Molecular phylogeny, morphology, pigment chemistry and ecology in Hygrophoraceae (Agaricales)

Science.gov (United States)

D. Jean Lodge; Mahajabeen Padamsee; P. Brandon Matheny; M. Catherine Aime; Sharon A. Cantrell; David Boertmann; Alexander Kovalenko; Alfredo Vizzini; Bryn T.M. Dentinger; Paul M. Kirk; A. Martin Ainsworth; Jean-Marc Moncalvo; Rytas Vilgalys; Ellen Larsson; Robert Lucking; Gareth W. Griffith; Matthew E. Smith; Lorilei L. Norvell; Dennis E. Desjardin; Scott A. Redhead; Clark L. Ovrebo; Edgar B. Lickey; Enrico Ercole; Karen W. Hughes; Regis Courtecuisse; Anthony Young; Manfred Binder; Andrew M. Minnis; Daniel L. Lindner; Beatriz Ortiz-Santana; John Haight; Thomas Laessoe; Timothy J. Baroni; Jozsef Geml; Tsutomu Hattori

2013-01-01

Molecular phylogenies using 1–4 gene regions and information on ecology, morphology and pigment chemistry were used in a partial revision of the agaric family Hygrophoraceae. The phylogenetically supported genera we recognize here in the Hygrophoraceae based on these and previous analyses are: Acantholichen, Ampulloclitocybe, Arrhenia, Cantharellula, Cantharocybe,...

Molecules, morphology, and ecology indicate a recent, amphibious ancestry for echidnas.

Science.gov (United States)

Phillips, Matthew J; Bennett, Thomas H; Lee, Michael S Y

2009-10-06

The semiaquatic platypus and terrestrial echidnas (spiny anteaters) are the only living egg-laying mammals (monotremes). The fossil record has provided few clues as to their origins and the evolution of their ecological specializations; however, recent reassignment of the Early Cretaceous Teinolophos and Steropodon to the platypus lineage implies that platypuses and echidnas diverged >112.5 million years ago, reinforcing the notion of monotremes as living fossils. This placement is based primarily on characters related to a single feature, the enlarged mandibular canal, which supplies blood vessels and dense electrosensory receptors to the platypus bill. Our reevaluation of the morphological data instead groups platypus and echidnas to the exclusion of Teinolophos and Steropodon and suggests that an enlarged mandibular canal is ancestral for monotremes (partly reversed in echidnas, in association with general mandibular reduction). A multigene evaluation of the echidna-platypus divergence using both a relaxed molecular clock and direct fossil calibrations reveals a recent split of 19-48 million years ago. Platypus-like monotremes (Monotrematum) predate this divergence, indicating that echidnas had aquatically foraging ancestors that reinvaded terrestrial ecosystems. This ecological shift and the associated radiation of echidnas represent a recent expansion of niche space despite potential competition from marsupials. Monotremes might have survived the invasion of marsupials into Australasia by exploiting ecological niches in which marsupials are restricted by their reproductive mode. Morphology, ecology, and molecular biology together indicate that Teinolophos and Steropodon are basal monotremes rather than platypus relatives, and that living monotremes are a relatively recent radiation.

Exploring the nature of ecological specialization in a coral reef fish community: morphology, diet and foraging microhabitat use.

Science.gov (United States)

Brandl, Simon J; Robbins, William D; Bellwood, David R

2015-09-22

Patterns of ecological specialization offer invaluable information about ecosystems. Yet, specialization is rarely quantified across several ecological niche axes and variables beyond the link between morphological and dietary specialization have received little attention. Here, we provide a quantitative evaluation of ecological specialization in a coral reef fish assemblage (f. Acanthuridae) along one fundamental and two realized niche axes. Specifically, we examined ecological specialization in 10 surgeonfish species with regards to morphology and two realized niche axes associated with diet and foraging microhabitat utilization using a recently developed multidimensional framework. We then investigated the potential relationships between morphological and behavioural specialization. These relationships differed markedly from the traditional ecomorphological paradigm. While morphological specialization showed no relationship with dietary specialization, it exhibited a strong relationship with foraging microhabitat specialization. However, this relationship was inverted: species with specialized morphologies were microhabitat generalists, whereas generalized morphotypes were microhabitat specialists. Interestingly, this mirrors relationships found in plant-pollinator communities and may also be applicable to other ecosystems, highlighting the potential importance of including niche axes beyond dietary specialization into ecomorphological frameworks. On coral reefs, it appears that morphotypes commonly perceived as most generalized may, in fact, be specialized in exploiting flat and easily accessible microhabitats. © 2015 The Author(s).

Morphological evolution, ecological diversification and climate change in rodents

OpenAIRE

Renaud, Sabrina; Michaux, Jacques; Schmidt, Daniela N; Aguilar, Jean-Pierre; Mein, Pierre; Auffray, Jean-Christophe

2005-01-01

Among rodents, the lineage from Progonomys hispanicus to Stephanomys documents a case of increasing size and dental specialization during an approximately 9 Myr time-interval. On the contrary, some contemporaneous generalist lineages like Apodemus show a limited morphological evolution. Dental shape can be related to diet and can be used to assess the ecological changes along the lineages. Consequently, size and shape of the first upper molar were measured in order to quantify the patterns of...

Intraspecific morphological and genetic differentiation in Scrophularia grayana (Scrophulariaceae).

Science.gov (United States)

Kamada, Takuro; Yamashiro, Tadashi; Maki, Masayuki

2007-05-01

Scrophularia grayana, which is distributed throughout northern Japan and Sakhalin, and its locally endemic variety var. grayanoides, have been examined morphometrically and genetically. Principal-component analysis using a total of 26 morphological characteristics revealed that these taxa are morphologically differentiated, but that the difference is not distinct. These two taxa have the same number of chromosomes in the somatic cells, 2n = 94, suggesting that ploidal level difference is not relevant to their divergence. The distributions of the taxa are adjoining in the north of Japanese mainland Honshu. Nevertheless, principal-coordinate analysis using putative 112 ISSR loci indicated they are genetically very distinct. Many taxon-specific alleles were found, and many of the alleles were fixed in each taxon. This genetic information suggests that a relatively long time has passed since the taxa became differentiated and that gene flow has rarely occurred between them, although morphological similarity has been maintained, probably because of natural selective forces.

Radiating despite a Lack of Character: Ecological Divergence among Closely Related, Morphologically Similar Honeyeaters (Aves: Meliphagidae) Co-occurring in Arid Australian Environments.

Science.gov (United States)

Miller, Eliot T; Wagner, Sarah K; Harmon, Luke J; Ricklefs, Robert E

2017-02-01

Quantifying the relationship between form and function can inform use of morphology as a surrogate for ecology. How the strength of this relationship varies continentally can inform understanding of evolutionary radiations; for example, does the relationship break down when certain lineages invade and diversify in novel habitats? The 75 species of Australian honeyeaters (Meliphagidae) are morphologically and ecologically diverse, with species feeding on nectar, insects, fruit, and other resources. We investigated Meliphagidae ecomorphology and community structure by (1) quantifying the concordance between morphology and ecology (foraging behavior), (2) estimating rates of trait evolution in relation to the packing of ecological space, and (3) comparing phylogenetic and trait community structure across the broad environmental gradients of the continent. We found that morphology explained 37% of the variance in ecology (and 62% vice versa), and we uncovered well-known bivariate relationships among the multivariate ecomorphological data. Ecological trait diversity declined less rapidly than phylogenetic diversity along a gradient of decreasing precipitation. We employ a new method (trait fields) and extend another (phylogenetic fields) to show that while species in phylogenetically clustered, arid-environment assemblages are similar morphologically, they are as varied in foraging behavior as those from more diverse assemblages. Thus, although closely related and similar morphologically, these arid-adapted species have diverged in ecological space to a similar degree as their mesic counterparts.

Quantitative assessment of the relationships among ecological, morphological and aesthetic values in a river rehabilitation initiative.

Science.gov (United States)

McCormick, Ashlee; Fisher, Karen; Brierley, Gary

2015-04-15

Promoting community support in rehabilitation efforts through incorporation of aesthetic considerations is an important component of environmental management. This research utilised a small-scale survey methodology to explore relationships among the ecological and morphological goals of scientists and the aesthetic goals of the public using the Twin Streams Catchment, Auckland, New Zealand, as a case study. Analyses using a linear model and a generalised linear mixed model showed statistically significant relationships between perceived naturalness of landscapes and their aesthetic ratings, and among ratings of perceived naturalness and ecological integrity and morphological condition. Expert measures of health and the aesthetic evaluations of the public were well aligned, indicating public preferences for landscapes of high ecological integrity with good morphological condition. Further analysis revealed participants used 'cues to care' to rate naturalness. This suggests that environmental education endeavours could further align values with these cues in efforts to enhance approaches to landscape sustainability. Copyright © 2014 Elsevier Ltd. All rights reserved.

The role of habitat shift in the evolution of lizard morphology: evidence from tropical Tropidurus

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Vitt, Laurie J.; Caldwell, Janalee P.; Zani, Peter A.; Titus, Tom A.

1997-01-01

We compared morphology of two geographically close populations of the tropical lizard Tropidurus hispidus to test the hypothesis that habitat structure influences the evolution of morphology and ecology at the population level. T. hispidus isolated on a rock outcrop surrounded by tropical forest use rock crevices for refuge and appear dorsoventrally compressed compared with those in open savanna. A principal components analysis revealed that the populations were differentially distributed along an axis representing primarily three components of shape: body width, body height, and hind-leg length. Morphological divergence was supported by a principal components analysis of size-free morphological variables. Mitochondrial DNA sequences of ATPase 6 indicate that these populations are closely related relative to other T. hispidus, the rock outcrop morphology and ecology are derived within T. hispidus, and morphological and ecological divergence has occurred more rapidly than genetic divergence. This suggests that natural selection can rapidly adjust morphology and ecology in response to a recent history of exposure to habitats differing in structure, a result heretofore implied from comparative studies among lizard species. PMID:9108063

The role of habitat shift in the evolution of lizard morphology: evidence from tropical Tropidurus.

Science.gov (United States)

Vitt, L J; Caldwell, J P; Zani, P A; Titus, T A

1997-04-15

We compared morphology of two geographically close populations of the tropical lizard Tropidurus hispidus to test the hypothesis that habitat structure influences the evolution of morphology and ecology at the population level. T. hispidus isolated on a rock outcrop surrounded by tropical forest use rock crevices for refuge and appear dorsoventrally compressed compared with those in open savanna. A principal components analysis revealed that the populations were differentially distributed along an axis representing primarily three components of shape: body width, body height, and hind-leg length. Morphological divergence was supported by a principal components analysis of size-free morphological variables. Mitochondrial DNA sequences of ATPase 6 indicate that these populations are closely related relative to other T. hispidus, the rock outcrop morphology and ecology are derived within T. hispidus, and morphological and ecological divergence has occurred more rapidly than genetic divergence. This suggests that natural selection can rapidly adjust morphology and ecology in response to a recent history of exposure to habitats differing in structure, a result heretofore implied from comparative studies among lizard species.

Evolutionary conservatism and convergence both lead to striking similarity in ecology, morphology and performance across continents in frogs.

Science.gov (United States)

Moen, Daniel S; Irschick, Duncan J; Wiens, John J

2013-12-22

Many clades contain ecologically and phenotypically similar species across continents, yet the processes generating this similarity are largely unstudied, leaving fundamental questions unanswered. Is similarity in morphology and performance across assemblages caused by evolutionary convergence or by biogeographic dispersal of evolutionarily conserved ecotypes? Does convergence to new ecological conditions erase evidence of past adaptation? Here, we analyse ecology, morphology and performance in frog assemblages from three continents (Asia, Australia and South America), assessing the importance of dispersal and convergent evolution in explaining similarity across regions. We find three striking results. First, species using the same microhabitat type are highly similar in morphology and performance across both clades and continents. Second, some species on different continents owe their similarity to dispersal and evolutionary conservatism (rather than evolutionary convergence), even over vast temporal and spatial scales. Third, in one case, an ecologically specialized ancestor radiated into diverse ecotypes that have converged with those on other continents, largely erasing traces of past adaptation to their ancestral ecology. Overall, our study highlights the roles of both evolutionary conservatism and convergence in explaining similarity in species traits over large spatial and temporal scales and demonstrates a statistical framework for addressing these questions in other systems.

Morphology, ecology and phylogeny of cyanobacteria belonging to genera Nostoc and Desmonostoc in Lithuania

OpenAIRE

Špakaitė, Ina

2014-01-01

The aim of the study was to investigate the morphology, ecology and phylogeny of cyanobacteria belonging to genera Nostoc and Desmonostoc in Lithuania. The detailed research of freshwater and terrestrial Nostoc and Desmonostoc species provided new data on taxonomy, biology and ecology of these cyanobacteria and the overall diversity of algae in Lithuania. 20 Nostoc species and two intraspecific taxa, and 18 taxa to the Nostoc genus level were identified. Twelve Nostoc species and intraspecifi...

Morphology-based prediction of osteogenic differentiation potential of human mesenchymal stem cells.

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Fumiko Matsuoka

Full Text Available Human bone marrow mesenchymal stem cells (hBMSCs are widely used cell source for clinical bone regeneration. Achieving the greatest therapeutic effect is dependent on the osteogenic differentiation potential of the stem cells to be implanted. However, there are still no practical methods to characterize such potential non-invasively or previously. Monitoring cellular morphology is a practical and non-invasive approach for evaluating osteogenic potential. Unfortunately, such image-based approaches had been historically qualitative and requiring experienced interpretation. By combining the non-invasive attributes of microscopy with the latest technology allowing higher throughput and quantitative imaging metrics, we studied the applicability of morphometric features to quantitatively predict cellular osteogenic potential. We applied computational machine learning, combining cell morphology features with their corresponding biochemical osteogenic assay results, to develop prediction model of osteogenic differentiation. Using a dataset of 9,990 images automatically acquired by BioStation CT during osteogenic differentiation culture of hBMSCs, 666 morphometric features were extracted as parameters. Two commonly used osteogenic markers, alkaline phosphatase (ALP activity and calcium deposition were measured experimentally, and used as the true biological differentiation status to validate the prediction accuracy. Using time-course morphological features throughout differentiation culture, the prediction results highly correlated with the experimentally defined differentiation marker values (R>0.89 for both marker predictions. The clinical applicability of our morphology-based prediction was further examined with two scenarios: one using only historical cell images and the other using both historical images together with the patient's own cell images to predict a new patient's cellular potential. The prediction accuracy was found to be greatly enhanced

Investigating ecological speciation in non-model organisms

DEFF Research Database (Denmark)

Foote, Andrew David

2012-01-01

Background: Studies of ecological speciation tend to focus on a few model biological systems. In contrast, few studies on non-model organisms have been able to infer ecological speciation as the underlying mechanism of evolutionary divergence. Questions: What are the pitfalls in studying ecological...... speciation in non-model organisms that lead to this bias? What alternative approaches might redress the balance? Organism: Genetically differentiated types of the killer whale (Orcinus orca) exhibiting differences in prey preference, habitat use, morphology, and behaviour. Methods: Review of the literature...... on killer whale evolutionary ecology in search of any difficulty in demonstrating causal links between variation in phenotype, ecology, and reproductive isolation in this non-model organism. Results: At present, we do not have enough evidence to conclude that adaptive phenotype traits linked to ecological...

Ecological associations of autopodial osteology in Neotropical geckos.

Science.gov (United States)

Rothier, Priscila S; Brandt, Renata; Kohlsdorf, Tiana

2017-03-01

Coevolution of form and function inspires investigation of associations between morphological variation and the exploitation of specific ecological settings. Such relationships, based mostly on traits of external morphology, have been extensively described for vertebrates, and especially so for squamates. External features are, however, composed by both soft tissues and bones, and these likely play different biomechanical roles during locomotion, such as in the autopodia. Therefore, ecological trends identified on the basis of external morphological measurements may not be directly correlated with equivalent variation in osteology. Here, we investigate how refined parameters of autopodial osteology relate to ecology, by contrasting climbing and nonclimbing geckos. Our first step consisted of inferring how external and osteological morphometric traits coevolved in the group. Our results corroborate the hypothesis of coevolution between external and osteological elements in the autopodia of geckos, and provides evidence for associations between specific osteological traits and preferred locomotor habit. Specifically, nonclimbers exhibit longer ultimate and penultimate phalanges of Digit V in the manus and pes and also a longer fifth metatarsal in comparison with climbers, a pattern discussed here in the context of the differential demands made upon locomotion in specific ecological contexts. Our study highlights the relevance of osteological information for discussing the evolution of ecological associations of the tetrapod autopodium. J. Morphol. 278:290-299, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Morphology and Ecological Notes on the Larvae and Pupae of Simulium (Simulium from Korea

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Sam-Kyu Kim

2015-10-01

Full Text Available Morphological features of larvae and pupae of twelve species of Simulium (Simulium from Korea are investigated and redescribed. Detailed descriptions of immature stages of each species are provided with photographs. For the Korean members of subgenus Simulium, combinations of the following characteristics can be used to separate them from other Korean subgenera: larval abdomen without a pair of conical-shaped ventral tubercles; postgenal cleft variously shaped, viz., miter shaped, spearhead, bullet shaped or triangular; rectal papillae 3 simple lobe or compound lobes; pupal gill of 6-16 filaments; cocoon shoe, boot or slipper shaped; and head trichomes 3 pairs (1 facial+2 frontal. Habitat information and other ecological aspects of each species are provided. Updated keys to larvae and pupae of the Korean species of the subgenus Simulium are also provided to facilitate species identification. Taxonomic treatment based on external morphologies of larvae and pupae of Korean species of the subgenus Simulium are focused and included in this study. To understand their interspecific relationships, phylogenetic analyses using multiple data from molecule, morphology, and ecology are warranted in future research. Also continued exploration for new character systems is needed to establish more stable boundaries for subgenus and species delimitations.

Anatomy, functional morphology, evolutionary ecology and systematics of the invasive gastropod Cipangopaludina japonica (Viviparidae: Bellamyinae)

NARCIS (Netherlands)

Bocxlaer, Van B.; Strong, E.E.

2016-01-01

The anatomy, functional morphology and evolutionary ecology of the Viviparidae, and the subfamily Bellamyinae in particular, are incompletely known. Partly as a result, genealogical relationships within the family remain poorly understood. Because of this lack in knowledge, few informed hypotheses

Triatominae as a model of morphological plasticity under ecological pressure

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Dujardin JP

1999-01-01

Full Text Available The use of biochemical and genetic characters to explore species or population relationships has been applied to taxonomic questions since the 60s. In responding to the central question of the evolutionary history of Triatominae, i.e. their monophyletic or polyphyletic origin, two important questions arise (i to what extent is the morphologically-based classification valid for assessing phylogenetic relationships? and (ii what are the main mechanisms underlying speciation in Triatominae? Phenetic and genetic studies so far developed suggest that speciation in Triatominae may be a rapid process mainly driven by ecological factors.

Impacts of channel morphology on residues and ecological risks of polychlorinated biphenyls in water and sediment in Chahe River

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Zhen-hua Zhao

2016-10-01

Full Text Available The impacts of channel morphology on the residues and ecological risks of 14 polychlorinated biphenyl (PCB congeners in water and sediment were investigated in summer (July and autumn (September in the Chahe River, in Nanjing, China. The residual concentrations of tri-chlorobiphenyls (tri-CBs, PCB 18 and tetra-CBs (PCB 52 in water were significantly higher than those of penta-CBs to deca-CBs, and the average residual concentration of ∑PCBs (sum of 14 PCB congeners in summer was about six times higher than in autumn. However, the residues in sediment did not change significantly. Redundancy analysis (RDA indicated that channel morphology and the corresponding environmental indices had significant impacts on PCB residues and their composition profiles in water and sediment. The overflow weir and lake-type watercourse may remarkably reduce the residual concentration and ecological risks of PCBs in water. The highest reduction percentages of the residual concentration and ecological risks of ∑PCBs induced by an overflow weir were 78% and 67%, respectively, and those induced by a lake-type watercourse were 36% and 70%, respectively. The watercourses with different channel morphologies were ranked by residual ∑PCBs concentrations in the following descending order: the natural ecological watercourse, vertical concrete watercourse, and vegetation-type riprap watercourse. However, they were ranked by residual ∑PCBs concentrations in sediment in the following descending order: the vertical concrete watercourse, vegetation-type riprap watercourse, and natural ecological watercourse.

Influence of morphology and amphibious lifestyle on the feeding ecology of the mudskipper Periophthalmus argentilineatus

NARCIS (Netherlands)

Kruitwagen, G.; Nagelkerken, I.; Lugendo, B.R.; Pratap, H.B.; Wendelaar Bonga, S.E.

2007-01-01

The potential feeding advantages that are offered to the barred mudskipper Periophthalmus argentilineatus by its amphibious life-style were investigated. To this end the feeding ecology of these fish, the position they occupy in the mangrove food web and the importance of different morphological

Genetic, Ecological and Morphological Distinctness of the Blue Mussels Mytilus trossulus Gould and M. edulis L. in the White Sea.

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Marina Katolikova

Full Text Available Two blue mussel lineages of Pliocene origin, Mytilus edulis (ME and M. trossulus (MT, co-occur and hybridize in several regions on the shores of the North Atlantic. The two species were distinguished from each other by molecular methods in the 1980s, and a large amount of comparative data on them has been accumulated since that time. However, while ME and MT are now routinely distinguished by various genetic markers, they tend to be overlooked in ecological studies since morphological characters for taxonomic identification have been lacking, and no consistent habitat differences between lineages have been reported. Surveying a recently discovered area of ME and MT co-occurrence in the White Sea and employing a set of allozyme markers for identification, we address the issue whether ME and MT are true biological species with distinct ecological characteristics or just virtual genetic entities with no matching morphological and ecological identities. We find that: (1 in the White Sea, the occurrence of MT is largely concentrated in harbors, in line with observations from other subarctic regions of Europe; (2 mixed populations of ME and MT are always dominated by purebred individuals, animals classified as hybrids constituting only ca. 18%; (3 in terms of shell morphology, 80% of MT bear a distinct uninterrupted dark prismatic strip under the ligament while 97% of ME lack this character; (4 at sites of sympatry MT is more common on algal substrates while ME mostly lives directly on the bottom. This segregation by the substrate may contribute to maintaining reproductive isolation and decreasing competition between taxa. We conclude that while ME and MT are not fully reproductively isolated, they do represent clearly distinguishable biological, ecological and morphological entities in the White Sea. It remains to be documented whether the observed morphological and ecological differences are of a local character, or whether they have simply been

Ecological divergence and evolutionary transition of resprouting types in Banksia attenuata.

Science.gov (United States)

He, Tianhua

2014-08-01

Resprouting is a key functional trait that allows plants to survive diverse disturbances. The fitness benefits associated with resprouting include a rapid return to adult growth, early flowering, and setting seed. The resprouting responses observed following fire are varied, as are the ecological outcomes. Understanding the ecological divergence and evolutionary pathways of different resprouting types and how the environment and genetics interact to drive such morphological evolution represents an important, but under-studied, topic. In the present study, microsatellite markers and microevolutionary approaches were used to better understand: (1) whether genetic differentiation is related to morphological divergence among resprouting types and if so, whether there are any specific genetic variations associated with morphological divergence and (2) the evolutionary pathway of the transitions between two resprouting types in Banksia attenuata (epicormic resprouting from aerial stems or branch; resprouting from a underground lignotuber). The results revealed an association between population genetic differentiation and the morphological divergence of postfire resprouting types in B. attenuata. A microsatellite allele has been shown to be associated with epicormic populations. Approximate Bayesian Computation analysis revealed a likely evolutionary transition from epicormic to lignotuberous resprouting in B. attenuata. It is concluded that the postfire resprouting type in B. attenuata is likely determined by the fire's characteristics. The differentiated expression of postfire resprouting types in different environments is likely a consequence of local genetic adaptation. The capacity to shift the postfire resprouting type to adapt to diverse fire regimes is most likely the key factor explaining why B. attenuata is the most widespread member of the Banksia genus.

