina, Silvia C.; Chang, Peter L.; Leips, Jeff; Nuzhdin, Sergey V.; Hughes, Kimberly A.

    2015-01-01

    Natural diversity in aging and other life history patterns is a hallmark of organismal variation. Related species, populations, and individuals within populations show genetically based variation in life span and other aspects of age-related performance. Population differences are especially informative because these differences can be large relative to within-population variation and because they occur in organisms with otherwise similar genomes. We used experimental evolution to produce populations divergent for life span and late-age fertility and then used deep genome sequencing to detect sequence variants with nucleotide-level resolution. Several genes and genome regions showed strong signatures of selection, and the same regions were implicated in independent comparisons, suggesting that the same alleles were selected in replicate lines. Genes related to oogenesis, immunity, and protein degradation were implicated as important modifiers of late-life performance. Expression profiling and functional annotation narrowed the list of strong candidate genes to 38, most of which are novel candidates for regulating aging. Life span and early-age fecundity were negatively correlated among populations; therefore the alleles we identified also are candidate regulators of a major life-history trade-off. More generally, we argue that hitchhiking mapping can be a powerful tool for uncovering the molecular bases of quantitative genetic variation. PMID:23106705

  8. The nature and dynamics of world religions: a life-history approach.

    Science.gov (United States)

    Baumard, Nicolas; Chevallier, Coralie

    2015-11-07

    In contrast with tribal and archaic religions, world religions are characterized by a unique emphasis on extended prosociality, restricted sociosexuality, delayed gratification and the belief that these specific behaviours are sanctioned by some kind of supernatural justice. Here, we draw on recent advances in life history theory to explain this pattern of seemingly unrelated features. Life history theory examines how organisms adaptively allocate resources in the face of trade-offs between different life-goals (e.g. growth versus reproduction, exploitation versus exploration). In particular, recent studies have shown that individuals, including humans, adjust their life strategy to the environment through phenotypic plasticity: in a harsh environment, organisms tend to adopt a 'fast' strategy, pursuing smaller but more certain benefits, while in more affluent environments, organisms tend to develop a 'slow' strategy, aiming for larger but less certain benefits. Reviewing a range of recent research, we show that world religions are associated with a form of 'slow' strategy. This framework explains both the promotion of 'slow' behaviours such as altruism, self-regulation and monogamy in modern world religions, and the condemnation of 'fast' behaviours such as selfishness, conspicuous sexuality and materialism. This ecological approach also explains the diffusion pattern of world religions: why they emerged late in human history (500-300 BCE), why they are currently in decline in the most affluent societies and why they persist in some places despite this overall decline. © 2015 The Author(s).

  9. The nature and dynamics of world religions: a life-history approach

    Science.gov (United States)

    Baumard, Nicolas; Chevallier, Coralie

    2015-01-01

    In contrast with tribal and archaic religions, world religions are characterized by a unique emphasis on extended prosociality, restricted sociosexuality, delayed gratification and the belief that these specific behaviours are sanctioned by some kind of supernatural justice. Here, we draw on recent advances in life history theory to explain this pattern of seemingly unrelated features. Life history theory examines how organisms adaptively allocate resources in the face of trade-offs between different life-goals (e.g. growth versus reproduction, exploitation versus exploration). In particular, recent studies have shown that individuals, including humans, adjust their life strategy to the environment through phenotypic plasticity: in a harsh environment, organisms tend to adopt a ‘fast' strategy, pursuing smaller but more certain benefits, while in more affluent environments, organisms tend to develop a ‘slow' strategy, aiming for larger but less certain benefits. Reviewing a range of recent research, we show that world religions are associated with a form of ‘slow' strategy. This framework explains both the promotion of ‘slow' behaviours such as altruism, self-regulation and monogamy in modern world religions, and the condemnation of ‘fast' behaviours such as selfishness, conspicuous sexuality and materialism. This ecological approach also explains the diffusion pattern of world religions: why they emerged late in human history (500–300 BCE), why they are currently in decline in the most affluent societies and why they persist in some places despite this overall decline. PMID:26511055

  10. Life-history strategies as a tool to identify conservation constraints: A case-study on ants in chalk grasslands

    NARCIS (Netherlands)

    Noordwijk, C.G.E.; Boer, P.; Mabelis, A.A.; Verberk, W.C.E.P.; Siepel, H.

    2012-01-01

    Species’ life-history traits underlie species–environment relationships. Therefore, analysis of species traits, combined into life-history strategies, can be used to identify key factors shaping the local species composition. This is demonstrated in a case-study on ants in chalk grasslands. We

  11. The contribution of developmental experience vs. condition to life history, trait variation and individual differences.

    Science.gov (United States)

    DiRienzo, Nicholas; Montiglio, Pierre-Olivier

    2016-07-01

    1. Developmental experience, for example food abundance during juvenile stages, is known to affect life history and behaviour. However, the life history and behavioural consequences of developmental experience have rarely been studied in concert. As a result, it is still unclear whether developmental experience affects behaviour through changes in life history, or independently of it. 2. The effect of developmental experience on life history and behaviour may also be masked or affected by individual condition during adulthood. Thus, it is critical to tease apart the effects of developmental experience and current individual condition on life history and behaviour. 3. In this study, we manipulated food abundance during development in the western black widow spider, Latrodectus hesperus, by rearing spiders on either a restricted or ad lib diet. We separated developmental from condition-dependent effects by assaying adult foraging behaviour (tendency to attack prey and to stay on out of the refuge following an attack) and web structure multiple times under different levels of satiation following different developmental treatments. 4. Spiders reared under food restriction matured slower and at a smaller size than spiders reared in ad lib conditions. Spiders reared on a restricted diet were more aggressive towards prey and built webs structured for prey capture, while spiders reared on an ad lib diet were less aggressive and built safer webs. Developmental treatment affected which traits were plastic as adults: restricted spiders built safer webs when their adult condition increased, while ad lib spiders reduced their aggression when their adult condition increased. The amount of individual variation in behaviour and web structure varied with developmental treatment. Spiders reared on a restricted diet exhibited consistent variation in all aspects of foraging behaviour and web structure, while spiders reared on an ad lib diet exhibited consistent individual variation in

  12. Astrobiology, history, and society life beyond earth and the impact of discovery

    CERN Document Server

    2013-01-01

    This book addresses important current and historical topics in astrobiology and the search for life beyond Earth, including the search for extraterrestrial intelligence (SETI). The first section covers the plurality of worlds debate from antiquity through the nineteenth century, while section two covers the extraterrestrial life debate from the twentieth century to the present. The final section examines the societal impact of discovering life beyond Earth, including both cultural and religious dimensions. Throughout the book, authors draw links between their own chapters and those of other contributors, emphasizing the interconnections between the various strands of the history and societal impact of the search for extraterrestrial life. The chapters are all written by internationally recognized experts and are carefully edited by Douglas Vakoch, professor of clinical psychology at the California Institute of Integral Studies and Director of Interstellar Message Composition at the SETI Institute. This interd...

  13. The Influence of Life History Milestones and Association Networks on Crop-Raiding Behavior in Male African Elephants

    Science.gov (United States)

    Chiyo, Patrick I.; Moss, Cynthia J.; Alberts, Susan C.

    2012-01-01

    Factors that influence learning and the spread of behavior in wild animal populations are important for understanding species responses to changing environments and for species conservation. In populations of wildlife species that come into conflict with humans by raiding cultivated crops, simple models of exposure of individual animals to crops do not entirely explain the prevalence of crop raiding behavior. We investigated the influence of life history milestones using age and association patterns on the probability of being a crop raider among wild free ranging male African elephants; we focused on males because female elephants are not known to raid crops in our study population. We examined several features of an elephant association network; network density, community structure and association based on age similarity since they are known to influence the spread of behaviors in a population. We found that older males were more likely to be raiders than younger males, that males were more likely to be raiders when their closest associates were also raiders, and that males were more likely to be raiders when their second closest associates were raiders older than them. The male association network had sparse associations, a tendency for individuals similar in age and raiding status to associate, and a strong community structure. However, raiders were randomly distributed between communities. These features of the elephant association network may limit the spread of raiding behavior and likely determine the prevalence of raiding behavior in elephant populations. Our results suggest that social learning has a major influence on the acquisition of raiding behavior in younger males whereas life history factors are important drivers of raiding behavior in older males. Further, both life-history and network patterns may influence the acquisition and spread of complex behaviors in animal populations and provide insight on managing human-wildlife conflict. PMID:22347468

  14. Ecological life histories of the three aquatic nuisance plants, Myriophyllum spicatum, Potamogeton crispus and Elodea canadensis

    Science.gov (United States)

    Nichols, S.A.; Shaw, B.H.

    1986-01-01

    The life histories of Myriophyllum spicatum L., Elodea canadensis Michx., and Potamogeton crispus L., serious aquatic nuisances in many regions of the world, are reviewed to provide insights into the life style of successful aquatic nuisance plants. Specifically, their distribution and spread in North America; their life cycle, productive and reproductive potential; and their ecosystem relationships are reviewed. Hopefully this review will improve a manager's ability to deal with aquatic nuisance problems. It also provides suggestions for basic research needed to develop more effective management practices. It was found that all three species possess a number of adaptations, including an ability to rapidly propagate vegetatively, an opportunistic nature for obtaining nutrients, a life cycle that favors cool weather, and a number of mechanisms which enhance photosynthetic efficiency, which allow them to proliferate. These three species do provide benefits to the ecosystem through their roles in materials cycling and energy flow. Therefore, management of these species should take an integrated approach which recognizes these benefits. The life history information available about the three species varies tremendously; however, a better understanding of resource gain and allocation is needed to manage all three species. Specifically, more research is needed to provide a better understanding of: 1) the role bicarbonate plays in photosynthesis, 2) the role roots play in supplying CO2 to the plabts, 3) resource accumulation and allocation under different temperature and light regimes, 4) resource allocation on a seasonal basis, and 5) nutrient cycling under different management regimes. ?? 1986 Dr W. Junk Publishers.

  15. Early Life-History Consequences of Growth-Hormone Transgenesis in Rainbow Trout Reared in Stream Ecosystem Mesocosms

    Science.gov (United States)

    Vandersteen, Wendy E.; Devlin, Robert H.

    2015-01-01

    There is persistent commercial interest in the use of growth modified fishes for shortening production cycles and increasing overall food production, but there is concern over the potential impact that transgenic fishes might have if ever released into nature. To explore the ecological consequences of transgenic fish, we performed two experiments in which the early growth and survival of growth-hormone transgenic rainbow trout (Oncorhynchus mykiss) were assessed in naturalized stream mesocosms that either contained predators or were predator-free. We paid special attention to the survival bottleneck that occurs during the early life-history of salmonids, and conducted experiments at two age classes (first-feeding fry and 60 days post-first-feeding) that lie on either side of the bottleneck. In the late summer, the first-feeding transgenic trout could not match the growth potential of their wild-type siblings when reared in a hydrodynamically complex and oligotrophic environment, irrespective of predation pressure. Furthermore, overall survival of transgenic fry was lower than in wild-type (transgenic = 30% without predators, 8% with predators; wild-type = 81% without predators, 31% with predators). In the experiment with 60-day old fry, we explored the effects of the transgene in different genetic backgrounds (wild versus domesticated). We found no difference in overwinter survival but significantly higher growth by transgenic trout, irrespective of genetic background. We conclude that the high mortality of GH-transgenic trout during first-feeding reflects an inability to sustain the basic metabolic requirements necessary for life in complex, stream environments. However, when older, GH-transgenic fish display a competitive advantage over wild-type fry, and show greater growth and equal survival as wild-type. These results demonstrate how developmental age and time of year can influence the response of genotypes to environmental conditions. We therefore urge

  16. Selection for life-history traits to maximize population growth in an invasive marine species

    DEFF Research Database (Denmark)

    Jaspers, Cornelia; Marty, Lise; Kiørboe, Thomas

    2018-01-01

    Species establishing outside their natural range, negatively impacting local ecosystems, are of increasing global concern. They often display life-history features characteristic for r-selected populations with fast growth and high reproduction rates to achieve positive population growth rates (r......) in invaded habitats. Here, we demonstrate substantially earlier maturation at a 2 orders of magnitude lower body mass at first reproduction in invasive compared to native populations of the comb jelly Mnemiopsis leidyi. Empirical results are corroborated by a theoretical model for competing life...... populations is an underappreciated determinant of invasiveness, acting as substrate upon which selection can act during the invasion process....

  17. Philosophy, history and sociology of science: interdisciplinary relations and complex social identities.

    Science.gov (United States)

    Riesch, Hauke

    2014-12-01

    Sociology and philosophy of science have an uneasy relationship, while the marriage of history and philosophy of science has--on the surface at least--been more successful I will take a sociological look at the history of the relationships between philosophy and history as well as philosophy and sociology of science. Interdisciplinary relations between these disciplines will be analysed through social identity complexity theory in oider to draw out some conclusions on how the disciplines interact and how they might develop. I will use the relationships between the disciplines as a pointer for a more general social theory of interdisciplinarity which will then be used to sound a caution on how interdisciplinary relations between the three disciplines might be managed.

  18. Life history traits and life table analysis of Lobiopa insularis (Coleoptera: Nitidulidae) fed on strawberry.

    Science.gov (United States)

    Greco, Nancy; Cluigt, Nicolás; Cline, Andrew; Liljesthröm, Gerardo

    2017-01-01

    Lobiopa insularis is a newly reported pest of strawberry in Argentina. We investigated characteristics of its biology in the laboratory, including survivorship and reproduction. We also estimated population growth for L. insularis fed ripe strawberry fruits. Lobiopa insularis was not observed ovipositing on strawberry fruits. A higher proportion of egg masses were recorded from a depth of 1 cm within the soil than on either the soil surface or deeper than 1cm (i.e. between 1and 2 cm) within the soil. The duration of preimaginal developmental stages represented ~18.5% of the total life cycle, while the adult stage represented 81.5%. Survival from egg to adult was 64.20% and mean longevity of females and males adults was 121.84, (SE = 8.86) and 118.58 (SE = 5.90) days, respectively. Females laid eggs only when they were with a male, so reproductive period was dependent on male presence. The number of eggs/female/day was 18.01 (SE = 1.71); and total fecundity was 1655 (ES = 249.53) eggs/female. The long life span of adults and high reproductive output, i.e high fecundity and long reproductive period, indicate that availability and concentration of suitable developmental resources are important factors in the population dynamics of Lobiopa insularis associated with strawberry crops.

  19. Life history traits and life table analysis of Lobiopa insularis (Coleoptera: Nitidulidae fed on strawberry.

    Directory of Open Access Journals (Sweden)

    Nancy Greco

    Full Text Available Lobiopa insularis is a newly reported pest of strawberry in Argentina. We investigated characteristics of its biology in the laboratory, including survivorship and reproduction. We also estimated population growth for L. insularis fed ripe strawberry fruits. Lobiopa insularis was not observed ovipositing on strawberry fruits. A higher proportion of egg masses were recorded from a depth of 1 cm within the soil than on either the soil surface or deeper than 1cm (i.e. between 1and 2 cm within the soil. The duration of preimaginal developmental stages represented ~18.5% of the total life cycle, while the adult stage represented 81.5%. Survival from egg to adult was 64.20% and mean longevity of females and males adults was 121.84, (SE = 8.86 and 118.58 (SE = 5.90 days, respectively. Females laid eggs only when they were with a male, so reproductive period was dependent on male presence. The number of eggs/female/day was 18.01 (SE = 1.71; and total fecundity was 1655 (ES = 249.53 eggs/female. The long life span of adults and high reproductive output, i.e high fecundity and long reproductive period, indicate that availability and concentration of suitable developmental resources are important factors in the population dynamics of Lobiopa insularis associated with strawberry crops.

  20. Local adaptation in brown trout early life-history traits: implications for climate change adaptability

    DEFF Research Database (Denmark)

    Jensen, L.F.; Hansen, Michael Møller; Pertoldi, C.

    2008-01-01

      Knowledge of local adaptation and adaptive potential of natural populations is becoming increasingly relevant due to anthropogenic changes in the environment, such as climate change. The concern is that populations will be negatively affected by increasing temperatures without the capacity...... to adapt. Temperature-related adaptability in traits related to phenology and early life history are expected to be particularly important in salmonid fishes. We focused on the latter and investigated whether four populations of brown trout (Salmo trutta) are locally adapted in early life-history traits...... traits, indicating local adaptation. A temperature effect was observed for three traits. However, this effect varied among populations due to locally adapted reaction norms, corresponding to the temperature regimes experienced by the populations in their native environments. Additive genetic variance...

  1. Predicting the natural mortality of marine fish from life history characteristics

    DEFF Research Database (Denmark)

    Gislason, Henrik

    the information necessary to estimate the scaling of natural mortality with size and asymptotic size. The estimated scaling is compared with output from multispecies fish stock models, with the empirical scaling of the maximum number of recruits per unit of spawning stock biomass with body size......, and with estimates from a comprehensive compilation of empirical data on the natural mortality of marine fishes. The comparisons are all in aggreement with the predictions from the model. We conclude that natural mortality scales with body length raised to a power around -1.6, with the asymptotic length......For fish much of the life history is determined by body size. Body size and asymptotic size significantly influences important life history processes such as growth, maturity, egg production, and natural mortality. Futhermore, for a population to persist, offspring must be able to replace...

  2. Shifting the life-history paradigm: discovery of novel habitat use by hawksbill turtles

    Science.gov (United States)

    Gaos, Alexander R.; Lewison, Rebecca L.; Yañez, Ingrid L.; Wallace, Bryan P.; Liles, Michael J.; Nichols, Wallace J.; Baquero, Andres; Hasbún, Carlos R.; Vasquez, Mauricio; Urteaga, José; Seminoff, Jeffrey A.

    2012-01-01

    Adult hawksbill turtles (Eretmochelys imbricata) are typically described as open-coast, coral reef and hard substrate dwellers. Here, we report new satellite tracking data on female hawksbills from several countries in the eastern Pacific that revealed previously undocumented behaviour for adults of the species. In contrast to patterns of habitat use exhibited by their Caribbean and Indo-Pacific counterparts, eastern Pacific hawksbills generally occupied inshore estuaries, wherein they had strong associations with mangrove saltwater forests. The use of inshore habitats and affinities with mangrove saltwater forests presents a previously unknown life-history paradigm for adult hawksbill turtles and suggests a potentially unique evolutionary trajectory for the species. Our findings highlight the variability in life-history strategies that marine turtles and other wide-ranging marine wildlife may exhibit among ocean regions, and the importance of understanding such disparities from an ecological and management perspective. PMID:21880620

  3. The life-history of a springtail Folsomia candida living in soil contaminated with nonylphenol

    DEFF Research Database (Denmark)

    Widarto, T. H.; Krogh, P. H.; Forbes, V.

    Nonylphenol (NP) has been known for long time as a suspected endocrine disruptor in animals. We have conducted an experiment to look at the effect of NP on the life-history of the parthenogenetic springtail, Folsomia candida. Six sub-lethal concentrations (0, 8,16, 24, 32, 40 mg/kg dry soil......) were applied to 6 replicates of soil containing an individual of 0-1 day old juvenile. During continuous exposure (63 days), we assessed springtail life-history traits such as: survival, growth rate, molting time, time between molting, time to first reproduction, egg production, and viability...... in response to different concentrations of NP. The juveniles did not survive the highest concentration of the chemical. In linking the effects on individuals to the population level and for identifying which trait(s) was (were) responsible for the effect on l, we used a simple two-stage model to estimate...

  4. Harsh Environments, Life History Strategies, and Adjustment: A Longitudinal Study of Oregon Youth

    OpenAIRE

    Hampson, Sarah E.; Andrews, Judy A.; Barckley, Maureen; Gerrard, Meg; Gibbons, Frederick X.

    2016-01-01

    We modeled the effects of harsh environments in childhood on adjustment in early emerging adulthood, through parenting style and the development of fast Life History Strategies (LHS; risky beliefs and behaviors) in adolescence. Participants were from the Oregon Youth Substance Use Project (N = 988; 85.7% White). Five cohorts of children in Grades 1–5 at recruitment were assessed through one-year post high school. Greater environmental harshness (neighborhood quality and family poverty) in Gra...

  5. Age-dependent male mating tactics in a spider mite-A life-history perspective.

    Science.gov (United States)

    Sato, Yukie; Rühr, Peter T; Schmitz, Helmut; Egas, Martijn; Blanke, Alexander

    2016-10-01

    Males often fight with rival males for access to females. However, some males display nonfighting tactics such as sneaking, satellite behavior, or female mimicking. When these mating tactics comprise a conditional strategy, they are often thought to be explained by resource holding potential (RHP), that is, nonfighting tactics are displayed by less competitive males who are more likely to lose a fight. The alternative mating tactics, however, can also be explained by life-history theory, which predicts that young males avoid fighting, regardless of their RHP, if it pays off to wait for future reproduction. Here, we test whether the sneaking tactic displayed by young males of the two-spotted spider mite can be explained by life-history theory. We tested whether young sneaker males survive longer than young fighter males after a bout of mild or strong competition with old fighter males. We also investigated whether old males have a more protective outer skin-a possible proxy for RHP-by measuring cuticle hardness and elasticity using nanoindentation. We found that young sneaker males survived longer than young fighter males after mild male competition. This difference was not found after strong male competition, which suggests that induction of sneaking tactic is affected by male density. Hardness and elasticity of the skin did not vary with male age. Given that earlier work could also not detect morphometric differences between fighter and sneaker males, we conclude that there is no apparent increase in RHP with age in the mite and age-dependent male mating tactics in the mite can be explained only by life-history theory. Because it is likely that fighting incurs a survival cost, age-dependent alternative mating tactics may be explained by life-history theory in many species when reproduction of old males is a significant factor in fitness.

  6. Endogenous Fishing Mortality in Life History Models: Relaxing Some Implicit Assumptions

    OpenAIRE

    Smith, Martin D.

    2007-01-01

    Life history models can include a wide range of biological and ecological features that affect exploited fish populations. However, they typically treat fishing mortality as an exogenous parameter. Implicitly, this approach assumes that the supply of fishing effort is perfectly inelastic. That is, the supply curve of effort is vertical. Fishery modelers often run simulations for different values of fishing mortality, but his exercise also assumes vertical supply and simply explores a series o...

  7. Can sexual selection drive female life histories? A comparative study on Galliform birds.

    Science.gov (United States)

    Kolm, N; Stein, R W; Mooers, A Ø; Verspoor, J J; Cunningham, E J A

    2007-03-01

    Sexual selection has been identified as a major evolutionary force shaping male life history traits but its impact on female life history evolution is less clear. Here we examine the impact of sexual selection on three key female traits (body size, egg size and clutch size) in Galliform birds. Using comparative independent contrast analyses and directional discrete analyses, based on published data and a new genera-level supertree phylogeny of Galliform birds, we investigated how sexual selection [quantified as sexual size dimorphism (SSD) and social mating system (MS)] affects these three important female traits. We found that female body mass was strongly and positively correlated with egg size but not with clutch size, and that clutch size decreased as egg size increased. We established that SSD was related to MS, and then used SSD as a proxy of the strength of sexual selection. We found both a positive relationship between SSD and female body mass and egg size and that increases in female body mass and egg size tend to occur following increases in SSD in this bird order. This pattern of female body mass increases lagging behind changes in SSD, established using our directional discrete analysis, suggests that female body mass increases as a response to increases in the level of sexual selection and not simply through a strong genetic relationship with male body mass. This suggests that sexual selection is linked to changes in female life history traits in Galliformes and we discuss how this link may shape patterns of life history variation among species.

  8. Diversity of .i.Daphnia galeata./i. life history traits in a vertically structured environment

    Czech Academy of Sciences Publication Activity Database

    Macháček, Jiří; Seďa, Jaromír

    2008-01-01

    Roč. 30, č. 3 (2008), s. 221-231 ISSN 0142-7873 R&D Projects: GA ČR(CZ) GA206/03/1537; GA ČR(CZ) GA206/04/0190; GA AV ČR(CZ) IAA6017301 Institutional research plan: CEZ:AV0Z60170517 Keywords : D. galeata * life history * vertical segregation * intraspecific diversity * thermal stratification Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.707, year: 2008

  9. Distribution, ecology, life history, genetic variation, and risk of extinction of nonhuman primates from Costa Rica

    OpenAIRE

    Zaldívar, María E.; Rocha, Oscar; Glander, Kenneth E.; Aguilar, Gabriel; Huertas, Ana S; Sánchez, Ronald; Wong, Grace

    2014-01-01

    We examined the association between geographic distribution, ecological traits, life history, genetic diversity, and risk of extinction in nonhuman primate species from Costa Rica. All of the current nonhuman primate species from Costa Rica are included in the study; spider monkeys (Ateles geoffroyi), howling monkeys (Alouatta palliata), capuchins (Cebus capucinus), and squirrel monkeys (Saimiri oerstedii). Geographic distribution was characterized accessing existing databases. Data on ecolog...

  10. Distribution, ecology, life history, genetic variation, and risk of extinction of nonhuman primates from Costa Rica

    OpenAIRE

    María E Zaldívar; Oscar Rocha; Kenneth E Glander; Gabriel Aguilar; Ana S Huertas; Ronald Sánchez; Grace Wong

    2004-01-01

    We examined the association between geographic distribution, ecological traits, life history, genetic diversity, and risk of extinction in nonhuman primate species from Costa Rica. All of the current nonhuman primate species from Costa Rica are included in the study; spider monkeys (Ateles geoffroyi), howling monkeys (Alouatta palliata), capuchins (Cebus capucinus), and squirrel monkeys (Saimiri oerstedii). Geographic distribution was characterized accessing existing databases. Data on ecolog...