Spatial structure of morphological and neutral genetic variation in Brook Trout

Science.gov (United States)

Kazyak, David C.; Hilderbrand, Robert H.; Keller, Stephen R.; Colaw, Mark C.; Holloway, Amanda E.; Morgan, Raymond P.; King, Timothy L.

2015-01-01

Brook Trout Salvelinus fontinalis exhibit exceptional levels of life history variation, remarkable genetic variability, and fine-scale population structure. In many cases, neighboring populations may be highly differentiated from one another to an extent that is comparable with species-level distinctions in other taxa. Although genetic samples have been collected from hundreds of populations and tens of thousands of individuals, little is known about whether differentiation at neutral markers reflects phenotypic differences among Brook Trout populations. We compared differentiation in morphology and neutral molecular markers among populations from four geographically proximate locations (all within 24 km) to examine how genetic diversity covaries with morphology. We found significant differences among and/or within streams for all three morphological axes examined and identified the source stream of many individuals based on morphology (52.3% classification efficiency). Although molecular and morphological differentiation among streams ranged considerably (mean pairwise FST: 0.023–0.264; pairwise PST: 0.000–0.339), the two measures were not significantly correlated. While in some cases morphological characters appear to have diverged to a greater extent than expected by neutral genetic drift, many traits were conserved to a greater extent than were neutral genetic markers. Thus, while Brook Trout exhibit fine-scale spatial patterns in both morphology and neutral genetic diversity, these types of biological variabilities are being structured by different ecological and evolutionary processes. The relative influences of genetic drift versus selection and phenotypic plasticity in shaping morphology appear to vary among populations occupying nearby streams.

ALS/FTLD-linked TDP-43 regulates neurite morphology and cell survival in differentiated neurons

International Nuclear Information System (INIS)

Han, Jeong-Ho; Yu, Tae-Hoon; Ryu, Hyun-Hee; Jun, Mi-Hee; Ban, Byung-Kwan; Jang, Deok-Jin; Lee, Jin-A

2013-01-01

Tar-DNA binding protein of 43 kDa (TDP-43) has been characterized as a major component of protein aggregates in brains with neurodegenerative diseases such as frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). However, physiological roles of TDP-43 and early cellular pathogenic effects caused by disease associated mutations in differentiated neurons are still largely unknown. Here, we investigated the physiological roles of TDP-43 and the effects of missense mutations associated with diseases in differentiated cortical neurons. The reduction of TDP-43 by siRNA increased abnormal neurites and decreased cell viability. ALS/FTLD-associated missense mutant proteins (A315T, Q331K, and M337V) were partially mislocalized to the cytosol and neurites when compared to wild-type and showed abnormal neurites similar to those observed in cases of loss of TDP-43. Interestingly, cytosolic expression of wild-type TDP-43 with mutated nuclear localization signals also induced abnormal neurtie morphology and reduction of cell viability. However, there was no significant difference in the effects of cytosolic expression in neuronal morphology and cell toxicity between wild-type and missense mutant proteins. Thus, our results suggest that mislocalization of missense mutant TDP-43 may contribute to loss of TDP-43 function and affect neuronal morphology, probably via dominant negative action before severe neurodegeneration in differentiated cortical neurons. Highlights: • The function of nuclear TDP-43 in neurite morphology in mature neurons. • Partial mislocalization of TDP-43 missense mutants into cytosol from nucleus. • Abnormal neurite morphology caused by missense mutants of TDP-43. • The effect of cytosolic expression of TDP-43 in neurite morphology and in cell survival

ALS/FTLD-linked TDP-43 regulates neurite morphology and cell survival in differentiated neurons

Energy Technology Data Exchange (ETDEWEB)

Han, Jeong-Ho; Yu, Tae-Hoon; Ryu, Hyun-Hee; Jun, Mi-Hee; Ban, Byung-Kwan [Department of Biotechnology, College of Life Science and Nanotechnology, Hannam University, Dajeon 305-811 (Korea, Republic of); Jang, Deok-Jin [Department of Applied Biology, College of Ecology and Environment, Kyungpook National University, 386, Gajang-dong, Sangju-si, Kyungbuk 742-711 (Korea, Republic of); Lee, Jin-A, E-mail: leeja@hnu.kr [Department of Biotechnology, College of Life Science and Nanotechnology, Hannam University, Dajeon 305-811 (Korea, Republic of)

2013-08-01

Tar-DNA binding protein of 43 kDa (TDP-43) has been characterized as a major component of protein aggregates in brains with neurodegenerative diseases such as frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). However, physiological roles of TDP-43 and early cellular pathogenic effects caused by disease associated mutations in differentiated neurons are still largely unknown. Here, we investigated the physiological roles of TDP-43 and the effects of missense mutations associated with diseases in differentiated cortical neurons. The reduction of TDP-43 by siRNA increased abnormal neurites and decreased cell viability. ALS/FTLD-associated missense mutant proteins (A315T, Q331K, and M337V) were partially mislocalized to the cytosol and neurites when compared to wild-type and showed abnormal neurites similar to those observed in cases of loss of TDP-43. Interestingly, cytosolic expression of wild-type TDP-43 with mutated nuclear localization signals also induced abnormal neurtie morphology and reduction of cell viability. However, there was no significant difference in the effects of cytosolic expression in neuronal morphology and cell toxicity between wild-type and missense mutant proteins. Thus, our results suggest that mislocalization of missense mutant TDP-43 may contribute to loss of TDP-43 function and affect neuronal morphology, probably via dominant negative action before severe neurodegeneration in differentiated cortical neurons. Highlights: • The function of nuclear TDP-43 in neurite morphology in mature neurons. • Partial mislocalization of TDP-43 missense mutants into cytosol from nucleus. • Abnormal neurite morphology caused by missense mutants of TDP-43. • The effect of cytosolic expression of TDP-43 in neurite morphology and in cell survival.

Morphology and Differentiation of MG63 Osteoblast Cells on Saliva Contaminated Implant Surfaces

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Neda Shams

2015-11-01

Full Text Available Objectives: Osteoblasts are the most important cells in the osseointegration process. Despite years of study on dental Implants, limited studies have discussed the effect of saliva on the adhesion process of osteoblasts to implant surfaces. The aim of this in vitro study was to evaluate the effect of saliva on morphology and differentiation of osteoblasts attached to implant surfaces.Materials and Methods: Twelve Axiom dental implants were divided into two groups. Implants of the case group were placed in containers, containing saliva, for 40 minutes. Then, all the implants were separately stored in a medium containing MG63 human osteoblasts for a week. Cell morphology and differentiation were assessed using a scanning electron microscope and their alkaline phosphatase (ALP activity was determined. The t-test was used to compare the two groups.Results: Scanning electron microscopic observation of osteoblasts revealed round or square cells with fewer and shorter cellular processes in saliva contaminated samples, whereas elongated, fusiform and well-defined cell processes were seen in the control group. ALP level was significantly lower in case compared to control group (P<0.05.Conclusion: Saliva contamination alters osteoblast morphology and differentiation and may subsequently interfere with successful osseointegration. Thus, saliva contamination of bone and implant must be prevented or minimized.

Micro morphological and Chemical Approaches to Understand Changes in Ecological Functions of Metal-Impacted Soils under Various Land Uses

International Nuclear Information System (INIS)

Acosta, J.A; Martinez, S.M; Faz, A; Van Mourik, J.M; Arocena, J.M

2011-01-01

We investigated the changes in faunal activities as measures of the ecological functions of soils impacted by potentially toxic metals (PTMs) under urban, industrial, agricultural, and natural uses. Concentrations and distributions of Zn, Cd, Pb, Cu, Mn, and Fe were estimated by sequential chemical extractions, while relicts and present faunal activities were studied by micro morphological analyses. Urban and natural lands were contaminated with Pb, Cd, and Zn. Micro arthropods and fungi are observed to be active in the litter decomposition in natural, agricultural and urban lands which indicates that total concentration of PTMs in soils is not a good indicator to evaluate the limitations of PTMs to fauna activity. Metals immobilization on carbonates and Fe/Mn oxides, and fertilizations reduced the negative effects of metals on faunal activity. Micro morphological analyses showed the impacts of metal on soil ecological functions in industrial site, where the surface soils are devoid of any evidence of faunal activity; likely due to high proportion of Pb and Zn in organic components. Therefore, the impacts of metals in soil fauna activities, hence ecological functions of soils, are best evaluated by the knowledge of metal partitioning on solid phases in combination with observations of fauna activities using micro morphological techniques.

The role of habitat shift in the evolution of lizard morphology: evidence from tropical Tropidurus

OpenAIRE

Vitt, Laurie J.; Caldwell, Janalee P.; Zani, Peter A.; Titus, Tom A.

1997-01-01

We compared morphology of two geographically close populations of the tropical lizard Tropidurus hispidus to test the hypothesis that habitat structure influences the evolution of morphology and ecology at the population level. T. hispidus isolated on a rock outcrop surrounded by tropical forest use rock crevices for refuge and appear dorsoventrally compressed compared with those in open savanna. A principal components analysis revealed that the populations were differentially distributed alo...

Morphology and ecology of sibon snakes (Squamata: Dipsadidae) from two forests in Central America

OpenAIRE

Todd R. Lewis; Rowland K. Griffin; Paul B. C. Grant; Alex Figueroa; Julie M. Ray; Kirsty E. Graham; Gabriel David

2013-01-01

Physical measurements, abundance, and ecological observations were recorded for Sibon annulatus,S. argus, S. longifrens, and S. nebulatus at two Neotropical habitats: a lowland swamp forest in Costa Rica and a montane cloud forest in Panama. Fourty-four and 58 adult snakes were recorded from Costa Rica and Panama, respectively. Differences in morphology and body condition showed minimal significant differences among species from both geographical locations. Observations of feeding, reproducti...

Evolutionary dynamics of ecological niche in three Rhinogobio fishes from the upper Yangtze River inferred from morphological traits

Science.gov (United States)

Wang, Meirong; Liu, Fei; Lin, Pengcheng; Yang, Shaorong; Liu, Huanzhang

2015-01-01

In the past decades, it has been debated whether ecological niche should be conserved among closely related species (phylogenetic niche conservatism, PNC) or largely divergent (traditional ecological niche theory and ecological speciation) and whether niche specialist and generalist might remain in equilibrium or niche generalist could not appear. In this study, we employed morphological traits to describe ecological niche and test whether different niche dimensions exhibit disparate evolutionary patterns. We conducted our analysis on three Rhinogobio fish species (R. typus,R. cylindricus, and R. ventralis) from the upper Yangtze River, China. Among the 32 measured morphological traits except body length, PCA extracted the first four principal components with their loading scores >1.000. To find the PNC among species, Mantel tests were conducted with the Euclidean distances calculated from the four principal components (representing different niche dimensions) against the pairwise distances calculated from mitochondrial cytochrome b sequence variations. The results showed that the second and the third niche dimension, both related to swimming ability and behavior, exhibited phylogenetic conservatism. Further comparison on niche breadth among these three species revealed that the fourth dimension of R. typus showed the greatest width, indicating that this dimension exhibited niche generalism. In conclusion, our results suggested that different niche dimensions could show different evolutionary dynamic patterns: they may exhibit PNC or not, and some dimensions may evolve generalism. PMID:25691981

Morphology captures diet and locomotor types in rodents.

Science.gov (United States)

Verde Arregoitia, Luis D; Fisher, Diana O; Schweizer, Manuel

2017-01-01

To understand the functional meaning of morphological features, we need to relate what we know about morphology and ecology in a meaningful, quantitative framework. Closely related species usually share more phenotypic features than distant ones, but close relatives do not necessarily have the same ecologies. Rodents are the most diverse group of living mammals, with impressive ecomorphological diversification. We used museum collections and ecological literature to gather data on morphology, diet and locomotion for 208 species of rodents from different bioregions to investigate how morphological similarity and phylogenetic relatedness are associated with ecology. After considering differences in body size and shared evolutionary history, we find that unrelated species with similar ecologies can be characterized by a well-defined suite of morphological features. Our results validate the hypothesized ecological relevance of the chosen traits. These cranial, dental and external (e.g. ears) characters predicted diet and locomotion and showed consistent differences among species with different feeding and substrate use strategies. We conclude that when ecological characters do not show strong phylogenetic patterns, we cannot simply assume that close relatives are ecologically similar. Museum specimens are valuable records of species' phenotypes and with the characters proposed here, morphology can reflect functional similarity, an important component of community ecology and macroevolution.

Why do morphological phylogenies vary in quality? An investigation based on the comparative history of lizard clades.

Science.gov (United States)

Arnold, E N

1990-05-22

Phylogenies based on morphology vary considerably in their quality: some are robust and explicit with little conflict in the data set, whereas others are far more tenuous, with much conflict and many possible alternatives. The main primary reasons for untrue or inexplicit morphological phylogenies are: not enough characters developed between branching points, uncertain character polarity, poorly differentiated character states, homoplasy caused by parallelism or reversal, and extinction, which may remove species entirely from consideration and can make originally conflicting data sets misleadingly compatible, increasing congruence at the expense of truth. Extinction differs from other confounding factors in not being apparent either in the data set or in subsequent analysis. One possibility is that variation in the quality of morphological phylogenies has resulted from exposure to different ecological situations. To investigate this, it is necessary to compare the histories of the clades concerned. In the case of explicit morphological phylogenies, ecological and behavioural data can be integrated with them and it may then be possible to decide whether morphological characters are likely to have been elicited by the environments through which the clade has passed. The credibility of such results depends not only on the phylogeny being robust but also on its detailed topology: a pectinate phylogeny will often allow more certain and more explicit statements to be made about historical events. In the case of poor phylogenies, it is not possible to produce detailed histories, but they can be compared with robust phylogenies in the range of ecological situations occupied, and whether they occupy novel situations in comparison with their outgroups. LeQuesne testing can give information about niche homoplasy, and it may also be possible to see if morphological features are functionally associated with ecological parameters, even if the direction of change is unknown

Morphological differentiation of Carollia brevicauda and C. perspicillata (Chiroptera: Phyllostomidae from Peru and Ecuador

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Dennisse Ruelas

2017-12-01

Full Text Available In the bat genus Carollia, C. brevicauda and C. perspicillata are the most abundant and widely distributed in South America; also, their distributional ranges are almost completely overlapped. Because these species are morphologically very similar, they are frequently misidentified. The aims of this study were to determine the morphological and morphometric differences of C. brevicauda and C. perspicillata. For that reason, I employed a detail morphological assessment and several multivariate morphometric tools. I evaluated 26 normally craniodental variables in 375 adult specimens from Peruvian and Ecuadorian populations. In addition, 54 specimens of C. benkeithi, C. manu, and Carollia sp. were included for comparisons. I found that C. brevicauda and C. perspicillata are differentiated by 28 discrete characters, and are significantly different in 25 morphometric variables. Also, C. brevicauda, C. perspicillata, and C. manu are clustered in a different group from the group of C. benkeithi and Carollia sp. My results complement previous studies adding several characters that confidently differentiate C. brevicauda from C. perspicillata; which needs to be tested in other regions.

Morphology and ecology of Daphnia middendorffiana, Fisher 1851 (Crustacea, Daphniidae from four new populations in the Alps

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Rocco TIBERTI

2011-08-01

Full Text Available Daphnia middendorffiana has an arctic, circumpolar distribution, with some isolated southerly populations restricted to mountainous areas, including the Alps. In this paper, new records of Daphnia middendorffiana on the Alps are reported. The species was regularly recorded in several samples collected from 2006 to 2009 in four high altitude lakes in the Gran Paradiso National Park (GPNP during the ice free period. This is the third finding for the Alps and the described populations are the largest. Chemical and morphometric features of the lakes are provided, the morphology of the Daphnia middendorffiana from GPNP is described as well as some aspects concerning its ecology. The studied lakes are small, oligotrophic (total phosphorus ranged from 0 to 7 μg L-1 and well preserved from acidification risk (pH ranged from 6.45 to 8.14. D. middendorffiana is the largest zooplanktonic crustacean inhabiting the Alpine lakes in GPNP reaching 3.43 mm in length; the morphological analysis noted some differences within the studied populations; however there is a clear resemblance to the only Alpine population previously described (from Central Alps, Bognanco Valley, Lake Campo IV and to the arctic populations. D. middendorffiana in GPNP lives at low density levels, reaching higher densities in late August and early September. No males have been found during the sample campaign confirming its ability to produce asexual viable diapauses eggs. This study confirms the attitude of this species for cold and oligotrophic waters and increases the current knowledge on the geographical distribution, morphology and ecology of this species in Alpine environments. The finding of D. middendordorffiana in the GPNP poses interesting issues concerning the phylogeography of Alpine Daphnia middendorffiana, as well as raising need for conservation efforts aimed at keeping the populations safe from several global and local threats, such as climate warming and the ecological

Ecological differentiation of Lemna minor L. and Spirodela polyrrhiza (L. Schleiden populations

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Hanna Wożakowska-Natkaniec

2015-01-01

Full Text Available The subject of thep resent study are 19 natural, ecological populations of Lemna minor and Spirodela polyrrhiza coming from sixteen habitats in Lower Silesia. The study showed the essential differences between ecological populations of both species, conditioned on chemistry (pH, level N, P, K, Ca, Mg and Fe and the natural water radioactivity. It was shown experimentally that these populations, in nature, establish a set of ecotypes or ecophene variability. Ecotypic differentiation of populations of Lemna minor and Spirodela polyrrhiza is based upon individual features and population characteristics such as: shape and size of plants, plant frequency of two, three, and four fronds, the ratio of right- to left-handed plants, and the dynamics of growth and biomass production.

Ecological niche modelling and nDNA sequencing support a new, morphologically cryptic beetle species unveiled by DNA barcoding.

Science.gov (United States)

Hawlitschek, Oliver; Porch, Nick; Hendrich, Lars; Balke, Michael

2011-02-09

DNA sequencing techniques used to estimate biodiversity, such as DNA barcoding, may reveal cryptic species. However, disagreements between barcoding and morphological data have already led to controversy. Species delimitation should therefore not be based on mtDNA alone. Here, we explore the use of nDNA and bioclimatic modelling in a new species of aquatic beetle revealed by mtDNA sequence data. The aquatic beetle fauna of Australia is characterised by high degrees of endemism, including local radiations such as the genus Antiporus. Antiporus femoralis was previously considered to exist in two disjunct, but morphologically indistinguishable populations in south-western and south-eastern Australia. We constructed a phylogeny of Antiporus and detected a deep split between these populations. Diagnostic characters from the highly variable nuclear protein encoding arginine kinase gene confirmed the presence of two isolated populations. We then used ecological niche modelling to examine the climatic niche characteristics of the two populations. All results support the status of the two populations as distinct species. We describe the south-western species as Antiporus occidentalis sp.n. In addition to nDNA sequence data and extended use of mitochondrial sequences, ecological niche modelling has great potential for delineating morphologically cryptic species.

Morphological, hydrological, biogeochemical and ecological changes and challenges in river restoration - the Thur River case study

Science.gov (United States)

Schirmer, M.; Luster, J.; Linde, N.; Perona, P.; Mitchell, E. A. D.; Barry, D. A.; Hollender, J.; Cirpka, O. A.; Schneider, P.; Vogt, T.; Radny, D.; Durisch-Kaiser, E.

2014-06-01

River restoration can enhance river dynamics, environmental heterogeneity and biodiversity, but the underlying processes governing the dynamic changes need to be understood to ensure that restoration projects meet their goals, and adverse effects are prevented. In particular, we need to comprehend how hydromorphological variability quantitatively relates to ecosystem functioning and services, biodiversity as well as ground- and surface water quality in restored river corridors. This involves (i) physical processes and structural properties, determining erosion and sedimentation, as well as solute and heat transport behavior in surface water and within the subsurface; (ii) biogeochemical processes and characteristics, including the turnover of nutrients and natural water constituents; and (iii) ecological processes and indicators related to biodiversity and ecological functioning. All these aspects are interlinked, requiring an interdisciplinary investigation approach. Here, we present an overview of the recently completed RECORD (REstored CORridor Dynamics) project in which we combined physical, chemical, and biological observations with modeling at a restored river corridor of the perialpine Thur River in Switzerland. Our results show that river restoration, beyond inducing morphologic changes that reshape the river bed and banks, triggered complex spatial patterns of bank infiltration, and affected habitat type, biotic communities and biogeochemical processes. We adopted an interdisciplinary approach of monitoring the continuing changes due to restoration measures to address the following questions: How stable is the morphological variability established by restoration? Does morphological variability guarantee an improvement in biodiversity? How does morphological variability affect biogeochemical transformations in the river corridor? What are some potential adverse effects of river restoration? How is river restoration influenced by catchment-scale hydraulics

Morphology and ecology of sibon snakes (Squamata: Dipsadidae from two forests in Central America

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Todd R. Lewis

2013-06-01

Full Text Available Physical measurements, abundance, and ecological observations were recorded for Sibon annulatus,S. argus, S. longifrens, and S. nebulatus at two Neotropical habitats: a lowland swamp forest in Costa Rica and a montane cloud forest in Panama. Fourty-four and 58 adult snakes were recorded from Costa Rica and Panama, respectively. Differences in morphology and body condition showed minimal significant differences among species from both geographical locations. Observations of feeding, reproduction, abundance, distribution and a new size record for S. annulatus are discussed.

The ROCK isoforms differentially regulate the morphological characteristics of carcinoma cells.

Science.gov (United States)

Jerrell, Rachel J; Leih, Mitchell J; Parekh, Aron

2017-06-26

Rho-associated kinase (ROCK) activity drives cell migration via actomyosin contractility. During invasion, individual cancer cells can transition between 2 modes of migration, mesenchymal and amoeboid. Changes in ROCK activity can cause a switch between these migration phenotypes which are defined by distinct morphologies. However, recent studies have shown that the ROCK isoforms are not functionally redundant as previously thought. Therefore, it is unclear whether the ROCK isoforms play different roles in regulating migration phenotypes. Here, we found that ROCK1 and ROCK2 differentially regulate carcinoma cell morphology resulting in intermediate phenotypes that share some mesenchymal and amoeboid characteristics. These findings suggest that the ROCK isoforms play unique roles in the phenotypic plasticity of mesenchymal carcinoma cells which may have therapeutic implications.

Differential effects of ephemeral colonization by arbuscular mycorrhizal fungi in two Cuscuta species with different ecology.

Science.gov (United States)

Behdarvandi, Behrang; Guinel, Frédérique C; Costea, Mihai

2015-10-01

Seedlings of parasitic Cuscuta species are autotrophic but can survive only a short period of time, during which they must locate and attach to a suitable host. They have an ephemeral root-like organ considered not a "true" root by most studies. In the present study, two species with contrasting ecology were examined: Cuscuta gronovii, a North American riparian species, and Cuscuta campestris, an invasive dodder that thrives in disturbed habitats. The morphology, structure, and absorptive capability of their root-like organ were compared, their potential for colonization by two species of arbuscular mycorrhizal fungi (AMF) was assessed, and the effect of the AMF on seedling growth and survival was determined. The root of both species absorbed water and interacted with AMF, but the two species exhibited dissimilar growth and survival patterns depending on the colonization level of their seedlings. The extensively colonized seedlings of C. gronovii grew more and survived longer than non-colonized seedlings. In contrast, the scarce colonization of C. campestris seedlings did not increase their growth or longevity. The differential growth responses of the AMF-colonized and non-colonized Cuscuta species suggest a mycorrhizal relationship and reflect their ecology. While C. gronovii roots have retained a higher ability to interact with AMF and are likely to take advantage of fungal communities in riparian habitats, the invasive C. campestris has largely lost this ability possibly as an adaptation to disturbed ecosystems. These results indicate that dodders have a true root, even if much reduced and ephemeral, that can interact with AMF.

Blind to morphology: Genetics identifies several widespread ecologically common species and few endemics among Indo-Pacific cauliflower corals (Pocillopora, Scleractinia)

KAUST Repository

Pinzón, Jorge H C

2013-04-05

Aim: Using high-resolution genetic markers on samples gathered from across their wide distributional range, we endeavoured to delimit species diversity in reef-building Pocillopora corals. They are common, ecologically important, and widespread throughout the Indo-Pacific, but their phenotypic plasticity in response to environmental conditions and their nearly featureless microskeletal structures confound taxonomic assignments and limit an understanding of their ecology and evolution. Location: Indo-Pacific, Red Sea, Arabian/Persian Gulf. Methods: Sequence analysis of nuclear ribosomal (internal transcribed spacer 2, ITS2) and mitochondrial (open reading frame) loci were combined with population genetic data (seven microsatellite loci) for Pocillopora samples collected throughout the Indo-Pacific, Red Sea and Arabian Gulf, in order to assess the evolutionary divergence, reproductive isolation, frequency of hybridization and geographical distributions of the genus. Results: Between five and eight genetically distinct lineages comparable to species were identified with minimal or no hybridization between them. Colony morphology was generally incongruent with genetics across the full range of sampling, and the total number of species is apparently consistent with lower estimates from competing morphologically based hypotheses (about seven or eight taxa). The most commonly occurring genetic lineages were widely distributed and exhibited high dispersal and gene flow, factors that have probably minimized allopatric speciation. Uniquely among scleractinian genera, this genus contains a monophyletic group of broadcast spawners that evolved recently from an ancestral brooder. Main conclusions: The delineation of species diversity guided by genetics fundamentally advances our understanding of Pocillopora geographical distributions, ecology and evolution. Because traditional diagnostic features of colony and branch morphology are proving to be of limited utility, the

Blind to morphology: Genetics identifies several widespread ecologically common species and few endemics among Indo-Pacific cauliflower corals (Pocillopora, Scleractinia)

KAUST Repository

Pinzó n, Jorge H C; Sampayo, Eugenia M.; Cox, Evelyn F.; Chauka, Leonard J.; Chen, Chaolun Allen; Voolstra, Christian R.; LaJeunesse, Todd C.

2013-01-01

Aim: Using high-resolution genetic markers on samples gathered from across their wide distributional range, we endeavoured to delimit species diversity in reef-building Pocillopora corals. They are common, ecologically important, and widespread throughout the Indo-Pacific, but their phenotypic plasticity in response to environmental conditions and their nearly featureless microskeletal structures confound taxonomic assignments and limit an understanding of their ecology and evolution. Location: Indo-Pacific, Red Sea, Arabian/Persian Gulf. Methods: Sequence analysis of nuclear ribosomal (internal transcribed spacer 2, ITS2) and mitochondrial (open reading frame) loci were combined with population genetic data (seven microsatellite loci) for Pocillopora samples collected throughout the Indo-Pacific, Red Sea and Arabian Gulf, in order to assess the evolutionary divergence, reproductive isolation, frequency of hybridization and geographical distributions of the genus. Results: Between five and eight genetically distinct lineages comparable to species were identified with minimal or no hybridization between them. Colony morphology was generally incongruent with genetics across the full range of sampling, and the total number of species is apparently consistent with lower estimates from competing morphologically based hypotheses (about seven or eight taxa). The most commonly occurring genetic lineages were widely distributed and exhibited high dispersal and gene flow, factors that have probably minimized allopatric speciation. Uniquely among scleractinian genera, this genus contains a monophyletic group of broadcast spawners that evolved recently from an ancestral brooder. Main conclusions: The delineation of species diversity guided by genetics fundamentally advances our understanding of Pocillopora geographical distributions, ecology and evolution. Because traditional diagnostic features of colony and branch morphology are proving to be of limited utility, the

Morphological and ecological preadaptations as the basis of bird synanthropization under transformed environment conditions

Science.gov (United States)

Rakhimov, I. I.; Ibragimova, K. K.

2018-01-01

Bird synanthropization is connected with a thorough and serious reconstruction of their biology and is a demonstration of changes currently occurring in the biosphere due to human influence. Nutritional and nesting conditions as well as protection due to urban characteristics are advantage factors that affect their populations. Under these conditions, the adaptive potential of species can be realized. Adaptations to a new and in-distinctive environment appear due to preadaptations. The synanthropization process of species happens without speciation by expression of existing genetic variation of morphological and ecological characteristics.

Ecological differentiation in cryptic rotifer species: what we can learn from the Brachionus plicatilis complex.

Czech Academy of Sciences Publication Activity Database

Gabaldón, Carmen; Fontaneto, D.; Carmona, M.J.; Montero-Pau, J.; Serra, M.

2017-01-01

Roč. 796, č. 1 (2017), s. 7-18 ISSN 0018-8158 Institutional support: RVO:60077344 Keywords : Brachionus plicatilis * coexistence * ecological differentiation * molecular taxonomy Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 2.056, year: 2016

Identification of major and minor QTL for ecologically important morphological traits in three-spined sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Liu, Jun; Shikano, Takahito; Leinonen, Tuomas; Cano, José Manuel; Li, Meng-Hua; Merilä, Juha

2014-04-16

Quantitative trait locus (QTL) mapping studies of Pacific three-spined sticklebacks (Gasterosteus aculeatus) have uncovered several genomic regions controlling variability in different morphological traits, but QTL studies of Atlantic sticklebacks are lacking. We mapped QTL for 40 morphological traits, including body size, body shape, and body armor, in a F2 full-sib cross between northern European marine and freshwater three-spined sticklebacks. A total of 52 significant QTL were identified at the 5% genome-wide level. One major QTL explaining 74.4% of the total variance in lateral plate number was detected on LG4, whereas several major QTL for centroid size (a proxy for body size), and the lengths of two dorsal spines, pelvic spine, and pelvic girdle were mapped on LG21 with the explained variance ranging from 27.9% to 57.6%. Major QTL for landmark coordinates defining body shape variation also were identified on LG21, with each explaining ≥15% of variance in body shape. Multiple QTL for different traits mapped on LG21 overlapped each other, implying pleiotropy and/or tight linkage. Thus, apart from providing confirmatory data to support conclusions born out of earlier QTL studies of Pacific sticklebacks, this study also describes several novel QTL of both major and smaller effect for ecologically important traits. The finding that many major QTL mapped on LG21 suggests that this linkage group might be a hotspot for genetic determinants of ecologically important morphological traits in three-spined sticklebacks.

Differential models in ecology

International Nuclear Information System (INIS)

Barco Gomez, Carlos; Barco Gomez, German

2002-01-01

The models mathematical writings with differential equations are used to describe the populational behavior through the time of the animal species. These models can be lineal or no lineal. The differential models for unique specie include the exponential pattern of Malthus and the logistical pattern of Verlhust. The lineal differential models to describe the interaction between two species include the competition relationships, predation and symbiosis

X-ray morphology of the eburnated vertebral body - diagnostic and differential diagnostic problems

Energy Technology Data Exchange (ETDEWEB)

Krug, B; Lorenz, R; Steinbrich, W

1988-08-01

1. Numerous diseases may become manifest as eburnated vertebral bodies, and hence the X-ray morphological sign of eburnation is an unspecific one. Isolated characteristics such as the involvement of one or several vertebrae, an intact vertebral space, a broadening of the paravertebral accompanying shadow, and the remaining radiological skeletal status enable narrowing down the differential diagnosis, although anamnesis and clinical findings will supply the main pointers. 2. In primary tumorous eburnations radiotherapy or chemotherapy will render an X-ray morphological assessment of therapeutic success impossible. 3. In primary diagnosis of an eburnated vertebral body it is possible to apply sonography. CT and MR as diagnostic tools step by step to narrow down the differential diagnosis by detecting or excluding pathological abdominal processes such as liver or lymphatic node metastases, paravertebral or intraspinal soft-part dense space-occupying growths or bone infiltration, but it will only rarely be possible to classify the phenomenon properly as being caused by a well-defined process, even if CT and MR are employed.

Label-free morphology-based prediction of multiple differentiation potentials of human mesenchymal stem cells for early evaluation of intact cells.

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Hiroto Sasaki

Full Text Available Precise quantification of cellular potential of stem cells, such as human bone marrow-derived mesenchymal stem cells (hBMSCs, is important for achieving stable and effective outcomes in clinical stem cell therapy. Here, we report a method for image-based prediction of the multiple differentiation potentials of hBMSCs. This method has four major advantages: (1 the cells used for potential prediction are fully intact, and therefore directly usable for clinical applications; (2 predictions of potentials are generated before differentiation cultures are initiated; (3 prediction of multiple potentials can be provided simultaneously for each sample; and (4 predictions of potentials yield quantitative values that correlate strongly with the experimental data. Our results show that the collapse of hBMSC differentiation potentials, triggered by in vitro expansion, can be quantitatively predicted far in advance by predicting multiple potentials, multi-lineage differentiation potentials (osteogenic, adipogenic, and chondrogenic and population doubling potential using morphological features apparent during the first 4 days of expansion culture. In order to understand how such morphological features can be effective for advance predictions, we measured gene-expression profiles of the same early undifferentiated cells. Both senescence-related genes (p16 and p21 and cytoskeleton-related genes (PTK2, CD146, and CD49 already correlated to the decrease of potentials at this stage. To objectively compare the performance of morphology and gene expression for such early prediction, we tested a range of models using various combinations of features. Such comparison of predictive performances revealed that morphological features performed better overall than gene-expression profiles, balancing the predictive accuracy with the effort required for model construction. This benchmark list of various prediction models not only identifies the best morphological feature

Differentiation of Three Centella Species in Australia as Inferred from Morphological Characteristics, ISSR Molecular Fingerprinting and Phytochemical Composition.

Science.gov (United States)

Alqahtani, Ali; Cho, Jun-Lae; Wong, Ka Ho; Li, Kong M; Razmovski-Naumovski, Valentina; Li, George Q

2017-01-01

Centella asiatica is one of the popular herbs used for inflammatory and neural conditions. Its differentiation from similar species is currently lacking. The aims of this study were to differentiate the three closely related Centella species using methods based on morphological characters, genetic biodiversity, phytochemical compositions and antioxidant activities. According to the morphological characteristics, the collected samples were identified as three species: C. asiatica, Centella cordifolia and Centella erecta and clustered into three groups based on their morphometric variability. Dendogram constructed on the basis of the intersimple sequence repeats (ISSR) analyses were consistent with the morphological grouping. Centella cordifolia had the highest triterpene glycosides, phenolics and antioxidant capacity, followed by C. asiatica , then C. erecta , therefore, was genetically and chemically closer to C. asiatica , while C. erecta was distinctively different from them. The results confirm the occurrence of the closely related three species of Centella in Australia, and the differentiation among them can be achieved via the combination of morphometric, molecular and phytochemical methods. This first comparative botanical study on Centella species provides a foundation for further systematic study and medicinal development of Centella .

Differentiation of Three Centella Species in Australia as Inferred from Morphological Characteristics, ISSR Molecular Fingerprinting and Phytochemical Composition

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Ali Alqahtani

2017-11-01

Full Text Available Centella asiatica is one of the popular herbs used for inflammatory and neural conditions. Its differentiation from similar species is currently lacking. The aims of this study were to differentiate the three closely related Centella species using methods based on morphological characters, genetic biodiversity, phytochemical compositions and antioxidant activities. According to the morphological characteristics, the collected samples were identified as three species: C. asiatica, Centella cordifolia and Centella erecta and clustered into three groups based on their morphometric variability. Dendogram constructed on the basis of the intersimple sequence repeats (ISSR analyses were consistent with the morphological grouping. Centella cordifolia had the highest triterpene glycosides, phenolics and antioxidant capacity, followed by C. asiatica, then C. erecta, therefore, was genetically and chemically closer to C. asiatica, while C. erecta was distinctively different from them. The results confirm the occurrence of the closely related three species of Centella in Australia, and the differentiation among them can be achieved via the combination of morphometric, molecular and phytochemical methods. This first comparative botanical study on Centella species provides a foundation for further systematic study and medicinal development of Centella.

Studies on geo-morphology, ecology and fish production of the 92 rivers of Rajshahi Division, Bangladesh

OpenAIRE

Rahman, M.K.; Akhter, J.N.; Nima, A.; Ahmed, S.U.; Mazid, M.A.

2003-01-01

Geo-morphology, ecology and fish production of the 92 rivers of Rajshahi division have been presented in this paper. Fifteen rivers are dead and 11 rivers have severe erosion problem. Siltation has increased in 66 rivers and depth has decreased in 11 rivers. Sixty nine rivers are suffering from low flow conditions. Fish diversity has decreased in 20 rivers while fish production has declined in 75 rivers. A total of 31 fish species have extinct, 25 species are under threat of extinction and 43...

New data on distribution, morphology and ecology of Oedogonium capillare Kützing ex Hirn (Oedogoniales, Chlorophyta in Poland

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Marta Pikosz

2015-12-01

Full Text Available Algological investigations were focused on taxonomy, chorology and ecology of threatened filamentous green alga species in Poland. Studies on Oedogonium capillare Kützing ex Hirn growing in large quantities in association with Cladophora rivularis (Linnaeus Hoek in pond were conducted. The aim of these studies was to describe the distribution, ecology and morphology of O. capillare as part of a more comprehensive study of this filamentous green alga. It is the eighth record in Poland for O. capillare. Filaments of O. capillare were grown over a wide pH range (7.3-9.6 and in high variability of nutrients. Vegetative cells, oogonia and antheridia were observed, which allowed taxonomic identification. O. capillare occurs in eutrophic waters which requires protection of its habitat.

Genetic and Morphological Differentiation of the Semiterrestrial Crab Armases angustipes (Brachyura: Sesarmidae) along the Brazilian Coast.

Science.gov (United States)

Marochi, Murilo Zanetti; Masunari, Setuko; Schubart, Christoph D

2017-02-01

The genetic and morphometric population structures of the semiterrestrial crab Armases angustipes from along the Brazilian coast were examined. The influence of the Central South Equatorial Current on larval dispersal of A. angustipes also was evaluated. Six populations were sampled from estuarine areas in São Luis do Maranhão, Maranhão; Natal, Rio Grande do Norte; Maceió, Alagoas; Ilhéus, Bahia; Aracruz, Espírito Santo; and Guaratuba, Paraná. Patterns of genetic differentiation were assessed using DNA sequence data corresponding to parts of the mitochondrial cytochrome c oxidase subunit 1. Geometric morphometric techniques were used to evaluate morphological variation in shape and size of the carapace and right cheliped propodus. Our results revealed low genetic variability and lack of phylogeographic structure; geometric morphometrics showed statistically significant morphological differentiation and geographic structuring. Our data indicate the absence of possible barriers to gene flow for this mobile species, and no clear correlation of morphological or genetic variation with ocean currents and/or geographic distance. Our results also suggest that historical geological and climatological events and/or possible bottleneck effects influenced the current low genetic variability among the populations of A. angustipes.

Low genetic differentiation among morphologically distinct ...

African Journals Online (AJOL)

Labeobarbus altianalis and L. bynni bynni are hexaploid cyprinid fishes in the genus Labeobarbus. In the Great Lakes region of Africa, these two large-bodied barbs exhibit considerable morphological variations. Their intraspecific classification, currently based on geographical distribution and morphological variation, is of ...

Morphological analysis of energy services: Paving the way to quality differentiation in the power sector

International Nuclear Information System (INIS)

Salah, Florian; Flath, Christoph M.; Schuller, Alexander; Will, Christian; Weinhardt, Christof

2017-01-01

The activation of the still predominantly passive demand side is necessary to further guarantee a stable power system in the short term and ensure capacity adequacy in the long run. A system with a high share of generators with nearly no marginal costs requires new services that facilitate transmitting the right economic signals to the system stakeholders. To this end we refine the notion of energy services and propose a framework to systematically design quality differentiated energy services for consumers. This approach facilitates a value-based economic assessment of energy services that deviates from the marginal-cost-paradigm. We further illustrate pricing options for these new energy service products and outline infrastructural needs and additional use case-specific product properties. Moreover, we discuss how the morphological approach can be formalised using a mathematical programming formulation and introduce a complexity measure that facilitates assessing potential adoption obstacles for end consumers. Additionally, we illustrate the practical applicability of these findings by using a prototypical implementation of a decision support system. To foster differentiated energy services, we recommend a more lenient regulatory regime lowering the barriers for new market entrants. - Highlights: • Activating the demand side is necessary to further guarantee a stable power system. • We refine the notion of energy services helping to tackle this obstacle. • A morphological box to design quality differentiated energy services is proposed. • We extend this framework by implementing a prototypical decision support system. • A more lenient regulatory regime is needed to foster differentiated energy services.

What is dental ecology?

Science.gov (United States)

Cuozzo, Frank P; Sauther, Michelle L

2012-06-01

Teeth have long been used as indicators of primate ecology. Early work focused on the links between dental morphology, diet, and behavior, with more recent years emphasizing dental wear, microstructure, development, and biogeochemistry, to understand primate ecology. Our study of Lemur catta at the Beza Mahafaly Special Reserve, Madagascar, has revealed an unusual pattern of severe tooth wear and frequent tooth loss, primarily the result of consuming a fallback food for which these primates are not dentally adapted. Interpreting these data was only possible by combining our areas of expertise (dental anatomy [FC] and primate ecology [MS]). By integrating theoretical, methodological, and applied aspects of both areas of research, we adopted the term "dental ecology"-defined as the broad study of how teeth respond to the environment. Specifically, we view dental ecology as an interpretive framework using teeth as a vehicle for understanding an organism's ecology, which builds upon earlier work, but creates a new synthesis of anatomy and ecology that is only possible with detailed knowledge of living primates. This framework includes (1) identifying patterns of dental pathology and tooth use-wear, within the context of feeding ecology, behavior, habitat variation, and anthropogenic change, (2) assessing ways in which dental development and biogeochemical signals can reflect habitat, environmental change and/or stress, and (3) how dental microstructure and macro-morphology are adapted to, and reflect feeding ecology. Here we define dental ecology, provide a short summary of the development of this perspective, and place our new work into this context. Copyright © 2012 Wiley Periodicals, Inc.

Landscape Ecology

DEFF Research Database (Denmark)

Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

2017-01-01

Landscape ecology is an interdisciplinary field of research and practice that deals with the mutual association between the spatial configuration and ecological functioning of landscapes, exploring and describing processes involved in the differentiation of spaces within landscapes......, and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... pattern analysis and ecological interaction of land units. The landscape is seen as a holon: an assemblage of interrelated phenomena, both cultural and biophysical, that together form a complex whole. Enduring challenges to landscape ecology include the need to develop a systematic approach able...

Hydroxyapatite coatings with oriented nanoplate and nanorod arrays: Fabrication, morphology, cytocompatibility and osteogenic differentiation

Energy Technology Data Exchange (ETDEWEB)

Chen, Wei [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Tian, Bo [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Lei, Yong; Ke, Qin-Fei [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Zhu, Zhen-An, E-mail: zhuzhenan2006@126.com [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Guo, Ya-Ping, E-mail: ypguo@shnu.edu.cn [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China)

2016-10-01

Hydroxyapatite (HA) crystals exhibit rod-like shape with c-axis orientation and plate-like shape with a(b)-axis orientation in vertebrate bones and tooth enamel surfaces, respectively. Herein, we report the synthesis of HA coatings with the oriented nanorod arrays (RHACs) and HA coatings with oriented nanoplate arrays (PHACs) by using bioglass coatings as sacrificial templates. After soaking in simulated body fluid (SBF) at 120 °C, the bioglass coatings are hydrothermally converted into the HA coatings via a dissolution-precipitation reaction. If the Ca/P ratios in SBF are 2.50 and 1.25, the HA crystals on the coatings are oriented nanorod arrays and oriented nanoplate arrays, respectively. Moreover, the bioglass coatings are treated with SBF at 37 °C, plate-like HA coatings with a low crystallinity (SHACs) are prepared. As compared with the Ti6Al4V and SHACs, the human bone marrow stromal cells (hBMSCs) on the RHACs and PHACs have better cell adhesion, spreading, proliferation and osteogenic differentiation because of their moderately hydrophilic surfaces and similar chemical composition, morphology and crystal orientation to human hard tissues. Notably, the morphologies of HA crystals have no obvious effects on cytocompatibility and osteogenic differentiation. Hence, the HA coatings with oriented nanoplate arrays or oriented nanorod arrays have a great potential for orthopedic applications. - Highlights: • We prepare hydroxyapatite coatings with oriented nanoplate and nanorod arrays. • Hydroxyapatite coatings are in situ converted from bioglass coatings. • Hydroxyapatite coatings have good cytocompatibility and osteogenic differentiation. • Oriented hydroxyapatite coatings are used for orthopedic implants.

Hydroxyapatite coatings with oriented nanoplate and nanorod arrays: Fabrication, morphology, cytocompatibility and osteogenic differentiation

International Nuclear Information System (INIS)

Chen, Wei; Tian, Bo; Lei, Yong; Ke, Qin-Fei; Zhu, Zhen-An; Guo, Ya-Ping

2016-01-01

Hydroxyapatite (HA) crystals exhibit rod-like shape with c-axis orientation and plate-like shape with a(b)-axis orientation in vertebrate bones and tooth enamel surfaces, respectively. Herein, we report the synthesis of HA coatings with the oriented nanorod arrays (RHACs) and HA coatings with oriented nanoplate arrays (PHACs) by using bioglass coatings as sacrificial templates. After soaking in simulated body fluid (SBF) at 120 °C, the bioglass coatings are hydrothermally converted into the HA coatings via a dissolution-precipitation reaction. If the Ca/P ratios in SBF are 2.50 and 1.25, the HA crystals on the coatings are oriented nanorod arrays and oriented nanoplate arrays, respectively. Moreover, the bioglass coatings are treated with SBF at 37 °C, plate-like HA coatings with a low crystallinity (SHACs) are prepared. As compared with the Ti6Al4V and SHACs, the human bone marrow stromal cells (hBMSCs) on the RHACs and PHACs have better cell adhesion, spreading, proliferation and osteogenic differentiation because of their moderately hydrophilic surfaces and similar chemical composition, morphology and crystal orientation to human hard tissues. Notably, the morphologies of HA crystals have no obvious effects on cytocompatibility and osteogenic differentiation. Hence, the HA coatings with oriented nanoplate arrays or oriented nanorod arrays have a great potential for orthopedic applications. - Highlights: • We prepare hydroxyapatite coatings with oriented nanoplate and nanorod arrays. • Hydroxyapatite coatings are in situ converted from bioglass coatings. • Hydroxyapatite coatings have good cytocompatibility and osteogenic differentiation. • Oriented hydroxyapatite coatings are used for orthopedic implants.

Unrecognized coral species diversity masks differences in functional ecology.

Science.gov (United States)

Boulay, Jennifer N; Hellberg, Michael E; Cortés, Jorge; Baums, Iliana B

2014-02-07

Porites corals are foundation species on Pacific reefs but a confused taxonomy hinders understanding of their ecosystem function and responses to climate change. Here, we show that what has been considered a single species in the eastern tropical Pacific, Porites lobata, includes a morphologically similar yet ecologically distinct species, Porites evermanni. While P. lobata reproduces mainly sexually, P. evermanni dominates in areas where triggerfish prey on bioeroding mussels living within the coral skeleton, thereby generating asexual coral fragments. These fragments proliferate in marginal habitat not colonized by P. lobata. The two Porites species also show a differential bleaching response despite hosting the same dominant symbiont subclade. Thus, hidden diversity within these reef-builders has until now obscured differences in trophic interactions, reproductive dynamics and bleaching susceptibility, indicative of differential responses when confronted with future climate change.