  11. Life-history evolution in response to changes in metapopulation structure in an arthropod herbivore

    OpenAIRE

    De Roissart , Annelies; Wybouw , Nicky; Renault , David; Van Leeuwen , Thomas; Bonte , Dries

    2016-01-01

    International audience; The persistence and dynamics of populations largely depend on the way they are configured and integrated into space and the ensuing eco-evolutionary dynamics. * We manipulated spatial and temporal variation in patch size in replicated experimental metapopulations of the herbivore mite Tetranychus urticae and followed evolutionary dynamics over approximately 30 generations. * A significant divergence in life-history traits, physiological endpoints and gene expression wa...

  12. BRIDGING SCALES IN THE EVOLUTION OF INFECTIOUS DISEASE LIFE HISTORIES: APPLICATION

    OpenAIRE

    Mideo, Nicole; Nelson, William A.; Reece, Sarah E.; Bell, Andrew S.; Read, Andrew F.; Day, Troy

    2011-01-01

    Within- and between-host disease processes occur on the same timescales, therefore changes in the within-host dynamics of parasites, resources, and immunity can interact with changes in the epidemiological dynamics to affect evolutionary outcomes. Consequently, studies of the evolution of disease life histories, that is, infection-age-specific patterns of transmission and virulence, have been constrained by the need for a mechanistic understanding of within-host disease dynamics. In a compani...

  13. Growth, life history, and species interactions of bluegill sunfish (Lepomis macrochirus) under heavy predation

    Energy Technology Data Exchange (ETDEWEB)

    Belk, Mark Carl [Univ. of Georgia, Athens, GA (United States)

    1992-01-01

    The purpose of this study was, first, to compare growth and life history characteristics of an unfished population of bluegill sunfish (Lepomis macrochirus) in the presence of an abundant predator population to characteristic exhibited by bluegills in typical southeastern US reservoirs where the abundance of predators is reduced, but fishing is increased. The second objective was to determine if differences observed between populations were determined genetically or environmentally.

  14. Environmentally-induced plasticity of life history parameters in the cladoceran Simocephalus vetulus

    Czech Academy of Sciences Publication Activity Database

    Šorf, Michal; Cábová, M.; Rychtecký, Pavel

    2017-01-01

    Roč. 66, SEP 01 (2017), s. 40-43 ISSN 0075-9511 R&D Projects: GA ČR(CZ) GA14-29857S Institutional support: RVO:60077344 Keywords : cladocera * life history traits * feeding Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.427, year: 2016 http://www.sciencedirect.com/science/article/pii/S007595111630192X

  15. How universal are reserve design rules? A test using butterflies and their life history traits

    Czech Academy of Sciences Publication Activity Database

    Bartoňová, Alena; Beneš, Jiří; Faltýnek Fric, Zdeněk; Chobot, K.; Konvička, Martin

    2016-01-01

    Roč. 39, č. 5 (2016), s. 456-464 ISSN 0906-7590 R&D Projects: GA ČR GAP505/10/2167 Grant - others:GA JU(CZ) 04-168/2013/P Institutional support: RVO:60077344 Keywords : life history traits * butterflies * heterogeneity Subject RIV: EH - Ecology, Behaviour Impact factor: 4.902, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/ecog.01642/abstract

  16. Potential fitness benefits of the half-pounder life history in Klamath River steelhead

    Science.gov (United States)

    Hodge, Brian W.; Wilzbach, Peggy; Duffy, Walter G.

    2014-01-01

    Steelhead Oncorhynchus mykiss from several of the world's rivers display the half-pounder life history, a variant characterized by an amphidromous (and, less often, anadromous) return to freshwater in the year of initial ocean entry. We evaluated factors related to expression of the half-pounder life history in wild steelhead from the lower Klamath River basin, California. We also evaluated fitness consequences of the half-pounder phenotype using a simple life history model that was parameterized with our empirical data and outputs from a regional survival equation. The incidence of the half-pounder life history differed among subbasins of origin and smolt ages. Precocious maturation occurred in approximately 8% of half-pounders and was best predicted by individual length in freshwater preceding ocean entry. Adult steelhead of the half-pounder phenotype were smaller and less fecund at age than adult steelhead of the alternative (ocean contingent) phenotype. However, our data suggest that fish of the half-pounder phenotype are more likely to spawn repeatedly than are fish of the ocean contingent phenotype. Models predicted that if lifetime survivorship were equal between phenotypes, the fitness of the half-pounder phenotype would be 17–28% lower than that of the ocean contingent phenotype. To meet the condition of equal fitness between phenotypes would require that first-year ocean survival be 21–40% higher among half-pounders in freshwater than among their cohorts at sea. We concluded that continued expression of the half-pounder phenotype is favored by precocious maturation and increased survival relative to that of the ocean contingent phenotype.

  17. Trade-offs and spatial life-history strategies in classical metapopulations.

    Science.gov (United States)

    Crowley, Philip H; McLetchie, D Nicholas

    2002-02-01

    The metapopulation concept dichotomizes space into the local scale of an ephemeral patch and the broader scale of the persistent multipatch system. Here, we consider how the "best" (i.e., optimal or noninvasible) life history of asexually reproducing organisms might address this dichotomy along environmental gradients via shifts in two key trade-offs. The expansion-survival trade-off expresses the relation between the combined growth and propagule production rate and the mortality rate. The accumulation-export trade-off partitions expansion into a local accumulation of growth plus propagules retained within the patch and the potential-colonist propagules dispersed to other patches, although the dispersal linkages among patches are assumed to be weak (a characteristic of "classical" metapopulations). We identify the best life histories along gradients of productivity, stress, and patch extinction rates for a metapopulation with and without lottery or overgrowth competition, and we compare them with results for an isolated immortal patch. The two trade-offs interact in determining best life histories, but this effect is generally small, supporting the validity of studies addressing the trade-offs separately. The accumulation-export trade-off responds strongly to the three gradients, increasing export with productivity and with patch extinction rate when this rate is high but decreasing export with higher stress; the expansion-survival trade-off increases expansion with productivity but fails to respond to stress and patch extinction rate gradients, except when the other trade-off does not occur. By linking the trade-offs to life-history strategies (i.e., colonization, exploitation, and tolerance), we separate strategies from phenomenology (i.e., from export, accumulation, and survival) along the gradients.

  18. The cosmological model of eternal inflation and the transition from chance to biological evolution in the history of life

    Directory of Open Access Journals (Sweden)

    Koonin Eugene V

    2007-05-01

    Full Text Available Abstract Background Recent developments in cosmology radically change the conception of the universe as well as the very notions of "probable" and "possible". The model of eternal inflation implies that all macroscopic histories permitted by laws of physics are repeated an infinite number of times in the infinite multiverse. In contrast to the traditional cosmological models of a single, finite universe, this worldview provides for the origin of an infinite number of complex systems by chance, even as the probability of complexity emerging in any given region of the multiverse is extremely low. This change in perspective has profound implications for the history of any phenomenon, and life on earth cannot be an exception. Hypothesis Origin of life is a chicken and egg problem: for biological evolution that is governed, primarily, by natural selection, to take off, efficient systems for replication and translation are required, but even barebones cores of these systems appear to be products of extensive selection. The currently favored (partial solution is an RNA world without proteins in which replication is catalyzed by ribozymes and which serves as the cradle for the translation system. However, the RNA world faces its own hard problems as ribozyme-catalyzed RNA replication remains a hypothesis and the selective pressures behind the origin of translation remain mysterious. Eternal inflation offers a viable alternative that is untenable in a finite universe, i.e., that a coupled system of translation and replication emerged by chance, and became the breakthrough stage from which biological evolution, centered around Darwinian selection, took off. A corollary of this hypothesis is that an RNA world, as a diverse population of replicating RNA molecules, might have never existed. In this model, the stage for Darwinian selection is set by anthropic selection of complex systems that rarely but inevitably emerge by chance in the infinite universe

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

    Directory of Open Access Journals (Sweden)

    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.

  20. An ordination of life histories using morphological proxies: capital vs. income breeding in insects.

    Science.gov (United States)

    Davis, Robert B; Javoiš, Juhan; Kaasik, Ants; Õunap, Erki; Tammaru, Toomas

    2016-08-01

    Predictive classifications of life histories are essential for evolutionary ecology. While attempts to apply a single approach to all organisms may be overambitious, recent advances suggest that more narrow ordination schemes can be useful. However, these schemes mostly lack easily observable proxies of the position of a species on respective axes. It has been proposed that, in insects, the degree of capital (vs. income) breeding, reflecting the importance of adult feeding for reproduction, correlates with various ecological traits at the level of among-species comparison. We sought to prove these ideas via rigorous phylogenetic comparative analyses. We used experimentally derived life-history data for 57 species of European Geometridae (Lepidoptera), and an original phylogenetic reconstruction. The degree of capital breeding was estimated based on morphological proxies, including relative abdomen size of females. Applying Brownian-motion-based comparative analyses (with an original update to include error estimates), we demonstrated the associations between the degree of capital breeding and larval diet breadth, sexual size dimorphism, and reproductive season. Ornstein-Uhlenbeck model based phylogenetic analysis suggested a causal relationship between the degree of capital breeding and diet breadth. Our study indicates that the gradation from capital to income breeding is an informative axis to ordinate life-history strategies in flying insects which are affected by the fecundity vs. mobility trade off, with the availability of easy to record proxies contributing to its predictive power in practical contexts. © 2016 by the Ecological Society of America.

  1. Life history predicts risk of species decline in a stochastic world.

    Science.gov (United States)

    Van Allen, Benjamin G; Dunham, Amy E; Asquith, Christopher M; Rudolf, Volker H W

    2012-07-07

    Understanding what traits determine the extinction risk of species has been a long-standing challenge. Natural populations increasingly experience reductions in habitat and population size concurrent with increasing novel environmental variation owing to anthropogenic disturbance and climate change. Recent studies show that a species risk of decline towards extinction is often non-random across species with different life histories. We propose that species with life histories in which all stage-specific vital rates are more evenly important to population growth rate may be less likely to decline towards extinction under these pressures. To test our prediction, we modelled declines in population growth rates under simulated stochastic disturbance to the vital rates of 105 species taken from the literature. Populations with more equally important vital rates, determined using elasticity analysis, declined more slowly across a gradient of increasing simulated environmental variation. Furthermore, higher evenness of elasticity was significantly correlated with a reduced chance of listing as Threatened on the International Union for Conservation of Nature Red List. The relative importance of life-history traits of diverse species can help us infer how natural assemblages will be affected by novel anthropogenic and climatic disturbances.

  2. Can family risk-factors moderate the link between psychopathy and life-history strategy?

    Directory of Open Access Journals (Sweden)

    Međedović Janko

    2016-01-01

    Full Text Available Life History Theory is an explanatory evolutionary framework which explains differences in fitness-relevant outcomes using the characteristics of the environment and individual organisms. Basically, individuals can be positioned somewhere on the r/K continuum of the Life History Strategy (LHS: a K or slow strategy represents later maturity and reproduction, a smaller number of offspring with higher investment in them, while the r (or fast strategy follows the opposite pattern. Previous research offered evidence that psychopathy can represent a trait associated with fast LHS. In the present research we examined the relations between the family risk-factors, a four-factor model of psychopathy and the LHS in a sample of male convicts (N=181. The results have shown that a manipulative and deceitful interpersonal style is associated with slow LHS while shallow affect and antisocial tendencies are related to fast LHS. The interactions between psychopathy and family risk-factors revealed that parental criminal behaviour enhances the relation between fast LHS and psychopathic traits, including the manipulative interpersonal style. The findings are in accordance with the Life History Theory and provide a deeper understanding of the preservation of psychopathy in contemporary populations.

  3. Phenoloxidase activity in the infraorder Isoptera: unraveling life-history correlates of immune investment

    Science.gov (United States)

    Rosengaus, Rebeca B.; Reichheld, Jennifer L.

    2016-02-01

    Within the area of ecological immunology, the quantification of phenoloxidase (PO) activity has been used as a proxy for estimating immune investment. Because termites have unique life-history traits and significant inter-specific differences exist regarding their nesting and foraging habits, comparative studies on PO activity can shed light on the general principles influencing immune investment against the backdrop of sociality, reproductive potential, and gender. We quantified PO activity across four termite species ranging from the phylogenetically basal to the most derived, each with their particular nesting/foraging strategies. Our data indicate that PO activity varies across species, with soil-dwelling termites exhibiting significantly higher PO levels than the above-ground wood nester species which in turn have higher PO levels than arboreal species. Moreover, our comparative approach suggests that pathogenic risks can override reproductive potential as a more important driver of immune investment. No gender-based differences in PO activities were recorded. Although termite PO activity levels vary in accordance with a priori predictions made from life-history theory, our data indicate that nesting and foraging strategies (and their resulting pathogenic pressures) can supersede reproductive potential and other life-history traits in influencing investment in PO. Termites, within the eusocial insects, provide a unique perspective for inferring how different ecological pressures may have influenced immune function in general and their levels of PO activity, in particular.

  4. Evolution of dispersal and life history interact to drive accelerating spread of an invasive species.

    Science.gov (United States)

    Perkins, T Alex; Phillips, Benjamin L; Baskett, Marissa L; Hastings, Alan

    2013-08-01

    Populations on the edge of an expanding range are subject to unique evolutionary pressures acting on their life-history and dispersal traits. Empirical evidence and theory suggest that traits there can evolve rapidly enough to interact with ecological dynamics, potentially giving rise to accelerating spread. Nevertheless, which of several evolutionary mechanisms drive this interaction between evolution and spread remains an open question. We propose an integrated theoretical framework for partitioning the contributions of different evolutionary mechanisms to accelerating spread, and we apply this model to invasive cane toads in northern Australia. In doing so, we identify a previously unrecognised evolutionary process that involves an interaction between life-history and dispersal evolution during range shift. In roughly equal parts, life-history evolution, dispersal evolution and their interaction led to a doubling of distance spread by cane toads in our model, highlighting the potential importance of multiple evolutionary processes in the dynamics of range expansion. © 2013 John Wiley & Sons Ltd/CNRS.

  5. Parental care trade-offs and life-history relationships in insects.

    Science.gov (United States)

    Gilbert, James D J; Manica, Andrea

    2010-08-01

    Insect parental care is extensive and varied, but its life-history implications have never been comparatively tested. Using original and literature data, we tested predictions about egg size, egg number (lifetime fecundity), and body size under different parental care modes across a phylogeny of 287 insect species. Life-history theory and both comparative and intraspecific evidence from ectotherms suggest parental care should select for bigger, fewer eggs, but that allometric scaling of egg size and lifetime fecundity may depend on whether care consists of provisioning (density-dependent offspring survival) or merely guarding (density-independent offspring survival). Against expectation, egg size was indistinguishable among parental care modes, covarying only with body size. This refutes most theory of egg size evolution under parental care. Lifetime fecundity scaled differently depending on parental investment-positively under no care and guarding, as in most ectotherms, but negatively under provisioning. Reproductive allocation in provisioning insects resembled that in mammals and birds, also groups with obligate provisioning. We propose that the metabolic demands of multiple offspring must scale with species body size more steeply than the parent's provisioning capacity, resulting in larger females laying fewer eggs. These patterns lay the groundwork for a more general understanding of parental care and life history.

  6. Individual covariation in life-history traits: seeing the trees despite the forest

    Science.gov (United States)

    Cam, E.; Link, W.A.; Cooch, E.G.; Monnat, J.-Y.; Danchin, E.

    2002-01-01

    We investigated the influence of age on survival and breeding rates in a long-lived species Rissa tridactyla using models with individual random effects permitting variation and covariation in fitness components among individuals. Differences in survival or breeding probabilities among individuals are substantial, and there was positive covariation between survival and breeding probability; birds that were more likely to survive were also more likely to breed, given that they survived. The pattern of age-related variation in these rates detected at the individual level differed from that observed at the population level. Our results provided confirmation of what has been suggested by other investigators: within-cohort phenotypic selection can mask senescence. Although this phenomenon has been extensively studied in humans and captive animals, conclusive evidence of the discrepancy between population-level and individual-level patterns of age-related variation in life-history traits is extremely rare in wild animal populations. Evolutionary studies of the influence of age on life-history traits should use approaches differentiating population level from the genuine influence of age: only the latter is relevant to theories of life-history evolution. The development of models permitting access to individual variation in fitness is a promising advance for the study of senescence and evolutionary processes.

  7. Language and life history: a new perspective on the development and evolution of human language.

    Science.gov (United States)

    Locke, John L; Bogin, Barry

    2006-06-01

    It has long been claimed that Homo sapiens is the only species that has language, but only recently has it been recognized that humans also have an unusual pattern of growth and development. Social mammals have two stages of pre-adult development: infancy and juvenility. Humans have two additional prolonged and pronounced life history stages: childhood, an interval of four years extending between infancy and the juvenile period that follows, and adolescence, a stage of about eight years that stretches from juvenility to adulthood. We begin by reviewing the primary biological and linguistic changes occurring in each of the four pre-adult ontogenetic stages in human life history. Then we attempt to trace the evolution of childhood and juvenility in our hominin ancestors. We propose that several different forms of selection applied in infancy and childhood; and that, in adolescence, elaborated vocal behaviors played a role in courtship and intrasexual competition, enhancing fitness and ultimately integrating performative and pragmatic skills with linguistic knowledge in a broad faculty of language. A theoretical consequence of our proposal is that fossil evidence of the uniquely human stages may be used, with other findings, to date the emergence of language. If important aspects of language cannot appear until sexual maturity, as we propose, then a second consequence is that the development of language requires the whole of modern human ontogeny. Our life history model thus offers new ways of investigating, and thinking about, the evolution, development, and ultimately the nature of human language.

  8. Nutritional physiology of life-history trade-offs: how food protein-carbohydrate content influences life-history traits in the wing-polymorphic cricket Gryllus firmus.

    Science.gov (United States)

    Clark, Rebecca M; Zera, Anthony J; Behmer, Spencer T

    2015-01-15

    Although life-history trade-offs result from the differential acquisition and allocation of nutritional resources to competing physiological functions, many aspects of this topic remain poorly understood. Wing-polymorphic insects, which possess alternative morphs that trade off allocation to flight capability versus early reproduction, provide a good model system for exploring this topic. In this study, we used the wing-polymorphic cricket Gryllus firmus to test how expression of the flight capability versus reproduction trade-off was modified across a heterogeneous protein-carbohydrate nutritional landscape. Newly molted adult female long- and short-winged crickets were given one of 13 diets with different concentrations and ratios of protein and digestible carbohydrate; for each cricket, we measured consumption patterns, growth and allocation to reproduction (ovary mass) versus flight muscle maintenance (flight muscle mass and somatic lipid stores). Feeding responses in both morphs were influenced more by total macronutrient concentration than by protein-carbohydrate ratio, except at high-macronutrient concentration, where protein-carbohydrate balance was important. Mass gain tended to be greatest on protein-biased diets for both morphs, but was consistently lower across all diets for long-winged females. When long-winged females were fed high-carbohydrate foods, they accumulated greater somatic lipid stores; on high-protein foods, they accumulated greater somatic protein stores. Food protein-carbohydrate content also affected short-winged females (selected for early reproductive onset), which showed dramatic increases in ovary size, including ovarian stores of lipid and protein, on protein-biased foods. This is the first study to show how the concentration and ratio of dietary protein and carbohydrate affects consumption and allocation to key physiological features associated with the reproduction-dispersal life-history trade-off. © 2015. Published by The

  9. Comparison of family history and SNPs for predicting risk of complex disease.

    Directory of Open Access Journals (Sweden)

    Chuong B Do

    Full Text Available The clinical utility of family history and genetic tests is generally well understood for simple Mendelian disorders and rare subforms of complex diseases that are directly attributable to highly penetrant genetic variants. However, little is presently known regarding the performance of these methods in situations where disease susceptibility depends on the cumulative contribution of multiple genetic factors of moderate or low penetrance. Using quantitative genetic theory, we develop a model for studying the predictive ability of family history and single nucleotide polymorphism (SNP-based methods for assessing risk of polygenic disorders. We show that family history is most useful for highly common, heritable conditions (e.g., coronary artery disease, where it explains roughly 20%-30% of disease heritability, on par with the most successful SNP models based on associations discovered to date. In contrast, we find that for diseases of moderate or low frequency (e.g., Crohn disease family history accounts for less than 4% of disease heritability, substantially lagging behind SNPs in almost all cases. These results indicate that, for a broad range of diseases, already identified SNP associations may be better predictors of risk than their family history-based counterparts, despite the large fraction of missing heritability that remains to be explained. Our model illustrates the difficulty of using either family history or SNPs for standalone disease prediction. On the other hand, we show that, unlike family history, SNP-based tests can reveal extreme likelihood ratios for a relatively large percentage of individuals, thus providing potentially valuable adjunctive evidence in a differential diagnosis.

  10. Life histories of female elementary teachers and their science/teacher role construction

    Science.gov (United States)

    Ramseur, Aletha Johnson

    The research conducted in this study focuses on life histories of female elementary teachers and their science/teacher role construction. Identity theorists argue that the self consists of a collection of identities founded on occupying a particular role. Who we are depends on the roles we occupy. These roles are often referred to as "role identities". In the case of these participants, many role identities (mother, wife, sibling, and teacher) exist. This study focuses primarily on their (science) teacher role identity. Literature on women's lives, as learners and teachers, suggest that women's experiences, currently and throughout history influenced their teacher role construction. There is however, little knowledge of women's lives as elementary teachers of science and the affect of their experiences, currently and throughout history, on their (science) teacher identity construction. Schools delineated by race, class, and gender relations, are similar to other sectors of society's, social and cultural spheres within which race, class, and gender identities are constructed. Using in-depth-interviews female elementary teachers were encouraged to actively reconstruct their life and work-life experiences focusing on family, school and science interactions. They addressed the intellectual and emotional connections between their life and work experiences by focusing on details of their past and present experiences and examining the meaning of those experiences. It was the scrutiny of these connections between their life and work experiences, the meaning derived from them and historical events, and the constraints imposed on their personal choices by broader power relations, such as those of class, race, and gender that informed why we teach, how we teach, and what we teach.

  11. Association of abuse history with symptom severity and quality of life in patients with fibromyalgia.

    Science.gov (United States)

    Jiao, Juan; Vincent, Ann; Cha, Stephen S; Luedtke, Connie A; Oh, Terry H

    2015-03-01

    A high prevalence of abuse has been reported in patients with fibromyalgia. We aimed to examine the association between self-reported abuse history and symptom severity and quality of life (QOL) in 962 patients with fibromyalgia. All patients completed the Fibromyalgia Impact Questionnaire (FIQ) and the Short Form 36 health survey (SF-36). Multivariate regression analyses were performed. In total, 289 patients (30%) reported a history of abuse. Of those who specified abuse types, 161 patients (59%) reported more than 1 type of abuse (36% emotional, 32% physical, 25% sexual, and 7% verbal). Patients in the abuse group were younger and more likely to be female, unemployed, unmarried, and current smokers compared with patients who reported no abuse. After adjusting for these differences, abuse history was associated with worse symptoms, as indicated by a higher FIQ total score (P anxiety (P fibromyalgia was associated with worse symptoms and QOL compared with those patients without abuse history. Future studies are needed to assess whether additional tailored interventions as part of fibromyalgia treatment are helpful for patients with a history of abuse.

  12. Seasonal life history trade-offs in two leafwing butterflies: Delaying reproductive development increases life expectancy.

    Science.gov (United States)

    McElderry, Robert M

    2016-04-01

    Surviving inhospitable periods or seasons may greatly affect fitness. Evidence of this exists in the prevalence of dormant stages in the life cycles of most insects. Here I focused on butterflies with distinct seasonal morphological types (not a genetic polymorphism) in which one morphological type, or form, delays reproduction until favorable conditions return, while the other form develops in an environment that favors direct reproduction. For two butterflies, Anaea aidea and A. andria, I tested the hypothesis that the development of each seasonal form involves a differential allocation of resources to survival at eclosion. I assayed differences in adult longevity among summer and winter forms in either a warm, active environment or a cool, calm environment. Winter form adults lived 40 times longer than summer form but only in calm, cool conditions. The magnitude of this difference provided compelling evidence that the winter form body plan and metabolic strategy (i.e. resource conservatism) favor long term survival. This research suggests that winter form adults maintain lowered metabolic rate, a common feature of diapause, to conserve resources and delay senescence while overwintering. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Regulation of human life histories: the role of the inflammatory host response.

    Science.gov (United States)

    Van Bodegom, David; May, Linda; Meij, Hans J; Westendorp, Rudi G J

    2007-04-01

    Most species with a long life span have few offspring while species with a short life span have many offspring. This evolutionary trade-off between fertility and body maintenance, based on the theory of r/K-selection, is a central theme in the theory of life history regulation. This trade-off is not only found between various species but also between individuals within one species. There is accumulating evidence for this trade-off in humans. We hypothesize that the innate immune system is a critical factor skewing an individual into the direction of either a high fertility or better maintenance strategy. As over thousands of years human survival has been highly dependent on resistance to infectious diseases, genetic adaptations resulting in inflammatory responses were favored. An inflammatory host response is critical to fight infection necessary to survive up to reproductive age. An inflammatory host response is also negatively associated with fertility and can explain for the trade-off between fertility and body maintenance. After human reproductive age, these inflammatory responses contribute also to development of chronic degenerative diseases. These will especially become apparent in affluent societies where the majority of individuals reach old age. Identifying the inflammatory host response as a critical factor both in the regulation of human life histories and in the occurrence of chronic diseases at old age implies means for intervention allowing individuals to live healthier for longer.