Diversity and population structure of a dominant deciduous tree based on morphological and genetic data

Science.gov (United States)

Zhang, Qin-di; Jia, Rui-Zhi; Meng, Chao; Ti, Chao-Wen; Wang, Yi-Ling

2015-01-01

Knowledge of the genetic diversity and structure of tree species across their geographic ranges is essential for sustainable use and management of forest ecosystems. Acer grosseri Pax., an economically and ecologically important maple species, is mainly distributed in North China. In this study, the genetic diversity and population differentiation of 24 natural populations of this species were evaluated using sequence-related amplified polymorphism markers and morphological characters. The results show that highly significant differences occurred in 32 morphological traits. The coefficient of variation of 34 characters was 18.19 %. Principal component analysis indicated that 18 of 34 traits explained 60.20 % of the total variance. The phenotypic differentiation coefficient (VST) was 36.06 % for all morphological traits. The Shannon–Wiener index of 34 morphological characters was 6.09, while at the population level, it was 1.77. The percentage of polymorphic bands of all studied A. grosseri populations was 82.14 %. Nei's gene diversity (He) and Shannon's information index (I) were 0.35 and 0.50, respectively. Less genetic differentiation was detected among the natural populations (GST = 0.20, ΦST = 0.10). Twenty-four populations of A. grosseri formed two main clusters, which is consistent with morphological cluster analysis. Principal coordinates analysis and STRUCTURE analysis supported the UPGMA-cluster dendrogram. There was no significant correlation between genetic and geographical distances among populations. Both molecular and morphological data suggested that A. grosseri is rich in genetic diversity. The high level of genetic variation within populations could be affected by the biological characters, mating system and lifespan of A. grosseri, whereas the lower genetic diversity among populations could be caused by effective gene exchange, selective pressure from environmental heterogeneity and the species' geographical range. PMID:26311734

Genetic, ecological and morphological divergence between populations of the endangered Mexican Sheartail hummingbird (Doricha eliza.

Directory of Open Access Journals (Sweden)

Yuyini Licona-Vera

Full Text Available The Mexican Sheartail (Doricha eliza, an endangered hummingbird, is endemic to Mexico where two populations have a disjunct distribution. One population is distributed along the northern tip of the Yucatan Peninsula whereas the other is mostly restricted to central Veracruz. Despite their disjunct distribution, previous work has failed to detect morphological or behavioral differences between these populations. Here we use variation in morphology, mtDNA and nuDNA sequences to determine the degree of morphological and molecular divergence between populations, their divergence time, and historical demography. We use species distribution modeling and niche divergence tests to infer the relative roles of vicariance and dispersal in driving divergence in the genus. Our Bayesian and maximum likelihood phylogenetic analyses revealed that Doricha eliza populations form a monophyletic clade and support their sister relationship with D. enicura. We found marked genetic differentiation, with reciprocal monophyly of haplotypes and highly restricted gene flow, supporting a history of isolation over the last 120,000 years. Genetic divergence between populations is consistent with the lack of overlap in environmental space and slight morphological differences between males. Our findings indicate that the divergence of the Veracruz and Yucatan populations is best explained by a combination of a short period of isolation exacerbated by subsequent divergence in climate conditions, and that rather than vicariance, the two isolated ranges of D. eliza are the product of recent colonization and divergence in isolation.

Convergent and divergent patterns of morphological differentiation provide more evidence for reproductive character displacement in a wood cricket Gryllus fultoni (Orthoptera: Gryllidae

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Choe Jae

2009-02-01

Full Text Available Abstract Background In ecological character displacement, traits involved in reproductive isolation may not evolve in arbitrary directions when changes in these traits are by-products of adaptation to an ecological niche. In reproductive character displacement, however, selection acts directly on reproductive characters to enhance the degree of reproductive isolation between sympatric populations. Thus, the direction of change in reproductive characters may be arbitrary in relation to changes in other morphological characters. We characterized both tegminal characters and characters indicative of body size in sympatric and allopatric populations of Gryllus fultoni, a species displaying character displacement in its calling song characters in areas of sympatry with G. vernalis populations, to infer the nature and direction of selection acting on reproductive and morphological characters in sympatry. Results Except for mirror area, the number of teeth in a file, and ovipositor length of G. fultoni, all male and female morphological characters in G. fultoni and G. vernalis exhibited a uniform tendency to decrease in size with increasing latitude. There was no significant variation in female morphological characters between sympatric and allopatric G. fultoni populations. However, males of sympatric and allopatric G. fultoni populations significantly differed in head width, hind femur length, and mirror area even after controlling for clinal factors. Head width and hind femur length of G. fultoni were more similar to those of G. vernalis in sympatric populations than in allopatric populations, resulting in morphological convergence of G. fultoni and G. vernalis in sympatry. However, the mirror area of G. fultoni displayed the divergent pattern in relation to the sympatric G. vernalis populations. Conclusion Divergence-enhancing selection may be acting on mirror area as well as calling song characters, whereas local adaptation or clinal effects may

Parsing parallel evolution: ecological divergence and differential gene expression in the adaptive radiations of thick-lipped Midas cichlid fishes from Nicaragua.

Science.gov (United States)

Manousaki, Tereza; Hull, Pincelli M; Kusche, Henrik; Machado-Schiaffino, Gonzalo; Franchini, Paolo; Harrod, Chris; Elmer, Kathryn R; Meyer, Axel

2013-02-01

The study of parallel evolution facilitates the discovery of common rules of diversification. Here, we examine the repeated evolution of thick lips in Midas cichlid fishes (the Amphilophus citrinellus species complex)-from two Great Lakes and two crater lakes in Nicaragua-to assess whether similar changes in ecology, phenotypic trophic traits and gene expression accompany parallel trait evolution. Using next-generation sequencing technology, we characterize transcriptome-wide differential gene expression in the lips of wild-caught sympatric thick- and thin-lipped cichlids from all four instances of repeated thick-lip evolution. Six genes (apolipoprotein D, myelin-associated glycoprotein precursor, four-and-a-half LIM domain protein 2, calpain-9, GTPase IMAP family member 8-like and one hypothetical protein) are significantly underexpressed in the thick-lipped morph across all four lakes. However, other aspects of lips' gene expression in sympatric morphs differ in a lake-specific pattern, including the magnitude of differentially expressed genes (97-510). Generally, fewer genes are differentially expressed among morphs in the younger crater lakes than in those from the older Great Lakes. Body shape, lower pharyngeal jaw size and shape, and stable isotopes (δ(13)C and δ(15)N) differ between all sympatric morphs, with the greatest differentiation in the Great Lake Nicaragua. Some ecological traits evolve in parallel (those related to foraging ecology; e.g. lip size, body and head shape) but others, somewhat surprisingly, do not (those related to diet and food processing; e.g. jaw size and shape, stable isotopes). Taken together, this case of parallelism among thick- and thin-lipped cichlids shows a mosaic pattern of parallel and nonparallel evolution. © 2012 Blackwell Publishing Ltd.

Aspects of the morphology and the ecology of a Paradiplozoon species from Barbus aeneus in the Vaal Dam, South Africa

OpenAIRE

2014-01-01

M.Sc. Zoology Only a few species of the family Diplozoidae have previously been described from Africa, from various Labeo and Barbus species. An investigation was undertaken respectively in the Vaal Dam and Vaal River Barrage in the Vaal River system, South Africa to determine aspects of the morphology, taxonomy and ecology of specimens of this family collected from the gills of Barbus aeneus. Various fish species, namely B. aeneus, Barbus kimberleyensis, Labeo capensis, Labeo umbratus, Cy...

Trophic convergence drives morphological convergence in marine tetrapods.

Science.gov (United States)

Kelley, Neil P; Motani, Ryosuke

2015-01-01

Marine tetrapod clades (e.g. seals, whales) independently adapted to marine life through the Mesozoic and Caenozoic, and provide iconic examples of convergent evolution. Apparent morphological convergence is often explained as the result of adaptation to similar ecological niches. However, quantitative tests of this hypothesis are uncommon. We use dietary data to classify the feeding ecology of extant marine tetrapods and identify patterns in skull and tooth morphology that discriminate trophic groups across clades. Mapping these patterns onto phylogeny reveals coordinated evolutionary shifts in diet and morphology in different marine tetrapod lineages. Similarities in morphology between species with similar diets-even across large phylogenetic distances-are consistent with previous hypotheses that shared functional constraints drive convergent evolution in marine tetrapods.

Morphological Differentiation Towards Neuronal Phenotype of SH-SY5Y Neuroblastoma Cells by Estradiol, Retinoic Acid and Cholesterol.

Science.gov (United States)

Teppola, Heidi; Sarkanen, Jertta-Riina; Jalonen, Tuula O; Linne, Marja-Leena

2016-04-01

Human SH-SY5Y neuroblastoma cells maintain their potential for differentiation and regression in culture conditions. The induction of differentiation could serve as a strategy to inhibit cell proliferation and tumor growth. Previous studies have shown that differentiation of SH-SY5Y cells can be induced by all-trans-retinoic-acid (RA) and cholesterol (CHOL). However, signaling pathways that lead to terminal differentiation of SH-SY5Y cells are still largely unknown. The goal of this study was to examine in the RA and CHOL treated SH-SY5Y cells the additive impacts of estradiol (E2) and brain-derived neurotrophic factor (BDNF) on cell morphology, cell population growth, synaptic vesicle recycling and presence of neurofilaments. The above features indicate a higher level of neuronal differentiation. Our data show that treatment for 10 days in vitro (DIV) with RA alone or when combined with E2 (RE) or CHOL (RC), but not when combined with BDNF (RB), significantly (p differentiation.

Morphologic classification of ductal breast tumors on ultrasound : differential diagnosis of benign and malignant tumors

International Nuclear Information System (INIS)

Won, Mi Sook; Chung, Soo Young; Yang, Ik; Lee, Yul; Park, Hai Jung; Lee, Myoung Hwan; Yoon, In Sook; Koh, Mi Gyoung

1997-01-01

To evaluate the morphologic differential diagnosis of benign and malignant ductal breast tumors, as seen on US US findings in 29 pathologically proven cases of ductal breast tumor were retrospectively reviewed. All patients were female and their mean age was 42 years. Nineteen tumors were benign and ten were malignant, and all ductal or cystic lesions showed solid masses. According to the location of the mural nodule, we classified the sonographic appearance of these tumors into three types:intraductal, intracystic and amorphic. The intraductal type was divided into three subtypes:incompletely obstructive, completely obstructive and multiple mural nodules. For the intracystic type, too, three subtypes were designated:the intracystic mural nodule (mural cyst), intracystic mural nodule with the duct (mural cyst+duct) and intracystic multiple mural nodules. The amorphic type is defined as an atypical ductal tumor with the mural nodule extending into adjacent parenchyma. The margin of the duct or cyst was smooth in 68.4% of benign, and irregular in 90% of malignant ductal tumors. Internal echogeneity of the duct or cyst usually showed homogeneity in both benign and malignant tumors. 73.7% of tumors connecting the duct were benign and 50% were malignant. In benign tumors, 52.6% of mural nodule had an irregular margin, while in malignant tumors, the corresponding proportion was 100%;both types usually showed heterogeneous hypoechogeneity. Among benign tumors, the most common morphologic type was the intraductal incompletely obstructive subtype (36.8%);among those that were malignant, the amorphic type was most common, accounting for 40% of tumors. No amorphic type was benign and no incompletely obstructive subtype was malignant. When ductal breast tumors are morphologically classified on the basis of sonographic findings, the intraductal incompletely obstructive subtype suggests benignancy, and the amorphic type, malignancy. The morphologic classification of ductal

Morphological heterogeneity and population differentiation in the green chromid Etroplus suratensis (Pisces: Cichlidae in Sri Lanka

Directory of Open Access Journals (Sweden)

K. B. Suneetha Gunawickrama

2007-09-01

Full Text Available Morphological variation of the euryhaline cichlid fish Etroplus suratensis (Bloch from six geographically apart estuarine localities along the southern and western coasts of Sri Lanka was studied. Significant heterogeneity in morphology of the cichlid were found with respect to nine morphometric characters (n=218. Fish of Nilwala estuary and Garanduwa lagoon were not significantly different in morphology, yet they show discernible differences from the other four samples (Kahanda lagoon, Chilaw lagoon, Walawe estuary and Koggala lagoon with respect to the most of the studied characters. Concordant results were found by multivariate analysis of the sizecorrected morphological data as well. Three functions were significant in discriminating the populations of which the first two functions accounted for 95% of the covariance (CV1 85.4 % and CV2 9.7%. The function with the greatest discriminatory power (CV1 can clearly separate samples of Nilwala estuary (L5 and Garanduwa lagoon (L6 from the rest of the samples, while the magnitude of the discrimination between the latter samples is much smaller. Classification functions could correctly classify an average of 65.7% of the individuals into their respective a priori population units. No evidence was found for isolation-by-distance model. The results suggest that E. suratensis populations in some of the studied estuarine localities maintain significant morphological heterogeneity, and the morphological variation can be used to differentiate some of these populations.

MAINTENANCE OF ECOLOGICALLY SIGNIFICANT GENETIC VARIATION IN THE TIGER SWALLOWTAIL BUTTERFLY THROUGH DIFFERENTIAL SELECTION AND GENE FLOW.

Science.gov (United States)

Bossart, J L; Scriber, J M

1995-12-01

Differential selection in a heterogeneous environment is thought to promote the maintenance of ecologically significant genetic variation. Variation is maintained when selection is counterbalanced by the homogenizing effects of gene flow and random mating. In this study, we examine the relative importance of differential selection and gene flow in maintaining genetic variation in Papilio glaucus. Differential selection on traits contributing to successful use of host plants (oviposition preference and larval performance) was assessed by comparing the responses of southern Ohio, north central Georgia, and southern Florida populations of P. glaucus to three hosts: Liriodendron tulipifera, Magnolia virginiana, and Prunus serotina. Gene flow among populations was estimated using allozyme frequencies from nine polymorphic loci. Significant genetic differentiation was observed among populations for both oviposition preference and larval performance. This differentiation was interpreted to be the result of selection acting on Florida P. glaucus for enhanced use of Magnolia, the prevalent host in Florida. In contrast, no evidence of population differentiation was revealed by allozyme frequencies. F ST -values were very small and Nm, an estimate of the relative strengths of gene flow and genetic drift, was large, indicating that genetic exchange among P. glaucus populations is relatively unrestricted. The contrasting patterns of spatial differentiation for host-use traits and lack of differentiation for electrophoretically detectable variation implies that differential selection among populations will be counterbalanced by gene flow, thereby maintaining genetic variation for host-use traits. © 1995 The Society for the Study of Evolution.

Ecology of Meimuna mongolica (Hemiptera: Cicadidae) Nymphs: Instars, Morphological Variation, Vertical Distribution and Population Density, Host-Plant Selection, and Emergence Phenology

Science.gov (United States)

Li, Qinglong; Yang, Mingsheng; Liu, Yunxiang; Wei, Cong

2015-01-01

The cicada Meimuna mongolica (Distant) (Hemiptera: Cicadidae) is one of the most important pests of economic forest in Guanzhong Plain of Shaanxi Province, China. Information about ecological characteristics and some sustainable control measures of this species is urgently required for its control. In this study, nymphal instars, morphological variation, vertical distribution, and population density in soil, and emergence phenology of nymphs of M. mongolica on three main host plants (Pinus tabuliformis Carr., Populus tomentosa Carr., and Pyrus xerophila Yü) were studied, based on combined morphological and molecular identification, investigation of the first-instar nymphs hatched from eggs and others excavated from soil, and investigation of exuviae in the adult emergence period. Five nymphal instars of M. mongolica were redetermined according to the distribution plots of the head capsule widths of the nymphs. Nymphs of third and fourth instars showed morphological variation, which is closely related to host-plant association. The mean densities of nymphs in soil under the three host plants were significantly different, indicating a distinct host preference. The nymphs could extend their distribution from the 0–10 cm soil layer to the 51–60 cm soil layer underground but not beyond 60 cm soil layer under all the three host plants. The 21–30 cm soil layer under all the three host plants has the highest nymphal population density. The sex ratio of the entire population was nearly 50:50, but males dominated in the early half of the duration of the emergence. These ecological characteristics of M. mongolica could provide important information for sustainable control measures.

Methionine restriction alters bone morphology and affects osteoblast differentiation

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Amadou Ouattara

2016-12-01

Full Text Available Methionine restriction (MR extends the lifespan of a wide variety of species, including rodents, drosophila, nematodes, and yeasts. MR has also been demonstrated to affect the overall growth of mice and rats. The objective of this study was to evaluate the effect of MR on bone structure in young and aged male and female C57BL/6J mice. This study indicated that MR affected the growth rates of males and young females, but not aged females. MR reduced volumetric bone mass density (vBMD and bone mineral content (BMC, while bone microarchitecture parameters were decreased in males and young females, but not in aged females compared to control-fed (CF mice. However, when adjusted for bodyweight, the effect of MR in reducing vBMD, BMC and microarchitecture measurements was either attenuated or reversed suggesting that the smaller bones in MR mice is appropriate for its body size. In addition, CF and MR mice had similar intrinsic strength properties as measured by nanoindentation. Plasma biomarkers suggested that the low bone mass in MR mice could be due to increased collagen degradation, which may be influenced by leptin, IGF-1, adiponectin and FGF21 hormone levels. Mouse preosteoblast cell line cultured under low sulfur amino acid growth media attenuated gene expression levels of Col1al, Runx2, Bglap, Alpl and Spp1 suggesting delayed collagen formation and bone differentiation. Collectively, our studies revealed that MR altered bone morphology which could be mediated by delays in osteoblast differentiation. Keywords: Methionine restriction, Aged mice, Micro-computed tomography, Nanoindentation, MC3T3-E1 subclone 4

Ecological characterization and molecular differentiation of Culex pipiens complex taxa and Culex torrentium in eastern Austria.

Science.gov (United States)

Zittra, Carina; Flechl, Eva; Kothmayer, Michael; Vitecek, Simon; Rossiter, Heidemarie; Zechmeister, Thomas; Fuehrer, Hans-Peter

2016-04-11

Culex pipiens complex taxa differ in behaviour, ecophysiology and epidemiologic importance. Despite their epidemiologic significance, information on genetic diversity, occurrence and seasonal and spatial distribution patterns of the Cx. pipiens complex is still insufficient. Assessment of seasonal and spatial distribution patterns of Culex pipiens forms and their congener Cx. torrentium is crucial for the understanding of their vector-pathogen dynamics. Female mosquitoes were trapped from April-October 2014 twice a month for a 24-h time period with BG-sentinel traps at 24 sampling sites in eastern Austria, using carbon dioxide as attractant. Ecological forms of Cx. pipiens s.l. and their hybrids were differentiated using the CQ11 locus, and Cx. pipiens forms and their congener Cx. torrentium using the ACE-2 gene. Differential exploitation of ecological niches by Cx. pipiens forms and Cx. torrentium was analysed using likelihood ratio tests. Possible effects of environmental parameters on these taxa were tested using PERMANOVA based on distance matrices and, if significant, were modelled in nMDS ordination space to estimate non-linear relationships. For this study, 1476 Culex spp. were sampled. Culex pipiens f. pipiens representing 87.33 % of the total catch was most abundant, followed by hybrids of both forms (5.62 %), Cx. torrentium (3.79 %) and Cx. pipiens f. molestus (3.25 %). Differences in proportional abundances were found between land cover classes. Ecological parameters affecting seasonal and spatial distribution of these taxa in eastern Austria are precipitation duration, air temperature, sunlight and the interaction term of precipitation amount and the Danube water level, which can be interpreted as a proxy for breeding habitat availability. The Cx. pipiens complex of eastern Austria comprises both ecologically different forms, the mainly ornithophilic form pipiens and the mainly mammalophilic and anthropophilic form molestus. Heterogeneous agricultural

Genetics, morphology and ecology reveal a cryptic pika lineage in the Sikkim Himalaya.

Science.gov (United States)

Dahal, Nishma; Lissovsky, Andrey A; Lin, Zhenzhen; Solari, Katherine; Hadly, Elizabeth A; Zhan, Xiangjiang; Ramakrishnan, Uma

2017-01-01

Asian pika species are morphologically ∼similar and have overlapping ranges. This leads to uncertainty and species misidentification in the field. Phylogenetic analyses of such misidentified samples leads to taxonomic ambiguity. The ecology of many pika species remains understudied, particularly in the Himalaya, where sympatric species could be separated by elevation and/or substrate. We sampled, measured, and acquired genetic data from pikas in the Sikkim Himalaya. Our analyses revealed a cryptic lineage, Ochotona sikimaria, previously reported as a subspecies of O. thibetana. The results support the elevation of this lineage to the species level, as it is genetically divergent from O. thibetana, as well as sister species, O. cansus (endemic to central China) and O. curzoniae (endemic to the Tibetan plateau). The Sikkim lineage diverged from its sister species' about 1.7-0.8myrago, coincident with uplift events in the Himalaya. Our results add to the recent spate of cryptic diversity identified from the eastern Himalaya and highlight the need for further study within the Ochotonidae. Copyright © 2016 Elsevier Inc. All rights reserved.

[Clinical value of MRI united-sequences examination in diagnosis and differentiation of morphological sub-type of hilar and extrahepatic big bile duct cholangiocarcinoma].

Science.gov (United States)

Yin, Long-Lin; Song, Bin; Guan, Ying; Li, Ying-Chun; Chen, Guang-Wen; Zhao, Li-Ming; Lai, Li

2014-09-01

To investigate MRI features and associated histological and pathological changes of hilar and extrahepatic big bile duct cholangiocarcinoma with different morphological sub-types, and its value in differentiating between nodular cholangiocarcinoma (NCC) and intraductal growing cholangiocarcinoma (IDCC). Imaging data of 152 patients with pathologically confirmed hilar and extrahepatic big bile duct cholangiocarcinoma were reviewed, which included 86 periductal infiltrating cholangiocarcinoma (PDCC), 55 NCC, and 11 IDCC. Imaging features of the three morphological sub-types were compared. Each of the subtypes demonstrated its unique imaging features. Significant differences (P big bile duct cholangiocarcinoma. MRI united-sequences examination can accurately describe those imaging features for differentiation diagnosis.

Morphology and 18S rDNA gene sequence of Spirostomum minus and Spirostomum teres (Ciliophora: Heterotrichea) from Rio de Janeiro, Brazil

OpenAIRE

Noemi M. Fernandes; Inácio D. da Silva Neto

2013-01-01

Species of Spirostomum Ehrenberg, 1838 are widely used as model organisms in ecological studies of environmental impacts and symbioses between ciliates and human pathogenic bacteria. However, the taxonomy of this genus is confused by the superficiality of the morphological descriptions of its included species, and the use of only a few characters for their differentiation. The present study provides details of total infraciliature, nuclear apparatus, morphometric data and 18S rDNA gene sequen...

Insights into Penicillium roqueforti Morphological and Genetic Diversity

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Gillot, Guillaume; Jany, Jean-Luc; Coton, Monika; Le Floch, Gaétan; Debaets, Stella; Ropars, Jeanne; López-Villavicencio, Manuela; Dupont, Joëlle; Branca, Antoine; Giraud, Tatiana; Coton, Emmanuel

2015-01-01

Fungi exhibit substantial morphological and genetic diversity, often associated with cryptic species differing in ecological niches. Penicillium roqueforti is used as a starter culture for blue-veined cheeses, being responsible for their flavor and color, but is also a common spoilage organism in various foods. Different types of blue-veined cheeses are manufactured and consumed worldwide, displaying specific organoleptic properties. These features may be due to the different manufacturing methods and/or to the specific P. roqueforti strains used. Substantial morphological diversity exists within P. roqueforti and, although not taxonomically valid, several technological names have been used for strains on different cheeses (e.g., P. gorgonzolae, P. stilton). A worldwide P. roqueforti collection from 120 individual blue-veined cheeses and 21 other substrates was analyzed here to determine (i) whether P. roqueforti is a complex of cryptic species, by applying the Genealogical Concordance Phylogenetic Species Recognition criterion (GC-PSR), (ii) whether the population structure assessed using microsatellite markers correspond to blue cheese types, and (iii) whether the genetic clusters display different morphologies. GC-PSR multi-locus sequence analyses showed no evidence of cryptic species. The population structure analysis using microsatellites revealed the existence of highly differentiated populations, corresponding to blue cheese types and with contrasted morphologies. This suggests that the population structure has been shaped by different cheese-making processes or that different populations were recruited for different cheese types. Cheese-making fungi thus constitute good models for studying fungal diversification under recent selection. PMID:26091176

IDH1-associated primary glioblastoma in young adults displays differential patterns of tumour and vascular morphology.

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Sergey Popov

Full Text Available Glioblastoma is a highly aggressive tumour with marked heterogeneity at the morphological level in both the tumour cells and the associated highly prominent vasculature. As we begin to develop an increased biological insight into the underlying processes driving the disease, fewer attempts have thus far been made to understand these phenotypic differences. We sought to address this by carefully assessing the morphological characteristics of both the tumour cells and the associated vasculature, relating these observations to the IDH1/MGMT status, with a particular focus on the early onset population of young adults who develop primary glioblastoma. 276 primary glioblastoma specimens were classified into their predominant cell morphological type (fibrillary, gemistocytic, giant cell, small cell, oligodendroglial, sarcomatous, and assessed for specific tumour (cellularity, necrosis, palisades and vascular features (glomeruloid structures, arcades, pericyte proliferation. IDH1 positive glioblastomas were associated with a younger age at diagnosis, better clinical outcome, prominent oligodendroglial and small cell tumour cell morphology, pallisading necrosis and glomeruloid vascular proliferation in the absence of arcade-like structures. These features widen the phenotype of IDH1 mutation-positive primary glioblastoma in young adults and provide correlative evidence for a functional role of mutant IDH1 in the differential nature of neo-angiogenesis in different subtypes of glioblastoma.

Scale Morphology and Micro-Structure of Monitor Lizards (Squamata: Varanidae: Varanus spp.) and their Allies: Implications for Systematics, Ecology, and Conservation.

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Bucklitsch, Yannick; Böhme, Wolfgang; Koch, André

2016-08-17

We analysed scale morphology and micro-structure from five different body regions using scanning electron microscopy (SEM) across all nine recognized subgenera of the monitor lizard genus Varanus including 41 different species investigated. As far as we are aware, this qualitative visual technique was applied by us for the first time to most monitor lizard species and probably also to the primary outgroup and sister species Lanthanotus borneensis. A comprehensive list of 20 scalation characters each with up to seven corresponding character states was established and defined for the five body regions sampled. For the phylogenetic approach, parsimony analyses of the resulting morphological data matrix as well as Bremer and bootstrap support calculations were performed with the software TNT. Our results demonstrate that a variety of micro-ornamentations (i.e., ultra- or micro-dermatoglyphics) as seen in various squamate groups is hardly present in monitor lizards. In several species from six out of nine subgenera, however, we found a honeycomb-shaped micro-structure of foveate polygons. Two further samples of Euprepiosaurus Fitzinger, 1843 exhibit each another unique microscopic structure on the scale surface. Notably, the majority of species showing the honeycombed ultra-structure inhabit arid habitats in Australia, Africa and the Middle East. Therefore, it can be inferred that this microscopic scalation feature, which has also been identified in other desert dwelling lizard species, is taxonomically and ecologically correlated with a xeric habitat type in varanids, too. In addition, the systematic affiliation of V. spinulosus, an endemic monitor lizard species from the Solomon Islands with an extraordinary scale shape, is discussed in the light of current hypotheses about its phylogenetic position within the Varanidae. Due to its unique scalation characteristics, in combination with other morphological evidence, a new monotypic subgenus, Solomonsaurus subgen. nov

Morphological Variation and Ecological Structure of Iroko (Milicia excelsa Welw. C.C. Berg) Populations across Different Bio geographical Zones in Benin

International Nuclear Information System (INIS)

Ouinsavi, C.; Sokpon, N.

2010-01-01

Iroko (Milicia excelsa) is a commercially important timber tree species formerly known by local people in Benin. Because of the highly attractive technological properties of its wood and its multipurpose uses, the species was subjected to intensive human pressure. Apart from strong climate oscillation during the Pleistocene, human caused habitat fragmentation through continuous land clearing for agriculture, extensive forests exploitation and urbanization induced the occurrence of many isolated forest plots and trees species among which Milicia excelsa trees. As fragmentation was proved to have deleterious effects on genetic diversity within a species and its morphological structure, it was of interest to investigate the current demographic, morphological and genetic structure of M. excelsa before coming up with conservation strategies. In the current study, morphological variation and ecological structure of M. excelsa populations were assessed in Benin using transect sampling method and multivariate analyses including principal component, cluster and canonical discriminant analyses. On the basis of morphological parameters, M. excelsa individuals and populations were clustered into four and discrimination of groups indicated that most of variations were highly related to edaphic factors and annual rainfall. Erratic diameter distribution was found for many populations although most of them showed bell shaped diameter distribution.

Morphological and ecological parallels between sublittoral and abyssal foraminiferal species in the NE Atlantic: a comparison of Stainforthia fusiformis and Stainforthia sp.

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Gooday, Andrew J.; Alve, Elisabeth

Dead specimens of a minute fusiform rotaliid foraminifer are common in the 28-63 μm fraction of multiple corer samples from a 4850 m-deep site on the Porcupine Abyssal Plain (PAP). Their test morphology is remarkably similar to small specimens of Stainforthia fusiformis ( Williamson, 1858), a species which is well known from coastal settings (intertidal to outer shelf) around NW Europe and North America. A detailed comparison of the PAP form with typical individuals of S. fusiformis from Norwegian waters (55-203 m depth), however, reveals slight but consistent morphological differences. The PAP specimens are smaller (test length 40-140 μm) than those from Norway (test length 80-380 μm), the chambers tend to be rather less elongate, the density of pores in the test wall is much lower, and there are differences in apertural features. We therefore conclude that the diminutive abyssal form is a distinct species, here referred to as Stainforthia sp. This interpretation is consistent with increasing evidence for genetic differentiation in deep-sea organisms, particularly along bathymetric gradients. Stainforthia sp. was previously illustrated by Pawlowski as Fursenkoina sp. and appears to be widespread and abundant in the abyssal North Atlantic (>4000 m depth). Stainforthia fusiformis, on the other hand, is most abundant in continental shelf and coastal settings. It extends onto the continental slope in the North Atlantic but has not been reported reliably from depths greater than about 2500 m. We suggest that the striking morphological convergence between these two species reflects the adoption of similar ecological strategies in widely separated habitats. Both are enrichment opportunists, a life-style which may explain the rather broad bathymetric range of Stainforthia fusiformis. This is a dominant species in organically-enriched and sometimes extremely oxygen-depleted environments on the continental shelf, and is a rapid coloniser of formerly azoic habitats. Live

Ecological and Genetic Barriers Differentiate Natural Populations of Saccharomyces cerevisiae.

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Clowers, Katie J; Heilberger, Justin; Piotrowski, Jeff S; Will, Jessica L; Gasch, Audrey P

2015-09-01

How populations that inhabit the same geographical area become genetically differentiated is not clear. To investigate this, we characterized phenotypic and genetic differences between two populations of Saccharomyces cerevisiae that in some cases inhabit the same environment but show relatively little gene flow. We profiled stress sensitivity in a group of vineyard isolates and a group of oak-soil strains and found several niche-related phenotypes that distinguish the populations. We performed bulk-segregant mapping on two of the distinguishing traits: The vineyard-specific ability to grow in grape juice and oak-specific tolerance to the cell wall damaging drug Congo red. To implicate causal genes, we also performed a chemical genomic screen in the lab-strain deletion collection and identified many important genes that fell under quantitative trait loci peaks. One gene important for growth in grape juice and identified by both the mapping and the screen was SSU1, a sulfite-nitrite pump implicated in wine fermentations. The beneficial allele is generated by a known translocation that we reasoned may also serve as a genetic barrier. We found that the translocation is prevalent in vineyard strains, but absent in oak strains, and presents a postzygotic barrier to spore viability. Furthermore, the translocation was associated with a fitness cost to the rapid growth rate seen in oak-soil strains. Our results reveal the translocation as a dual-function locus that enforces ecological differentiation while producing a genetic barrier to gene flow in these sympatric populations. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Continental cichlid radiations: functional diversity reveals the role of changing ecological opportunity in the Neotropics.

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Arbour, Jessica Hilary; López-Fernández, Hernán

2016-08-17

Adaptive radiations have been hypothesized to contribute broadly to the diversity of organisms. Models of adaptive radiation predict that ecological opportunity and ecological release, the availability of empty ecological niches and the response by adapting lineages to occupy them, respectively, drive patterns of phenotypic and lineage diversification. Adaptive radiations driven by 'ecological opportunity' are well established in island systems; it is less clear if ecological opportunity influences continent-wide diversification. We use Neotropical cichlid fishes to test if variation in rates of functional evolution is consistent with changing ecological opportunity. Across a functional morphological axis associated with ram-suction feeding traits, evolutionary rates declined through time as lineages diversified in South America. Evolutionary rates of ram-suction functional morphology also appear to have accelerated as cichlids colonized Central America and encountered renewed opportunity. Our results suggest that ecological opportunity may play an important role in shaping patterns of morphological diversity of even broadly distributed lineages like Neotropical cichlids. © 2016 The Author(s).

Atomic force microscopy reveals a morphological differentiation of chromobacterium violaceum cells associated with biofilm development and directed by N-hexanoyl-L-homoserine lactone.

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Anara A Kamaeva

Full Text Available Chromobacterium violaceum abounds in soil and water ecosystems in tropical and subtropical regions and occasionally causes severe and often fatal human and animal infections. The quorum sensing (QS system and biofilm formation are essential for C. violaceum's adaptability and pathogenicity, however, their interrelation is still unknown. C. violaceum's cell and biofilm morphology were examined by atomic force microscopy (AFM in comparison with growth rates, QS-dependent violacein biosynthesis and biofilm biomass quantification. To evaluate QS regulation of these processes, the wild-type strain C. violaceum ATCC 31532 and its mini-Tn5 mutant C. violaceum NCTC 13274, cultivated with and without the QS autoinducer N-hexanoyl-L-homoserine lactone (C6-HSL, were used. We report for the first time the unusual morphological differentiation of C. violaceum cells, associated with biofilm development and directed by the QS autoinducer. AFM revealed numerous invaginations of the external cytoplasmic membrane of wild-type cells, which were repressed in the mutant strain and restored by exogenous C6-HSL. With increasing bacterial growth, polymer matrix extrusions formed in place of invaginations, whereas mutant cells were covered with a diffusely distributed extracellular substance. Thus, quorum sensing in C. violaceum involves a morphological differentiation that organises biofilm formation and leads to a highly differentiated matrix structure.

Atomic force microscopy reveals a morphological differentiation of chromobacterium violaceum cells associated with biofilm development and directed by N-hexanoyl-L-homoserine lactone.

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Kamaeva, Anara A; Vasilchenko, Alexey S; Deryabin, Dmitry G

2014-01-01

Chromobacterium violaceum abounds in soil and water ecosystems in tropical and subtropical regions and occasionally causes severe and often fatal human and animal infections. The quorum sensing (QS) system and biofilm formation are essential for C. violaceum's adaptability and pathogenicity, however, their interrelation is still unknown. C. violaceum's cell and biofilm morphology were examined by atomic force microscopy (AFM) in comparison with growth rates, QS-dependent violacein biosynthesis and biofilm biomass quantification. To evaluate QS regulation of these processes, the wild-type strain C. violaceum ATCC 31532 and its mini-Tn5 mutant C. violaceum NCTC 13274, cultivated with and without the QS autoinducer N-hexanoyl-L-homoserine lactone (C6-HSL), were used. We report for the first time the unusual morphological differentiation of C. violaceum cells, associated with biofilm development and directed by the QS autoinducer. AFM revealed numerous invaginations of the external cytoplasmic membrane of wild-type cells, which were repressed in the mutant strain and restored by exogenous C6-HSL. With increasing bacterial growth, polymer matrix extrusions formed in place of invaginations, whereas mutant cells were covered with a diffusely distributed extracellular substance. Thus, quorum sensing in C. violaceum involves a morphological differentiation that organises biofilm formation and leads to a highly differentiated matrix structure.

Ecological release in lizard assemblages of neotropical savannas.

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Mesquita, Daniel Oliveira; Colli, Guarino Rinaldi; Vitt, Laurie J

2007-08-01

We compare lizard assemblages of Cerrado and Amazonian savannas to test the ecological release hypothesis, which predicts that niche dimensions and abundance should be greater in species inhabiting isolated habitat patches with low species richness (Amazonian savannas and isolated Cerrado patches) when compared with nonisolated areas in central Cerrado with greater species richness. We calculated microhabitat and diet niche breadths with data from 14 isolated Cerrado patches and Amazon savanna areas and six central Cerrado populations. Morphological data were compared using average Euclidean distances, and lizard abundance was estimated using the number of lizards captured in pitfall traps over an extended time period. We found no evidence of ecological release with respect to microhabitat use, suggesting that historical factors are better microhabitat predictors than ecological factors. However, data from individual stomachs indicate that ecological release occurs in these areas for one species (Tropidurus) but not others (Ameiva ameiva, Anolis, Cnemidophorus, and Micrablepharus), suggesting that evolutionary lineages respond differently to environmental pressures, with tropidurids being more affected by ecological factors than polychrotids, teiids, and gymnophthalmids. We found no evidence that ecological release occurs in these areas using morphological data. Based on abundance data, our results indicate that the ecological release (density compensation) hypothesis is not supported: lizard species are not more abundant in isolated areas than in nonisolated areas. The ecology of species is highly conservative, varying little from assemblage to assemblage. Nevertheless, increases in niche breadth for some species indicate that ecological release occurs as well.

Mobilifilum chasei: morphology and ecology of a spirochete from an intertidal stratified microbial mat community

Science.gov (United States)

Margulis, L.; Hinkle, G.; Stolz, J.; Craft, F.; Esteve, I.; Guerrero, R.

1990-01-01

Spirochetes were found in the lower anoxiphototrophic layer of a stratified microbial mat (North Pond, Laguna Figueroa, Baja California, Mexico). Ultra-structural analysis of thin sections of field samples revealed spirochetes approximately 0.25 micrometer in diameter with 10 or more periplasmic flagella, leading to the interpretation that these spirochetes bear 10 flagellar insertions on each end. Morphometric study showed these free-living spirochetes greatly resemble certain symbiotic ones, i.e., Borrelia and certain termite spirochetes, the transverse sections of which are presented here. The ultrastructure of this spirochete also resembles Hollandina and Diplocalyx (spirochetes symbiotic in arthropods) more than it does Spirochaeta, the well known genus of mud-dwelling spirochetes. The new spirochete was detected in mat material collected both in 1985 and in 1987. Unique morphology (i.e., conspicuous outer coat of inner membrane, large number of periplasmic flagella) and ecology prompt us to name a new free-living spirochete.

CONTRIBUTIONS TO THE FUNCTIONAL MORPHOLOGY OF ...

African Journals Online (AJOL)

CONTRIBUTIONS TO THE FUNCTIONAL MORPHOLOGY OF FISHES ... The exact phylogeny of the chimaeroids is obscure due to difficulties encountered in ...... species was obtained from the University of Cape Town Ecological Records;.

Ecological character displacement in the face of gene flow: Evidence from two species of nightingales

Science.gov (United States)

2011-01-01

Background Ecological character displacement is a process of phenotypic differentiation of sympatric populations caused by interspecific competition. Such differentiation could facilitate speciation by enhancing reproductive isolation between incipient species, although empirical evidence for it at early stages of divergence when gene flow still occurs between the species is relatively scarce. Here we studied patterns of morphological variation in sympatric and allopatric populations of two hybridizing species of birds, the Common Nightingale (Luscinia megarhynchos) and the Thrush Nightingale (L. luscinia). Results We conducted principal component (PC) analysis of morphological traits and found that nightingale species converged in overall body size (PC1) and diverged in relative bill size (PC3) in sympatry. Closer analysis of morphological variation along geographical gradients revealed that the convergence in body size can be attributed largely to increasing body size with increasing latitude, a phenomenon known as Bergmann's rule. In contrast, interspecific interactions contributed significantly to the observed divergence in relative bill size, even after controlling for the effects of geographical gradients. We suggest that the divergence in bill size most likely reflects segregation of feeding niches between the species in sympatry. Conclusions Our results suggest that interspecific competition for food resources can drive species divergence even in the face of ongoing hybridization. Such divergence may enhance reproductive isolation between the species and thus contribute to speciation. PMID:21609448

Ecological character displacement in the face of gene flow: Evidence from two species of nightingales

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Reif Jiří

2011-05-01

Full Text Available Abstract Background Ecological character displacement is a process of phenotypic differentiation of sympatric populations caused by interspecific competition. Such differentiation could facilitate speciation by enhancing reproductive isolation between incipient species, although empirical evidence for it at early stages of divergence when gene flow still occurs between the species is relatively scarce. Here we studied patterns of morphological variation in sympatric and allopatric populations of two hybridizing species of birds, the Common Nightingale (Luscinia megarhynchos and the Thrush Nightingale (L. luscinia. Results We conducted principal component (PC analysis of morphological traits and found that nightingale species converged in overall body size (PC1 and diverged in relative bill size (PC3 in sympatry. Closer analysis of morphological variation along geographical gradients revealed that the convergence in body size can be attributed largely to increasing body size with increasing latitude, a phenomenon known as Bergmann's rule. In contrast, interspecific interactions contributed significantly to the observed divergence in relative bill size, even after controlling for the effects of geographical gradients. We suggest that the divergence in bill size most likely reflects segregation of feeding niches between the species in sympatry. Conclusions Our results suggest that interspecific competition for food resources can drive species divergence even in the face of ongoing hybridization. Such divergence may enhance reproductive isolation between the species and thus contribute to speciation.

Morphological analysis and differentiation of benign cystic neoplasms of the pancreas using computed tomography and magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Grieser, Christian; Heine, G.; Stelter, L.; Steffen, I.G.; Rothe, J.H.; Walter, T.C.; Denecke, T. [Charite - Universitaetsmedizin Berlin, Campus Virchow-Klinikum (Germany). Klinik fuer Radiologie; Fischer, C. [Charite - Universitaetsmedizin Berlin, Campus Virchow-Klinikum (Germany). Medizinische Klinik m. S. Hepatologie und Gastroenterologie; Bahra, M. [Charite - Universitaetsmedizin Berlin, Campus Virchow-Klinikum (Germany). Klinik fuer Allgemein, Viszeral- und Transplantationschirurgie

2013-03-15

Purpose: To evaluate morphologic characteristics and establish a standardized diagnostic algorithm to differentiate benign cystic pancreatic tumors (CPTs) in non-pancreatitis patients using multidetector computed tomography (CT) and magnetic resonance imaging (MRI). Materials and Methods: Patients with histopathologically proven CPTs who had undergone MRI and/or CT and subsequent tumor resection in our institution were retrospectively identified. Images were analyzed for morphology and enhancement patterns by three independent blinded observers. Preoperative image findings were correlated with histopathological results. Based on the evaluated morphologic parameters, a standardized diagnostic algorithm was designed to help characterize the lesions. Results: A total of 62 consecutive patients with 64 CPTs were identified from the surgical database (21 intraductal papillary mucinous neoplasms; 10 mucinous cystic neoplasms; 12 serous microcystic adenomas; 3 serous oligocystic adenomas; 6 solid pseudopapillary tumors; 12 neuroendocrine neoplasms). The overall averaged accuracy for the 3 observers was 89.9 % for CT and 93.1 % for MRI with increasing overall accuracy in relation to the experience of the observer (88.2 %, 91.5 %, and 93.8 %, respectively). Overall, the generalized kappa value was 0.69 (CT, 0.64; MRI, 0.76); p < 0.001. The accuracy of the standardized diagnostic algorithm was 91.1 %. Conclusion: It is possible to characterize benign CPTs with MRI and CT, while MRI appears to be superior to CT. Diagnostic accuracy depends on the observer's experience. The standardized algorithm can aid in the differential diagnosis but still needs to be tested in other patient populations. (orig.)

The value of whole lesion ADC histogram profiling to differentiate between morphologically indistinguishable ring enhancing lesions–comparison of glioblastomas and brain abscesses

Science.gov (United States)

Hoffmann, Karl-Titus; Garnov, Nikita; Vörkel, Cathrin; Kohlhof-Meinecke, Patricia; Ganslandt, Oliver; Bäzner, Hansjörg; Gihr, Georg Alexander; Kalman, Marcell; Henkes, Elina; Henkes, Hans; Schob, Stefan

2018-01-01

Background Morphologically similar appearing ring enhancing lesions in the brain parenchyma can be caused by a number of distinct pathologies, however, they consistently represent life-threatening conditions. The two most frequently encountered diseases manifesting as such are glioblastoma multiforme (GBM) and brain abscess (BA), each requiring disparate therapeutical approaches. As a result of their morphological resemblance, essential treatment might be significantly delayed or even ommited, in case results of conventional imaging remain inconclusive. Therefore, our study aimed to investigate, whether ADC histogram profiling reliably can distinguish between both entities, thus enhancing the differential diagnostic process and preventing treatment failure in this highly critical context. Methods 103 patients (51 BA, 52 GBM) with histopathologically confirmed diagnosis were enrolled. Pretreatment diffusion weighted imaging (DWI) was obtained in a 1.5T system using b values of 0, 500, and 1000 s/mm2. Whole lesion ADC volumes were analyzed using a histogram-based approach. Statistical analysis was performed using SPSS version 23. Results All investigated parameters were statistically different in comparison of both groups. Most importantly, ADCp10 was able to differentiate reliably between BA and GBM with excellent accuracy (0.948) using a cutpoint value of 70 × 10−5 mm2 × s−1. Conclusions ADC whole lesion histogram profiling provides a valuable tool to differentiate between morphologically indistinguishable mass lesions. Among the investigated parameters, the 10th percentile of the ADC volume distinguished best between GBM and BA. PMID:29719596

The value of whole lesion ADC histogram profiling to differentiate between morphologically indistinguishable ring enhancing lesions-comparison of glioblastomas and brain abscesses.

Science.gov (United States)

Horvath-Rizea, Diana; Surov, Alexey; Hoffmann, Karl-Titus; Garnov, Nikita; Vörkel, Cathrin; Kohlhof-Meinecke, Patricia; Ganslandt, Oliver; Bäzner, Hansjörg; Gihr, Georg Alexander; Kalman, Marcell; Henkes, Elina; Henkes, Hans; Schob, Stefan

2018-04-06

Morphologically similar appearing ring enhancing lesions in the brain parenchyma can be caused by a number of distinct pathologies, however, they consistently represent life-threatening conditions. The two most frequently encountered diseases manifesting as such are glioblastoma multiforme (GBM) and brain abscess (BA), each requiring disparate therapeutical approaches. As a result of their morphological resemblance, essential treatment might be significantly delayed or even ommited, in case results of conventional imaging remain inconclusive. Therefore, our study aimed to investigate, whether ADC histogram profiling reliably can distinguish between both entities, thus enhancing the differential diagnostic process and preventing treatment failure in this highly critical context. 103 patients (51 BA, 52 GBM) with histopathologically confirmed diagnosis were enrolled. Pretreatment diffusion weighted imaging (DWI) was obtained in a 1.5T system using b values of 0, 500, and 1000 s/mm 2 . Whole lesion ADC volumes were analyzed using a histogram-based approach. Statistical analysis was performed using SPSS version 23. All investigated parameters were statistically different in comparison of both groups. Most importantly, ADCp10 was able to differentiate reliably between BA and GBM with excellent accuracy (0.948) using a cutpoint value of 70 × 10 -5 mm 2 × s -1 . ADC whole lesion histogram profiling provides a valuable tool to differentiate between morphologically indistinguishable mass lesions. Among the investigated parameters, the 10th percentile of the ADC volume distinguished best between GBM and BA.

Cranial and mandibular shape variation in the genus Carollia (Mammalia: Chiroptera from Colombia: biogeographic patterns and morphological modularity

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Camilo López-Aguirre

2015-08-01

Full Text Available Neotropical bats of the genus Carollia are widely studied due to their abundance, distribution and relevance for ecosystems. However, the ecomorphological boundaries of these species are poorly differentiated, and consequently correspondence between their geographic distribution, ecological plasticity and morphological variation remains unclear. In this study, patterns of cranial and mandibular morphological variation were assessed for Carollia brevicauda, C. castanea and C. perspicillata from Colombia. Using geometric morphometrics, morphological variation was examined with respect to: differences in intraspecific variation, morphological modularity and integration, and biogeographic patterns. Patterns of intraspecific variation were different for each species in both cranial and mandibular morphology, with functional differences apparent according to diet. Cranial modularity varied between species whereas mandibular modularity did not. High cranial and mandibular correlation reflects Cranium-Mandible integration as a functional unit. Similarity between the biogeographic patterns in C. brevicauda and C. perspicillata indicates that the Andes do not act as a barrier but rather as an independent region, isolating the morphology of Andean populations of larger-bodied species. The biogeographic pattern for C. castanea was not associated with the physiography of the Andes, suggesting that large body size does not benefit C. brevicauda and C. perspicillata in maintaining homogeneous morphologies among populations.