  14. Young adult patients with a history of pediatric disease: impact on course of life and transition into adulthood

    NARCIS (Netherlands)

    Stam, Heleen; Hartman, Esther E.; Deurloo, Jacqueline A.; Groothoff, Jaap; Grootenhuis, Martha A.

    2006-01-01

    PURPOSE: To assess the course of life of young adults who grew up with a chronic or life-threatening disease, and to compare their course of life with that of peers from the general population. Optimal transition from pediatric to adult health care requires knowledge of the psychosocial history of

  15. Characteristics of Prison Hospice Patients: Medical History, Hospice Care, and End-of-Life Symptom Prevalence.

    Science.gov (United States)

    Cloyes, Kristin G; Berry, Patricia H; Martz, Kim; Supiano, Katherine

    2015-07-01

    Increasing numbers of prisoners in the United States are dying from age-related and chronic illnesses while incarcerated. This study is among the first to document characteristics of a population of prison hospice patients. Retrospective review of medical records for all patients admitted to the Louisiana State Penitentiary prison hospice program between January 1, 2004, and May 31, 2012 (N = 79) examined demographics, medical history, hospice diagnosis, length of stay, and end-of-life symptom prevalence on admission and during final 72 hours before death. Resulting data were contrasted with community-based end-of-life care study data, demonstrating a unique clinical profile of this group. As prisons consider adopting programs to meet the growing need for inmate end-of-life care, more research concerning the particular characteristics and unique needs of prison hospice patients will inform these efforts. © The Author(s) 2015.

  16. The roles of life-history selection and sexual selection in the adaptive evolution of mating behavior in a beetle.

    Science.gov (United States)

    Maklakov, Alexei A; Cayetano, Luis; Brooks, Robert C; Bonduriansky, Russell

    2010-05-01

    Although there is continuing debate about whether sexual selection promotes or impedes adaptation to novel environments, the role of mating behavior in such adaptation remains largely unexplored. We investigated the evolution of mating behavior (latency to mating, mating probability and duration) in replicate populations of seed beetles Callosobruchus maculatus subjected to selection on life-history ("Young" vs. "Old" reproduction) under contrasting regimes of sexual selection ("Monogamy" vs. "Polygamy"). Life-history selection is predicted to favor delayed mating in "Old" females, but sexual conflict under polygamy can potentially retard adaptive life-history evolution. We found that life-history selection yielded the predicted changes in mating behavior, but sexual selection regime had no net effect. In within-line crosses, populations selected for late reproduction showed equally reduced early-life mating probability regardless of mating system. In between-line crosses, however, the effect of life-history selection on early-life mating probability was stronger in polygamous lines than in monogamous ones. Thus, although mating system influenced male-female coevolution, removal of sexual selection did not affect the adaptive evolution of mating behavior. Importantly, our study shows that the interaction between sexual selection and life-history selection can result in either increased or decreased reproductive divergence depending on the ecological context.

  17. Multidisciplinary perspectives on the history of human interactions with life in the ocean

    DEFF Research Database (Denmark)

    MacDiarmid, Alison; MacKenzie, Brian; Ojaveer, Henn

    2016-01-01

    There is an essentially circular interaction between the human social system and the marine ecosystem. The Oceans Past V Conference "Multidisciplinary perspectives on the history of human interactions with life in the ocean" held in Tallinn, Estonia, in May 2015 was an opportunity for the present......There is an essentially circular interaction between the human social system and the marine ecosystem. The Oceans Past V Conference "Multidisciplinary perspectives on the history of human interactions with life in the ocean" held in Tallinn, Estonia, in May 2015 was an opportunity...... volume of the ICES JMS and highlight issues which arose during general discussion. We make two conclusions. First, to have greater impact and ensure more efficient use of knowledge gained from marine historical ecology (MHE) and marine environmental history (MEH) in ecosystem-based management and related...... policy development, practitioners need to work more routinely with population and ecological modellers and statisticians. This will allow greater processing of the available historical data to derive ecologically meaningful properties that can then be used to assess the ecological impact of long...

  18. Rapid evolution of parasite life history traits on an expanding range-edge.

    Science.gov (United States)

    Kelehear, Crystal; Brown, Gregory P; Shine, Richard

    2012-04-01

    Parasites of invading species undergoing range advance may be exposed to powerful new selective forces. Low host density in range-edge populations hampers parasite transmission, requiring the parasite to survive longer periods in the external environment before encountering a potential host. These conditions should favour evolutionary shifts in offspring size to maximise parasite transmission. We conducted a common-garden experiment to compare life history traits among seven populations of the nematode lungworm (Rhabdias pseudosphaerocephala) spanning from the parasite population core to the expanding range-edge in invasive cane toads (Rhinella marina) in tropical Australia. Compared to conspecifics from the population core, nematodes from the range-edge exhibited larger eggs, larger free-living adults and larger infective larvae, and reduced age at maturity in parasitic adults. These results support a priori predictions regarding adaptive changes in offspring size as a function of invasion history, and suggest that parasite life history traits can evolve rapidly in response to the selective forces exerted by a biological invasion. © 2012 Blackwell Publishing Ltd/CNRS.

  19. Revealing life-history traits by contrasting genetic estimations with predictions of effective population size.

    Science.gov (United States)

    Greenbaum, Gili; Renan, Sharon; Templeton, Alan R; Bouskila, Amos; Saltz, David; Rubenstein, Daniel I; Bar-David, Shirli

    2017-12-22

    Effective population size, a central concept in conservation biology, is now routinely estimated from genetic surveys, and can also be theoretically-predicted from demographic, life-history and mating-system hypotheses. However, by evaluating the consistency of theoretical predictions with empirically-estimated effective size, insights can be gained regarding life-history characteristics, as well as the relative impact of different life-history traits on genetic drift. These insights can be used to design and inform management strategies aimed at increasing effective population size. Here we describe and demonstrate this approach by addressing the conservation of a reintroduced population of Asiatic wild ass (Equus hemionus). We estimate the variance effective size (N ev ) from genetic data (N ev = 24.3), and we formulate predictions for the impacts on N ev of demography, polygyny, female variance in life-time reproductive success, and heritability of female reproductive success. By contrasting the genetic estimation with theoretical predictions, we find that polygyny is the strongest factor effecting genetic drift, as only when accounting for polygyny were predictions consistent with the genetically-measured N ev , with 10.6% mating males per generation when heritability of female RS was unaccounted for (polygyny responsible for 81% decrease in N ev ), and 19.5% when it was accounted for (polygyny responsible for 67% decrease in N ev ). Heritability of female reproductive success was also found to affect N ev , with h f 2 = 0.91 (heritability responsible for 41% decrease in N ev ). The low effective population size is of concern, and we suggest specific management actions focusing on factors identified as strongly affecting N ev -increasing the availability of artificial water sources to increase number of dominant males contributing to the gene pool. This approach - evaluating life-history hypotheses, in light of their impact on effective population size, and

  20. Life history tactics shape amphibians' demographic responses to the North Atlantic Oscillation.

    Science.gov (United States)

    Cayuela, Hugo; Joly, Pierre; Schmidt, Benedikt R; Pichenot, Julian; Bonnaire, Eric; Priol, Pauline; Peyronel, Olivier; Laville, Mathias; Besnard, Aurélien

    2017-11-01

    Over the last three decades, climate abnormalities have been reported to be involved in biodiversity decline by affecting population dynamics. A growing number of studies have shown that the North Atlantic Oscillation (NAO) influences the demographic parameters of a wide range of plant and animal taxa in different ways. Life history theory could help to understand these different demographic responses to the NAO. Indeed, theory states that the impact of weather variation on a species' demographic traits should depend on its position along the fast-slow continuum. In particular, it is expected that NAO would have a higher impact on recruitment than on adult survival in slow species, while the opposite pattern is expected occur in fast species. To test these predictions, we used long-term capture-recapture datasets (more than 15,000 individuals marked from 1965 to 2015) on different surveyed populations of three amphibian species in Western Europe: Triturus cristatus, Bombina variegata, and Salamandra salamandra. Despite substantial intraspecific variation, our study revealed that these three species differ in their position on a slow-fast gradient of pace of life. Our results also suggest that the differences in life history tactics influence amphibian responses to NAO fluctuations: Adult survival was most affected by the NAO in the species with the fastest pace of life (T. cristatus), whereas recruitment was most impacted in species with a slower pace of life (B. variegata and S. salamandra). In the context of climate change, our findings suggest that the capacity of organisms to deal with future changes in NAO values could be closely linked to their position on the fast-slow continuum. © 2017 John Wiley & Sons Ltd.

  1. Evolution of senescence in nature: physiological evolution in populations of garter snake with divergent life histories.

    Science.gov (United States)

    Robert, Kylie A; Bronikowski, Anne M

    2010-02-01

    Evolutionary theories of aging are linked to life-history theory in that age-specific schedules of reproduction and survival determine the trajectory of age-specific mutation/selection balances across the life span and thus the rate of senescence. This is predicted to manifest at the organismal level in the evolution of energy allocation strategies of investing in somatic maintenance and robust stress responses in less hazardous environments in exchange for energy spent on growth and reproduction. Here we report experiments from long-studied populations of western terrestrial garter snakes (Thamnophis elegans) that reside in low and high extrinsic mortality environments, with evolved long and short life spans, respectively. Laboratory common-environment colonies of these two ecotypes were tested for a suite of physiological traits after control and stressed gestations. In offspring derived from control and corticosterone-treated dams, we measured resting metabolism; mitochondrial oxygen consumption, ATP and free radical production rates; and erythrocyte DNA damage and repair ability. We evaluated whether these aging biomarkers mirrored the evolution of life span and whether they were sensitive to stress. Neonates from the long-lived ecotype (1) were smaller, (2) consumed equal amounts of oxygen when corrected for body mass, (3) had DNA that damaged more readily but repaired more efficiently, and (4) had more efficient mitochondria and more efficient cellular antioxidant defenses than short-lived snakes. Many ecotype differences were enhanced in offspring derived from stress-treated dams, which supports the conclusion that nongenetic maternal effects may further impact the cellular stress defenses of offspring. Our findings reveal that physiological evolution underpins reptilian life histories and sheds light on the connectedness between stress response and aging pathways in wild-dwelling organisms.

  2. Macroevolution of hyperdiverse flightless beetles reflects the complex geological history of the Sunda Arc.

    Science.gov (United States)

    Tänzler, Rene; Van Dam, Matthew H; Toussaint, Emmanuel F A; Suhardjono, Yayuk R; Balke, Michael; Riedel, Alexander

    2016-01-08

    The Sunda Arc forms an almost continuous chain of islands and thus a potential dispersal corridor between mainland Southeast Asia and Melanesia. However, the Sunda Islands have rather different geological histories, which might have had an important impact on actual dispersal routes and community assembly. Here, we reveal the biogeographical history of hyperdiverse and flightless Trigonopterus weevils. Different approaches to ancestral area reconstruction suggest a complex east to west range expansion. Out of New Guinea, Trigonopterus repeatedly reached the Moluccas and Sulawesi transgressing Lydekker's Line. Sulawesi repeatedly acted as colonization hub for different segments of the Sunda Arc. West Java, East Java and Bali are recognized as distinct biogeographic areas. The timing and diversification of species largely coincides with the geological chronology of island emergence. Colonization was not inhibited by traditional biogeographical boundaries such as Wallace's Line. Rather, colonization patterns support distance dependent dispersal and island age limiting dispersal.

  3. Understanding women's experiences of developing an eating disorder and recovering: a life-history approach.

    Science.gov (United States)

    Patching, Joanna; Lawler, Jocalyn

    2009-03-01

    Qualitative inquiry into eating disorders is burgeoning, offering valuable and innovative insights into various aspects of the condition. This study used life-history interviews with 20 women who had recovered from anorexia nervosa, bulimia nervosa or both and who had remained healthy. The interviews focused on the women's narratives and experience rather than a diagnostic therapeutic model. Three themes of control, connectedness and conflict emerged as significant in the development, experience of, and recovery from an eating disorder. The development of the condition was attributed to a lack of control, a sense of non-connectedness to family and peers and extreme conflict with significant others. Recovery occurred when the women re-engaged with life, developed skills necessary for conflict resolution and rediscovered their sense of self. Rather than viewing the development of, and recovery from an eating disorder as separate and discrete events, the data from the life-history interviews suggest they are better viewed as one entity - that is, the journey of an individual attempting to discover and develop their sense of self. This perspective challenges some current constructs of eating disorders; it is not a condition in and of itself but a symptom of deeper issues that if addressed, when the individual is 'ready' to make that choice, will lead to recovery.

  4. Life history comparison of two terrestrial isopods in relation to habitat specialization

    Science.gov (United States)

    Quadros, Aline Ferreira; Caubet, Yves; Araujo, Paula Beatriz

    2009-03-01

    For many animal species, there is a relationship between life history strategies, as predicted by the r- K-selection theory, degree of habitat specialization and response to habitat alteration and loss. Here we compare two sympatric woodlice species with contrasting patterns of habitat use and geographical distribution. We predict that Atlantoscia floridana (Philosciidae), considered a habitat generalist, would exhibit the r-selected traits, whereas Balloniscus glaber (Balloniscidae), considered a habitat specialist, should have the K-selected traits. We analyzed several life history traits as well as life and fecundity tables using 715 and 842 females of A. floridana and B. glaber, respectively, from populations living in syntopy in southern Brazil. As predicted, most evaluated traits allow A. floridana to be considered an r-strategist and B. glaber a K-strategist: A. floridana showed a shorter lifetime, faster development, earlier reproduction, a smaller parental investment, higher net reproductive rate ( R0), a higher growth rate ( r) and a shorter generation time ( T) in comparison to B. glaber. A. floridana seems to be a successful colonizer with a high reproductive output. These characteristics explain its local abundance, commonness and wide geographical distribution. On the contrary, B. glaber has a restricted geographical distribution that is mainly associated with Atlantic forest fragments, a biome threatened by deforestation and replacement by monocultures. Its narrow distribution combined with the K-selected traits may confer to this species an increased extinction risk.

  5. [Life expectancy, strenuous work and pension system's fairness. First evidence from the Work Histories Italian Panel].

    Science.gov (United States)

    Leombruni, Roberto; Richiardi, Matteo; Demaria, Moreno; Costa, Giuseppe

    2010-01-01

    the study aims to estimate the differentials in life expectancy by income and work history in Italy during the 2000's, in order to evaluate the level of actuarial equity of the recent Italian retirement reform in computing benefits proportional to the contributions paid. retrospective cohort study. mortality follow up of a 1% sample of the Italian workforce employed or self employed in the private sector, retired between 1985 and 2003 (about 63,000 people), whose work history and income since 1985 is registered in the National Institute for Social Insurance (INPS) data base. mortality differentials computed through Cox model. social inequalities in survival in favour of the more advantaged categories of income and occupational classes are observed. the principle of actuarial equity assumes that life expectancy varies only according to age and birth cohort; nevertheless inequalities in life expectancy exist also along other dimensions, like income and occupational class: this means that the system is producing an opposite redistribution, from the careers more socially disadvantaged to the less disadvantaged ones.

  6. Life history traits influence in gonad composition of two sympatric species of flatfish

    Directory of Open Access Journals (Sweden)

    Juan Luis Gadea Alvarez

    2015-09-01

    Full Text Available AbstractParalichthys orbignyanus and Paralichthys patagonicus are flatfish with different life history traits, having in common the condition of breeding in seawater. Paralichthys patagonicus remain their whole life in open seawater and Paralichthys orbignyanus are sometimes found in brackish water bodies. As marine and estuarine food webs have different fatty acid (FA compositions, the aim of this study was to characterize the gonadal maturation of P. orbignyanus and P. patagonicus females through the analysis of lipid content and FA profile in order to understand to what extent life history traits are reflected in the ovarian composition. During gonadal maturation lipid content increased and FA profiles changed in both species, but the lipid increase was greater in P. orbignyanus. The N-3FA and n-3HUFA proportions increased in both species but were higher in P. orbignyanus. The differences between the lifestyles of these species were reflected in the ovarian FA profile mainly as a result of differences in their FA metabolism, causing a greater accumulation of n-3FA and n-3HUFA in P. orbignyanus than in P. patagonicus. The higher lipid accumulation in P. orbignyanus’ ovaries could indicate that this species, feeding in brackish water bodies, has the possibility of storing more energy than P. patagonicus.

  7. Growing up in the Ocean: Complex Life Cycles of Common Marine Invertebrates

    Science.gov (United States)

    Bennett, Katie; Hiebert, Laurel

    2010-01-01

    Most people are familiar with the concept that animals come in all shapes and sizes and that the body plan of some animals can completely transform during their lifetime. Well-known examples of such complex life cycles of terrestrial animals include butterflies and frogs. Many people are unaware, however, that complex life cycles are exceedingly…

  8. Probabilities in quantum cosmological models: A decoherent histories analysis using a complex potential

    International Nuclear Information System (INIS)

    Halliwell, J. J.

    2009-01-01

    In the quantization of simple cosmological models (minisuperspace models) described by the Wheeler-DeWitt equation, an important step is the construction, from the wave function, of a probability distribution answering various questions of physical interest, such as the probability of the system entering a given region of configuration space at any stage in its entire history. A standard but heuristic procedure is to use the flux of (components of) the wave function in a WKB approximation. This gives sensible semiclassical results but lacks an underlying operator formalism. In this paper, we address the issue of constructing probability distributions linked to the Wheeler-DeWitt equation using the decoherent histories approach to quantum theory. The key step is the construction of class operators characterizing questions of physical interest. Taking advantage of a recent decoherent histories analysis of the arrival time problem in nonrelativistic quantum mechanics, we show that the appropriate class operators in quantum cosmology are readily constructed using a complex potential. The class operator for not entering a region of configuration space is given by the S matrix for scattering off a complex potential localized in that region. We thus derive the class operators for entering one or more regions in configuration space. The class operators commute with the Hamiltonian, have a sensible classical limit, and are closely related to an intersection number operator. The definitions of class operators given here handle the key case in which the underlying classical system has multiple crossings of the boundaries of the regions of interest. We show that oscillatory WKB solutions to the Wheeler-DeWitt equation give approximate decoherence of histories, as do superpositions of WKB solutions, as long as the regions of configuration space are sufficiently large. The corresponding probabilities coincide, in a semiclassical approximation, with standard heuristic procedures

  9. The life history of Pseudomonas syringae: linking agriculture to earth system processes.

    Science.gov (United States)

    Morris, Cindy E; Monteil, Caroline L; Berge, Odile

    2013-01-01

    The description of the ecology of Pseudomonas syringae is moving away from that of a ubiquitous epiphytic plant pathogen to one of a multifaceted bacterium sans frontières in fresh water and other ecosystems linked to the water cycle. Discovery of the aquatic facet of its ecology has led to a vision of its life history that integrates spatial and temporal scales spanning billions of years and traversing catchment basins, continents, and the planet and that confronts the implication of roles that are potentially conflicting for agriculture (as a plant pathogen and as an actor in processes leading to rain and snowfall). This new ecological perspective has also yielded insight into epidemiological phenomena linked to disease emergence. Overall, it sets the stage for the integration of more comprehensive contexts of ecology and evolutionary history into comparative genomic analyses to elucidate how P. syringae subverts the attack and defense responses of the cohabitants of the diverse environments it occupies.

  10. [Evaluation of quality of life in school children with a history of early severe malnutrition].

    Science.gov (United States)

    De Grandis, E S; Armelini, P A; Cuestas, E

    2014-12-01

    Severe malnutrition in young children may lead to long-term complications, in particular learning and psychosocial disorders linked to health related quality of life (HRQOL). The aim of this study was to evaluate HRQOL in children whit a history of severe malnutrition before 2 years of life, expecting to find lower scores in these patients. A comparative study was performed on schoolchildren between 5 and 12 years with a history of early severe malnutrition, excluding those with chronic diseases. The Controls were healthy siblings of patients. The sample size was estimated as 26 subjects per group (Total=52). Sociodemographic variables were recorded and the HRQOL was assessed with PedsQL4.0. Chi square and Student t test were applied. Significance level: P<.05. A total of 25 patients and 28 controls were studied. The HRQOL scores obtained from PedsQL for children with history of malnutrition, compared with their healthy siblings, were: Total: 80.82±1.94 vs 89.18±1.84 P<.0001), physical health/dimension: 87.75±3.37 vs 94.75±1.87 (P<.0001), psychosocial health: 77.77±2.90 vs 86.57±1.42 (P<.0001), emotional dimension: 67.80±4.40 vs 78.75±2.96 (P<.0001), social dimension: 88.80±3.05 vs 95.71±1.52 (P<.0001), and school dimension: 74.58±3.80 vs 85.00±3.51 (P<.0001). Patients with a history of early severe malnutrition, showed significantly lower HRQOL scores compared with controls. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  11. Model-based estimates of annual survival rate are preferable to observed maximum lifespan statistics for use in comparative life-history studies

    Science.gov (United States)

    Krementz, D.G.; Sauer, J.R.; Nichols, J.D.

    1989-01-01

    Estimates of longevity are available for many animals, and are commonly used in comparative life-history analyses. We suggest that annual survival rate is more appropriate life history parameter for most comparative life history analyses. Observed maximum longevities were not correlated with the annual survival rate estimates and appear to be unstable over time. We recommend that observed maximum lifespans not be used in life history analyses.

  12. Self-Complexity, Daily Events, and Perceived Quality of Life.

    Science.gov (United States)

    Kardash, CarolAnne M.; Okun, Morris A.

    Recent research has demonstrated that self-cognitions can play an important role in physical and emotional well-being. One important aspect of self-cognition concerns the complexity of self-representations. This study tested the hypothesis that self-complexity, as assessed by Linville's self-trait sorting task, would moderate the effects of…

  13. Habits of the heart: life history and the developmental neuroendocrinology of emotion.

    Science.gov (United States)

    Worthman, Carol M

    2009-01-01

    The centrality of emotion in cognition and social intelligence as well as its impact on health has intensified investigation into the causes and consequences of individual variation in emotion regulation. Central processing of experience directly informs regulation of endocrine axes, essentially forming a neuro-endocrine continuum integrating information intake, processing, and physiological and behavioral response. Two major elements of life history-resource allocation and niche partitioning-are served by linking cognitive-affective with physiologic and behavioral processes. Scarce cognitive resources (attention, memory, and time) are allocated under guidance from affective co-processing. Affective-cognitive processing, in turn, regulates physiologic activity through neuro-endocrine outflow and thereby orchestrates energetic resource allocation and trade-offs, both acutely and through time. Reciprocally, peripheral activity (e.g., immunologic, metabolic, or energetic markers) influences affective-cognitive processing. By guiding attention, memory, and behavior, affective-cognitive processing also informs individual stances toward, patterns of activity in, and relationships with the world. As such, it mediates processes of niche partitioning that adaptively exploit social and material resources. Developmental behavioral neurobiology has identified multiple factors that influence the ontogeny of emotion regulation to form affective and behavioral styles. Evidence is reviewed documenting roles for genetic, epigenetic, and experiential factors in the development of emotion regulation, social cognition, and behavior with important implications for understanding mechanisms that underlie life history construction and the sources of differential health. Overall, this dynamic arena for research promises to link the biological bases of life history theory with the psychobehavioral phenomena that figure so centrally in quotidian experience and adaptation, particularly, for

  14. Nematode parasite diversity in birds: the role of host ecology, life history and migration.

    Science.gov (United States)

    Leung, Tommy L F; Koprivnikar, Janet

    2016-11-01

    Previous studies have found that migratory birds generally have a more diverse array of pathogens such as parasites, as well as higher intensities of infection. However, it is not clear whether this is driven by the metabolic and physiological demands of migration, differential selection on host life-history traits or basic ecological differences between migratory and non-migratory species. Parasitic helminths can cause significant pathology in their hosts, and many are trophically transmitted such that host diet and habitat use play key roles in the acquisition of infections. Given the concurrent changes in avian habitats and migratory behaviour, it is critical to understand the degree to which host ecology influences their parasite communities. We examined nematode parasite diversity in 153 species of Anseriformes (water birds) and Accipitriformes (predatory birds) in relation to their migratory behaviour, diet, habitat use, geographic distribution and life history using previously published data. Overall, migrators, host species with wide geographic distributions and those utilizing multiple aquatic habitats had greater nematode richness (number of species), and birds with large clutches harboured more diverse nematode fauna with respect to number of superfamilies. Separate analyses for each host order found similar results related to distribution, habitat use and migration; however, herbivorous water birds played host to a less diverse nematode community compared to those that consume some animals. Birds using multiple aquatic habitats have a more diverse nematode fauna relative to primarily terrestrial species, likely because there is greater opportunity for contact with parasite infectious stages and/or consumption of infected hosts. As such, omnivorous and carnivorous birds using aquatic habitats may be more affected by environmental changes that alter their diet and range. Even though there were no overall differences in their ecology and life history

  15. Cellular Metabolic Rate Is Influenced by Life-History Traits in Tropical and Temperate Birds

    Science.gov (United States)

    Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B.