Cranial and mandibular shape variation in the genus Carollia (Mammalia: Chiroptera) from Colombia: biogeographic patterns and morphological modularity.

Science.gov (United States)

López-Aguirre, Camilo; Pérez-Torres, Jairo; Wilson, Laura A B

2015-01-01

Neotropical bats of the genus Carollia are widely studied due to their abundance, distribution and relevance for ecosystems. However, the ecomorphological boundaries of these species are poorly differentiated, and consequently correspondence between their geographic distribution, ecological plasticity and morphological variation remains unclear. In this study, patterns of cranial and mandibular morphological variation were assessed for Carollia brevicauda, C. castanea and C. perspicillata from Colombia. Using geometric morphometrics, morphological variation was examined with respect to: differences in intraspecific variation, morphological modularity and integration, and biogeographic patterns. Patterns of intraspecific variation were different for each species in both cranial and mandibular morphology, with functional differences apparent according to diet. Cranial modularity varied between species whereas mandibular modularity did not. High cranial and mandibular correlation reflects Cranium-Mandible integration as a functional unit. Similarity between the biogeographic patterns in C. brevicauda and C. perspicillata indicates that the Andes do not act as a barrier but rather as an independent region, isolating the morphology of Andean populations of larger-bodied species. The biogeographic pattern for C. castanea was not associated with the physiography of the Andes, suggesting that large body size does not benefit C. brevicauda and C. perspicillata in maintaining homogeneous morphologies among populations.

Floral traits and pollination ecology of European Arum hybrids.

Science.gov (United States)

Chartier, Marion; Liagre, Suzanne; Weiss-Schneeweiss, Hanna; Kolano, Bozena; Bessière, Jean-Marie; Schönenberger, Jürg; Gibernau, Marc

2016-02-01

Hybridisation is common in plants and can affect the genetic diversity and ecology of sympatric parental populations. Hybrids may resemble the parental species in their ecology, leading to competition and/or gene introgression; alternatively, they may diverge from the parental phenotypes, possibly leading to the colonisation of new ecological niches and to speciation. Here, we describe inflorescence morphology, ploidy levels, pollinator attractive scents, and pollinator guilds of natural hybrids of Arum italicum and A. maculatum (Araceae) from a site with sympatric parental populations in southern France to determine how these traits affect the hybrid pollination ecology. Hybrids were characterised by inflorescences with a size and a number of flowers more similar to A. italicum than to A. maculatum. In most cases, hybrid stamens were purple, as in A. maculatum, and spadix appendices yellow, as in A. italicum. Hybrid floral scent was closer to that of A. italicum, but shared some compounds with A. maculatum and comprised unique compounds. Also, the pollinator guild of the hybrids was similar to that of A. italicum. Nevertheless, the hybrids attracted a high proportion of individuals of the main pollinator of A. maculatum. We discuss the effects of hybridisation in sympatric parental zones in which hybrids exhibit low levels of reproductive success, the establishment of reproductive barriers between parental species, the role of the composition of floral attractive scents in the differential attraction of pollinators and in the competition between hybrids and their parental species, and the potential of hybridisation to give rise to new independent lineages.

Distribution, morphological variability, ecology and the present state of Nitella from Lake Ohrid and its surroundings

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Trajanovska Sonja

2012-01-01

Full Text Available Our research into 52 profiles of the littoral zone of the Macedonian part of Lake Ohrid and numerous samples taken from its surroundings has resulted in a detailed picture of the composition of the Charophyta vegetation in the lake. The results of the research also include data regarding the species composition and present state of Nitella. The dominant species of Nitella is Nitella opaca, which is characterized by a specific distribution, morphological variability and ecology. The present state of Nitella is not steady, especially in the watershed of the lake, since in this area there are some permanent changes in the hydrology of the terrain. Therefore, there is a need to establish long-term and complex monitoring which will result in the prompt detection of risk factors and influences, thereby enabling a rapid reaction to a possible newly emerged negative state.

THE DISTRIBUTION, MORPHOLOGY, AND ECOLOGY OF THREE INTRODUCED ASIATIC SPECIES OF PORPHYRA (BANGIALES, RHODOPHYTA) IN THE NORTHWESTERN ATLANTIC(1).

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Neefus, Christopher D; Mathieson, Arthur C; Bray, Troy L; Yarish, Charles

2008-12-01

Distributions of three Asiatic Porphyra species, Porphyra yezoensis Ueda, Porphyra katadae A. Miura, and Porphyra suborbiculata Kjellm., are reported from New England, USA. Species identifications were confirmed by rbcL and nuclear ribosomal DNA internal transcribed spacer-1 (ITS1) sequence comparisons with herbarium specimens, cultures, and GenBank accessions. Two distinct genotypes of P. yezoensis were detected: forma narawaensis A. Miura and f. yezoensis. Forma narawaensis occurs south of Cape Cod, Massachusetts, and has ITS1 sequences identical to cultivars widely grown in Japan. Forma yezoensis occurs in western Long Island Sound and from Cape Cod northward to midcoastal Maine; its ITS1 sequence is identical to a wild specimen from Hokkaido, Japan. P. katadae has been collected from five locations near Cape Cod; its ITS1 sequence is identical to a cultured specimen from Qingdao, China. P. suborbiculata has been collected at several locations south of Cape Cod; its presence in North Carolina and Delaware during the mid-1960s was confirmed from herbarium specimens. Morphological and ecological characteristics for New England populations of the three Asiatic species were compared to original descriptions. New England P. yezoensis f. yezoensis is similar to Ueda's original description of Japanese specimens, but there are morphological differences for P. yezoensis f. narawaensis. In New England, f. narawaensis typically does not attain the length reported in Japan (max. 19 cm versus 100 cm). New England P. katadae is similar to Miura's original description, except for slight differences in thallus thickness and reproductive patterns. By contrast, New England, Japanese, and other populations of P. suborbiculata exhibit pronounced differences in blade coloration, shape and dimensions, reproductive patterns, seasonal occurrence, and general ecology. © 2008 Phycological Society of America.

Differentiation of bacterial feeding nematodes in soil ecological studies by means of arbitrarily primed PCR

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Van Der Knaap, Esther; Rodriguez, Russell J.; Freckman, Diana W.

1993-01-01

Arbitrarily-primed polymerase chain reaction (ap-PCR) was used to differentiate closely related bacterial-feeding nematodes of the genera: Caenorhabditis, Acrobeloides, Cephalobus and Zeldia. Average percentage similarity of bands generated by ap-PCR with seven different primers between 14 isolates of Caenorhabditis elegans was ⪢ 90%, whereas between C. elegans, C. briggsae and C. remanei similarity was nematode populations were also obtained from ap-PCR analysis of single worms. Due to the difficulty of identification of soil nematodes, the ap-PCR offers potential as a rapid and reliable technique to assess biodiversity. Ap-PCR will make it feasible, for the first time, to study the ecological interactions of unique nematode genotypes in soil habitats.

Distinct spinning patterns gain differentiated loading tolerance of silk thread anchorages in spiders with different ecology.

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Wolff, Jonas O; van der Meijden, Arie; Herberstein, Marie E

2017-07-26

Building behaviour in animals extends biological functions beyond bodies. Many studies have emphasized the role of behavioural programmes, physiology and extrinsic factors for the structure and function of buildings. Structure attachments associated with animal constructions offer yet unrealized research opportunities. Spiders build a variety of one- to three-dimensional structures from silk fibres. The evolution of economic web shapes as a key for ecological success in spiders has been related to the emergence of high performance silks and thread coating glues. However, the role of thread anchorages has been widely neglected in those models. Here, we show that orb-web (Araneidae) and hunting spiders (Sparassidae) use different silk application patterns that determine the structure and robustness of the joint in silk thread anchorages. Silk anchorages of orb-web spiders show a greater robustness against different loading situations, whereas the silk anchorages of hunting spiders have their highest pull-off resistance when loaded parallel to the substrate along the direction of dragline spinning. This suggests that the behavioural 'printing' of silk into attachment discs along with spinneret morphology was a prerequisite for the evolution of extended silk use in a three-dimensional space. This highlights the ecological role of attachments in the evolution of animal architectures. © 2017 The Author(s).

Genetic and morphologic differentiation of the Lusitanian toadfish (Halobatrachus didactylus between estuarine and coastal areas in Portugal

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Joana F. Marques

2006-12-01

Full Text Available The Lusitanian toadfish, Halobatrachus didactylus (Bloch and Schneider, 1801, is distributed from the Ghana coast to the Iberian Peninsula, being particularly abundant on the south coast of Portugal. The differentiation of this species along the Portuguese coast was assessed through the analysis of 10 samples, considering morphological characters (20 morphometric and 16 meristic and genetic markers (10 allozymes, 11 loci. Southern samples included estuaries and their adjacent coastal areas, given that this species inhabits both environments, whereas western samples only comprised estuaries. Morphometric and meristic data discriminant analysis evidenced some differentiation between estuarine and coastal populations. This was not entirely corroborated by the genetic analysis, which showed an overall pattern of low FST (0.042 and Nei’s genetic distance, even between geographically distant areas. However, higher values of these parameters were found between estuaries of the south coast and their adjacent coastal areas, suggesting that estuarine systems play a major role in such differentiation. Results are discussed regarding toadfish life-history pattern and Portuguese coast geomorphology, giving an insight into the biological and environmental factors influencing population sub-structuring.

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

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

2016-01-01

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

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

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

2016-07-13

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

Comparative limb proportions reveal differential locomotor morphofunctions of alligatoroids and crocodyloids

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Iijima, Masaya; Kubo, Tai; Kobayashi, Yoshitsugu

2018-03-01

Although two major clades of crocodylians (Alligatoroidea and Crocodyloidea) were split during the Cretaceous period, relatively few morphological and functional differences between them have been known. In addition, interaction of multiple morphofunctional systems that differentiated their ecology has barely been assessed. In this study, we examined the limb proportions of crocodylians to infer the differences of locomotor functions between alligatoroids and crocodyloids, and tested the correlation of locomotor and feeding morphofunctions. Our analyses revealed crocodyloids including Gavialis have longer stylopodia (humerus and femur) than alligatoroids, indicating that two groups may differ in locomotor functions. Fossil evidence suggested that alligatoroids have retained short stylopodia since the early stage of their evolution. Furthermore, rostral shape, an indicator of trophic function, is correlated with limb proportions, where slender-snouted piscivorous taxa have relatively long stylopodia and short overall limbs. In combination, trophic and locomotor functions might differently delimit the ecological opportunity of alligatoroids and crocodyloids in the evolution of crocodylians.

Squamation and ecology of thelodonts.

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Humberto G Ferrón

Full Text Available Thelodonts are an enigmatic group of Paleozoic jawless vertebrates that have been well studied from taxonomical, biostratigraphic and paleogeographic points of view, although our knowledge of their ecology and mode of life is still scant. Their bodies were covered by micrometric scales whose morphology, histology and the developmental process are extremely similar to those of extant sharks. Based on these similarities and on the well-recognized relationship between squamation and ecology in sharks, here we explore the ecological diversity and lifestyles of thelodonts. For this we use classic morphometrics and discriminant analysis to characterize the squamation patterns of a significant number of extant shark species whose ecology is well known. Multivariate analyses have defined a characteristic squamation pattern for each ecological group, thus establishing a comparative framework for inferring lifestyles in thelodonts. We then use this information to study the squamation of the currently described 147 species of thelodonts, known from both articulated and disarticulated remains. Discriminant analysis has allowed recognizing squamation patterns comparable to those of sharks and links them to specific ecological groups. Our results suggest a remarkable ecological diversity in thelodonts. A large number of them were probably demersal species inhabiting hard substrates, within caves and crevices in rocky environments or reefs, taking advantage of the flexibility provided by their micromeric squamations. Contrary to classical interpretations, only few thelodonts were placed among demersal species inhabiting sandy and muddy substrates. Schooling species with defensive scales against ectoparasites could be also abundant suggesting that social interactions and pressure of ectoparasites were present in vertebrates as early the Silurian. The presence of species showing scales suggestive of low to moderate speed and a lifestyle presumably associated

Phenotypic disparity in Iberian short-horned grasshoppers (Acrididae): the role of ecology and phylogeny.

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García-Navas, Vicente; Noguerales, Víctor; Cordero, Pedro J; Ortego, Joaquín

2017-05-04

The combination of model-based comparative techniques, disparity analyses and ecomorphological correlations constitutes a powerful method to gain insight into the evolutionary mechanisms that shape morphological variation and speciation processes. In this study, we used a time-calibrated phylogeny of 70 Iberian species of short-horned grasshoppers (Acrididae) to test for patterns of morphological disparity in relation to their ecology and phylogenetic history. Specifically, we examined the role of substrate type and level of ecological specialization in driving different aspects of morphological evolution (locomotory traits, chemosensitive organs and cranial morphology) in this recent radiation. We found a bimodal distribution of locomotory attributes corresponding to the two main substrate type guilds (plant vs. ground); plant-perching species tend to exhibit larger wings and thicker femora than those that remain on the ground. This suggests that life form (i.e., substrate type) is an important driving force in the evolution of morphological traits in short-horned grasshoppers, irrespective of ancestry. Substrate type and ecological specialization had no significant influence on head shape, a trait that showed a strong phylogenetic conservatism. Finally, we also found a marginal significant association between the length of antennae and the level of ecological specialization, suggesting that the development of sensory organs may be favored in specialist species. Our results provide evidence that even in taxonomic groups showing limited morphological and ecological disparity, natural selection seems to play a more important role than genetic drift in driving the speciation process. Overall, this study suggests that morphostatic radiations should not necessarily be considered as "non-adaptive" and that the speciation process can bind both adaptive divergence mechanisms and neutral speciation processes related with allopatric and/or reproductive isolation.

Morphological divergence in a continental adaptive radiation: South American ovenbirds of the genus Cinclodes

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Rader, Jonathan A.; Dillon, Michael E.; Chesser, R. Terry; Sabat, Pablo; Martinez del Rio, Carlos

2015-01-01

Cinclodes is an ecologically diverse genus of South American passerine birds and represents a case of continental adaptive radiation along multiple axes. We investigated morphological diversification in Cinclodes using a comprehensive set of morphometric measurements of study skins. Principal component analysis identified 2 primary axes of morphological variation: one describing body size and a second capturing differences in wing-tip shape and toe length. Phylogenetic analyses of the first principal component suggest an early divergence ofCinclodes into 2 main clades characterized by large and small body sizes. We suggest that 2 morphological outliers within these main clades (C. antarcticus and C. palliatus) may be cases of island gigantism and that a third (C. patagonicus) may reflect ecological character displacement. Despite its ecological and physiological diversity, the genus Cinclodes does not appear to show morphological diversity beyond what is typical of other avian genera.

Trophic divergence despite morphological convergence in a continental radiation of snakes.

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Grundler, Michael C; Rabosky, Daniel L

2014-07-22

Ecological and phenotypic convergence is a potential outcome of adaptive radiation in response to ecological opportunity. However, a number of factors may limit convergence during evolutionary radiations, including interregional differences in biogeographic history and clade-specific constraints on form and function. Here, we demonstrate that a single clade of terrestrial snakes from Australia--the oxyuranine elapids--exhibits widespread morphological convergence with a phylogenetically diverse and distantly related assemblage of snakes from North America. Australian elapids have evolved nearly the full spectrum of phenotypic modalities that occurs among North American snakes. Much of the convergence appears to involve the recurrent evolution of stereotyped morphologies associated with foraging mode, locomotion and habitat use. By contrast, analysis of snake diets indicates striking divergence in feeding ecology between these faunas, partially reflecting regional differences in ecological allometry between Australia and North America. Widespread phenotypic convergence with the North American snake fauna coupled with divergence in feeding ecology are clear examples of how independent continental radiations may converge along some ecological axes yet differ profoundly along others. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Nesting biology, morphological remarks, and description of the mature larva of Mellinus arvensis obscurus (Hymenoptera: Crabronidae) in Nepal

International Nuclear Information System (INIS)

Boesi, R.; Polidori, C.; Andrietti, F.; Gayubo, S.F.; Tormos, J.; Asis, J.D.

2007-01-01

Recently re-named as a sub-species of Mellinus arvensis, Mellinus arvensis obscurus Handlirsch 1888 was investigated ecologically and morphologically in Nepal, in order to underline the most important differences with the well known M. arvensis arvensis. Mellinus arvensis obscurus females nested in clumped aggregations on inclined plains at high altitudes, both on sunny bare soil and on a shaded grassy one. Beginning of monsoon season probably interfered with wasp activity, and females performed few provisioning flights during the day. Prey consisted of a broad range of Diptera, except for one case of a spider. Many females were observed not provisioning a nest but floating on the nesting site, and many intraspecific interactions suggested a high degree of usurpation attempts. At least one species of flies and two of ants probably acted as natural enemies of the wasp. Morphological observations on females showed that the Nepal population shares more similarities (shape of tergite I, body punctation) with the European populations than with the closer Japanese population; melanization is strong, according to west-east and altitudinal cline. The mature larva of M. arvensis obscurus Handlirsch is described, illustrated, and compared with the other mature larva of the genus. The differences between both larvae mainly lie in the presence/absence, and number or differentiation of integumental structures. We conclude that morphological traits are more important than ecological and behavioral ones in distinguishing M. arvensis obscurus from M. arvensis arvensis. (author) [es

Preliminary research on morphological differentiation of avilamycin high-yield mutant strain H15

International Nuclear Information System (INIS)

Liang Xinle; Jin Yingyan; Chen Ming; Zhang Hong

2010-01-01

Morphological differentiation characters such as colony, sporotrichial, and conidiophores of mutant H15, which was derived from Streptomyces viridochromogenes 4.1119 treated with 60 Co γ-rays irradiation, were investigated by scanning electron microscope and fluorescence microscope. The results showed that mutant H15 was remarkable variation from the strain 4.1119. Cultured on agar surface, H15 had a grayish-whitish-green colony, linear sporotrichial, smooth and round conidiophore without any spike, whereas strain 4.1119 had spiral sporotrichial and round conidiophore with spike on the surface. In the submerged cultures, differentiation process of mycelia pellet of H15 was also different. Spores germinated as a compartmentalized mycelium, the young compartmentalized mycelium started to form pellets which grew in a radial pattern. After apoptosis took place in the center of the pellets, the pellet diameter growth arrested. Compared with the strain 4.1119, H15 required a long developing course for hyphae clustering and pellets formation (at 48 h, φ 245 μm). The stage of pellet arrest or apoptosis in the pellet centre were extended, which would benefit the avilamycin accumulation since the antibiotic was mainly produced at the same time. These suggested that pellet formation kinetics, relational balance between pellet diameter enlargement and mycelia apoptosis in the pellet arrest stage were key factors to avilamyin accumulation in submerged cultures of Streptomyces viridoehrongenes H15. (authors)

Morphological diversity in tenrecs (Afrosoricida, Tenrecidae: comparing tenrec skull diversity to their closest relatives

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Sive Finlay

2015-04-01

Full Text Available It is important to quantify patterns of morphological diversity to enhance our understanding of variation in ecological and evolutionary traits. Here, we present a quantitative analysis of morphological diversity in a family of small mammals, the tenrecs (Afrosoricida, Tenrecidae. Tenrecs are often cited as an example of an exceptionally morphologically diverse group. However, this assumption has not been tested quantitatively. We use geometric morphometric analyses of skull shape to test whether tenrecs are more morphologically diverse than their closest relatives, the golden moles (Afrosoricida, Chrysochloridae. Tenrecs occupy a wider range of ecological niches than golden moles so we predict that they will be more morphologically diverse. Contrary to our expectations, we find that tenrec skulls are only more morphologically diverse than golden moles when measured in lateral view. Furthermore, similarities among the species-rich Microgale tenrec genus appear to mask higher morphological diversity in the rest of the family. These results reveal new insights into the morphological diversity of tenrecs and highlight the importance of using quantitative methods to test qualitative assumptions about patterns of morphological diversity.

Mode of morphological differentiation in the Latitarsi-ground beetles (Coleoptera, Carabidae) of the world inferred from a phylogenetic tree of mitochondrial ND5 gene sequences.

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Su, Zhi-Hui; Imura, Yûki; Zhou, Hong-Zhang; Okamoto, Munehiro; Osawa, Syozo

2003-02-01

The Latitarsi is one large division of the subtribe Carabina (subfamily Carabinae, family Carabidae), and has been considered as a discrete morphological group consisting of 17 genera. The phylogenetic relationships and evolutionary pattern of the Latitarsi ground beetles have been investigated by analyzing mitochondrial NADH dehydrogenase subunit 5 (ND5) gene sequences. The phylogenetic tree suggests that the Latitarsi members do not form a single cluster, i.e., not monophyletic and at least 16 lineages belonging to the so-called Latitarsi emerged at about the same time of the Carabina radiation together with the members of other divisions. This suggests that these lineages (A, B, C, H, L, N, O, P, Q, R, S, T, U, V, W and X in Fig. 2a) may be treated each as a phylogenetically distinct division equivalent to other divisions. The group with bootstrap value of more than 80 percent has been considered as a single lineage (division) with two exceptions, V and X. The independency of each lineage has been assumed by the traditional morphology as well as a single clustering on the trees constructed by independent methods, unchanged topology by replacement of outgroups, etc. Generally speaking, the members in a single lineage are geographically linked. Many phylogenetic lineages are composed of a single or only a few species without conspicuous morphological differentiation. In contrast to such a "silent morphological evolution", a remarkable morphological differentiation occasionally took place in several lineages.

Ecological and phylogenetic influences on maxillary dentition in snakes

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Kate Jackson

2010-12-01

Full Text Available The maxillary dentition of snakes was used as a system with which to investigate the relative importance of the interacting forces of ecological selective pressures and phylogenetic constraints indetermining morphology. The maxillary morphology of three groups of snakes having different diets, with each group comprising two distinct lineages — boids and colubroids — was examined. Our results suggest that dietary selective pressures may be more significantthan phylogenetic history in shaping maxillary morphology.

Evolution of asynchronous motor activity in paired muscles: effects of ecology, morphology, and phylogeny.

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Gerry, Shannon P; Ramsay, Jason B; Dean, Mason N; Wilga, Cheryl D

2008-08-01

Many studies of feeding behavior have implanted electrodes unilaterally (in muscles on only one side of the head) to determine the basic motor patterns of muscles controlling the jaws. However, bilateral implantation has the potential to achieve a more comprehensive understanding of modification of the motor activity that may be occurring between the left and right sides of the head. In particular, complex processing of prey is often characterized by bilaterally asynchronous and even unilateral activation of the jaw musculature. In this study, we bilaterally implant feeding muscles in species from four orders of elasmobranchs (Squaliformes, Orectolobiformes, Carcharhiniformes, Rajoidea) in order to characterize the effects of type of prey, feeding behavior, and phylogeny on the degree of asynchronous muscle activation. Electrodes were implanted in three of the jaw adductors, two divisions of the quadratomandibularis and the preorbitalis, as well as in a cranial elevator in sharks, the epaxialis. The asynchrony of feeding events (measured as the degree to which activity of members of a muscle pair is out of phase) was compared across species for capture versus processing and simple versus complex prey, then interpreted in the contexts of phylogeny, morphology, and ecology to clarify determinants of asynchronous activity. Whereas capture and processing of prey were characterized by statistically similar degrees of asynchrony for data pooled across species, events involving complex prey were more asynchronous than were those involving simple prey. The two trophic generalists, Squalus acanthias and Leucoraja erinacea, modulated the degree of asynchrony according to type of prey, whereas the two behavioral specialists, Chiloscyllium plagiosum and Mustelus canis, activated the cranial muscles synchronously regardless of type of prey. These differences in jaw muscle activity would not have been detected with unilateral implantation. Therefore, we advocate bilateral

Ecological niche differentiation of polyploidization is not supported by environmental differences among species in a cosmopolitan grass genus.

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Visser, Vernon; Molofsky, Jane

2015-01-01

• Polyploidization frequently results in the creation of new plant species, the establishment of which is thought to often be facilitated by ecological niche differentiation from the diploid species. We tested this hypothesis using the cosmopolitan grass genus Phalaris (Poaceae), consisting of 19 species that range from diploid to tetraploid to hexaploid. Specifically, we tested whether (1) polyploids occupy more extreme environments and/or (2) have broader niche breadths and/or (3) whether the polyploid species' distributions indicate a niche shift from diploid species.• We employed a bootstrapping approach using distribution data for each species and eight environmental variables to investigate differences between species in the means, extremes, and breadths of each environmental variable. We used a kernel smoothing technique to quantify niche overlap between species.• Although we found some support for the three hypotheses for a few diploid-polyploid pairs and for specific environmental variables, none of these hypotheses were generally supported.• Our results suggest that these commonly held hypotheses about the effects of polyploidization on ecological distributions are not universally applicable. Correlative biogeographic studies like ours provide a necessary first step for suggesting specific hypotheses that require experimental verification. A combination of genetic, physiological, and ecological studies will be required to achieve a better understanding of the role of polyploidization in niche evolution. © 2015 Botanical Society of America, Inc.

Genetic, morphological, and spectral characterization of relictual Niobrara River hybrid aspens (Populus × smithii).

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Deacon, Nicholas John; Grossman, Jake Joseph; Schweiger, Anna Katharina; Armour, Isabella; Cavender-Bares, Jeannine

2017-12-01

Aspen groves along the Niobrara River in Nebraska have long been a biogeographic curiosity due to morphological differences from nearby remnant Populus tremuloides populations. Pleistocene hybridization between P. tremuloides and P. grandidentata has been proposed, but the nearest P. grandidentata populations are currently several hundred kilometers east. We tested the hybrid-origin hypothesis using genetic data and characterized putative hybrids phenotypically. We compared nuclear microsatellite loci and chloroplast sequences of Niobrara River aspens to their putative parental species. Parental species and putative hybrids were also grown in a common garden for phenotypic comparison. On the common garden plants, we measured leaf morphological traits and leaf-level spectral reflectance profiles, from which chemical traits were derived. The genetic composition of the three unique Niobrara aspen genotypes is consistent with the hybridization hypothesis and with maternal chloroplast inheritance from P. grandidentata . Leaf margin dentition and abaxial pubescence differentiated taxa, with the hybrids showing intermediate values. Spectral profiles allowed statistical separation of taxa in short-wave infrared wavelengths, with hybrids showing intermediate values, indicating that traits associated with internal structure of leaves and water absorption may vary among taxa. However, reflectance values in the visible region did not differentiate taxa, indicating that traits related to pigments are not differentiated. Both genetic and phenotypic results support the hypothesis of a hybrid origin for these genetically unique aspens. However, low genetic diversity and ongoing ecological and climatic threats to the hybrid taxon present a challenge for conservation of these relictual boreal communities. © 2017 Botanical Society of America.

Morphological variation among populations of Hemigrammus coeruleus (Characiformes: Characidae in a Negro River tributary, Brazilian Amazon

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Henrique Lazzarotto

2017-03-01

Full Text Available ABSTRACT We explored patterns of phenotypic variation in Hemigrammus coeruleus from the Unini River basin, a blackwater river in the Brazilian Amazon. Geometric morphometrics was used to evaluate variation in body shape among populations from four tributaries (UN2-UN5. We found no evidence for sexual dimorphism in body size and shape. However, morphological differences among populations were detected as the analyses recovered significant groups corresponding to each sub-basin, with some overlap among them. The populations from UN2, UN3 and UN5 had more elongate bodies than fish from UN4. The most morphologically divergent population belonged to UN4, the tributary with the most divergent environmental conditions and the only one with seasonally-muddy waters. The morphological variation found among these populations is likely due to phenotypic plasticity or local adaptation, arising as a product of divergent ecological selection pressures among sub-basins. This work constitutes one of the first to employ a population-level geometric morphometric approach to assess phenotypic variation in Amazonian fishes. This method was able to distinguish subtle differences in body morphology, and its use with additional species can bring novel perspectives on the evaluation of general patterns of phenotypic differentiation in the Amazon.

An approach to unraveling the coexistence of snappers (Lutjanidae using otolith morphology

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Zahra Sadighzadeh

2014-09-01

Full Text Available The sagittae otolith morphology of marine fishes has been used in many ecomorphological studies to explain certain ecological adaptations of species to habitat. Our study compares the sagittal otolith shapes of ten species of snappers (Family Lutjanidae inhabiting the Persian Gulf. We used a morphometric analysis of the otolith measurements (length, height, perimeter, area and weight and of the ratio between the area of the sulcus acusticus and the area of the otolith (S:O. The otolith contour was also analysed using wavelets as a mathematical descriptor. Morphological variations in the otoliths were associated with the morphology and external colouration of snappers as well as ecological traits. An analysis of the interspecific S:O ratio suggested that the highest ratios occurred in snappers inhabiting shallower waters. A categorical multivariate analysis, including morphological, ecological and otolith size factors, showed that the species adapted to dim light conditions had a greater otolith perimeter. An analysis of variance of the otolith contour revealed zones with a higher interspecific variability, although only the antero-dorsal zone showed differing patterns. Although the otolith patterns appear to have a phylogenetic component, they might also be related to diel activity rhythms or to the light conditions in the habitat. The results of the study showed that variation in otolith morphology can be used to explain the coexistence of sympatric species.

A genomic investigation of ecological differentiation between free-living and Drosophila-associated bacteria.

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Winans, Nathan J; Walter, Alec; Chouaia, Bessem; Chaston, John M; Douglas, Angela E; Newell, Peter D

2017-09-01

Various bacterial taxa have been identified both in association with animals and in the external environment, but the extent to which related bacteria from the two habitat types are ecologically and evolutionarily distinct is largely unknown. This study investigated the scale and pattern of genetic differentiation between bacteria of the family Acetobacteraceae isolated from the guts of Drosophila fruit flies, plant material and industrial fermentations. Genome-scale analysis of the phylogenetic relationships and predicted functions was conducted on 44 Acetobacteraceae isolates, including newly sequenced genomes from 18 isolates from wild and laboratory Drosophila. Isolates from the external environment and Drosophila could not be assigned to distinct phylogenetic groups, nor are their genomes enriched for any different sets of genes or category of predicted gene functions. In contrast, analysis of bacteria from laboratory Drosophila showed they were genetically distinct in their universal capacity to degrade uric acid (a major nitrogenous waste product of Drosophila) and absence of flagellar motility, while these traits vary among wild Drosophila isolates. Analysis of the competitive fitness of Acetobacter discordant for these traits revealed a significant fitness deficit for bacteria that cannot degrade uric acid in culture with Drosophila. We propose that, for wild populations, frequent cycling of Acetobacter between Drosophila and the external environment prevents genetic differentiation by maintaining selection for traits adaptive in both the gut and external habitats. However, laboratory isolates bear the signs of adaptation to persistent association with the Drosophila host under tightly defined environmental conditions. © 2017 John Wiley & Sons Ltd.

Comparative ecological and behavioral adaptations of Ovibos moschatus and Rangifer tarandus

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David R. Klein

1992-10-01

Full Text Available Caribou/reindeer and muskoxen are the only two ungulate species that have successfully occupied arctic tundra habitats. Although confronted with similar environmental constraints, their morphological dissimilarities have enabled them to develop unique behavioral and ecological adaptations that under most circumstances result in minimal overlap in use of forage resources. The large body and gut capacity of muskoxen have enabled them to adopt a strategy maximizing rate of forage intake and energy conservation, whereas caribou/reindeer of substantially smaller body size must pursue selective feeding, requiring high mobility and high energy expenditure. Responses to predators and insects by the two species show similar contrasts in associated energy costs. When confronted with environmental extremes that limit forage availability, competition for food may occur and the resulting differential success is a reflection of their divergent evolutionary routes.

Morphological integration of soft-tissue facial morphology in Down Syndrome and siblings.

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Starbuck, John; Reeves, Roger H; Richtsmeier, Joan

2011-12-01

Down syndrome (DS), resulting from trisomy of chromosome 21, is the most common live-born human aneuploidy. The phenotypic expression of trisomy 21 produces variable, though characteristic, facial morphology. Although certain facial features have been documented quantitatively and qualitatively as characteristic of DS (e.g., epicanthic folds, macroglossia, and hypertelorism), all of these traits occur in other craniofacial conditions with an underlying genetic cause. We hypothesize that the typical DS face is integrated differently than the face of non-DS siblings, and that the pattern of morphological integration unique to individuals with DS will yield information about underlying developmental associations between facial regions. We statistically compared morphological integration patterns of immature DS faces (N = 53) with those of non-DS siblings (N = 54), aged 6-12 years using 31 distances estimated from 3D coordinate data representing 17 anthropometric landmarks recorded on 3D digital photographic images. Facial features are affected differentially in DS, as evidenced by statistically significant differences in integration both within and between facial regions. Our results suggest a differential affect of trisomy on facial prominences during craniofacial development. 2011 Wiley Periodicals, Inc.

Diversification in the South American Pampas: the genetic and morphological variation of the widespread Petunia axillaris complex (Solanaceae).

Science.gov (United States)

Turchetto, Caroline; Fagundes, Nelson J R; Segatto, Ana L A; Kuhlemeier, Cris; Solís Neffa, Viviana G; Speranza, Pablo R; Bonatto, Sandro L; Freitas, Loreta B

2014-02-01

Understanding the spatiotemporal distribution of genetic variation and the ways in which this distribution is connected to the ecological context of natural populations is fundamental for understanding the nature and mode of intraspecific and, ultimately, interspecific differentiation. The Petunia axillaris complex is endemic to the grasslands of southern South America and includes three subspecies: P. a. axillaris, P. a. parodii and P. a. subandina. These subspecies are traditionally delimited based on both geography and floral morphology, although the latter is highly variable. Here, we determined the patterns of genetic (nuclear and cpDNA), morphological and ecological (bioclimatic) variation of a large number of P. axillaris populations and found that they are mostly coincident with subspecies delimitation. The nuclear data suggest that the subspecies are likely independent evolutionary units, and their morphological differences may be associated with local adaptations to diverse climatic and/or edaphic conditions and population isolation. The demographic dynamics over time estimated by skyline plot analyses showed different patterns for each subspecies in the last 100 000 years, which is compatible with a divergence time between 35 000 and 107 000 years ago between P. a. axillaris and P. a. parodii, as estimated with the IMa program. Coalescent simulation tests using Approximate Bayesian Computation do not support previous suggestions of extensive gene flow between P. a. axillaris and P. a. parodii in their contact zone. © 2013 John Wiley & Sons Ltd.

Morphology and ecological characteristics of Sparganium × longifolium (Typhaceae in the Central part of European Russia

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E. A. Belyakov

2017-05-01

Full Text Available The increasing impact of anthropogenic factors and climate change affect the growth of a number of taxa of hybrid nature. These taxa are widespread among various taxonomic groups of aquatic and semi-aquatic plants. The genus Sparganium L. В is not an exception. In that regard, the aim of this study is to conduct biomorphological investigation of Sparganium × longifolium Turcz. ex Ledeb., evaluate qualitative and quantitative criteria for the hybrid similarities and differences with its parental species, as well as to analyze data on its habitat characteristics. Samples were collected in 2014–2016 from waterbodies in European Russia (Tver and Yaroslavl oblasts. In the study on biomorphology of S. × longifolium we used live and fixed materials, as well as herbarium funds of IBIW, MXA and MW. To establish and specify taxonomic features of the hybrid under study, indicating to its similarity with a certain ancestral species, our data on the morphology and ecology of S. emersum Rehm. and S. gramineum Georgi. are used. During field studies, the type of water object where the hybrid was detected, ecological characteristics of its habitat (type of soil, depth, water temperature and pH are determined; the list of taxa which enter into the cenosis composition is compiled. The biomorphological investigation of S. × longifolium shows that by life form this hybrid, as well as its parental species, is a vegetative-mobile evidently-polycentric annual or biennial plant of vegetative origin with a racemose root system. The following should be attributed to the characteristic features justifying the hybrid origin of S. × longifolium: 1 a wider, slightly carinated lamina (as in S. emersum; 2 a branched inflorescence (as in S. gramineum; 3 the lower covering leaf of inflorescence, often exceeding the total length of the latter; 4 fruits with a straight (as in S. emersum as well as bent (as in S. gramineum style. Interestingly, some populations of S. �

Nematode taxonomy: from morphology to metabarcoding

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Ahmed, M.; Sapp, M.; Prior, T.; Karssen, G.; Back, M.

2015-11-01

Nematodes represent a species rich and morphologically diverse group of metazoans inhabiting both aquatic and terrestrial environments. Their role as biological indicators and as key players in nutrient cycling has been well documented. Some groups of nematodes are also known to cause significant losses to crop production. In spite of this, knowledge of their diversity is still limited due to the difficulty in achieving species identification using morphological characters. Molecular methodology has provided very useful means of circumventing the numerous limitations associated with classical morphology based identification. We discuss herein the history and the progress made within the field of nematode systematics, the limitations of classical taxonomy and how the advent of high throughput sequencing is facilitating advanced ecological and molecular studies.

Insights into population ecology and sexual selection in snakes through the application of DNA-based genetic markers.

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Gibbs, H L; Weatherhead, P J

2001-01-01

Hypervariable genetic markers have revolutionized studies of kinship, behavioral ecology, and population biology in vertebrate groups such as birds, but their use in snakes remains limited. To illustrate the value of such markers in snakes, we review studies that have used microsatellite DNA loci to analyze local population differentiation and parentage in snakes. Four ecologically distinct species of snakes all show evidence for differentiation at small spatial scales (2-15 km), but with substantial differences among species. This result highlights how genetic analysis can reveal hidden aspects of the natural history of difficult-to-observe taxa, and it raises important questions about the ecological factors that may contribute to restricted gene flow. A 3-year study of genetic parentage in marked populations of the northern water snake showed that (1) participation in mating aggregations was a poor predictor of genetic-based measures of reproductive success; (2) multiple paternity was high, yet there was no detectable fitness advantage to multiple mating by females; and (3) the opportunity for selection was far higher in males than in females due to a larger variance in male reproductive success, and yet this resulted in no detectable selection on morphological variation in males. Thus genetic markers have provided accurate measures of individual reproductive success in this species, an important step toward resolving the adaptive significance of key features including multiple paternity and reversed sexual size dimorphism. Overall these studies illustrate how genetic analyses of snakes provide previously unobtainable information of long-standing interest to behavioral ecologists.

Technical efficiency in rice ecologies of north central Nigeria ...

African Journals Online (AJOL)

Two mini-ecologies were identified within the lowland rice ecology in the study area, namely, River Basin Authority Catchment area (RBAC) and Non River Basin Authority Catchment area (NRBAC). Differentials in rice output were determined with the Chow test while the stochastic frontier production approach was ...

Time-dependent regulation of morphological changes and cartilage differentiation markers in the mouse pubic symphysis during pregnancy and postpartum recovery.

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Castelucci, Bianca Gazieri; Consonni, Sílvio Roberto; Rosa, Viviane Souza; Sensiate, Lucimara Aparecida; Delatti, Paula Cristina Rugno; Alvares, Lúcia Elvira; Joazeiro, Paulo Pinto

2018-01-01

Animal models commonly serve as a bridge between in vitro experiments and clinical applications; however, few physiological processes in adult animals are sufficient to serve as proof-of-concept models for cartilage regeneration. Intriguingly, some rodents, such as young adult mice, undergo physiological connective tissue modifications to birth canal elements such as the pubic symphysis during pregnancy; therefore, we investigated whether the differential expression of cartilage differentiation markers is associated with cartilaginous tissue morphological modifications during these changes. Our results showed that osteochondral progenitor cells expressing Runx2, Sox9, Col2a1 and Dcx at the non-pregnant pubic symphysis proliferated and differentiated throughout pregnancy, giving rise to a complex osteoligamentous junction that attached the interpubic ligament to the pubic bones until labour occurred. After delivery, the recovery of pubic symphysis cartilaginous tissues was improved by the time-dependent expression of these chondrocytic lineage markers at the osteoligamentous junction. This process potentially recapitulates embryologic chondrocytic differentiation to successfully recover hyaline cartilaginous pads at 10 days postpartum. Therefore, we propose that this physiological phenomenon represents a proof-of-concept model for investigating the mechanisms involved in cartilage restoration in adult animals.

Manifold Shape : from Differential Geometry to Mathematical Morphology

NARCIS (Netherlands)

Roerdink, J.B.T.M.

1994-01-01

Much progress has been made in extending Euclidean mathematical morphology to more complex structures such as complete lattices or spaces with a non-commutative symmetry group. Such generalizations are important for practical situations such as translation and rotation invariant pattern recognition

Discordance between morphological and molecular species boundaries among Caribbean species of the reef sponge Callyspongia.

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DeBiasse, Melissa B; Hellberg, Michael E

2015-02-01

Sponges are among the most species-rich and ecologically important taxa on coral reefs, yet documenting their diversity is difficult due to the simplicity and plasticity of their morphological characters. Genetic attempts to identify species are hampered by the slow rate of mitochondrial sequence evolution characteristic of sponges and some other basal metazoans. Here we determine species boundaries of the Caribbean coral reef sponge genus Callyspongia using a multilocus, model-based approach. Based on sequence data from one mitochondrial (COI), one ribosomal (28S), and two single-copy nuclear protein-coding genes, we found evolutionarily distinct lineages were not concordant with current species designations in Callyspongia. While C. fallax,C. tenerrima, and C. plicifera were reciprocally monophyletic, four taxa with different morphologies (C. armigera,C. longissima,C. eschrichtii, and C. vaginalis) formed a monophyletic group and genetic distances among these taxa overlapped distances within them. A model-based method of species delimitation supported collapsing these four into a single evolutionary lineage. Variation in spicule size among these four taxa was partitioned geographically, not by current species designations, indicating that in Callyspongia, these key taxonomic characters are poor indicators of genetic differentiation. Taken together, our results suggest a complex relationship between morphology and species boundaries in sponges.

Ecological, morphological, and histological studies on Blaps polycresta (Coleoptera: Tenebrionidae) as biomonitors of cadmium soil pollution.

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Osman, Wafaa; El-Samad, Lamia M; Mokhamer, El-Hassan; El-Touhamy, Aya; Shonouda, Mourad

2015-09-01

Soil pollution in Egypt became far more serious than before due to either the heavy usage of different toxic pesticides or aerosol deposition of industrial pollutants. The present mentioned ground beetle, Blaps polycresta Tschinkel 1975 (Coleoptera: Tenebrionidae), showed ecological, morphological, and histological alterations in adult insects as biomonitors. Two cultivated sites (reference and polluted) were chosen for sampling the insects. The results indicated a significant increase in soil cadmium concentration of the polluted site leading to sex-specific difference in cadmium accumulation in gonads and alimentary canal of insects that being higher in males than females. The cadmium pollution leads significantly to a decrease in population density, a reduction in body weight, an increase in mortality rate, and an increase in sex ratio of the insects. The results also revealed a striking decrease in body length of the polluted insects with a marked increase in the percentage of deformed gonads and alimentary canal of both sexes. Some histopathological alterations were also recorded in testis, ovary, and midgut of the polluted insects. Our results confirmed that beetles are a good bioindicator for soil pollution, and the different studied parameters could be easily employed as sensitive monitors for cadmium soil pollution.

Civic Ecology: A Postmodern Approach to Ecological Sustainability

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Lopes, V. L.

2013-12-01

and fragmentary modes of existence, to a more relational (ecological) view of the world in which balance and harmony are achieved by ever-changing complexity and differentiation. Central to this view is the recognition that human communities will become increasingly more just and sustainable if their citizens understand, are committed to, and share, a set of values and ecological principles. Shared purposes and principles, however, cannot be handed down from above but must be developed from the bottom-up through community engagement and ecological citizenship.

Morphological differentiation despite gene flow in an endangered grasshopper.

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Dowle, Eddy J; Morgan-Richards, Mary; Trewick, Steven A

2014-10-16

Gene flow is traditionally considered a limitation to speciation because selection is required to counter the homogenising effect of allele exchange. Here we report on two sympatric short-horned grasshoppers species in the South Island of New Zealand; one (Sigaus australis) widespread and the other (Sigaus childi) a narrow endemic. Of the 79 putatively neutral markers (mtDNA, microsatellite loci, ITS sequences and RAD-seq SNPs) all but one marker we examined showed extensive allele sharing, and similar or identical allele frequencies in the two species where they co-occur. We found no genetic evidence of deviation from random mating in the region of sympatry. However, analysis of morphological and geometric traits revealed no evidence of morphological introgression. Based on phenotype the two species are clearly distinct, but their genotypes thus far reveal no divergence. The best explanation for this is that some loci associated with the distinguishing morphological characters are under strong selection, but exchange of neutral loci is occurring freely between the two species. Although it is easier to define species as requiring a barrier between them, a dynamic model that accommodates gene flow is a biologically more reasonable explanation for these grasshoppers.

Linking Diversity and Differentiation

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Hans-Rolf Gregorius

2010-03-01

Full Text Available Generally speaking, the term differentiation refers to differences between collections for the distribution of specified traits of their members, while diversity deals with (effective numbers of trait states (types. Counting numbers of types implies discrete traits such as alleles and genotypes in population genetics or species and taxa in ecology. Comparisons between the concepts of differentiation and diversity therefore primarily refer to discrete traits. Diversity is related to differentiation through the idea that the total diversity of a subdivided collection should be composed of the diversity within the subcollections and a complement called “diversity between subcollections”. The idea goes back to the perception that the mixing of differentiated collections increases diversity. Several existing concepts of “diversity between subcollections” are based on this idea. Among them, β-diversity and fixation (inadvertently called differentiation are the most prominent in ecology and in population genetics, respectively. The pertaining measures are shown to quantify the effect of differentiation in terms of diversity components, though from a dual perspective: the classical perspective of differentiation between collections for their type compositions, and the reverse perspective of differentiation between types for their collection affiliations. A series of measures of diversity-oriented differentiation is presented that consider this dual perspective at two levels of diversity partitioning: the overall type or subcollection diversity and the joint type-subcollection diversity. It turns out that, in contrast with common notions, the measures of fixation (such as FST or GST refer to the perspective of type rather than subcollection differentiation. This unexpected observation strongly suggests that the popular interpretations of fixation measures must be reconsidered.

Beyond neutral and forbidden links: morphological matches and the assembly of mutualistic hawkmoth-plant networks.

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Sazatornil, Federico D; Moré, Marcela; Benitez-Vieyra, Santiago; Cocucci, Andrea A; Kitching, Ian J; Schlumpberger, Boris O; Oliveira, Paulo E; Sazima, Marlies; Amorim, Felipe W

2016-11-01

A major challenge in evolutionary ecology is to understand how co-evolutionary processes shape patterns of interactions between species at community level. Pollination of flowers with long corolla tubes by long-tongued hawkmoths has been invoked as a showcase model of co-evolution. Recently, optimal foraging models have predicted that there might be a close association between mouthparts' length and the corolla depth of the visited flowers, thus favouring trait convergence and specialization at community level. Here, we assessed whether hawkmoths more frequently pollinate plants with floral tube lengths similar to their proboscis lengths (morphological match hypothesis) against abundance-based processes (neutral hypothesis) and ecological trait mismatches constraints (forbidden links hypothesis), and how these processes structure hawkmoth-plant mutualistic networks from five communities in four biogeographical regions of South America. We found convergence in morphological traits across the five communities and that the distribution of morphological differences between hawkmoths and plants is consistent with expectations under the morphological match hypothesis in three of the five communities. In the two remaining communities, which are ecotones between two distinct biogeographical areas, interactions are better predicted by the neutral hypothesis. Our findings are consistent with the idea that diffuse co-evolution drives the evolution of extremely long proboscises and flower tubes, and highlight the importance of morphological traits, beyond the forbidden links hypothesis, in structuring interactions between mutualistic partners, revealing that the role of niche-based processes can be much more complex than previously known. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

An inventory of continental U.S. terrestrial candidate ecological restoration areas based on landscape context

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James Wickham; Kurt Riitters; Peter Vogt; Jennifer Costanza; Anne Neale

2017-01-01

Landscape context is an important factor in restoration ecology, but the use of landscape context for site prioritization has not been as fully developed.We used morphological image processing to identify candidate ecological restoration areas based on their proximity to existing natural vegetation. We identified 1,102,720 candidate ecological restoration areas across...