    2014-01-01

    In general, tropical birds have a “slow pace of life,” lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal’s life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species. PMID:24498080

  16. A continuum of life histories in deep-sea demersal fishes

    Science.gov (United States)

    Drazen, Jeffrey C.; Haedrich, Richard L.

    2012-03-01

    It is generally perceived that all deep-sea fishes have great longevity, slow growth, and low reproductive output in comparison to shelf dwelling species. However, such a dichotomy is too simplistic because some fishes living on continental slopes are relatively fecund and fast growing, important considerations in respect to the management of expanding deep-sea fisheries. We tested two hypotheses that might explain variation in life history attributes of commercially exploited demersal fishes: (1) phylogeny best explains the differences because deep-sea species are often in different families from shelf dwelling ones and, alternatively, (2) environmental factors affecting individual life history attributes that change with depth account for the observed variation. Our analysis was based on 40 species from 9 orders, including all major commercially exploited deep-sea fishes and several phylogenetically related shelf species. Depth of occurrence correlated significantly with age at 50% maturity increasing linearly with depth (r2=0.46), while the von Bertalanffy growth coefficient, maximum fecundity and potential rate of population increase declined significantly and exponentially with depth (r2=0.41, 0.25 and 0.53, respectively). These trends were still significant when phylogenetically independent contrasts were applied. The trends were also consistent with similar slopes amongst members of the order Gadiformes and the order Scorpaeniformes. Reduced temperatures, predation pressure, food availability, or metabolic rates may all contribute to such changes with depth. Regardless of the mechanisms, by analyzing a suite of fishes from the shelves to the slope the present analysis has shown that rather than a simple dichotomy between deep-sea fishes and shelf fishes there is a continuum of life history attributes in fishes which correlate strongly with depth of occurrence.

  17. Host-Parasite Relationships and Life Histories of Trypanosomes in Australia.

    Science.gov (United States)

    Cooper, C; Clode, P L; Peacock, C; Thompson, R C A

    2017-01-01

    Trypanosomes constitute a group of flagellate protozoan parasites responsible for a number of important, yet neglected, diseases in both humans and livestock. The most significantly studied include the causative agents of African sleeping sickness (Trypanosoma brucei) and Chagas disease (Trypanosoma cruzi) in humans. Much of our knowledge about trypanosome host-parasite relationships and life histories has come from these two human pathogens. Recent investigations into the diversity and life histories of wildlife trypanosomes in Australia highlight that there exists a great degree of biological and behavioural variation within and between trypanosomes. In addition, the genetic relationships between some Australian trypanosomes show that they are unexpectedly more closely related to species outside Australia than within it. These findings have led to a growing focus on the importance of understanding parasites occurring naturally in wildlife to (1) better document parasite biodiversity, (2) determine evolutionary relationships and degree of host specificity, (3) understand host-parasite interactions and the role of parasites in the natural ecosystem and (4) identify biosecurity issues of emerging disease in both wildlife and human populations. Here we review what is known about the diversity, life histories, host-parasite interactions and evolutionary relationships of trypanosomes in Australian wildlife. In this context, we focus upon the genetic proximity of key Australian species to the pathogenic T. cruzi and discuss similarities in their biology and behaviour that present a potential risk of human disease transmission by Australian vectors and wildlife. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Effect of watermelon silver mottle virus on the life history and feeding preference of Thrips palmi.

    Directory of Open Access Journals (Sweden)

    Wei-Te Chen

    Full Text Available Thrips-borne tospoviruses cause numerous plant diseases that produce severe economic losses worldwide. In the disease system, thrips not only damage plants through feeding but also transmit causative agents of epidemics. In addition, thrips are infected with tospoviruses in the course of virus transmission. Most studies on the effect of tospoviruses on vector thrips have focused on the Tomato spotted wilt virus-Frankliniella occidentalis system. Thus, we focused on another thrips-borne tospovirus, Watermelon silver mottle virus (WSMoV, to examine the effect of virus infection on its vector, Thrips palmi. In this study, the direct and indirect effects of WSMoV on the life history traits and feeding preference of T. palmi were examined. The survival rate and developmental time of the WSMoV-infected larval thrips did not differ significantly from those of the virus-free thrips. Comparing the developmental time of larval thrips fed on the healthy plants, thrips-damaged plants, and thrips-inoculated plants (the WSMoV-infected plants caused by thrips feeding, feeding on the thrips-damaged plants reduced the developmental time, and the WSMoV infection in host plants partially canceled the effect of thrips damage on the developmental time. In addition, no significant variations between the virus-free and WSMoV-infected adult thrips regarding longevity and fecundity were observed. These results implied that WSMoV did not directly affect the life history traits of T. palmi, but the WSMoV infection indirectly affected the development of T. palmi through the virus-infected plants. Furthermore, feeding preference tests indicated that T. palmi preferred feeding on either the thrips-damaged plants or the thrips-inoculated plants to the healthy plants. The effect of tospoviruses on the life history and feeding preference of vector thrips might vary among host plants, virus species, vector species, and environmental factors.

  19. The life of concepts: Georges Canguilhem and the history of science.

    Science.gov (United States)

    Schmidgen, Henning

    2014-01-01

    Twelve years after his famous Essay on Some Problems Concerning the Normal and the Pathological (1943), the philosopher Georges Canguilhem (1904-1995) published a book-length study on the history of a single biological concept. Within France, his Formation of the Reflex Concept in the Seventeenth and Eighteenth Centuries (1955) contributed significantly to defining the "French style" of writing on the history of science. Outside of France, the book passed largely unnoticed. This paper re-reads Canguilhem's study of the reflex concept with respect to its historiographical and epistemological implications. Canguilhem defines concepts as complex and dynamic entities combining terms, definitions, and phenomena. As a consequence, the historiography of science becomes a rather complex task. It has to take into account textual and contextual aspects that develop independently of individual authors. In addition, Canguilhem stresses the connection between conceptual activities and other functions of organic individuals in their respective environments. As a result, biological concepts become tied to a biology of conceptual thinking, analogical reasoning, and technological practice. The paper argues that this seemingly circular structure is a major feature in Canguilhem's philosophical approach to the history of the biological sciences.

  20. Post-Mastectomy and Phantom Breast Pain: Risk Factors, Natural History, and Impact on Quality of Life

    National Research Council Canada - National Science Library

    Dworkin, Robert

    1999-01-01

    ... from substantial reductions in quality of life. The primary aims of this research project are to identify risk factors for these chronic pain syndromes following surgical procedures for breast cancer, characterize their natural history...

  1. Description of the immature stages and life history of Euselasia (Lepidoptera: Riodinidae) on Miconia (Melastomataceae) in Costa Rica

    Science.gov (United States)

    K. Nishida

    2010-01-01

    The immature stages and life histories of Euselasia chrysippe (Bates, 1866) and E. bettina (Hewitson, 1869) are described, providing the first detailed morphological characters for the subfamily Euselasiinae. The larvae of Euselasia chrysippe and E. bettina ...

  2. Aggradational and erosional history of the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Dechert, T.V.; McDaniel, P.A.; Falen, A.L.

    1994-09-01

    Long-term performance of the low-level waste disposal site at the Radioactive Waste Management Complex (RWMC) is partially dependent on the stability of the land surface with respect to erosion of cover materials. This document discusses the aggradational and erosional history of the naturally occurring sediments and soils in and around the RWMC, focusing on the late-Pleistocene and Holocene epochs. Other related issues include the ages of the various deposits, the extent to which they have been altered by soil formation and other processes, their relationships to the basalt flows in the area, and the impact of human activity on the materials at the RWMC

  3. Aggradational and erosional history of the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Dechert, T.V.; McDaniel, P.A.; Falen, A.L. [Idaho Univ., Moscow, ID (United States)

    1994-09-01

    Long-term performance of the low-level waste disposal site at the Radioactive Waste Management Complex (RWMC) is partially dependent on the stability of the land surface with respect to erosion of cover materials. This document discusses the aggradational and erosional history of the naturally occurring sediments and soils in and around the RWMC, focusing on the late-Pleistocene and Holocene epochs. Other related issues include the ages of the various deposits, the extent to which they have been altered by soil formation and other processes, their relationships to the basalt flows in the area, and the impact of human activity on the materials at the RWMC.

  4. History of science, physics, and art: a complex approach in Brazilian syllabuses

    Science.gov (United States)

    Braga, Marco; Guerra, Andreia; Reis, José Claudio

    2013-09-01

    This paper is about new contents that can be introduced into science education. It is a description of an experience aimed at introducing a complex approach into the final grade of a Brazilian elementary school. The aim is to show the transformation of the conception of space and time from the Middle Ages with the physics of Aristotle to the 20th century, when a new conception arose with the physics of Einstein. These changes were accompanied by new visions of space and time in both physics and arts. Comparison between these two expressions of human culture is used to introduce science as a human construct inserted into history.

  5. Mutation accumulation may be a minor force in shaping life history traits

    DEFF Research Database (Denmark)

    Dańko, Maciej Jan; Kozłowski, Jan; Vaupel, James Walton

    2012-01-01

    Is senescence the adaptive result of tradeoffs between younger and older ages or the nonadaptive burden of deleterious mutations that act at older ages? To shed new light on this unresolved question we combine adaptive and nonadaptive processes in a single model. Our model uses Penna's bit......-frequencies is reached. The mutation-selection equilibrium provides information about mutational load and the differential effects of mutations on a life history trait--the optimal age at maturity. We find that mutations accumulate only at ages with negligible impact on fitness and that mutation accumulation has very...

  6. Stochastic population dynamics in populations of western terrestrial garter snakes with divergent life histories.

    Science.gov (United States)

    Miller, David A; Clark, William R; Arnold, Stevan J; Bronikowski, Anne M

    2011-08-01

    Comparative evaluations of population dynamics in species with temporal and spatial variation in life-history traits are rare because they require long-term demographic time series from multiple populations. We present such an analysis using demographic data collected during the interval 1978-1996 for six populations of western terrestrial garter snakes (Thamnophis elegans) from two evolutionarily divergent ecotypes. Three replicate populations from a slow-living ecotype, found in mountain meadows of northeastern California, were characterized by individuals that develop slowly, mature late, reproduce infrequently with small reproductive effort, and live longer than individuals of three populations of a fast-living ecotype found at lakeshore locales. We constructed matrix population models for each of the populations based on 8-13 years of data per population and analyzed both deterministic dynamics based on mean annual vital rates and stochastic dynamics incorporating annual variation in vital rates. (1) Contributions of highly variable vital rates to fitness (lambda(s)) were buffered against the negative effects of stochastic variation, and this relationship was consistent with differences between the meadow (M-slow) and lakeshore (L-fast) ecotypes. (2) Annual variation in the proportion of gravid females had the greatest negative effect among all vital rates on lambda(s). The magnitude of variation in the proportion of gravid females and its effect on lambda(s) was greater in M-slow than L-fast populations. (3) Variation in the proportion of gravid females, in turn, depended on annual variation in prey availability, and its effect on lambda(s) was 4 23 times greater in M-slow than L-fast populations. In addition to differences in stochastic dynamics between ecotypes, we also found higher mean mortality rates across all age classes in the L-fast populations. Our results suggest that both deterministic and stochastic selective forces have affected the evolution of

  7. [Martin Luther's somatic diseases. A short life-history 450 years after his death].

    Science.gov (United States)

    Iversen, O H

    1996-12-10

    The article contains a short life-history of the religious reformer Martin Luther (1483-1546) with main emphasis on his many somatic diseases. The list comprises varicose ulcer, angina pectoris with anxiety, obesity, hypertension arterialis, Ménière's disease with vertigo, tinnitus and fainting fits, gastralgia, constipation with anal ulcers and haemorrhoids with bleeding, urolithiasis, arthritis urica, Roemheld's syndrome, and cataract in one eye. Mentally he had a manic-depressive cast of personality, and a tendency to emotional lability. In spite of this he had an enormous capacity for work.

  8. Light intensity controls anti-predator defences in Daphnia: the suppression of life-history changes

    OpenAIRE

    Effertz, Christoph; von Elert, Eric

    2014-01-01

    A huge variety of organisms respond to the presence of predators with inducible defences, each of which is associated with costs. Many genotypes have the potential to respond with more than one defence, and it has been argued that it would be maladaptive to exhibit all possible responses at the same time. Here, we test how a well-known anti-fish defence in Daphnia, life-history changes (LHC), is controlled by light. We show that the kairomone-mediated reduction in size at first reproduction i...

  9. Phylogeny and evolution of life history strategies of the Parasitic Barnacles (Crustacea, Cirripedia, Rhizocephala)

    DEFF Research Database (Denmark)

    Glenner, Henrik; Hebsgaard, Martin Bay

    2006-01-01

    to resolve the phylogenetic relationship of the order Rhizocephala and elucidate the evolution of the different life history strategies found within the Rhizocephala, we have performed the first comprehensive phylogenetic analysis of the group. Our results indicate that Rhizocephala is monophyletic...... in the suborder Akentrogonida, where the last pelagic larval stage directly injects the parasitic material into the heamolymph of the host is derived, and has evolved only once within the Rhizocephala. Lastly, our results show that the ancestral host for extant rhizocephalans appears to be the anomuran...

  10. Survival trees: an alternative non-parametric multivariate technique for life history analysis.

    Science.gov (United States)

    De Rose, A; Pallara, A

    1997-01-01

    "In this paper an extension of tree-structured methodology to cover censored survival analysis is discussed.... The tree-shaped diagram...can be used to draw meaningful patterns of behaviour throughout the individual life history.... The fundamentals of tree methodology are outlined; [then] an application of the technique to real data from a survey on the progression to marriage among adult women in Italy is illustrated; [and] some comments are presented on the main advantages and problems related to tree-structured methodology for censored survival analysis." (EXCERPT)

  11. The major stressful life events and cancer: stress history and cancer.

    Science.gov (United States)

    Tas, Faruk; Karalar, Umran; Aliustaoglu, Mehmet; Keskin, Serkan; Can, Gulbeyaz; Cinar, Fatma Ebru

    2012-06-01

    The objective of this study was to analyze the extent of stressful life events' etiology and to compare socio-demographic and medical characteristics of the presence and absence of stress in Turkish cancer patients. Patients with cancer who attended ambulatory patient care units answered the questionnaires. Medical information was reviewed from chart data. The study population comprised 465 women (60.5%) and 303 men (39.5%), in total 768 cases. The median age was 53 years, ranging between 18 and 94. Three-hundred and twenty patients (41.7%) had at least one type of stress since last year of the time of initial diagnosis. Among patients had stress, the median number of stress modalities presented was 1 (range 1-6). Death, lack of livelihood, quarrel, illness, and debt almost always consisted of stress types. History of stress within last year was found more in women (66.3% vs. 56.5%, P = 0.006) and overweight patients (57.5% vs. 47.2%, P = 0.005). Similarly, among cancer types, only patients with breast cancer (41.9% vs. 31.7%, P = 0.04) had lived more stressful situation. However, the married patients (72.2% vs. 80.6%, P = 0.03) had less stress. Patients with gastric cancer had more frequent debt (29.0%, P history (21.4%, P = 0.001). Additionally, in lung cancer patients, their rate of livelihood difficulty was highly less than average (2.4%, P = 0.003). We found that overweight patients had more illness history (68.9% vs. 51.6%, P = 0.004), patients who were not working had more death history (89.7% vs. 78%, P = 0.01), and female patients had more quarrel history (78.2% vs. 60.5%, P = 0.002). Likewise, history of debt in patients who is a member of large family (56.2% vs. 27.4%, P = 0.01) was more frequent. Additionally, the lack of livelihood was prominent in urban patients (92.8% vs. 78.6%, P = 0.002) and in patients with low income (48.5% vs. 66.7%, P = 0.004). The question of whether or not psychological factors originated from stressful life events have an

  12. Habitat-specific differences alter traditional biogeographic patterns of life history in a climate-change induced range expansion

    OpenAIRE

    Riley, Megan E.; Griffen, Blaine D.

    2017-01-01

    Range shifts and expansions resulting from global climate change have the potential to create novel communities with unique plant-animal interactions. Organisms expanding their range into novel biotic and abiotic environments may encounter selection pressures that alter traditional biogeographic patterns of life history traits. Here, we used field surveys to examine latitudinal patterns of life history traits in a broadly distributed ectotherm (mangrove tree crab Aratus pisonii) that has rece...

  13. Prediction of Fatigue Life of a Continuous Bridge Girder Based on Vehicle Induced Stress History

    Directory of Open Access Journals (Sweden)

    V.G. Rao

    2003-01-01

    Full Text Available The fatigue damage assessment of bridge components by conducting a full scale fatigue testing is often prohibitive. A need, therefore, exists to estimate the fatigue damage in bridge components by a simulation of bridge-vehicle interaction dynamics due to the action of the actual traffic. In the present paper, a systematic method has been outlined to find the fatigue damage in the continuous bridge girder based on stress range frequency histogram and fatigue strength parameters of the bridge materials. Vehicle induced time history of maximum flexural stresses has been obtained by Monte Carlo simulation process and utilized to develop the stress range frequency histogram taking into consideration of the annual traffic volume. The linear damage accumulation theory is then applied to calculate cumulative damage index and fatigue life of the bridge. Effect of the bridge span, pavement condition, increase of vehicle operating speed, weight and suspension characteristics on fatigue life of the bridge have been examined.

  14. The Lutzomyia longipalpis complex: a brief natural history of aggregation-sex pheromone communication.

    Science.gov (United States)

    Spiegel, Carolina N; Dias, Denise B Dos Santos; Araki, Alejandra S; Hamilton, James G C; Brazil, Reginaldo P; Jones, Théresa M

    2016-11-14

    In this paper we review the natural history of pheromone communication and the current diversity of aggregation-sex pheromones in the sand fly Lutzomyia longipalpis. This species complex is the main vector of Leishmania infantum, the agent of visceral leishmaniasis in the Americas. The identification of variation in pheromone chemotypes combined with molecular and sound analyses have all contributed to our understanding of the extent of divergence among cryptic members of this complex. The importance of chemical signals as pre-mating barriers and drivers of speciation is discussed. Moreover, the importance of aggregation-sex pheromones as sexually selected signals is highlighted with evidence from the literature suggesting their potential role in species and mate recognition as well as mate assessment. The distinct evolutionary forces possibly involved are briefly reviewed and discussed in the context of this intriguing insect.

  15. The Lutzomyia longipalpis complex: a brief natural history of aggregation-sex pheromone communication

    Directory of Open Access Journals (Sweden)

    Carolina N. Spiegel

    2016-11-01

    Full Text Available Abstract In this paper we review the natural history of pheromone communication and the current diversity of aggregation-sex pheromones in the sand fly Lutzomyia longipalpis. This species complex is the main vector of Leishmania infantum, the agent of visceral leishmaniasis in the Americas. The identification of variation in pheromone chemotypes combined with molecular and sound analyses have all contributed to our understanding of the extent of divergence among cryptic members of this complex. The importance of chemical signals as pre-mating barriers and drivers of speciation is discussed. Moreover, the importance of aggregation-sex pheromones as sexually selected signals is highlighted with evidence from the literature suggesting their potential role in species and mate recognition as well as mate assessment. The distinct evolutionary forces possibly involved are briefly reviewed and discussed in the context of this intriguing insect.

  16. (Trans)National Language Ideologies and Family Language Practices: A Life History Inquiry of Judeo-Spanish in Turkey

    Science.gov (United States)

    Seloni, Lisya; Sarfati, Yusuf

    2013-01-01

    This article explores the diminished use of Judeo-Spanish among Jews living in Turkey and asks the following research question: What factors, ideologies, and practices contribute to the demise of Judeo-Spanish? To address this question, we employed life history inquiry based on two oral history archives documenting elderly Turkish-Jewish community…

  17. Mother's Childrearing History and Current Parenting: Patterns of Association and the Moderating Role of Current Life Stress

    Science.gov (United States)

    Hill, Carri; Stein, Jennifer; Keenan, Kate; Wakschlag, Lauren S.

    2006-01-01

    This study examined the association between positive and negative aspects of childrearing history and current parenting and the moderating effect of current stress. Seventy mother-child dyads participated in this study. Mothers provided retrospective reports of childrearing histories and current reports of life stress. Parenting was assessed via…

  18. Life history of the Small Sandeel, Ammodytes tobianus, inferred from otolith microchemistry. A methodological approach

    Science.gov (United States)

    Laugier, F.; Feunteun, E.; Pecheyran, C.; Carpentier, A.

    2015-11-01

    Knowledge of life history and connectivity between essential ecological habitats are relevant for conservation and management of species and some natural tracers could be used to study the lifecycles of small or short-lived marine fishes. Although sandeels are central in marine food webs and are key species, there is incomplete knowledge about population mixing and migration patterns. For the first time the use of the otolith microchemistry on sandeel species is evaluated in the case of the Small Sandeel. Variations in microchemical fingerprints of 13 trace elements are performed with a Femtosecond LA-ICPM from the core to the margin of sagittal otolith and are compared within and between otoliths extracted from 34 fishes sampled in three different sites along the coast of the south-western English Channel in France. Firstly, preliminary investigations on the validity of the method revealed that Mg/Ca was the only ratio significantly dependant on fish ontogeny and sampling season. Secondly, the Mn/Ca, Zn/Ca, and Cu/Ca ratios enabled us to significantly discriminate among sampling sites. Thirdly, microchemical fingerprints of each life stage varied significantly among sampling sites but not within them, suggesting high site fidelity over relatively short distances. Finally, the fingerprints of all life stages were significantly different from those of the larval and metamorphosis stages. The otolith microchemistry could detect change of signature relative to the shift from a pelagic behaviour to a resident bentho-pelagic behaviour during the middle of the juvenile stage in Small Sandeels. Hence, analysis of trace element fingerprints in otoliths appears to be a valuable method to further studies on ontogenic habitat change, population mixing and variation of life history and be helpful for the management at local or regional scales of short-lived species such as those belonging to other Ammodytidae.

  19. Effect of temperature and cultivar on pea aphid, Acyrthosiphon pisum (Hemiptera: Aphididae) life history.

    Science.gov (United States)

    Morgan, D; Walters, K F; Aegerter, J N

    2001-02-01

    Life history parameters of the pea aphid, Acyrthosiphon pisum were studied at five constant temperatures on two cultivars of peas, Scout and Sancho. The development and mortality of juveniles and the life-span, age-specific fecundity and survivorship of adult aphids were recorded and used to construct life tables. The juvenile development period (from birth to adulthood) was longest at 11.9 degrees C (16.8 days on cv. Scout and 16.2 days on cv. Sancho) and shortest at 26.7 degrees C (8.5 days on cv. Scout and 8.8 days on cv. Sancho). At all temperatures, except 26.7 degrees C, juveniles developed faster on cv. Sancho than on cv. Scout. On both pea varieties juvenile mortality was highest at temperatures above 19.6 degrees C and lowest at 19.6 degrees C. Highest cumulative juvenile mortality was recorded on cv. Scout at 26.7 degrees C when only 9% of aphids survived from birth to reproductively mature adults. Fecundity rates were unaffected by temperature in the range tested on cv. Sancho but increased with increasing temperatures between 11.9 and 19.6 degrees C on cv. Scout. These differences in life history parameters were reflected in the population growth (rm) of aphids on both pea cultivars which increased with increasing temperatures between 11.9 and 23.1 degrees C on cv. Sancho and 11.9 and 19.6 degrees C on cv. Scout, declining thereafter. Population growth was consistently greater at all temperatures for aphids reared on cv. Sancho than those reared on cv. Scout.

  20. Climatic and geographic predictors of life history variation in Eastern Massasauga (Sistrurus catenatus: A range-wide synthesis.

    Directory of Open Access Journals (Sweden)

    Eric T Hileman

    Full Text Available Elucidating how life history traits vary geographically is important to understanding variation in population dynamics. Because many aspects of ectotherm life history are climate-dependent, geographic variation in climate is expected to have a large impact on population dynamics through effects on annual survival, body size, growth rate, age at first reproduction, size-fecundity relationship, and reproductive frequency. The Eastern Massasauga (Sistrurus catenatus is a small, imperiled North American rattlesnake with a distribution centered on the Great Lakes region, where lake effects strongly influence local conditions. To address Eastern Massasauga life history data gaps, we compiled data from 47 study sites representing 38 counties across the range. We used multimodel inference and general linear models with geographic coordinates and annual climate normals as explanatory variables to clarify patterns of variation in life history traits. We found strong evidence for geographic variation in six of nine life history variables. Adult female snout-vent length and neonate mass increased with increasing mean annual precipitation. Litter size decreased with increasing mean temperature, and the size-fecundity relationship and growth prior to first hibernation both increased with increasing latitude. The proportion of gravid females also increased with increasing latitude, but this relationship may be the result of geographically varying detection bias. Our results provide insights into ectotherm life history variation and fill critical data gaps, which will inform Eastern Massasauga conservation efforts by improving biological realism for models of population viability and climate change.

  1. Effects of temperature and salinity on life history of the marine amphipod Gammarus locusta. Implications for ecotoxicological testing.

    Science.gov (United States)

    Neuparth, T; Costa, F O; Costa, M H

    2002-02-01

    The life history of Gammarus locusta was analysed in the laboratory under the following temperature and salinity combinations: 20 degrees C-33/1000, 15 degrees C-20/1000 and 15 degrees C-33/1000 (reference condition). Life history analysis comprised survival, individual growth, reproductive traits and life table parameters. Compared to 15 degrees C, life history at 20 degrees C was characterised by at least a four-week reduction in the life-span, lower life expectancy, shorter generation time, faster individual growth, anticipation of age at maturity and higher population growth rate. These temperature effects constituted an acceleration and condensation of the life cycle, compared to the reference condition. Concerning salinity effects, with few exceptions, results show that overall this amphipod life history did not differ significantly between the salinity conditions tested. Regarding ecotoxicological testing implications, findings from this study indicate that the range of temperature and salinity conditions acceptable for testing was substantially expanded both for acute and chronic assays. A temperature of 20 degrees C or higher (for a salinity of 33/1000) is suggested for routine chronic sediment toxicity testing with G. locusta, in order to reduce the life cycle and consequently improve cost-effectiveness and standardisation. Results also suggest that a multiple-response approach, including survival, growth and reproduction, should be applied in chronic toxicity tests.

  2. Physical activity history and end-of-life hospital and long-term care

    DEFF Research Database (Denmark)

    von Bonsdorff, Mikaela B; Rantanen, Taina; Leinonen, Raija

    2009-01-01

    BACKGROUND: Little is known about the early predictors of need for care in late life. The purpose of this study was to investigate whether physical activity from midlife onward was associated with hospital and long-term care in the last year of life. METHODS: We studied a decedent population of 846...... had been consistently physically active, whereas use of long-term care did not correlate with physical activity history. Among women, the risk for long-term care was higher for those who had been sedentary (IRR 2.03, 95% CI 1.28-3.21) or only occasionally physically active (IRR 1.60, 95% CI 1...... 138 days (SD 6.2) of inpatient care in the last year of life. Among men, the risk for all-cause hospital care in the last year of life was higher for those who had been sedentary since midlife (adjusted incidence rate ratio [IRR] 1.98, 95% confidence interval [CI] 1.14-3.42) compared with those who...

  3. Life history traits influence the strength of distance- and density-dependence at different life stages of two Amazonian palms.

    Science.gov (United States)

    Choo, Juanita; Carasco, Cecilia; Alvarez-Loayza, Patricia; Simpson, Beryl B; Economo, Evan P

    2017-07-01

    Natural enemies are known to be important in regulating plant populations and contributing to species coexistence (Janzen-Connell effects). The strength of Janzen-Connell effects (both distance- and density-effects) varies across species, but the life history traits that may mediate such a variation are not well understood. This study examined Janzen-Connell effects across the life stages (seed through adult stages) of two sympatric palm species with distinct phenologies and shade tolerances, two traits that may mediate the strength and timing of Janzen-Connell effects. Populations of two common palm species, Attalea phalerata and Astrocaryum murumuru , were studied in Manu National Park, Peru. Seed predation experiments were conducted to assess Janzen-Connell effects at the seed stage. In the post-seed stages, spatial point pattern analyses of the distributions of individuals and biomass were used to infer the strength of distance- and density-effects. Seed predation was both negative distance- and density-dependent consistent with the Janzen-Connell effects. However, only seedling recruitment for asynchronously fruiting Attalea phalerata was depressed near adults while recruitment remained high for synchronously fruiting Astrocaryum murumuru , consistent with weak distance-effects. Negative density-effects were strong in the early stages for shade-intolerant Attalea phalerata but weak or absent in shade-tolerant Astrocaryum murumuru. Distance- and density-effects varied among the life stages of the two palm species in a manner that corresponded to their contrasting phenology and shade tolerance. Generalizing such connections across many species would provide a route to understanding how trait-mediated Janzen-Connell effects scale up to whole communities of species. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  4. The proteomic complexity and rise of the primordial ancestor of diversified life

    Directory of Open Access Journals (Sweden)

    Kim Kyung

    2011-05-01

    Full Text Available Abstract Background The last universal common ancestor represents the primordial cellular organism from which diversified life was derived. This urancestor accumulated genetic information before the rise of organismal lineages and is considered to be either a simple 'progenote' organism with a rudimentary translational apparatus or a more complex 'cenancestor' with almost all essential biological processes. Recent comparative genomic studies support the latter model and propose that the urancestor was similar to modern organisms in terms of gene content. However, most of these studies were based on molecular sequences, which are fast evolving and of limited value for deep evolutionary explorations. Results Here we engage in a phylogenomic study of protein domain structure in the proteomes of 420 free-living fully sequenced organisms. Domains were defined at the highly conserved fold superfamily (FSF level of structural classification and an iterative phylogenomic approach was used to reconstruct max_set and min_set FSF repertoires as upper and lower bounds of the urancestral proteome. While the functional make up of the urancestral sets was complex, they represent only 5-11% of the 1,420 FSFs of extant proteomes and their make up and reuse was at least 5 and 3 times smaller than proteomes of free-living organisms, repectively. Trees of proteomes reconstructed directly from FSFs or from molecular functions, which included the max_set and min_set as articial taxa, showed that urancestors were always placed at their base and rooted the tree of life in Archaea. Finally, a molecular clock of FSFs suggests the min_set reflects urancestral genetic make up more reliably and confirms diversified life emerged about 2.9 billion years ago during the start of planet oxygenation. Conclusions The minimum urancestral FSF set reveals the urancestor had advanced metabolic capabilities, was especially rich in nucleotide metabolism enzymes, had pathways for the

  5. Patterns of genomic diversification reflect differences in life history and reproductive biology between figs (Ficus) and the stone oaks (Lithocarpus).

    Science.gov (United States)

    Kua, Chai-Shian; Cannon, Charles H

    2017-09-01

    One of the remarkable aspects of the tremendous biodiversity found in tropical forests is the wide range of evolutionary strategies that have produced this diversity, indicating many paths to diversification. We compare two diverse groups of trees with profoundly different biologies to discover whether these differences are reflected in their genomes. Ficus (Moraceae), with its complex co-evolutionary relationship with obligate pollinating wasps, produces copious tiny seeds that are widely dispersed. Lithocarpus (Fagaceae), with generalized insect pollination, produces large seeds that are poorly dispersed. We hypothesize that these different reproductive biologies and life history strategies should have a profound impact on the basic properties of genomic divergence within each genus. Using shallow whole genome sequencing for six species of Ficus, seven species of Lithocarpus, and three outgroups, we examined overall genomic diversity, how it is shared among the species within each genus, and the fraction of this shared diversity that agrees with the major phylogenetic pattern. A substantially larger fraction of the genome is shared among species of Lithocarpus, a considerable amount of this shared diversity was incongruent with the general background history of the genomes, and each fig species possessed a substantially larger fraction of unique diversity than Lithocarpus.

  6. A unique life history among tetrapods: an annual chameleon living mostly as an egg.

    Science.gov (United States)

    Karsten, Kristopher B; Andriamandimbiarisoa, Laza N; Fox, Stanley F; Raxworthy, Christopher J

    2008-07-01

    The approximately 28,300 species of tetrapods (four-limbed vertebrates) almost exclusively have perennial life spans. Here, we report the discovery of a remarkable annual tetrapod from the arid southwest of Madagascar: the chameleon Furcifer labordi, with a posthatching life span of just 4-5 months. At the start of the active season (November), an age cohort of hatchlings emerges; larger juveniles or adults are not present. These hatchlings grow rapidly, reach sexual maturity in less than 2 months, and reproduce in January-February. After reproduction, senescence appears, and the active season concludes with population-wide adult death. Consequently, during the dry season, the entire population is represented by developing eggs that incubate for 8-9 months before synchronously hatching at the onset of the following rainy season. Remarkably, this chameleon spends more of its short annual life cycle inside the egg than outside of it. Our review of tetrapod longevity (>1,700 species) finds no others with such a short life span. These findings suggest that the notorious rapid death of chameleons in captivity may, for some species, actually represent the natural adult life span. Consequently, a new appraisal may be warranted concerning the viability of chameleon breeding programs, which could have special significance for species of conservation concern. Additionally, because F. labordi is closely related to other perennial species, this chameleon group may prove also to be especially well suited for comparative studies that focus on life history evolution and the ecological, genetic, and/or hormonal determinants of aging, longevity, and senescence.

  7. On (not) overcoming our history of hierarchy: Complexities of university/school collaboration

    Science.gov (United States)

    Carlone, Heidi B.; Webb, Sandra M.

    2006-05-01

    Science educators have recently begun to enact and study new, collaborative forms of professional development. Yet, few recognize that doing so requires contesting historical meanings of university-school collaboration and professional development, both of which may operate to sustain a hierarchy model of collaboration. The hierarchy model maintains the flow of information and knowledge from universities to teachers to students. In science education, the hierarchy model may be strengthened by science's own history of hierarchy. This study describes the authors' attempt to contest the hierarchy model by facilitating a collaborative planning project with elementary teachers. Critical discourse analysis is used as the primary theoretical and methodological tool to (1) explain how the hierarchy model was shaped by and shaped the group's actions, interactions, and identities; (2) explain the complexities of collaboration by moving beyond deficit-based explanations (e.g., blaming individuals or organizational structures); (3) offer theoretical and methodological approaches for understanding better the nature of collaboration and practical solutions for those attempting to challenge the history of hierarchy. In focusing on how meaning is made in interaction, the authors demonstrate how language and interaction are inextricably bound with history and culture.

  8. Genetic diversity through life history of Dioon edule Lindley (Zamiaceae, Cycadales).

    Science.gov (United States)

    Octavio-Aguilar, P; González-Astorga, J; Vovides, A P

    2009-07-01

    The distribution of genetic diversity and structure for three populations of Dioon edule Lindley (Zamiaceae) at Monte Oscuro (MO), El Farallón (EF) and Rancho del Niño (RN) in Veracruz, Mexico was studied using 20 allozyme loci, considering four life history classes: seeds, seedlings, juveniles and adults. The MO population is genetically less diverse than the EF and RN populations. Total and local inbreeding differ significantly between life history classes. An increment of inbreeding among all classes was observed, and genetic differentiation among populations was higher in seeds and seedlings than in juveniles and adults. In terms of percentage of polymorphic loci, the MO seeds showed least (80%), followed by RN (95%) and EF had the highest values (100%), probably because of a reduction in effective population size and habitat fragmentation processes. In this context, the mean effective population size was 23.2 +/- 11.3 for all populations. We conclude that seed cohorts in EF and RN represent a reservoir of genetic diversity within these two populations. Also, preservation of adult plants is an essential aspect to consider in management and conservation efforts for populations of Dioon edule in natural conditions.

  9. Accounting for measurement error in human life history trade-offs using structural equation modeling.

    Science.gov (United States)

    Helle, Samuli

    2018-03-01

    Revealing causal effects from correlative data is very challenging and a contemporary problem in human life history research owing to the lack of experimental approach. Problems with causal inference arising from measurement error in independent variables, whether related either to inaccurate measurement technique or validity of measurements, seem not well-known in this field. The aim of this study is to show how structural equation modeling (SEM) with latent variables can be applied to account for measurement error in independent variables when the researcher has recorded several indicators of a hypothesized latent construct. As a simple example of this approach, measurement error in lifetime allocation of resources to reproduction in Finnish preindustrial women is modelled in the context of the survival cost of reproduction. In humans, lifetime energetic resources allocated in reproduction are almost impossible to quantify with precision and, thus, typically used measures of lifetime reproductive effort (e.g., lifetime reproductive success and parity) are likely to be plagued by measurement error. These results are contrasted with those obtained from a traditional regression approach where the single best proxy of lifetime reproductive effort available in the data is used for inference. As expected, the inability to account for measurement error in women's lifetime reproductive effort resulted in the underestimation of its underlying effect size on post-reproductive survival. This article emphasizes the advantages that the SEM framework can provide in handling measurement error via multiple-indicator latent variables in human life history studies. © 2017 Wiley Periodicals, Inc.

  10. Sense of control under uncertainty depends on people's childhood environment: a life history theory approach.

    Science.gov (United States)

    Mittal, Chiraag; Griskevicius, Vladas

    2014-10-01

    Past research found that environmental uncertainty leads people to behave differently depending on their childhood environment. For example, economic uncertainty leads people from poor childhoods to become more impulsive while leading people from wealthy childhoods to become less impulsive. Drawing on life history theory, we examine the psychological mechanism driving such diverging responses to uncertainty. Five experiments show that uncertainty alters people's sense of control over the environment. Exposure to uncertainty led people from poorer childhoods to have a significantly lower sense of control than those from wealthier childhoods. In addition, perceptions of control statistically mediated the effect of uncertainty on impulsive behavior. These studies contribute by demonstrating that sense of control is a psychological driver of behaviors associated with fast and slow life history strategies. We discuss the implications of this for theory and future research, including that environmental uncertainty might lead people who grew up poor to quit challenging tasks sooner than people who grew up wealthy. 2014 APA, all rights reserved

  11. Life-history theory and climate change: resolving population and parental investment paradoxes.

    Science.gov (United States)

    Caudell, Mark; Quinlan, Robert

    2016-11-01

    Population growth in the next half-century is on pace to raise global carbon emissions by half. Carbon emissions are associated with fertility as a by-product of somatic and parental investment, which is predicted to involve time orientation/preference as a mediating psychological mechanism. Here, we draw upon life-history theory (LHT) to investigate associations between future orientation and fertility, and their impacts on carbon emissions. We argue ' K -strategy' life history (LH) in high-income countries has resulted in parental investment behaviours involving future orientation that, paradoxically, promote unsustainable carbon emissions, thereby lowering the Earth's K or carrying capacity. Increasing the rate of approach towards this capacity are ' r -strategy' LHs in low-income countries that promote population growth. We explore interactions between future orientation and development that might slow the rate of approach towards global K . Examination of 67 000 individuals across 75 countries suggests that future orientation interacts with the relationship between environmental risk and fertility and with development related parental investment, particularly investment in higher education, to slow population growth and mitigate per capita carbon emissions. Results emphasize that LHT will be an important tool in understanding the demographic and consumption patterns that drive anthropogenic climate change.

  12. Fast life history traits promote invasion success in amphibians and reptiles.

    Science.gov (United States)

    Allen, William L; Street, Sally E; Capellini, Isabella

    2017-02-01

    Competing theoretical models make different predictions on which life history strategies facilitate growth of small populations. While 'fast' strategies allow for rapid increase in population size and limit vulnerability to stochastic events, 'slow' strategies and bet-hedging may reduce variance in vital rates in response to stochasticity. We test these predictions using biological invasions since founder alien populations start small, compiling the largest dataset yet of global herpetological introductions and life history traits. Using state-of-the-art phylogenetic comparative methods, we show that successful invaders have fast traits, such as large and frequent clutches, at both establishment and spread stages. These results, together with recent findings in mammals and plants, support 'fast advantage' models and the importance of high potential population growth rate. Conversely, successful alien birds are bet-hedgers. We propose that transient population dynamics and differences in longevity and behavioural flexibility can help reconcile apparently contrasting results across terrestrial vertebrate classes. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  13. Environmental contingency in life history strategies: the influence of mortality and socioeconomic status on reproductive timing.

    Science.gov (United States)

    Griskevicius, Vladas; Delton, Andrew W; Robertson, Theresa E; Tybur, Joshua M

    2011-02-01

    Why do some people have children early, whereas others delay reproduction? By considering the trade-offs between using one's resources for reproduction versus other tasks, the evolutionary framework of life history theory predicts that reproductive timing should be influenced by mortality and resource scarcity. A series of experiments examined how mortality cues influenced the desire to have children sooner rather than later. The effects of mortality depended critically on whether people grew up in a relatively resource-scarce or resource-plentiful environment. For individuals growing up relatively poor, mortality cues produced a desire to reproduce sooner--to want children now, even at the cost of furthering one's education or career. Conversely, for individuals growing up relatively wealthy, mortality cues produced a desire to delay reproduction--to further one's education or career before starting a family. Overall, mortality cues appear to shift individuals into different life history strategies as a function of childhood socioeconomic status, suggesting important implications for how environmental factors can influence fertility and family size. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  14. A Life History Theory of Father Absence and Menarche: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Gregory D. Webster

    2014-04-01

    Full Text Available Is the absence of biological fathers related to their daughters' earlier age at menarche? Drawing on evolutionary psychology and life history theory, prior research has suggested such a relationship (Belsky, Steinberg, and Draper, 1991; Draper and Harpending, 1982; Ellis, 2004. Although qualitative reviews have shown narrative support for this relationship (Allison and Hyde, 2013; Ellis, 2004; Kim, Smith, and Palermiti, 1997; Susman and Dorn, 2009, no quantitative review exists to provide empirical support for this relationship or to explain mixed results. Thus, we conducted a random-effects meta-analysis of correlations (Card, 2012 on father absence and daughter menarcheal age (k = 33; N = 70,403. The weighted mean correlation was .14, 95% CI [.09, .19], suggesting that father absence was significantly related to earlier menarche; effect sizes were heterogeneous. Egger's regression (Egger, Smith, Schneider, and Minder, 1997 showed no evidence of publication bias (file-drawer effect; r = .34, p = .052. Outcome measure differences (menarcheal age vs. menarcheal age embedded in a multi-item pubertal timing scale did not moderate effect sizes. Study year effects (Schooler, 2011 were also non-significant. Our findings support one aspect of the life history model and provide groundwork for subsequent examination of other pathways in the model.

  15. Life history constrains biochemical development in the highly specialized odontocete echolocation system.

    Science.gov (United States)

    Koopman, Heather N; Zahorodny, Zoey P

    2008-10-22

    The vertebrate head has undergone enormous modification from the features borne by early ancestors. The growth of skull bones has been well studied in many species, yet little is known about corresponding soft tissue development. Among mammals, some of the most unusual examples of cranial evolution exist in the toothed whales (odontocetes). Specialized fat bodies in toothed whale heads play important roles in sound transmission and reception. These fat bodies contain unique endogenous lipids, with favourable acoustic properties, arranged in highly organized, three-dimensional patterns. We link variation in developmental rates of acoustic fats with life-history strategy, using bottlenose dolphins and harbour porpoises. Porpoise acoustic fats attain adult configurations earlier (less than 1 year) and at a faster pace than dolphins. The accelerated lipid accumulation in porpoises reflects the earlier need for fully functional echolocation systems. Dolphins enjoy 3-6 years of maternal care; porpoises must achieve total independence by approximately nine months. Further, a stereotypic 'blueprint' for the spatial distribution of lipids is established prior to birth, demonstrating the highly conserved nature of the intricate biochemical arrangement in acoustic tissues. This system illustrates an unusual case of soft tissue development being constrained by life history, rather than the more commonly observed mechanistic or phyletic constraints.

  16. Meeting Report: International Symposium on the Genetics of Aging and Life History II.

    Science.gov (United States)

    Artan, Murat; Hwang, Ara B; Lee, Seung V; Nam, Hong Gil

    2015-06-01

    The second International Symposium on the Genetics of Aging and Life History was held at the campus of Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea, from May 14 to 16, 2014. Many leading scientists in the field of aging research from all over the world contributed to the symposium by attending and presenting their recent work and thoughts. The aim of the symposium was to stimulate international collaborations and interactions among scientists who work on the biology of aging. In the symposium, the most recent and exciting work on aging research was presented, covering a wide range of topics, including the genetics of aging, age-associated diseases, and cellular senescence. The work was conducted in various organisms, includingC. elegans, mice, plants, and humans. Topics covered in the symposium stimulated discussion of novel directions for future research on aging. The meeting ended with a commitment for the third International Symposium on the Genetics of Aging and Life History, which will be held in 2016.

  17. Life history, predation and flight initiation distance in a migratory bird.

    Science.gov (United States)

    Møller, A P

    2014-06-01

    Life-history trade-offs occur as a consequence of the compromise between maximization of different components such as the size and the number of clutches. Flight initiation distance (FID) potentially constitutes a general proximate factor influencing such trade-offs reflecting the risks that individuals take. Therefore, greater investment in reproduction occurs at a higher risk of death, resulting in selection for efficient flight morphology. I analysed long-term data on FID in a population of barn swallows Hirundo rustica during 1984-2013 with 2196 records of FID for 1789 individuals. FID had a repeatability of 0.62 (SE = 0.04) and a heritability of 0.48 (SE = 0.07). FID varied between individuals and sites, and it increased over time as climate ameliorated. FID showed a U-shaped relationship with age, with young and very old individuals having the longest FIDs. Barn swallows that arrived early from spring migration, started to breed early and produced many fledglings had the longest FID. Individuals with the longest tails had the longest FID, and individuals with the shortest aspect ratios and wing loadings had the longest FID. Individuals that died from predation had shorter FID than survivors. These findings are consistent with the hypothesis that FID relates directly to life history, with longer FIDs being associated with smaller levels of risk-taking. © 2014 The Author. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  18. Patterns and drivers of intraspecific variation in avian life history along elevational gradients: a meta-analysis.

    Science.gov (United States)

    Alice Boyle, W; Sandercock, Brett K; Martin, Kathy

    2016-05-01

    Elevational gradients provide powerful natural systems for testing hypotheses regarding the role of environmental variation in the evolution of life-history strategies. Case studies have revealed shifts towards slower life histories in organisms living at high elevations yet no synthetic analyses exist of elevational variation in life-history traits for major vertebrate clades. We examined (i) how life-history traits change with elevation in paired populations of bird species worldwide, and (ii) which biotic and abiotic factors drive elevational shifts in life history. Using three analytical methods, we found that fecundity declined at higher elevations due to smaller clutches and fewer reproductive attempts per year. By contrast, elevational differences in traits associated with parental investment or survival varied among studies. High-elevation populations had shorter and later breeding seasons, but longer developmental periods implying that temporal constraints contribute to reduced fecundity. Analyses of clutch size data, the trait for which we had the largest number of population comparisons, indicated no evidence that phylogenetic history constrained species-level plasticity in trait variation associated with elevational gradients. The magnitude of elevational shifts in life-history traits were largely unrelated to geographic (altitude, latitude), intrinsic (body mass, migratory status), or habitat covariates. Meta-population structure, methodological issues associated with estimating survival, or processes shaping range boundaries could potentially explain the nature of elevational shifts in life-history traits evident in this data set. We identify a new risk factor for montane populations in changing climates: low fecundity will result in lower reproductive potential to recover from perturbations, especially as fewer than half of the species experienced higher survival at higher elevations. © 2015 Cambridge Philosophical Society.

  19. Bringing dinosaurs back to life: exhibiting prehistory at the American Museum of Natural History.

    Science.gov (United States)

    Rieppel, Lukas

    2012-09-01

    This essay examines the exhibition of dinosaurs at the American Museum of Natural History during the first two decades of the twentieth century. Dinosaurs provide an especially illuminating lens through which to view the history of museum display practices for two reasons: they made for remarkably spectacular exhibits; and they rested on contested theories about the anatomy, life history, and behavior of long-extinct animals to which curators had no direct observational access. The American Museum sought to capitalize on the popularity of dinosaurs while mitigating the risks of mounting an overtly speculative display by fashioning them into a kind of mixed-media installation made of several elements, including fossilized bone, shellac, iron, and plaster. The resulting sculptures provided visitors with a vivid and lifelike imaginative experience. At the same time, curators, who were anxious to downplay the speculative nature of mounted dinosaurs, drew systematic attention to the material connection that tied individual pieces of fossilized bone to the actual past. Freestanding dinosaurs can therefore be read to have functioned as iconic sculptures that self-consciously advertised their indexical content.

  20. A molecular timescale of eukaryote evolution and the rise of complex multicellular life

    Directory of Open Access Journals (Sweden)

    Venturi Maria L

    2004-01-01

    Full Text Available Abstract Background The pattern and timing of the rise in complex multicellular life during Earth's history has not been established. Great disparity persists between the pattern suggested by the fossil record and that estimated by molecular clocks, especially for plants, animals, fungi, and the deepest branches of the eukaryote tree. Here, we used all available protein sequence data and molecular clock methods to place constraints on the increase in complexity through time. Results Our phylogenetic analyses revealed that (i animals are more closely related to fungi than to plants, (ii red algae are closer to plants than to animals or fungi, (iii choanoflagellates are closer to animals than to fungi or plants, (iv diplomonads, euglenozoans, and alveolates each are basal to plants+animals+fungi, and (v diplomonads are basal to other eukaryotes (including alveolates and euglenozoans. Divergence times were estimated from global and local clock methods using 20–188 proteins per node, with data treated separately (multigene and concatenated (supergene. Different time estimation methods yielded similar results (within 5%: vertebrate-arthropod (964 million years ago, Ma, Cnidaria-Bilateria (1,298 Ma, Porifera-Eumetozoa (1,351 Ma, Pyrenomycetes-Plectomycetes (551 Ma, Candida-Saccharomyces (723 Ma, Hemiascomycetes-filamentous Ascomycota (982 Ma, Basidiomycota-Ascomycota (968 Ma, Mucorales-Basidiomycota (947 Ma, Fungi-Animalia (1,513 Ma, mosses-vascular plants (707 Ma, Chlorophyta-Tracheophyta (968 Ma, Rhodophyta-Chlorophyta+Embryophyta (1,428 Ma, Plantae-Animalia (1,609 Ma, Alveolata-plants+animals+fungi (1,973 Ma, Euglenozoa-plants+animals+fungi (1,961 Ma, and Giardia-plants+animals+fungi (2,309 Ma. By extrapolation, mitochondria arose approximately 2300-1800 Ma and plastids arose 1600-1500 Ma. Estimates of the maximum number of cell types of common ancestors, combined with divergence times, showed an increase from two cell types at 2500 Ma to ~10

  1. A molecular timescale of eukaryote evolution and the rise of complex multicellular life

    Science.gov (United States)

    Hedges, S. Blair; Blair, Jaime E.; Venturi, Maria L.; Shoe, Jason L.

    2004-01-01

    BACKGROUND: The pattern and timing of the rise in complex multicellular life during Earth's history has not been established. Great disparity persists between the pattern suggested by the fossil record and that estimated by molecular clocks, especially for plants, animals, fungi, and the deepest branches of the eukaryote tree. Here, we used all available protein sequence data and molecular clock methods to place constraints on the increase in complexity through time. RESULTS: Our phylogenetic analyses revealed that (i) animals are more closely related to fungi than to plants, (ii) red algae are closer to plants than to animals or fungi, (iii) choanoflagellates are closer to animals than to fungi or plants, (iv) diplomonads, euglenozoans, and alveolates each are basal to plants+animals+fungi, and (v) diplomonads are basal to other eukaryotes (including alveolates and euglenozoans). Divergence times were estimated from global and local clock methods using 20-188 proteins per node, with data treated separately (multigene) and concatenated (supergene). Different time estimation methods yielded similar results (within 5%): vertebrate-arthropod (964 million years ago, Ma), Cnidaria-Bilateria (1,298 Ma), Porifera-Eumetozoa (1,351 Ma), Pyrenomycetes-Plectomycetes (551 Ma), Candida-Saccharomyces (723 Ma), Hemiascomycetes-filamentous Ascomycota (982 Ma), Basidiomycota-Ascomycota (968 Ma), Mucorales-Basidiomycota (947 Ma), Fungi-Animalia (1,513 Ma), mosses-vascular plants (707 Ma), Chlorophyta-Tracheophyta (968 Ma), Rhodophyta-Chlorophyta+Embryophyta (1,428 Ma), Plantae-Animalia (1,609 Ma), Alveolata-plants+animals+fungi (1,973 Ma), Euglenozoa-plants+animals+fungi (1,961 Ma), and Giardia-plants+animals+fungi (2,309 Ma). By extrapolation, mitochondria arose approximately 2300-1800 Ma and plastids arose 1600-1500 Ma. Estimates of the maximum number of cell types of common ancestors, combined with divergence times, showed an increase from two cell types at 2500 Ma to

  2. Statistical inference on genetic data reveals the complex demographic history of human populations in central Asia.

    Science.gov (United States)

    Palstra, Friso P; Heyer, Evelyne; Austerlitz, Frédéric

    2015-06-01

    The demographic history of modern humans constitutes a combination of expansions, colonizations, contractions, and remigrations. The advent of large scale genetic data combined with statistically refined methods facilitates inference of this complex history. Here we study the demographic history of two genetically admixed ethnic groups in Central Asia, an area characterized by high levels of genetic diversity and a history of recurrent immigration. Using Approximate Bayesian Computation, we infer that the timing of admixture markedly differs between the two groups. Admixture in the traditionally agricultural Tajiks could be dated back to the onset of the Neolithic transition in the region, whereas admixture in Kyrgyz is more recent, and may have involved the westward movement of Turkic peoples. These results are confirmed by a coalescent method that fits an isolation-with-migration model to the genetic data, with both Central Asian groups having received gene flow from the extremities of Eurasia. Interestingly, our analyses also uncover signatures of gene flow from Eastern to Western Eurasia during Paleolithic times. In conclusion, the high genetic diversity currently observed in these two Central Asian peoples most likely reflects the effects of recurrent immigration that likely started before historical times. Conversely, conquests during historical times may have had a relatively limited genetic impact. These results emphasize the need for a better understanding of the genetic consequences of transmission of culture and technological innovations, as well as those of invasions and conquests. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Reproductive effects on skeletal health in Shuar women of Amazonian Ecuador: a life history perspective.

    Science.gov (United States)

    Madimenos, Felicia C; Snodgrass, J Josh; Liebert, Melissa A; Cepon, Tara J; Sugiyama, Lawrence S

    2012-01-01

    Clinical and epidemiological research suggest that bone mineral density (BMD) in women is shaped by various reproductive factors such as parity and lactation patterns. However, the extent of these effects on BMD remains unclear because of contradictory findings and a focus on industrialized populations. Because fertility patterns in these groups are vastly different than those of women from non-Western, subsistence populations, our current understanding of the reproductive effects on skeletal health is incomplete. Using a life history perspective, this study examines the relationship between reproductive factors and bone density among women from the Indigenous Shuar population, an Amazonian Ecuadorian forager-horticulturalist group. This preliminary, cross-sectional study included 130 premenopausal and postmenopausal women (14-86 years old) from the Morona-Santiago region of Ecuador. Anthropometrics were recorded, as was estimated BMD using a calcaneal ultrasonometer. A reproductive history questionnaire was administered that included questions regarding menarche, parity, lactation patterns, and menopause. Among postmenopausal women, early menarche and greater stature were significantly associated with higher bone density values. Among premenopausal women, few significant relationships between bone values and reproductive variables were documented; effects of lactation appeared to be transient and restored following weaning. Although preliminary and not based on longitudinal data, these findings suggest that the effects of reproduction are transient as the system of calcium homeostasis in premenopausal women efficiently restores the bone loss that results from metabolically active reproductive states. Further, this research suggests that the timing of early life history events may canalize bone density phenotype. Copyright © 2012 Wiley Periodicals, Inc.

  4. [The life of Dr. RO Kishun, a reflection of modern Korean medical history of the borders].

    Science.gov (United States)

    Shin, Young-Jeon; Park, Se-Hong

    2009-06-01

    borderlands or frontiers of Joseon Korea, China, and Japan, where the history of the three nations met and intermingled with one another. He was a biochemist and researcher, practicing physician and medical professor of the era under Japanese Rule and the one following it. In modern Korean medicine, his life is viewed as a history of the borders, or a transnational legacy going beyond individual history of Korea, China, and Japan.

  5. The Life History and Shelter Building Behavior of Vettius Coryna Coryna Hewitson, 1866 in Eastern Ecuador (Lepidoptera: Hesperiidae: Hesperiinae)

    Science.gov (United States)

    Greeney, Harold F.; Warren, Andrew D.

    2009-01-01

    We describe all life-stages of Vettius coryna coryna Hewitson, 1866 in eastern Ecuador. The details of larval shelter structure and associated shelter building behavior are described and illustrated, as observed on two grass species (Poaceae). We provide brief observations on V. coryna adult behavior and a review of known life history information for other species of Vettius Godman, 1901. PMID:19613868

  6. High and low, fast or slow : the complementary contributions of altitude and latitude to understand life-history variation

    NARCIS (Netherlands)

    Tieleman, B. Irene; Bradshaw, Corey

    H. Bears, K. Martin & G.C. White (2009) Breeding in high-elevation habitat results in shift to slower life-history strategy within a single species. Journal of Animal Ecology, 78, 365-375. Dark-eyed juncos (Junco hyemalis) from two elevations in the Rocky Mountains of Canada display different life

  7. A widespread chromosomal inversion polymorphism contributes to a major life-history transition, local adaptation, and reproductive isolation.

    Directory of Open Access Journals (Sweden)

    David B Lowry

    2010-09-01

    Full Text Available The role of chromosomal inversions in adaptation and speciation is controversial. Historically, inversions were thought to contribute to these processes either by directly causing hybrid sterility or by facilitating the maintenance of co-adapted gene complexes. Because inversions suppress recombination when heterozygous, a recently proposed local adaptation mechanism predicts that they will spread if they capture alleles at multiple loci involved in divergent adaptation to contrasting environments. Many empirical studies have found inversion polymorphisms linked to putatively adaptive phenotypes or distributed along environmental clines. However, direct involvement of an inversion in local adaptation and consequent ecological reproductive isolation has not to our knowledge been demonstrated in nature. In this study, we discovered that a chromosomal inversion polymorphism is geographically widespread, and we test the extent to which it contributes to adaptation and reproductive isolation under natural field conditions. Replicated crosses between the prezygotically reproductively isolated annual and perennial ecotypes of the yellow monkeyflower, Mimulus guttatus, revealed that alternative chromosomal inversion arrangements are associated with life-history divergence over thousands of kilometers across North America. The inversion polymorphism affected adaptive flowering time divergence and other morphological traits in all replicated crosses between four pairs of annual and perennial populations. To determine if the inversion contributes to adaptation and reproductive isolation in natural populations, we conducted a novel reciprocal transplant experiment involving outbred lines, where alternative arrangements of the inversion were reciprocally introgressed into the genetic backgrounds of each ecotype. Our results demonstrate for the first time in nature the contribution of an inversion to adaptation, an annual/perennial life-history shift, and

  8. Cancer survivorship: history, quality-of-life issues, and the evolving multidisciplinary approach to implementation of cancer survivorship care plans.

    Science.gov (United States)

    Morgan, Mary Ann

    2009-07-01

    To discuss the history of cancer survivorship, related quality-of-life issues, and cancer survivorship care plans (CSCPs). CINAHL, PubMed, published articles, and Web sites. A cancer survivor is an individual who has been diagnosed with cancer, regardless of when that diagnosis was received, who is still living. Cancer survivorship is complex and involves many aspects of care. Major areas of concern for survivors are recurrence, secondary malignancies, and long-term treatment sequelae that affect quality of life. Four essential components of survivorship care are prevention, surveillance, intervention, and coordination. A CSCP should address the survivor's long-term care, such as type of cancer, treatments received, potential side effects, and recommendations for follow-up. It should include preventive practices, how to maintain health and well-being, information on legal protections regarding employment and health insurance, and psychosocial services in the community. Survivorship care for patients with cancer requires a multidisciplinary effort and team approach. Enhanced knowledge of long-term complications of survivorship is needed for healthcare providers. Further research on evidence-based practice for cancer survivorship care also is necessary. Nurses can review CSCPs with patients, instruct them when to seek treatment, promote recommended surveillance protocols, and encourage behaviors that lead to cancer prevention and promote well-being for cancer survivors.

  9. Nautilus pompilius life history and demographics at the Osprey Reef Seamount, Coral Sea, Australia.

    Directory of Open Access Journals (Sweden)

    Andrew J Dunstan

    Full Text Available Nautiloids are the subject of speculation as to their threatened status arising from the impacts of targeted fishing for the ornamental shell market. Life history knowledge is essential to understand the susceptibility of this group to overfishing and to the instigation of management frameworks. This study provides a comprehensive insight into the life of Nautilus in the wild. At Osprey Reef from 1998-2008, trapping for Nautilus was conducted on 354 occasions, with 2460 individuals of one species, Nautilus pompilius, captured and 247 individuals recaptured. Baited remote underwater video systems (BRUVS were deployed on 15 occasions and six remotely operated vehicle (ROV dives from 100-800 m were conducted to record Nautilus presence and behavior. Maturity, sex and size data were recorded, while measurements of recaptured individuals allowed estimation of growth rates to maturity, and longevity beyond maturity. We found sexual dimorphism in size at maturity (males: 131.9±SD = 2.6 mm; females: 118.9±7.5 mm shell diameter in a population dominated by mature individuals (58%. Mean growth rates of 15 immature recaptured animals were 0.061±0.023 mm day(-1 resulting in an estimate of around 15.5 years to maturation. Recaptures of mature animals after five years provide evidence of a lifespan exceeding 20 years. Juvenile Nautilus pompilius feeding behavior was recorded for the first time within the same depth range (200-610 m as adults. Our results provide strong evidence of a K-selected life history for Nautilus from a detailed study of a 'closed' wild population. In conjunction with population size and density estimates established for the Osprey Reef Nautilus, this work allows calculations for sustainable catch and provides mechanisms to extrapolate these findings to other extant nautiloid populations (Nautilus and Allonautilus spp. throughout the Indo-Pacific.

  10. Nautilus pompilius life history and demographics at the Osprey Reef Seamount, Coral Sea, Australia.

    Science.gov (United States)

    Dunstan, Andrew J; Ward, Peter D; Marshall, N Justin

    2011-02-10

    Nautiloids are the subject of speculation as to their threatened status arising from the impacts of targeted fishing for the ornamental shell market. Life history knowledge is essential to understand the susceptibility of this group to overfishing and to the instigation of management frameworks. This study provides a comprehensive insight into the life of Nautilus in the wild. At Osprey Reef from 1998-2008, trapping for Nautilus was conducted on 354 occasions, with 2460 individuals of one species, Nautilus pompilius, captured and 247 individuals recaptured. Baited remote underwater video systems (BRUVS) were deployed on 15 occasions and six remotely operated vehicle (ROV) dives from 100-800 m were conducted to record Nautilus presence and behavior. Maturity, sex and size data were recorded, while measurements of recaptured individuals allowed estimation of growth rates to maturity, and longevity beyond maturity. We found sexual dimorphism in size at maturity (males: 131.9±SD = 2.6 mm; females: 118.9±7.5 mm shell diameter) in a population dominated by mature individuals (58%). Mean growth rates of 15 immature recaptured animals were 0.061±0.023 mm day(-1) resulting in an estimate of around 15.5 years to maturation. Recaptures of mature animals after five years provide evidence of a lifespan exceeding 20 years. Juvenile Nautilus pompilius feeding behavior was recorded for the first time within the same depth range (200-610 m) as adults. Our results provide strong evidence of a K-selected life history for Nautilus from a detailed study of a 'closed' wild population. In conjunction with population size and density estimates established for the Osprey Reef Nautilus, this work allows calculations for sustainable catch and provides mechanisms to extrapolate these findings to other extant nautiloid populations (Nautilus and Allonautilus spp.) throughout the Indo-Pacific.

  11. Life-History Traits of the Miocene Hipparion concudense (Spain) Inferred from Bone Histological Structure

    Science.gov (United States)

    Martinez-Maza, Cayetana; Alberdi, Maria Teresa; Nieto-Diaz, Manuel; Prado, José Luis

    2014-01-01

    Histological analyses of fossil bones have provided clues on the growth patterns and life history traits of several extinct vertebrates that would be unavailable for classical morphological studies. We analyzed the bone histology of Hipparion to infer features of its life history traits and growth pattern. Microscope analysis of thin sections of a large sample of humeri, femora, tibiae and metapodials of Hipparion concudense from the upper Miocene site of Los Valles de Fuentidueña (Segovia, Spain) has shown that the number of growth marks is similar among the different limb bones, suggesting that equivalent skeletochronological inferences for this Hipparion population might be achieved by means of any of the elements studied. Considering their abundance, we conducted a skeletechronological study based on the large sample of third metapodials from Los Valles de Fuentidueña together with another large sample from the Upper Miocene locality of Concud (Teruel, Spain). The data obtained enabled us to distinguish four age groups in both samples and to determine that Hipparion concudense tended to reach skeletal maturity during its third year of life. Integration of bone microstructure and skeletochronological data allowed us to identify ontogenetic changes in bone structure and growth rate and to distinguish three histologic ontogenetic stages corresponding to immature, subadult and adult individuals. Data on secondary osteon density revealed an increase in bone remodeling throughout the ontogenetic stages and a lesser degree thereof in the Concud population, which indicates different biomechanical stresses in the two populations, likely due to environmental differences. Several individuals showed atypical growth patterns in the Concud sample, which may also reflect environmental differences between the two localities. Finally, classification of the specimens’ age within groups enabled us to characterize the age structure of both samples, which is typical of

  12. Life-history traits of the Miocene Hipparion concudense (Spain inferred from bone histological structure.

    Directory of Open Access Journals (Sweden)

    Cayetana Martinez-Maza

    Full Text Available Histological analyses of fossil bones have provided clues on the growth patterns and life history traits of several extinct vertebrates that would be unavailable for classical morphological studies. We analyzed the bone histology of Hipparion to infer features of its life history traits and growth pattern. Microscope analysis of thin sections of a large sample of humeri, femora, tibiae and metapodials of Hipparion concudense from the upper Miocene site of Los Valles de Fuentidueña (Segovia, Spain has shown that the number of growth marks is similar among the different limb bones, suggesting that equivalent skeletochronological inferences for this Hipparion population might be achieved by means of any of the elements studied. Considering their abundance, we conducted a skeletechronological study based on the large sample of third metapodials from Los Valles de Fuentidueña together with another large sample from the Upper Miocene locality of Concud (Teruel, Spain. The data obtained enabled us to distinguish four age groups in both samples and to determine that Hipparion concudense tended to reach skeletal maturity during its third year of life. Integration of bone microstructure and skeletochronological data allowed us to identify ontogenetic changes in bone structure and growth rate and to distinguish three histologic ontogenetic stages corresponding to immature, subadult and adult individuals. Data on secondary osteon density revealed an increase in bone remodeling throughout the ontogenetic stages and a lesser degree thereof in the Concud population, which indicates different biomechanical stresses in the two populations, likely due to environmental differences. Several individuals showed atypical growth patterns in the Concud sample, which may also reflect environmental differences between the two localities. Finally, classification of the specimens' age within groups enabled us to characterize the age structure of both samples, which is

  13. Leaf and life history traits predict plant growth in a green roof ecosystem.

    Directory of Open Access Journals (Sweden)

    Jeremy Lundholm

    Full Text Available Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that

  14. Leaf and life history traits predict plant growth in a green roof ecosystem.

    Science.gov (United States)

    Lundholm, Jeremy; Heim, Amy; Tran, Stephanie; Smith, Tyler

    2014-01-01

    Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth) to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies) for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that favor less

  15. Deep simplicity chaos, complexity and the emergence of life

    CERN Document Server

    Gribbin, John

    2005-01-01

    The world around us can be a complex, confusing place. Earthquakes happen without warning, stock markets fluctuate, weather forecasters seldom seem to get it right - even other people continue to baffle us. How do we make sense of it all? This title illuminates the harmony underlying our existence.

  16. Inquiry learning for gender equity using History of Science in Life and Earth Sciences’ learning environments

    Directory of Open Access Journals (Sweden)

    C. Sousa

    2016-03-01

    Full Text Available The main objective of the present work is the selection and integration of objectives and methods of education for gender equity within the Life and Earth Sciences’ learning environments in the current portuguese frameworks of middle and high school. My proposal combines inquiry learning-teaching methods with the aim of promoting gender equity, mainly focusing in relevant 20th century women-scientists with a huge contribute to the History of Science. The hands-on and minds-on activities proposed for high scholl students of Life and Earth Sciences onstitute a learnig environment enriched in features of science by focusing on the work of two scientists: Lynn Margulis (1938-2011  and her endosymbiosis theory of the origin of life on Earth and Inge Leehman (1888-1993 responsible for a breakthrough regarding the internal structure of Earth, by caracterizing a discontinuity within the nucleus, contributing to the current geophysical model. For middle scholl students the learning environment includes Inge Leehman and Mary Tharp (1920-2006 and her first world map of the ocean floor. My strategy includes features of science, such as: theory-laden nature of scientific knowledge, models, values and socio-scientific issues, technology contributes to science and feminism.  In conclusion, I consider that this study may constitute an example to facilitate the implementation, by other teachers, of active inquiry strategies focused on features of science within a framework of social responsibility of science, as well as the basis for future research.

  17. Source criticism and cultural models: constructing life histories of women missionaries

    Directory of Open Access Journals (Sweden)

    Eila Helander

    1999-01-01

    Full Text Available Research work is an interpretive enterprise. The variety of sources poses some central methodological questions for constructing religious life histories. There is an apparent discrepancy between the source categories concerning the content of the information. Private diaries and letters provide information on women's work and life which is not available in official reports and letters. They reveal dates, events and individuals which are not mentioned elsewhere. In histography the question of discrepancy is normally solved by comparing the sources with an aim to arrive at the "true picture" of how things have been. Such a picture is believed to portray not only the true life situation of the individual or group in question but, depending on the nature of the data, also the epoch and time situation itself. From the viewpoint of social sciences and comparative religion one will ask: could the variety of sources be approached and utilized in some other way? The second question posed by the data concerns the content of each source category. The information can be located on the continuum "highly subjective — stereotyped". Subjective information, including reflections on personal experiences may not be the best source e.g. for constructing the flow of historical events, but it is of uttermost importance if we want to show how individuals respond to social constraints and actively assemble social worlds.

  18. Does thermal variability experienced at the egg stage influence life history traits across life cycle stages in a small invertebrate?

    Directory of Open Access Journals (Sweden)

    Kun Xing

    Full Text Available Although effects of thermal stability on eggs have often been considered in vertebrates, there is little data thermal stability in insect eggs even though these eggs are often exposed in nature to widely fluctuating ambient conditions. The modularity of development in invertebrates might lead to compensation across life cycle stages but this remains to be tested particularly within the context of realistic temperature fluctuations encountered in nature. We simulated natural temperate fluctuations on eggs of the worldwide cruciferous insect pest, the diamondback moth (DBM, Plutella xylostella (L., while maintaining the same mean temperature (25°C±0°C, 25±4°C, 25±6°C, 25±8°C, 25±10°C, 25±12°C and assessed egg development, survival and life history traits across developmental stages. Moderate fluctuations (25±4°C, 25±6°C did not influence performance compared to the constant temperature treatment, and none of the treatments influenced egg survival. However the wide fluctuating temperatures (25±10°C, 25±12°C slowed development time and led to an increase in pre-pupal mass, although these changes did not translate into any effects on longevity or fecundity at the adult stage. These findings indicate that environmental effects can extend across developmental stages despite the modularity of moth development but also highlight that there are few fitness consequences of the most variable thermal conditions likely to be experienced by Plutella xylostella.

  19. Topics in Complexity: From Physical to Life Science Systems

    Science.gov (United States)

    Charry, Pedro David Manrique

    Complexity seeks to unwrap the mechanisms responsible for collective phenomena across the physical, biological, chemical, economic and social sciences. This thesis investigates real-world complex dynamical systems ranging from the quantum/natural domain to the social domain. The following novel understandings are developed concerning these systems' out-of-equilibrium and nonlinear behavior. Standard quantum techniques show divergent outcomes when a quantum system comprising more than one subunit is far from thermodynamic equilibrium. Abnormal photon inter-arrival times help fulfill the metabolic needs of a terrestrial photosynthetic bacterium. Spatial correlations within incident light can act as a driving mechanism for an organism's adaptation toward more ordered structures. The group dynamics of non-identical objects, whose assembly rules depend on mutual heterogeneity, yield rich transition dynamics between isolation and cohesion, with the cohesion regime reproducing a particular universal pattern commonly found in many real-world systems. Analyses of covert networks reveal collective gender superiority in the connectivity that provides benefits for system robustness and survival. Nodal migration in a network generates complex contagion profiles that lie beyond traditional approaches and yet resemble many modern-day outbreaks.

  20. Growth in fossil and extant deer and implications for body size and life history evolution.

    Science.gov (United States)

    Kolb, Christian; Scheyer, Torsten M; Lister, Adrian M; Azorit, Concepcion; de Vos, John; Schlingemann, Margaretha A J; Rössner, Gertrud E; Monaghan, Nigel T; Sánchez-Villagra, Marcelo R

    2015-02-14

    Body size variation within clades of mammals is widespread, but the developmental and life-history mechanisms by which this variation is achieved are poorly understood, especially in extinct forms. An illustrative case study is that of the dwarfed morphotypes of Candiacervus from the Pleistocene of Crete versus the giant deer Megaloceros giganteus, both in a clade together with Dama dama among extant species. Histological analyses of long bones and teeth in a phylogenetic context have been shown to provide reliable estimates of growth and life history patterns in extant and extinct mammals. Similarity of bone tissue types across the eight species examined indicates a comparable mode of growth in deer, with long bones mainly possessing primary plexiform fibrolamellar bone. Low absolute growth rates characterize dwarf Candiacervus sp. II and C. ropalophorus compared to Megaloceros giganteus displaying high rates, whereas Dama dama is characterized by intermediate to low growth rates. The lowest recorded rates are those of the Miocene small stem cervid Procervulus praelucidus. Skeletal maturity estimates indicate late attainment in sampled Candiacervus and Procervulus praelucidus. Tooth cementum analysis of first molars of two senile Megaloceros giganteus specimens revealed ages of 16 and 19 years whereas two old dwarf Candiacervus specimens gave ages of 12 and 18 years. There is a rich histological record of growth across deer species recorded in long bones and teeth, which can be used to understand ontogenetic patterns within species and phylogenetic ones across species. Growth rates sensu Sander & Tückmantel plotted against the anteroposterior bone diameter as a proxy for body mass indicate three groups: one with high growth rates including Megaloceros, Cervus, Alces, and Dama; an intermediate group with Capreolus and Muntiacus; and a group showing low growth rates, including dwarf Candiacervus and Procervulus. Dwarf Candiacervus, in an allometric context, show an

  1. Comparative phylogeographic analyses illustrate the complex evolutionary history of threatened cloud forests of northern Mesoamerica.

    Science.gov (United States)

    Ornelas, Juan Francisco; Sosa, Victoria; Soltis, Douglas E; Daza, Juan M; González, Clementina; Soltis, Pamela S; Gutiérrez-Rodríguez, Carla; de los Monteros, Alejandro Espinosa; Castoe, Todd A; Bell, Charles; Ruiz-Sanchez, Eduardo

    2013-01-01

    Comparative phylogeography can elucidate the influence of historical events on current patterns of biodiversity and can identify patterns of co-vicariance among unrelated taxa that span the same geographic areas. Here we analyze temporal and spatial divergence patterns of cloud forest plant and animal species and relate them to the evolutionary history of naturally fragmented cloud forests--among the most threatened vegetation types in northern Mesoamerica. We used comparative phylogeographic analyses to identify patterns of co-vicariance in taxa that share geographic ranges across cloud forest habitats and to elucidate the influence of historical events on current patterns of biodiversity. We document temporal and spatial genetic divergence of 15 species (including seed plants, birds and rodents), and relate them to the evolutionary history of the naturally fragmented cloud forests. We used fossil-calibrated genealogies, coalescent-based divergence time inference, and estimates of gene flow to assess the permeability of putative barriers to gene flow. We also used the hierarchical Approximate Bayesian Computation (HABC) method implemented in the program msBayes to test simultaneous versus non-simultaneous divergence of the cloud forest lineages. Our results show shared phylogeographic breaks that correspond to the Isthmus of Tehuantepec, Los Tuxtlas, and the Chiapas Central Depression, with the Isthmus representing the most frequently shared break among taxa. However, dating analyses suggest that the phylogeographic breaks corresponding to the Isthmus occurred at different times in different taxa. Current divergence patterns are therefore consistent with the hypothesis of broad vicariance across the Isthmus of Tehuantepec derived from different mechanisms operating at different times. This study, coupled with existing data on divergence cloud forest species, indicates that the evolutionary history of contemporary cloud forest lineages is complex and often lineage

  2. Comparative phylogeographic analyses illustrate the complex evolutionary history of threatened cloud forests of northern Mesoamerica.

    Directory of Open Access Journals (Sweden)

    Juan Francisco Ornelas

    Full Text Available Comparative phylogeography can elucidate the influence of historical events on current patterns of biodiversity and can identify patterns of co-vicariance among unrelated taxa that span the same geographic areas. Here we analyze temporal and spatial divergence patterns of cloud forest plant and animal species and relate them to the evolutionary history of naturally fragmented cloud forests--among the most threatened vegetation types in northern Mesoamerica. We used comparative phylogeographic analyses to identify patterns of co-vicariance in taxa that share geographic ranges across cloud forest habitats and to elucidate the influence of historical events on current patterns of biodiversity. We document temporal and spatial genetic divergence of 15 species (including seed plants, birds and rodents, and relate them to the evolutionary history of the naturally fragmented cloud forests. We used fossil-calibrated genealogies, coalescent-based divergence time inference, and estimates of gene flow to assess the permeability of putative barriers to gene flow. We also used the hierarchical Approximate Bayesian Computation (HABC method implemented in the program msBayes to test simultaneous versus non-simultaneous divergence of the cloud forest lineages. Our results show shared phylogeographic breaks that correspond to the Isthmus of Tehuantepec, Los Tuxtlas, and the Chiapas Central Depression, with the Isthmus representing the most frequently shared break among taxa. However, dating analyses suggest that the phylogeographic breaks corresponding to the Isthmus occurred at different times in different taxa. Current divergence patterns are therefore consistent with the hypothesis of broad vicariance across the Isthmus of Tehuantepec derived from different mechanisms operating at different times. This study, coupled with existing data on divergence cloud forest species, indicates that the evolutionary history of contemporary cloud forest lineages is complex

  3. Revitalizing sociology: urban life and mental illness between history and the present.

    Science.gov (United States)

    Fitzgerald, Des; Rose, Nikolas; Singh, Ilina

    2016-03-01

    This paper proposes a re-thinking of the relationship between sociology and the biological sciences. Tracing lines of connection between the history of sociology and the contemporary landscape of biology, the paper argues for a reconfiguration of this relationship beyond popular rhetorics of 'biologization' or 'medicalization'. At the heart of the paper is a claim that, today, there are some potent new frames for re-imagining the traffic between sociological and biological research - even for 'revitalizing' the sociological enterprise as such. The paper threads this argument through one empirical case: the relationship between urban life and mental illness. In its first section, it shows how this relationship enlivened both early psychiatric epidemiology, and some forms of the new discipline of sociology; it then traces the historical division of these sciences, as the sociological investment in psychiatric questions waned, and 'the social' become marginalized within an increasingly 'biological' psychiatry. In its third section, however, the paper shows how this relationship has lately been revivified, but now by a nuanced epigenetic and neurobiological attention to the links between mental health and urban life. What role can sociology play here? In its final section, the paper shows how this older sociology, with its lively interest in the psychiatric and neurobiological vicissitudes of urban social life, can be our guide in helping to identify intersections between sociological and biological attention. With a new century now underway, the paper concludes by suggesting that the relationship between urban life and mental illness may prove a core testing-ground for a 'revitalized' sociology. © London School of Economics and Political Science 2016.

  4. Origin and Dispersal History of Two Colonial Ascidian Clades in the Botryllus schlosseri Species Complex.

    Directory of Open Access Journals (Sweden)

    Marie L Nydam

    Full Text Available Human-induced global warming and species introductions are rapidly altering the composition and functioning of Earth's marine ecosystems. Ascidians (Phylum Chordata, Subphylum Tunicata, Class Ascidiacea are likely to play an increasingly greater role in marine communities. The colonial ascidian B. schlosseri is a cryptic species complex comprising five genetically divergent clades (A-E. Clade A is a global species, and Clade E has so far been identified in European waters only. Using the largest mitochondrial cytochrome oxidase I datasets yet assembled, we determine the origin and dispersal history of these species. Nucleotide diversity and Approximate Bayesian Computation analyses support a Pacific origin for Clade A, with two likely dispersal scenarios that both show the northwestern Atlantic populations establishing early in the history of the species. Both Discrete Phylogeographic Analysis and Approximate Bayesian Computation support an origin of Clade E on the French side of the English Channel. An unsampled lineage evolved from the French lineage, which reflects the conclusion from the median joining network that not all Clade E lineages have been sampled. This unsampled lineage gave rise to the haplotypes on the English side of the English Channel, which were the ancestors to the Mediterranean and Bay of Biscay populations. Clade E has a wider geographic range than previously thought, and shows evidence of recent range expansion. Both Clade A and Clade E should be considered widespread species: Clade A globally and Clade E within Europe.

  5. Origin and Dispersal History of Two Colonial Ascidian Clades in the Botryllus schlosseri Species Complex.

    Science.gov (United States)

    Nydam, Marie L; Giesbrecht, Kirsten B; Stephenson, Emily E

    2017-01-01

    Human-induced global warming and species introductions are rapidly altering the composition and functioning of Earth's marine ecosystems. Ascidians (Phylum Chordata, Subphylum Tunicata, Class Ascidiacea) are likely to play an increasingly greater role in marine communities. The colonial ascidian B. schlosseri is a cryptic species complex comprising five genetically divergent clades (A-E). Clade A is a global species, and Clade E has so far been identified in European waters only. Using the largest mitochondrial cytochrome oxidase I datasets yet assembled, we determine the origin and dispersal history of these species. Nucleotide diversity and Approximate Bayesian Computation analyses support a Pacific origin for Clade A, with two likely dispersal scenarios that both show the northwestern Atlantic populations establishing early in the history of the species. Both Discrete Phylogeographic Analysis and Approximate Bayesian Computation support an origin of Clade E on the French side of the English Channel. An unsampled lineage evolved from the French lineage, which reflects the conclusion from the median joining network that not all Clade E lineages have been sampled. This unsampled lineage gave rise to the haplotypes on the English side of the English Channel, which were the ancestors to the Mediterranean and Bay of Biscay populations. Clade E has a wider geographic range than previously thought, and shows evidence of recent range expansion. Both Clade A and Clade E should be considered widespread species: Clade A globally and Clade E within Europe.

  6. Assessing variation in life-history tactics within a population using mixture regression models: a practical guide for evolutionary ecologists.

    Science.gov (United States)

    Hamel, Sandra; Yoccoz, Nigel G; Gaillard, Jean-Michel

    2017-05-01

    violated in life-history data. Mixed models were quite robust to this violation in the sense that fixed effects were unbiased at the population level. However, fixed effects at the cluster level and random effects were better estimated using mixture models. Our empirical analyses demonstrated that using mixture models facilitates the identification of the diversity of growth and reproductive tactics occurring within a population. Therefore, using this modelling framework allows testing for the presence of clusters and, when clusters occur, provides reliable estimates of fixed and random effects for each cluster of the population. In the presence or expectation of clusters, using mixture models offers a suitable extension of mixed models, particularly when evolutionary ecologists aim at identifying how ecological and evolutionary processes change within a population. Mixture regression models therefore provide a valuable addition to the statistical toolbox of evolutionary ecologists. As these models are complex and have their own limitations, we provide recommendations to guide future users. © 2016 Cambridge Philosophical Society.

  7. Violence, teenage pregnancy, and life history : ecological factors and their impact on strategy-driven behavior.

    Science.gov (United States)

    Copping, Lee T; Campbell, Anne; Muncer, Steven

    2013-06-01

    Guided by principles of life history strategy development, this study tested the hypothesis that sexual precocity and violence are influenced by sensitivities to local environmental conditions. Two models of strategy development were compared: The first is based on indirect perception of ecological cues through family disruption and the second is based on both direct and indirect perception of ecological stressors. Results showed a moderate correlation between rates of violence and sexual precocity (r = 0.59). Although a model incorporating direct and indirect effects provided a better fit than one based on family mediation alone, significant improvements were made by linking some ecological factors directly to behavior independently of strategy development. The models support the contention that violence and teenage pregnancy are part of an ecologically determined pattern of strategy development and suggest that while the family unit is critical in affecting behavior, individuals' direct experiences of the environment are also important.

  8. Spatial variation in life history characteristics of common megrim (Lepidorhombus whiffiagonis) on the Northern Shelf

    Science.gov (United States)

    Macdonald, P.; Angus (née Laurenson), C. H.; Marshall, C. T.

    2013-01-01

    In recent years stock structure recommendations for megrim on the Northern Shelf have varied, primarily due to a lack of biological and fishery data. In this study, we compared a number of life history characteristics of the common megrim Lepidorhombus whiffiagonis (Walbaum) between the northern North Sea and Rockall, the latitudinal extremes of the species' distribution on the Northern Shelf. Reproductive timing, sex ratio, maturity and growth were different between the two study areas. Reproductive timing in the northern North Sea was more protracted than at Rockall and other areas. There were differences in sex ratio between the study areas and female megrim in the northern North Sea exhibited different growth rates and larger size at maturity than at Rockall. The results of this study support the recent changes to the definition of the Northern Shelf stocks which recommend that the northern North Sea be treated separately to Rockall.

  9. Viviparity and K-selected life history in a Mesozoic marine plesiosaur (Reptilia, Sauropterygia).

    Science.gov (United States)

    O'Keefe, F R; Chiappe, L M

    2011-08-12

    Viviparity is known in several clades of Mesozoic aquatic reptiles, but evidence for it is lacking in the Plesiosauria. Here, we report a Late Cretaceous plesiosaur fossil consisting of a fetus preserved within an adult of the same taxon. We interpret this occurrence as a gravid female and unborn young and hence as definitive evidence for plesiosaur viviparity. Quantitative analysis indicates that plesiosaurs gave birth to large, probably single progeny. The combination of viviparity, large offspring size, and small brood number differs markedly from the pattern seen in other marine reptiles but does resemble the K-selected strategy of all extant marine mammals and a few extant lizards. Plesiosaurs may have shared other life history traits with these clades, such as sociality and maternal care.

  10. Attachment within life history theory: an evolutionary perspective on individual differences in attachment.

    Science.gov (United States)

    Szepsenwol, Ohad; Simpson, Jeffry A

    2018-03-15

    In this article, we discuss theory and research on how individual differences in adult attachment mediate the adaptive calibration of reproductive strategies, cognitive schemas, and emotional expression and regulation. We first present an integration of attachment theory and life history theory. Then, we discuss how early harsh and/or unpredictable environments may promote insecure attachment by hampering parents' ability to provide sensitive and reliable care to their children. Finally, we discuss how, in the context of harsh and/or unpredictable environments, different types of insecure attachment (i.e. anxiety and avoidance) may promote evolutionary adaptive reproductive strategies, cognitive schemas, and emotional expression and regulation profiles. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. The ASTRA (Ancient instruments Sound/Timbre Reconstruction Application) Project brings history to life!

    Science.gov (United States)

    Avanzo, Salvatore; Barbera, Roberto; de Mattia, Francesco; Rocca, Giuseppe La; Sorrentino, Mariapaola; Vicinanza, Domenico

    ASTRA (Ancient instruments Sound/Timbre Reconstruction Application) is a project coordinated at Conservatory of Music of Parma which aims to bring history to life. Ancient musical instruments can now be heard for the first time in hundreds of years, thanks to the successful synergy between art/humanities and science. The Epigonion, an instrument of the past, has been digitally recreated using gLite, an advanced middleware developed in the context of the EGEE project and research networks such as GÉANT2 in Europe and EUMEDCONNECT2 in the Mediterranean region. GÉANT2 and EUMEDCONNECT2, by connecting enormous and heterogeneous computing resources, provided the needed infrastructures to speed up the overall computation time and enable the computer-intensive modeling of musical sounds. This paper summarizes the most recent outcomes of the project underlining how the Grid aspect of the computation can support the Cultural Heritage community.

  12. Ancient biomolecules: their origins, fossilization, and role in revealing the history of life.

    Science.gov (United States)

    Briggs, Derek E G; Summons, Roger E

    2014-05-01

    The discovery of traces of a blood meal in the abdomen of a 50-million-year-old mosquito reminds us of the insights that the chemistry of fossils can provide. Ancient DNA is the best known fossil molecule. It is less well known that new fossil targets and a growing database of ancient gene sequences are paralleled by discoveries on other classes of organic molecules. New analytical tools, such as the synchrotron, reveal traces of the original composition of arthropod cuticles that are more than 400 my old. Pigments such as melanin are readily fossilized, surviving virtually unaltered for ∼200 my. Other biomarkers provide evidence of microbial processes in ancient sediments, and have been used to reveal the presence of demosponges, for example, more than 635 mya, long before their spicules appear in the fossil record. Ancient biomolecules are a powerful complement to fossil remains in revealing the history of life. © 2014 WILEY Periodicals, Inc.

  13. A burning story: The role of fire in the history of life

    Science.gov (United States)

    Pausas, J.G.; Keeley, J.E.

    2009-01-01

    Ecologists, biogeographers, and paleobotanists have long thought that climate and soils controlled the distribution of ecosystems, with the role of fire getting only limited appreciation. Here we review evidence from different disciplines demonstrating that wildfire appeared concomitant with the origin of terrestrial plants and played an important role throughout the history of life. The importance of fire has waxed and waned in association with changes in climate and paleoatmospheric conditions. Well before the emergence of humans on Earth, fire played a key role in the origins of plant adaptations as well as in the distribution of ecosystems. Humans initiated a new stage in ecosystem fire, using it to make the Earth more suited to their lifestyle. However, as human populations have expanded their use of fire, their actions have come to dominate some ecosystems and change natural processes in ways that threaten the sustainability of some landscapes. ?? 2009 by American Institute of Biological Sciences.

  14. Work Identity and Contradictory Experiences of Welfare Workers in a Life-history Perspective

    DEFF Research Database (Denmark)

    Dybbroe, Betina

    2013-01-01

    of identification. Social dynamics interact with subjective dynamics in ways that illuminate not only habitual and creative orientations and practices of professionals in care, but also the contradictory transformations of the work, e.g. marketization and democratization in the work place.......»Arbeitsidentität und widersprüchliche Erfahrungen in der Lebensgeschichte von Sozialarbeiter/innen und Krankenschwestern«. Transformation of the welfare sectors challenge professional identities of care and welfare workers in Scandinavia. At the same time welfare and care workers take part...... of Alfred Lorenzer's cultural theory is applied to understand societal transformations, here in the work place and of professionals in relation to their present scene of work and in relation to their life history. Two concepts are applied, interaction form and scenic understanding, because...

  15. How life history characteristics and environmental forcing shape settlement success of coral reef fishes

    DEFF Research Database (Denmark)

    Wong-Ala, Jennifer; Comfort, Christina; Gove, Jamison

    2018-01-01

    Larval settlement is shaped by the interaction of biological processes (e.g., life history strategies, behavior etc.) and the environment (e.g., temperature, currents etc.). This is particularly true for many reef fishes where larval stages disperse offshore, often spending weeks to months...... in the pelagic realm before settling to shallow-water reefs. Our ability to predict reef fish settlement and subsequent recruitment and population dynamics depends on our ability to characterize how biological processes interact with the dynamic physical environment. Here we develop and apply an individual......-based model that combines biological processes with high-resolution physical forcing to predict larval fish dispersal and settlement over time and space. Our model tracks individual larval fish from spawning to settlement and allows for the inclusion of biologically relevant stochasticity (individual...

  16. Spatially varying selection shapes life history clines among populations of Drosophila melanogaster from sub-Saharan Africa.

    Science.gov (United States)

    Fabian, D K; Lack, J B; Mathur, V; Schlötterer, C; Schmidt, P S; Pool, J E; Flatt, T

    2015-04-01

    Clines in life history traits, presumably driven by spatially varying selection, are widespread. Major latitudinal clines have been observed, for example, in Drosophila melanogaster, an ancestrally tropical insect from Africa that has colonized temperate habitats on multiple continents. Yet, how geographic factors other than latitude, such as altitude or longitude, affect life history in this species remains poorly understood. Moreover, most previous work has been performed on derived European, American and Australian populations, but whether life history also varies predictably with geography in the ancestral Afro-tropical range has not been investigated systematically. Here, we have examined life history variation among populations of D. melanogaster from sub-Saharan Africa. Viability and reproductive diapause did not vary with geography, but body size increased with altitude, latitude and longitude. Early fecundity covaried positively with altitude and latitude, whereas lifespan showed the opposite trend. Examination of genetic variance-covariance matrices revealed geographic differentiation also in trade-off structure, and QST -FST analysis showed that life history differentiation among populations is likely shaped by selection. Together, our results suggest that geographic and/or climatic factors drive adaptive phenotypic differentiation among ancestral African populations and confirm the widely held notion that latitude and altitude represent parallel gradients. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  17. Endogenous ROS levels in C. elegans under exogenous stress support revision of oxidative stress theory of life-history tradeoffs.

    Science.gov (United States)

    Smith, Samson W; Latta, Leigh C; Denver, Dee R; Estes, Suzanne

    2014-07-24

    The oxidative stress theory of life-history tradeoffs states that oxidative stress caused by damaging free radicals directly underpins tradeoffs between reproduction and longevity by altering the allocation of energetic resources between these tasks. We test this theory by characterizing the effects of exogenous oxidative insult and its interaction with thermal stress and diet quality on a suite of life-history traits and correlations in Caenorhabditis elegans nematodes. We also quantify demographic aging rates and endogenous reactive oxygen species (ROS) levels in live animals. Our findings indicate a tradeoff between investment in reproduction and antioxidant defense (somatic maintenance) consistent with theoretical predictions, but correlations between standard life-history traits yield little evidence that oxidative stress generates strict tradeoffs. Increasing oxidative insult, however, shows a strong tendency to uncouple positive phenotypic correlations and, in particular, to reduce the correlation between reproduction and lifespan. We also found that mild oxidative insult results in lower levels of endogenous ROS accompanied by hormetic changes in lifespan, demographic aging, and reproduction that disappear in combined-stress treatments--consistent with the oxidative stress theory of aging. Our findings demonstrate that oxidative stress is a direct contributor to life-history trait variation and that traditional tradeoffs are not necessary to invoke oxidative stress as a mediator of relationships between life-history traits, supporting previous calls for revisions to theory.

  18. Joint reconstruction of divergence times and life-history evolution in placental mammals using a phylogenetic covariance model.

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    Lartillot, Nicolas; Delsuc, Frédéric

    2012-06-01

    Violation of the molecular clock has been amply documented, and is now routinely taken into account by molecular dating methods. Comparative analyses have revealed a systematic component in rate variation, relating it to the evolution of life-history traits, such as body size or generation time. Life-history evolution can be reconstructed using Brownian models. However, the resulting estimates are typically uncertain, and potentially sensitive to the underlying assumptions. As a way of obtaining more accurate ancestral trait and divergence time reconstructions, correlations between life-history traits and substitution rates could be used as an additional source of information. In this direction, a Bayesian framework for jointly reconstructing rates, traits, and dates was previously introduced. Here, we apply this model to a 17 protein-coding gene alignment for 73 placental taxa. Our analysis indicates that the coupling between molecules and life history can lead to a reevaluation of ancestral life-history profiles, in particular for groups displaying convergent evolution in body size. However, reconstructions are sensitive to fossil calibrations and to the Brownian assumption. Altogether, our analysis suggests that further integrating inference of rates and traits might be particularly useful for neontological macroevolutionary comparative studies. © 2012 The Author(s). Evolution © 2012 The Society for the Study of Evolution.

  19. The Cosmic Zoo: The (Near Inevitability of the Evolution of Complex, Macroscopic Life

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    William Bains

    2016-06-01

    Full Text Available Life on Earth provides a unique biological record from single-cell microbes to technologically intelligent life forms. Our evolution is marked by several major steps or innovations along a path of increasing complexity from microbes to space-faring humans. Here we identify various major key innovations, and use an analytical toolset consisting of a set of models to analyse how likely each key innovation is to occur. Our conclusion is that once the origin of life is accomplished, most of the key innovations can occur rather readily. The conclusion for other worlds is that if the origin of life can occur rather easily, we should live in a cosmic zoo, as the innovations necessary to lead to complex life will occur with high probability given sufficient time and habitat. On the other hand, if the origin of life is rare, then we might live in a rather empty universe.

  20. Prognosis of remaining useful life for complex engineering systems

    International Nuclear Information System (INIS)

    Hines, J. W.; Usynin, A.; Urmanov, A.

    2006-01-01

    There has been a growing interest in extending conventional maintenance strategies, such as corrective and predictive maintenance, towards the implementations that would allow forecasting of system degradation through a prognostic procedure. The recent progress in sensor and computer technologies employed in complex engineering systems facilitates the integration of model-based and data-driven diagnostics and prognostics leading to condition-based maintenance and extended availability of equipment. This paper describes data-driven models and methods aimed at performing the tasks constituting the diagnostic/prognostic framework. The proposed models and methods allow performing Prognostic and Health Management (PHM) routines over a fleet of equipment populating complex engineering systems. Although several approaches to PHM implementation have been categorized in recently published literature, this paper focuses on PHM techniques associated with observing features related to anomalous system behavior. Observed anomalous patterns in the system behavior are considered to be precursors of impending failures. Measurements taken on the observed deviations are used to deduce a quantitative estimate of how long the system will stay within its specification-defined operational ranges. (authors)

  1. Host life history strategy, species diversity, and habitat influence Trypanosoma cruzi vector infection in Changing landscapes.

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    Nicole L Gottdenker

    Full Text Available Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama.R. pallescens vectors (N = 643 were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3% vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3% dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as r(max, the maximum intrinsic rate of population increase, and habitat type (forest fragments and peridomiciliary sites were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of r(max were positively associated with higher vector infection rate at a site.In this study, anthropogenic landscape disturbance increased vector infection with T. cruzi, potentially by changing host community structure to favor hosts

  2. Variation in brain organization of coral reef fish larvae according to life history traits.

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    Lecchini, David; Lecellier, Gael; Lanyon, Rynae Greta; Holles, Sophie; Poucet, Bruno; Duran, Emilio

    2014-01-01

    In coral reefs, one of the great mysteries of teleost fish ecology is how larvae locate the relatively rare patches of habitat to which they recruit. The recruitment of fish larvae to a reef, after a pelagic phase lasting between 10 and 120 days, depends strongly on larval ability to swim and detect predators, prey and suitable habitat via sensory cues. However, no information is available about the relationship between brain organization in fish larvae and their sensory and swimming abilities at recruitment. For the first time, we explore the structural diversity of brain organization (comparative sizes of brain subdivisions: telencephalon, mesencephalon, cerebellum, vagal lobe and inferior lobe) among larvae of 25 coral reef fish species. We then investigate links between variation in brain organization and life history traits (swimming ability, pelagic larval duration, social behavior, diel activity and cue use relying on sensory perception). After accounting for phylogeny with independent contrasts, we found that brain organization covaried with some life history traits: (1) fish larvae with good swimming ability (>20 cm/s), a long pelagic duration (>30 days), diurnal activity and strong use of cues relying on sensory perception for detection of recruitment habitat had a larger cerebellum than other species. (2) Fish larvae with a short pelagic duration (fish larvae exhibiting solitary behavior during their oceanic phase had larger inferior and vagal lobes. Overall, we hypothesize that a well-developed cerebellum may allow fish larvae to improve their chances of successful recruitment after a long pelagic phase in the ocean. Our study is the first one to bring together quantitative information on brain organization and the relative development of major brain subdivisions across coral reef fish larvae, and more specifically to address the way in which this variation correlates with the recruitment process.

  3. Responses of coral reef fishes to past climate changes are related to life-history traits.

    Science.gov (United States)

    Ottimofiore, Eduardo; Albouy, Camille; Leprieur, Fabien; Descombes, Patrice; Kulbicki, Michel; Mouillot, David; Parravicini, Valeriano; Pellissier, Loïc

    2017-03-01

    Coral reefs and their associated fauna are largely impacted by ongoing climate change. Unravelling species responses to past climatic variations might provide clues on the consequence of ongoing changes. Here, we tested the relationship between changes in sea surface temperature and sea levels during the Quaternary and present-day distributions of coral reef fish species. We investigated whether species-specific responses are associated with life-history traits. We collected a database of coral reef fish distribution together with life-history traits for the Indo-Pacific Ocean. We ran species distribution models (SDMs) on 3,725 tropical reef fish species using contemporary environmental factors together with a variable describing isolation from stable coral reef areas during the Quaternary. We quantified the variance explained independently by isolation from stable areas in the SDMs and related it to a set of species traits including body size and mobility. The variance purely explained by isolation from stable coral reef areas on the distribution of extant coral reef fish species largely varied across species. We observed a triangular relationship between the contribution of isolation from stable areas in the SDMs and body size. Species, whose distribution is more associated with historical changes, occurred predominantly in the Indo-Australian archipelago, where the mean size of fish assemblages is the lowest. Our results suggest that the legacy of habitat changes of the Quaternary is still detectable in the extant distribution of many fish species, especially those with small body size and the most sedentary. Because they were the least able to colonize distant habitats in the past, fish species with smaller body size might have the most pronounced lags in tracking ongoing climate change.

  4. Evolution of male life histories and age-dependent sexual signals under female choice

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    Joel J. Adamson

    2013-12-01

    Full Text Available Sexual selection theory models evolution of sexual signals and preferences using simple life histories. However, life-history models predict that males benefit from increasing sexual investment approaching old age, producing age-dependent sexual traits. Age-dependent traits require time and energy to grow, and will not fully mature before individuals enter mating competition. Early evolutionary stages pose several problems for these traits. Age-dependent traits suffer from strong viability selection and gain little benefit from mate choice when rare. Few males will grow large traits, and they will rarely encounter choosy females. The evolutionary origins of age-dependent traits therefore remain unclear. I used numerical simulations to analyze evolution of preferences, condition (viability and traits in an age-structured population. Traits in the model depended on age and condition (“good genes” in a population with no genetic drift. I asked (1 if age-dependent indicator traits and their preferences can originate depending on the strength of selection and the size of the trait; (2 which mode of development (age-dependent versus age-independent eventually predominates when both modes occur in the population; and (3 if age-independent traits can invade a population with age-dependent traits. Age-dependent traits evolve under weaker selection and at smaller sizes than age-independent traits. This result held in isolation and when the types co-occur. Evolution of age-independent traits depends only on trait size, whereas evolution of age-dependent traits depends on both strength of selection and growth rate. Invasion of age-independence into populations with established traits followed a similar pattern with age-dependence predominating at small trait sizes. I suggest that reduced adult mortality facilitates sexual selection by favoring the evolution of age-dependent sexual signals under weak selection.

  5. Life History Traits, Protein Evolution, and the Nearly Neutral Theory in Amniotes.

    Science.gov (United States)

    Figuet, Emeric; Nabholz, Benoît; Bonneau, Manon; Mas Carrio, Eduard; Nadachowska-Brzyska, Krystyna; Ellegren, Hans; Galtier, Nicolas

    2016-06-01

    The nearly neutral theory of molecular evolution predicts that small populations should accumulate deleterious mutations at a faster rate than large populations. The analysis of nonsynonymous (dN) versus synonymous (dS) substitution rates in birds versus mammals, however, has provided contradictory results, questioning the generality of the nearly neutral theory. Here we analyzed the impact of life history traits, taken as proxies of the effective population size, on molecular evolutionary and population genetic processes in amniotes, including the so far neglected reptiles. We report a strong effect of species body mass, longevity, and age of sexual maturity on genome-wide patterns of polymorphism and divergence across the major groups of amniotes, in agreement with the nearly neutral theory. Our results indicate that the rate of protein evolution in amniotes is determined in the first place by the efficiency of purifying selection against deleterious mutations-and this is true of both radical and conservative amino acid changes. Interestingly, the among-species distribution of dN/dS in birds did not follow this general trend: dN/dS was not higher in large, long-lived than in small, short-lived species of birds. We show that this unexpected pattern is not due to a more narrow range of life history traits, a lack of correlation between traits and Ne, or a peculiar distribution of fitness effects of mutations in birds. Our analysis therefore highlights the bird dN/dS ratio as a molecular evolutionary paradox and a challenge for future research. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Fundamental difference in life history traits of two species of Cataglyphis ants

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    Knaden Markus

    2006-12-01

    Full Text Available Abstract Background The two sympatric species of Tunisian desert ants, Cataglyphis bicolor and C. mauritanica, do not exhibit any differences in their foraging ecology, e.g. in food preferences and in their spatial and temporal activity patterns. Here we show that instead the two species markedly differ in their life histories. Results We analysed mtDNA of specimens that were collected along a 250-km transect. C. bicolor exhibited a genetically unstructured population (with the genetic and geographic distances among colonies not being correlated. On the contrary the populations of the polygynous C. mauritanica were clearly structured, i.e. exhibited a strong correlation between genetic and geographic distances. This difference is in accordance with large queen dispersal distances due to far-reaching mating flights in C. bicolor and small queen dispersal distances due to colony foundation by budding in C. mauritanica. Furthermore, wherever we found populations of both species to coexist within the same habitat, the habitat was used agriculturally. Mapping nest positions over periods of several years showed that plowing dramatically decreased the nest densities of either species. Conclusion We conclude that owing to its greater queen dispersal potential C. bicolor might be more successful in quickly re-colonizing disturbed areas, while the slowly dispersing C. mauritanica could later out-compete C. bicolor by adopting its effective nest-budding strategy. According to this scenario the observed sympatry of the two species might be an intermediate stage in which faster colonization by one species and more powerful exploitation of space by the other species have somehow balanced each other out. In conclusion, C. bicolor and C. mauritanica represent an example where environmental disturbances in combination with different life histories might beget sympatry in congeneric species with overlapping niches.

  7. Leptin affects life history decisions in a passerine bird: a field experiment.

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    Mare Lõhmus

    Full Text Available BACKGROUND: Organisms face trade-offs regarding their life-history strategies, such as decisions of single or multiple broods within a year. In passerines displaying facultative multiple breeding, the probability of laying a second clutch is influenced by several life-history factors. However, information about the mechanistic background of these trade-offs is largely lacking. Leptin is a protein hormone produced by white fat cells, and acts as a signal between peripheral energy depots and the central nervous system. In addition, leptin affects cells at all levels of the reproductive axis and plays a critical role in regulating the allocation of metabolic energy to reproduction. As such, it is possible that leptin levels influence the decision of whether or not to invest time and energy into a second clutch. Accordingly, we expect a treatment with exogenous leptin to result in an increased number of second broods. METHODOLOGY/PRINCIPAL FINDINGS: At a later stage during the first brood, female great tits were treated either with long-term leptin-filled cholesterol pellets (the experimental birds or with pellets containing only cholesterol (the control birds. We found that leptin-treated females were significantly more likely to have a second brood and that the earlier females were more likely to lay a second clutch than the late females. CONCLUSIONS/SIGNIFICANCE: As both timing of first brood and treatment with leptin were important in the decision of having multiple broods, the trade-offs involved in the breeding strategy most likely depend on multiple factors. Presumably leptin has evolved as a signal of energy supply status to regulate the release of reproductive hormones so that reproduction is coordinated with periods of sufficient nutrients. This study investigated the role of leptin as a mediator between energy resources and reproductive output, providing a fundamentally new insight into how trade-offs work on a functional basis.

  8. Phosphorus-mediated changes in life history traits of the invasive New Zealand mudsnail (Potamopyrgus antipodarum).

    Science.gov (United States)

    Tibbets, Teresa M; Krist, Amy C; Hall, Robert O; Riley, Leslie A

    2010-07-01

    Understanding the mechanisms that species use to succeed in new environments is vital to predicting the extent of invasive species impacts. Food quality is potentially important because it can affect population dynamics by affecting life history traits. The New Zealand mudsnail, Potamopyrgus antipodarum, is a worldwide invader. We examined how mudsnail growth rate and fecundity responded to the C:P ratio of algal food in laboratory conditions. Mudsnails fed low-P algae (C:P 1,119) grew more slowly, matured later, produced smaller offspring, and grew to a smaller adult size than snails reared on algae with high levels of P. A relatively small increase in algal C:P (203-270) significantly increased mudsnail age at maturity. We suggest that the relatively high body P requirements of mudsnails make them susceptible to allocation trade-offs between growth and reproduction under P-limited conditions. The elemental composition of algae varies greatly in nature, and over half of the rock biofilms in streams surveyed within the introduced range of mudsnails in the Greater Yellowstone Area had C:P ratios above which could potentially pose P limitation of life history traits. High growth rate and fecundity are common traits of many species that become invasive and are also associated with high-P demands. Therefore, fast-growing consumers with high P demands, such as mudsnails, are potentially more sensitive to P limitation suggesting that limitation of growth and reproduction by food quality is an important factor in understanding the resource demands of invasive species.

  9. Effect of plant nutrition on aphid size, prey consumption, and life history characteristics of green lacewing.

    Science.gov (United States)

    Aqueel, Muhammad A; Collins, Catherine M; Raza, Abu-bakar M; Ahmad, Shahbaz; Tariq, Muhammad; Leather, Simon R

    2014-02-01

    Plant quality can directly and indirectly affect the third trophic level. The predation by all the instars of green lacewing, Chrysoperla carnea (S.) (Neuroptera: Chrysopidae) on the cereal aphids, Rhopalosiphum padi (L.), and Sitobion avenae (F.) at varying nitrogen fertilizer levels was calculated under laboratory conditions. Wheat plants were grown on four nitrogen fertilizer levels and aphids were fed on these plants and subsequently offered as food to the C. carnea. Aphid densities of 10, 30, and 90 were offered to first, second, and third instar larvae of green lacewing. Increased nitrogen application improved nitrogen contents of the plants and also the body weight of cereal aphids feeding on them. Aphid consumption by green lacewings was reduced with the increase in nitrogen content in the host plants of aphids. Predation of both aphid species by first, second, and third instars larvae of C. carnea was highest on aphids reared on plants with the lowest rate of fertilization, suggesting a compensatory consumption to overcome reduced biomass (lower aphid size). Total biomass devoured by C. carnea on all nitrogen fertilizer treatments was not statistically different. Additionally, the heavier host prey influenced by the plant nutrition had an effect on the life history characteristics of green lacewings. The larval duration, pupal weight, pupal duration, fecundity, and male and female longevity were significantly affected by the level of nitrogen fertilization to the aphid's host plants, except for pupal duration when fed on S. avenae. This study showed that quantity of prey supplied to the larvae affects the prey consumption and thereafter the life history characteristics of green lacewings. © 2013 Institute of Zoology, Chinese Academy of Sciences.

  10. Life history, population viability, and the potential for local adaptation in isolated trout populations

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    K.J. Carim

    2017-04-01

    Full Text Available Habitat loss and fragmentation have caused population decline across taxa through impacts on life history diversity, dispersal patterns, and gene flow. Yet, intentional isolation of native fish populations is a frequently used management strategy to protect against negative interactions with invasive fish species. We evaluated the population viability and genetic diversity of 12 isolated populations of Oncorhynchus clarkii lewisi located on the Flathead Indian Reservation in Montana, USA. Length-structured integral projection models (IPMs were used to project population growth rate (lambda and its sensitivity to underlying vital rates and parameters. We examined relationships between lambda, genetic diversity, and habitat size and quality. Lambda ranged from 0.68 to 1.1 with 10 of 12 populations projected to be in decline. A sensitivity analysis of lambda with respect to projection matrix elements indicated that lambda was generally sensitive to changes in early life history stages (survival/growth, but patterns differed among populations. Another sensitivity analysis with respect to underlying model parameters showed highly consistent pattern across populations, with lambda being most sensitive to the slope of probability of maturity (estimated from published literature, generally followed by adult survival, and the slope of somatic growth rate (directly measured from each population. Lambda was not correlated with genetic diversity. For populations residing in small isolated streams (≤5 km of occupied habitat, lambda significantly increased with base flow discharge (r2=0.50, p<0.02. Our results highlight the potential importance of local adaptation for persistence of small, isolated populations. Specifically we saw evidence for higher probability of maturity at smaller sizes in the smallest, coldest isolated systems, increasing probability of persistence for these populations. Climate change threatens to further fragment populations of

  11. Life history traits and exploitation affect the spatial mean-variance relationship in fish abundance.

    Science.gov (United States)

    Kuo, Ting-chun; Mandal, Sandip; Yamauchi, Atsushi; Hsieh, Chih-hao

    2016-05-01

    Fishing is expected to alter the spatial heterogeneity of fishes. As an effective index to quantify spatial heterogeneity, the exponent b in Taylor's power law (V = aMb) measures how spatial variance (V) varies with changes in mean abundance (M) of a population, with larger b indicating higher spatial aggregation potential (i.e., more heterogeneity). Theory predicts b is related with life history traits, but empirical evidence is lacking. Using 50-yr spatiotemporal data from the California Current Ecosystem, we examined fishing and life history effects on Taylor's exponent by comparing spatial distributions of exploited and unexploited fishes living in the same environment. We found that unexploited species with smaller size and generation time exhibit larger b, supporting theoretical prediction. In contrast, this relationship in exploited species is much weaker, as the exponents of large exploited species were higher than unexploited species with similar traits. Our results suggest that fishing may increase spatial aggregation potential of a species, likely through degrading their size/age structure. Results of moving-window cross-correlation analyses on b vs. age structure indices (mean age and age evenness) for some exploited species corroborate our findings. Furthermore, through linking our findings to other fundamental ecological patterns (occupancy-abundance and size-abundance relationships), we provide theoretical arguments for the usefulness of monitoring the exponent b for management purposes. We propose that age/size-truncated species might have lower recovery rate in spatial occupancy, and the spatial variance-mass relationship of a species might be non-linear. Our findings provide theoretical basis explaining why fishery management strategy should be concerned with changes to the age and spatial structure of exploited fishes.

  12. Effect of dietary components on larval life history characteristics in the medfly (Ceratitis capitata: Diptera, Tephritidae.

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    William J Nash

    Full Text Available BACKGROUND: The ability to respond to heterogenous nutritional resources is an important factor in the adaptive radiation of insects such as the highly polyphagous Medfly. Here we examined the breadth of the Medfly's capacity to respond to different developmental conditions, by experimentally altering diet components as a proxy for host quality and novelty. METHODOLOGY/PRINCIPAL FINDINGS: We tested responses of larval life history to diets containing protein and carbohydrate components found in and outside the natural host range of this species. A 40% reduction in the quantity of protein caused a significant increase in egg to adult mortality by 26.5%±6% in comparison to the standard baseline diet. Proteins and carbohydrates had differential effects on larval versus pupal development and survival. Addition of a novel protein source, casein (i.e. milk protein, to the diet increased larval mortality by 19.4%±3% and also lengthened the duration of larval development by 1.93±0.5 days in comparison to the standard diet. Alteration of dietary carbohydrate, by replacing the baseline starch with simple sugars, increased mortality specifically within the pupal stage (by 28.2%±8% and 26.2%±9% for glucose and maltose diets, respectively. Development in the presence of the novel carbohydrate lactose (milk sugar was successful, though on this diet there was a decrease of 29.8±1.6 µg in mean pupal weight in comparison to pupae reared on the baseline diet. CONCLUSIONS: The results confirm that laboratory reared Medfly retain the ability to survive development through a wide range of fluctuations in the nutritional environment. We highlight new facets of the responses of different stages of holometabolous life histories to key dietary components. The results are relevant to colonisation scenarios and key to the biology of this highly invasive species.

  13. Life-history traits in an evergreen Mediterranean oak respond differentially to previous experimental environments

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    J. M. Rey Benayas

    2008-06-01

    Full Text Available Living organisms respond both to current and previous environments, which can have important consequences on population dynamics. However, there is little experimental evidence based on long-term field studies of the effects of previous environments on the performance of individuals. We tested the hypothesis that trees that establish under different environmental conditions perform differently under similar post-establishment conditions. We used the slow-growing, evergreen Mediterranean oak Quercus ilex subsp. rotundifolia as target species. We analyzed the effects of previous environments, competition effects and tradeoffs among life-history traits (survival, growth, and reproduction. We enhanced seedling establishment for three years by reducing abiotic environmental harshness by means of summer irrigation and artificial shading in 12 experimental plots, while four plots remained as controls. Then these treatments were interrupted for ten years. Seedlings under ameliorated environmental conditions survived and grew faster during early establishment. During the post-management period, previous treatments 1 did not have any effect on survival, 2 experienced a slower above-ground growth, 3 decreased root biomass as indicated from reflectivity of Ground Penetration Radar, 4 increased acorn production mostly through a greater canopy volume and 5 increased acorn production effort. The trees exhibited a combination of effects related to acclimation for coping with abiotic stress and effects of intra-specific competition. In accordance with our hypothesis, tree performance overall depended on previous environmental conditions, and the response was different for different life-history traits. We recommend early management because it increased plot cover, shortened the time to attain sexual maturity and increased the amount of acorn production. Plots such as those assessed in this study may act as sources of propagules in deforested

  14. Life-history strategies of the rock hind grouper Epinephelus adscensionis at Ascension Island.

    Science.gov (United States)

    Nolan, E T; Downes, K J; Richardson, A; Arkhipkin, A; Brickle, P; Brown, J; Mrowicki, R J; Shcherbich, Z; Weber, N; Weber, S B

    2017-12-01

    Epinephelus adscensionis sampled from Ascension Island, South Atlantic Ocean, exhibits distinct life-history traits, including larger maximum size and size at sexual maturity than previous studies have demonstrated for this species in other locations. Otolith analysis yielded a maximum estimated age of 25 years, with calculated von Bertalanffy growth parameters of: L ∞  = 55·14, K = 0·19, t 0  = -0·88. Monthly gonad staging and analysis of gonad-somatic index (I G ) provide evidence for spawning from July to November with an I G peak in August (austral winter), during which time somatic growth is also suppressed. Observed patterns of sexual development were supportive of protogyny, although further work is needed to confirm this. Mean size at sexual maturity for females was 28·9 cm total length (L T ; 95% C.I. 27·1-30·7 cm) and no females were found >12 years and 48·0 cm L T , whereas all confirmed males sampled were mature, >35·1 cm L T with an age range from 3 to 18 years. The modelled size at which 50% of individuals were male was 41·8 cm (95% C.I. 40·4-43·2 cm). As far as is known, this study represents the first comprehensive investigation into the growth and reproduction of E. adscensionis at its type locality of Ascension Island and suggests that the population may be affected less by fisheries than elsewhere in its range. Nevertheless, improved regulation of the recreational fishery and sustained monitoring of abundance, length frequencies and life-history parameters are needed to inform long-term management measures, which could include the creation of marine reserves, size or temporal catch limits and stricter export controls. © 2017 The Fisheries Society of the British Isles.

  15. Comparison of life history parameters of two Frankliniella occidentalis (Thysanoptera: Thripidae) strains in New Zealand.

    Science.gov (United States)

    Nielsen, M-C; Teulon, D A J; Chapman, R B; Butler, R C; Drayton, G M; Philipsen, H

    2010-04-01

    Two strains of western flower thrips, Frankliniella occidentalis (Pergande), are reputedly found in New Zealand. One strain was recorded in 1934, and it is most common in flowers of Lupinus arboreus outdoors (lupin strain); the other strain was first recorded in New Zealand in 1992 and is found mostly indoors on greenhouse crops (greenhouse strain). Laboratory studies were conducted to compare the life history parameters of these two strains. Thrips from each strain were fed sucrose solution and capsicum or lupin pollen and reared at 25 degrees C, >60% RH, and 16 L:8 D photoperiod. Significant differences in life history parameters were found. Preoviposition time was significantly shorter, and oviposition rate and fecundity were markedly higher (four-fold) for the greenhouse than for the lupin strain. The lupin strain performed significantly better on the capsicum pollen, laying more than twice as many eggs than on the lupin pollen over a 14-d period. The greenhouse strain development time from larvae to adult was marginally faster (0.7-1.1 d less) than the lupin strain because of a shorter prepupal and a marginally shorter pupal development time. Females of the greenhouse strain lived on average 69% longer than females from the lupin strain. Large differences in the intrinsic growth rate (r(m)) were found, with r(m) being 1.4-1.8 times higher for the greenhouse strain than the lupin strain, depending on pollen source. The results are discussed in relation to different ecological requirements and pest status of the two strains.

  16. Stressful life events and psychological dysfunction in complex regional pain syndrome type I

    NARCIS (Netherlands)

    Geertzen, JHB; de Bruijn-Kofman, AT; de Bruijn, HP; van de Wiel, HBM; Dijkstra, PU

    Objective: To determine to what extent stressful life events and psychological dysfunction play a role in the pathogenesis of Complex Regional Pain Syndrome type I (CRPS). Design: A comparative study between a CRPS group and a control group. Stressful life events and psychological dysfunction

  17. The South China Sea Deep: A Research Project on Life History of Marginal Sea

    Science.gov (United States)

    Wang, P.

    2011-12-01

    A major research project has been launched in China to investigate evolution and various processes in the deep-water part a of the South China Sea. The "South China Sea Deep" project (2011-2018) is supported by the NSF of China with a total budget no less than ~23 US Dollar (150 Million Chinese yuan), and covers a broad spectrum of scientific topics. Advanced geophysical and geochemical tools will be applied to re-estimate the age of its oceanic crust, to verify the existence of the "Hainan Mantle Plume", and to explore the origin of volcanic chains in the deep basin. Sedimentary archives, both off-shore and on-shore, will be analyzed to reconstruct the history of sediment response to the basin evolution, with focus on changes of deep-water circulation driven by tectonic deformation of the basin. Deep-water observations will be organized to examine near-bottom sediment transport, methane seepages, and microbial distribution and ecology above and below sea-floor. With a combination of tectonic-magmatic, sedimentologic-paleoceanographic, and microbiological-geochemical approaches, the project is expected to reveal the life history of the South China Sea, the largest low-latitude marginal sea in the modern world. Recent progress of the project will be presented, and perspectives of international cooperation will be discussed.

  18. [Anxiety, life style and obstetric history of women working in a high-fashion clothing industry].

    Science.gov (United States)

    Kouri, S; Di Giampaolo, L; Toto, E; Cerrone, T; Boscolo, P

    2001-01-01

    Women with a mean age of 38 years (range 20-62) were employed in an industry producing clothes of high fashion. A part of them (n = 210) performed their activities with hands and others (n = 90) utilising machines with more repetitive procedures. All the recruited women answered to a questionnaire including the state-trait anxiety inventory (STAI) test, working activities, lifestyle and obstetric history. There was no relation between obstetric history and working activities. The group of women with age ranging from 35 to 42 years showed the score of the STAI higher than that of the younger women and slightly lower than that of the subjects with older age. This may depend on the "healthy worker effect" in the old subjects able to continue their job. The scores of the STAI were also slightly influenced by the repetitive tasks utilising machines. On the whole, the working activity of women had beneficial effect on their role inside the family and in the social life.

  19. Morphological homoplasy, life history evolution, and historical biogeography of plethodontid salamanders inferred from complete mitochondrial genomes

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Rachel Lockridge; Macey, J. Robert; Jaekel, Martin; Wake, David B.; Boore, Jeffrey L.

    2004-08-01

    The evolutionary history of the largest salamander family (Plethodontidae) is characterized by extreme morphological homoplasy. Analysis of the mechanisms generating such homoplasy requires an independent, molecular phylogeny. To this end, we sequenced 24 complete mitochondrial genomes (22 plethodontids and two outgroup taxa), added data for three species from GenBank, and performed partitioned and unpartitioned Bayesian, ML, and MP phylogenetic analyses. We explored four dataset partitioning strategies to account for evolutionary process heterogeneity among genes and codon positions, all of which yielded increased model likelihoods and decreased numbers of supported nodes in the topologies (PP > 0.95) relative to the unpartitioned analysis. Our phylogenetic analyses yielded congruent trees that contrast with the traditional morphology-based taxonomy; the monophyly of three out of four major groups is rejected. Reanalysis of current hypotheses in light of these new evolutionary relationships suggests that (1) a larval life history stage re-evolved from a direct-developing ancestor multiple times, (2) there is no phylogenetic support for the ''Out of Appalachia'' hypothesis of plethodontid origins, and (3) novel scenarios must be reconstructed for the convergent evolution of projectile tongues, reduction in toe number, and specialization for defensive tail loss. Some of these novel scenarios imply morphological transformation series that proceed in the opposite direction than was previously thought. In addition, they suggest surprising evolutionary lability in traits previously interpreted to be conservative.

  20. Impact of depression on quality of life of patients having history of recent myocardial infarction

    Directory of Open Access Journals (Sweden)

    Hemanta Dutta

    2015-01-01

    Full Text Available Background: Major depressive disorder is very common in patients having history of myocardial infarction (MI. Quality of life (QOL is seen to be poorer in persons having post MI depression than who are non depressed. Aims: To compare QOL between depressed and non depressed patients with history of recent MI. Settings and design: The study was conducted on patients of acute MI (n=50 attending cardiology outpatient department of Assam Medical College Hospital, Dibrugarh, Assam, India at four to six weeks after the index event. Methods: Screening and diagnosis of depression were done by Primary Care Evaluation of Mental Disorder (PRIME-MD and the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV, respectively. Severity of depression was assessed by Beck Depression Inventory (BDI. QOL was assessed twice, four to six and six to eight weeks after the index event by the World Health Organization QOL (WHOQOL scale. Comparisons of QOL between depressed and non depressed patients were done by standard statistical procedures. Results: The results showed that there was significant variation in QOL (p<0.0001 in non depression and depression groups. More deterioration was seen in psychological domain than other domains of QOL scale in subsequent visit. Conclusion: The non depressed MI patients scored higher in all domains of QOL than the depressed group. Routine screening of depressive symptoms should be mandatory in post MI patient to provide a holistic approach to the patient.