Habitat-specific morphological variation among threespine sticklebacks (Gasterosteus aculeatus within a drainage basin.

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Mike M Webster

Full Text Available Habitat-specific morphological variation, often corresponding to resource specialization, is well documented in freshwater fishes. In this study we used landmark based morphometric analyses to investigate morphological variation among threespine sticklebacks (Gasterosteus aculeatus L. from four interconnected habitat types within a single lowland drainage basin in eastern England. These included the upper and lower reaches of the river, the estuary, a connected ditch network and a coastal salt marsh. We found significant habitat-specific differences in morphology, with three axes of variation describing differences in orbit diameter, body depth, caudal peduncle shape and pectoral fin positioning as well as variation in relative dorsal and pelvic spine size. Interestingly, the ditch system, an artificial and heavily managed habitat, is populated by sticklebacks with a characteristic morphology, suggesting that human management of habitats can in some circumstances lead to morphological variation among the animals that inhabit them. We discuss the mechanisms that conceivably underlie the observed morphological variation and the further work necessary to identify them. Finally, we consider the implications of habitat-specific body shape variation for the behavioural ecology of this ecologically generalist species.

Habitat-Specific Morphological Variation among Threespine Sticklebacks (Gasterosteus aculeatus) within a Drainage Basin

Science.gov (United States)

Webster, Mike M.; Atton, Nicola; Hart, Paul J. B.; Ward, Ashley J. W.

2011-01-01

Habitat-specific morphological variation, often corresponding to resource specialization, is well documented in freshwater fishes. In this study we used landmark based morphometric analyses to investigate morphological variation among threespine sticklebacks (Gasterosteus aculeatus L.) from four interconnected habitat types within a single lowland drainage basin in eastern England. These included the upper and lower reaches of the river, the estuary, a connected ditch network and a coastal salt marsh. We found significant habitat-specific differences in morphology, with three axes of variation describing differences in orbit diameter, body depth, caudal peduncle shape and pectoral fin positioning as well as variation in relative dorsal and pelvic spine size. Interestingly, the ditch system, an artificial and heavily managed habitat, is populated by sticklebacks with a characteristic morphology, suggesting that human management of habitats can in some circumstances lead to morphological variation among the animals that inhabit them. We discuss the mechanisms that conceivably underlie the observed morphological variation and the further work necessary to identify them. Finally, we consider the implications of habitat-specific body shape variation for the behavioural ecology of this ecologically generalist species. PMID:21698269

Ecological-biological Aspects of Stipa krylovii Roshev Adaptation at the Initial Stages of Ontogenesis

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N.S. Chistyakova

2016-08-01

Full Text Available Xerophytic cereal Stipa krylovii Roshev is interesting as a relic with extensive capabilities to adapt to severe climatic conditions of Eastern Zabaikal’ye, which allows it to occupy a vast areal. The species under study is characterized by distinctive ecological-biological peculiarities, which are underpinned by not only distribution, but historical establishment of the species. The primary goal of the research was to study ecological-biological peculiarities of adaptation of wild cereal Stipa krylovii to the habitat in Eastern Zabaikal’ye. According to the observations, Stipa krylovii is characterized by late development rate coinciding with the period of optimal heat and moisture availability. Seed embryos have a well-developed scutellum, distinct structures and well differentiated embryo axis. The studies identified no lateral or secondary roots in the cereal. In nature, seeds of S. krylovii are characterized by profound organic peace period, which persists in the course of sprouting under optimal conditions. Peace period of S. krylovii caryopses is likely to be due to the presence of sprouting inhibitors and is overcome in moist autumn period. Seed viability was determined under various soil moisture parameters up to its complete water capacity; the impact of moisture content on seed sprouting rate was studied. The results of the tests on caryopses sprouting with various moisture content demonstrated that at minimum moisture content (10% S. krylovii forms epidermal hairs on coleorhiza; 30% of soil water content is enough for growth activation, viability and sprouting rate of this cereal, which is due to its xerophytic nature. This morphological peculiarity is likely to ensure in nature sprouting of these species in early spring, when soil contain minimum water. Intensity of the initial growth was determined by a number of parameters: rate of change in linear growth of trunk and root parts of the embryo, growth of dry substance of

Morphological and transcriptomic effects of endocrine modulators on the gonadal differentiation of chicken embryos: The case of tributyltin (TBT).

Science.gov (United States)

Scheider, Jessica; Afonso-Grunz, Fabian; Jessl, Luzie; Hoffmeier, Klaus; Winter, Peter; Oehlmann, Jörg

2018-03-01

Morphological malformations induced by tributyltin (TBT) exposure during embryonic development have already been characterized in various taxonomic groups, but, nonetheless, the molecular processes underlying these changes remain obscure. The present study provides the first genome-wide screening for differentially expressed genes that are linked to morphological alterations of gonadal tissue from chicken embryos after exposure to TBT. We applied a single injection of TBT (between 0.5 and 30 pg as Sn/g egg) into incubated fertile eggs to simulate maternal transfer of the endocrine disruptive compound. Methyltestosterone (MT) served as a positive control (30 pg/g egg). After 19 days of incubation, structural features of the gonads as well as genome-wide gene expression profiles were assessed simultaneously. TBT induced significant morphological and histological malformations of gonadal tissue from female embryos that show a virilization of the ovaries. This phenotypical virilization was mirrored by altered expression profiles of sex-dependent genes. Among these are several transcription and growth factors (e.g. FGF12, CTCF, NFIB), whose altered expression might serve as a set of markers for early identification of endocrine active chemicals that affect embryonic development by transcriptome profiling without the need of elaborate histological analyses. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Extreme morphologies of mantis shrimp larvae

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Carolin Haug

Full Text Available ABSTRACT Larvae of stomatopods (mantis shrimps are generally categorized into four larval types: antizoea, pseudozoea (both representing early larval stages, alima and erichthus (the latter two representing later larval stages. These categories, however, do not reflect the existing morphological diversity of stomatopod larvae, which is largely unstudied. We describe here four previously unknown larval types with extreme morphologies. All specimens were found in the collections of the Zoological Museum, University of Copenhagen and were collected during the Danish Dana Expedition round the world 1928-30. These new larval types all represent erichthus-type larvae, especially differing in their shield morphologies. The shield morphology ranges from almost spherical to rather disc-like, with sometimes extremely elongated spines, but only a general systematic assignment of the larvae was possible. Further investigations of these larvae are crucial to understand their life habits and ecological impact, especially as stomatopod and other crustacean larvae might have a much more important position in the marine ecosystems than their corresponding adults.

Identifying plant traits: a key aspect for suitable species selection in ecological restoration of semiarid slopes

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Bochet, Esther; García-Fayos, Patricio

2017-04-01

In the context of ecological restoration, one of the greatest challenges for practitioners and scientists is to select suitable species for revegetation purposes. In semiarid environments where restoration projects often fail, little attention has been paid so far to the contribution of plant traits to species success. The objective of this study was to (1) identify plant traits associated with species success on four roadside situations along an erosion-productivity gradient, and (2) to provide an ecological framework for selecting suitable species on the basis of their morphological and functional traits, applied to semiarid environments. We analyzed the association of 10 different plant traits with species success of 296 species surveyed on the four roadside situations in a semiarid region (Valencia, Spain). Plant traits included general plant traits (longevity, woodiness) and more specific root-, seed- and leaf-related traits (root type, sprouting ability, seed mucilage, seed mass, seed susceptibility to removal, specific leaf area and leaf dry matter content). All of them were selected according to the prevailing limiting ecogeomorphological processes acting along the erosion-productivity gradient. We observed strong shifts along the erosion-productivity gradient in the traits associated to species success. At the harshest end of the gradient, the most intensely eroded and driest one, species success was mainly associated to seed resistance to removal by runoff and to resistance to drought. At the opposite end of the gradient, the most productive one, species success was associated to a competitive-ruderal plant strategy (herbaceous successful species with high specific leaf area and low leaf dry matter content). Our study provides an ecologically-based approach for selecting suitable native species on the basis or their morphological and functional traits and supports a differential trait-based selection of species as regards roadslope type and aspect. In

A three-dimensional morphometric analysis of upper forelimb morphology in the enigmatic tapir (Perissodactyla: Tapirus) hints at subtle variations in locomotor ecology.

Science.gov (United States)

MacLaren, Jamie A; Nauwelaerts, Sandra

2016-11-01

Forelimb morphology is an indicator for terrestrial locomotor ecology. The limb morphology of the enigmatic tapir (Perissodactyla: Tapirus) has often been compared to that of basal perissodactyls, despite the lack of quantitative studies comparing forelimb variation in modern tapirs. Here, we present a quantitative assessment of tapir upper forelimb osteology using three-dimensional geometric morphometrics to test whether the four modern tapir species are monomorphic in their forelimb skeleton. The shape of the upper forelimb bones across four species (T. indicus; T. bairdii; T. terrestris; T. pinchaque) was investigated. Bones were laser scanned to capture surface morphology and 3D landmark analysis was used to quantify shape. Discriminant function analyses were performed to reveal features which could be used for interspecific discrimination. Overall our results show that the appendicular skeleton contains notable interspecific differences. We demonstrate that upper forelimb bones can be used to discriminate between species (>91% accuracy), with the scapula proving the most diagnostic bone (100% accuracy). Features that most successfully discriminate between the four species include the placement of the cranial angle of the scapula, depth of the humeral condyle, and the caudal deflection of the olecranon. Previous studies comparing the limbs of T. indicus and T. terrestris are corroborated by our quantitative findings. Moreover, the mountain tapir T. pinchaque consistently exhibited the greatest divergence in morphology from the other three species. Despite previous studies describing tapirs as functionally mediportal in their locomotor style, we find osteological evidence suggesting a spectrum of locomotor adaptations in the tapirs. We conclude that modern tapir forelimbs are neither monomorphic nor are tapirs as conserved in their locomotor habits as previously described. J. Morphol. 277:1469-1485, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals

Patterns of cranial ontogeny in lacertid lizards: morphological and allometric disparity.

Science.gov (United States)

Urošević, A; Ljubisavljević, K; Ivanović, A

2013-02-01

We explored the ontogenetic dynamics of the morphological and allometric disparity in the cranium shapes of twelve lacertid lizard species. The analysed species (Darevskia praticola, Dinarolacerta mosorensis, Iberolacerta horvathi, Lacerta agilis, L. trilineata, L. viridis, Podarcis erhardii, P. melisellensis, P. muralis, P. sicula, P. taurica and Zootoca vivipara) can be classified into different ecomorphs: terrestrial lizards that inhabit vegetated habitats (habitats with lush or sparse vegetation), saxicolous and shrub-climbing lizards. We observed that there was an overall increase in the morphological disparity (MD) during the ontogeny of the lacertid lizards. The ventral cranium, which is involved in the mechanics of jaw movement and feeding, showed higher levels of MD, an ontogenetic shift in the morphospace planes and more variable allometric patterns than more conserved dorsal crania. With respect to ecology, the allometric trajectories of the shrub-climbing species tended to cluster together, whereas the allometric trajectories of the saxicolous species were highly dispersed. Our results indicate that the ontogenetic patterns of morphological and allometric disparity in the lacertid lizards are modified by ecology and functional constraints and that the identical mechanisms that lead to intraspecific morphological variation also produce morphological divergence at higher taxonomic levels. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

The morphology of the inner ear of squamate reptiles and its bearing on the origin of snakes

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Palci, Alessandro; Hutchinson, Mark N.; Caldwell, Michael W.; Lee, Michael S. Y.

2017-08-01

The inner ear morphology of 80 snake and lizard species, representative of a range of ecologies, is here analysed and compared to that of the fossil stem snake Dinilysia patagonica, using three-dimensional geometric morphometrics. Inner ear morphology is linked to phylogeny (we find here a strong phylogenetic signal in the data that can complicate ecological correlations), but also correlated with ecology, with Dinilysia resembling certain semi-fossorial forms (Xenopeltis and Cylindrophis), consistent with previous reports. We here also find striking resemblances between Dinilysia and some semi-aquatic snakes, such as Myron (Caenophidia, Homalopsidae). Therefore, the inner ear morphology of Dinilysia is consistent with semi-aquatic as well as semi-fossorial habits: the most similar forms are either semi-fossorial burrowers with a strong affinity to water (Xenopeltis and Cylindrophis) or amphibious, intertidal forms which shelter in burrows (Myron). Notably, Dinilysia does not cluster as closely with snakes with exclusively terrestrial or obligate burrowing habits (e.g. scolecophidians and uropeltids). Moreover, despite the above similarities, Dinilysia also occupies a totally unique morphospace, raising issues with linking it with any particular ecological category.

Ecological approach in constructing residential areas

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Bogdanović Ružica

2004-01-01

Full Text Available As a concept sustainable development has evolved over the past two decades from a concept closely associated with the biophysical environment to become much more complex, embracing social, cultural, economic political and esthetic phenomenon, which are invariably in mutual interaction, so they influence sustainability of natural environment. The very notion of "sustainable" we are meeting today in almost all significance areas of human activities. Contemporary planning, projecting and building techniques undoubtedly implied integration of goals of environmental prevention with goals of socio-economic development, all with respecting the esthetic standards. This paper represents experience from foreign praxis. Project defines and resolves objectives from social, economical, morphological and ecological aspects. Most important is aspect of Ecological Optimisation, which consists of main components: energy use optimization, water concept, exemplary waste management concept and ecological soil management.

Ordinary differential equations

CERN Document Server

Greenberg, Michael D

2014-01-01

Features a balance between theory, proofs, and examples and provides applications across diverse fields of study Ordinary Differential Equations presents a thorough discussion of first-order differential equations and progresses to equations of higher order. The book transitions smoothly from first-order to higher-order equations, allowing readers to develop a complete understanding of the related theory. Featuring diverse and interesting applications from engineering, bioengineering, ecology, and biology, the book anticipates potential difficulties in understanding the various solution steps

Low ecological disparity in Early Cretaceous birds

Science.gov (United States)

Mitchell, Jonathan S.; Makovicky, Peter J.

2014-01-01

Ecological divergence is thought to be coupled with evolutionary radiations, yet the strength of this coupling is unclear. When birds diversified ecologically has received much less attention than their hotly debated crown divergence time. Here, we quantify how accurately skeletal morphology can predict ecology in living and extinct birds, and show that the earliest known assemblage of birds (= pygostylians) from the Jehol Biota (≈ 125 Ma) was substantially impoverished ecologically. The Jehol avifauna has few representatives of highly preservable ecomorphs (e.g. aquatic forms) and a notable lack of ecomorphological overlap with the pterosaur assemblage (e.g. no large or aerially foraging pygostylians). Comparisons of the Jehol functional diversity with modern and subfossil avian assemblages show that taphonomic bias alone cannot explain the ecomorphological impoverishment. However, evolutionary simulations suggest that the constrained ecological diversity of the Early Cretaceous pygostylians is consistent with what is expected from a relatively young radiation. Regardless of the proximate biological explanation, the anomalously low functional diversity of the Jehol birds is evidence both for ecological vacancies in Cretaceous ecosystems, which were subsequently filled by the radiation of crown Aves, and for discordance between taxonomic richness and ecological diversity in the best-known Mesozoic ecosystem. PMID:24870044

Beach morphology monitoring in the Elwha River Littoral Cell, 2004-2009

Science.gov (United States)

Warrick, Jonathon A.; George, Douglas A.; Stevens, Andrew W.; Eshleman, Jodi; Gelfenbaum, Guy; Kaminsky, George M.; Schwartz, Andrew K.; Bierne, Matt

2007-01-01

This report describes the methods used, data collected, and results of the Beach Morphology Monitoring Program in the Elwha River Littoral Cell, starting in 2004. The U.S. Geological Survey and the Washington State Department of Ecology collaborated in the data collection with the support of the local Lower Elwha Klallam Tribe. Beach monitoring efforts consisted of collecting topographic and bathymetric horizontal and vertical position data by using a Real Time Kinematic Differential Global Positioning System (RTK-DGPS). The monitoring program was designed to characterize the littoral system of the Elwha River before the scheduled removal of two large dams in 2012. A primary objective of this work is to quantitatively describe the topography and bathymetry of the Elwha River littoral system so that the effects of dam removal may be quantified. Sediment inputs following dam removal are hypothesized to result in (A) larger amounts of fine sediment grain-sizes entering the littoral system and, (B) a reduction or reversal of coastal erosion.

Multiparameter Stochastic Dynamics of Ecological Tourism System with Continuous Visitor Education Interventions

Directory of Open Access Journals (Sweden)

Dongping Wei

2015-01-01

Full Text Available Management of ecological tourism in protected areas faces many challenges, with visitation-related resource degradations and cultural impacts being two of them. To address those issues, several strategies including regulations, site managements, and visitor education programs have been commonly used in China and other countries. This paper presents a multiparameter stochastic differential equation model of an Ecological Tourism System to study how the populations of stakeholders vary in a finite time. The solution of Ordinary Differential Equation of Ecological Tourism System reveals that the system collapses when there is a lack of visitor educational intervention. Hence, the Stochastic Dynamic of Ecological Tourism System is introduced to suppress the explosion of the system. But the simulation results of the Stochastic Dynamic of Ecological Tourism System show that the system is still unstable and chaos in some small time interval. The Multiparameters Stochastic Dynamics of Ecological Tourism System is proposed to improve the performance in this paper. The Multiparameters Stochastic Dynamics of Ecological Tourism System not only suppresses the explosion of the system in a finite time, but also keeps the populations of stakeholders in an acceptable level. In conclusion, the Ecological Tourism System develops steadily and sustainably when land managers employ effective visitor education intervention programs to deal with recreation impacts.

The geographic scale of diversification on islands: genetic and morphological divergence at a very small spatial scale in the Mascarene grey white-eye (Aves: Zosterops borbonicus

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Thébaud Christophe

2010-05-01

Full Text Available Abstract Background Oceanic islands provide unique scenarios for studying the roles of geography and ecology in driving population divergence and speciation. Assessing the relative importance of selective and neutral factors in driving population divergence is central to understanding how such divergence may lead to speciation in small oceanic islands, where opportunities for gene flow and population mixing are potentially high. Here we report a case of genetic and morphological structure in the Mascarene grey white-eye (Zosterops borbonicus a species that shows a striking, geographically structured plumage polymorphism on the topographically and ecologically complex island of Réunion, yet is monotypic on the relatively uniform neighbouring island of Mauritius. Results Analysis of 276 AFLP loci in 197 individuals revealed prolonged independent evolution of Réunion and Mauritius populations, which is congruent with previous mtDNA assessments. Furthermore, populations on Réunion showed significant differentiation into three main genetic groups separating lowland from highland areas despite the small geographic distances involved. Genetic differentiation along the altitudinal gradient is consistent with morphometric analysis of fitness-related traits. Birds in the highlands were larger, yet had relatively smaller beaks than in the lowlands, suggesting the role of selection in shaping morphology and restricting gene flow along the gradient. No genetic differentiation between plumage morphs was detected in neutral markers, suggesting that plumage differences are of recent origin. Conclusions Our results suggest a dual role of vicariance and natural selection in differentiating populations of a passerine bird in an oceanic island at very small spatial scales. We propose a combination of past microallopatry driven by volcanic activity and selection-constrained dispersal along steep ecological gradients to explain the striking levels of population

Interactions between Genetic and Ecological Effects on the Evolution of Life Cycles.

Science.gov (United States)

Rescan, Marie; Lenormand, Thomas; Roze, Denis

2016-01-01

Sexual reproduction leads to an alternation between haploid and diploid phases, whose relative length varies widely across taxa. Previous genetical models showed that diploid or haploid life cycles may be favored, depending on dominance interactions and on effective recombination rates. By contrast, niche differentiation between haploids and diploids may favor biphasic life cycles, in which development occurs in both phases. In this article, we explore the interplay between genetical and ecological factors, assuming that deleterious mutations affect the competitivity of individuals within their ecological niche and allowing different effects of mutations in haploids and diploids (including antagonistic selection). We show that selection on a modifier gene affecting the relative length of both phases can be decomposed into a direct selection term favoring the phase with the highest mean fitness (due to either ecological differences or differential effects of mutations) and an indirect selection term favoring the phase in which selection is more efficient. When deleterious alleles occur at many loci and in the presence of ecological differentiation between haploids and diploids, evolutionary branching often occurs and leads to the stable coexistence of alleles coding for haploid and diploid cycles, while temporal variations in niche sizes may stabilize biphasic cycles.

Melt behaviour, crystallinity and morphology of poly(p-dioxanone)

NARCIS (Netherlands)

Pezzin, APT; van Ekenstein, GOR; Duek, EAR

The melt behaviour of poly(p-dioxanone) (PPD) has been studied by differential scanning calorimetry (DSC). Crystallinity and morphology were evaluated by modulated differential scanning calorimetry (MDSC) and polarizing optical microscopy. The melting curves showed two melting endotherms, a higher

On the methodology of feeding ecology in fish

Directory of Open Access Journals (Sweden)

Saikia Surjya Kumar

2016-06-01

Full Text Available Feeding ecology explains predator’s preference to some preys over others in their habitat and their competitions thereof. The subject, as a functional and applied biology, is highly neglected, and in case of fish, a uniform and consistent methodology is absent. The currently practiced methods are largely centred on mathematical indices and highly erroneous because of non-uniform outcomes. Therefore, it requires a relook into the subject to elucidate functional contributions and to make it more comparable and comprehensive science. In this article, approachable methodological strategies have been forwarded in three hierarchical steps, namely, food occurrence, feeding biology and interpretative ecology. All these steps involve wide ranges of techniques, within the scope of ecology but not limited to, and traverse from narrative to functional evolutionary ecology. The first step is an assumption-observation practice to assess food of fish, followed by feeding biology that links morphological, histological, cytological, bacteriological or enzymological correlations to preferred food in the environment. Interpretative ecology is the higher level of analysis in which the outcomes are tested and discussed against evolutionary theories. A description of possible pedagogics on the methods of feeding ecological studies has also been forwarded.

Morphological and molecular diagnostics of Phytoseiulus persimilis and Phytoseiulus macropilis (Acari: Phytoseiidae).

Science.gov (United States)

Okassa, Mireille; Tixier, Marie-Stéphane; Kreiter, Serge

2010-11-01

This study focuses on the diagnostics of two natural enemy species, belonging to the genus Phytoseiulus in the family Phytoseiidae (sub-family Amblyseiinae): P. macropilis and P. persimilis. These two species are of primary importance in biological control all over the world. However, they are morphologically very similar and specific diagnostics is difficult. This study utilizes mitochondrial molecular markers (12S rRNA and Cytb mtDNA) to differentiate these two species. Morphological analyses showed significant differences between P. persimilis and P. macropilis for 17 morphological characters of the 32 considered. However, despite these significant differences, the ranges of all characters overlap. Only the serration of the macroseta on the basitarsus (StIV) allows the differentiation between P. persimilis and P. macropilis. Despite these small morphological differences, molecular results, for both mitochondrial DNA fragments considered (rRNA and Cytb mtDNA), showed a clear delineation between the specimens of P. macropilis and P. persimilis. This study emphasizes (i) that only one morphological character (serration of the seta StIV) clearly separates these two species, and (ii) the usefulness of an automatical molecular and simple diagnostic tool for accurate differentiation of the two species and ensure the morphological diagnostics. Further studies are proposed, including more DNA sequences especially for P. macropilis.

Corallite skeletal morphological variation in Hawaiian Porites lobata

Science.gov (United States)

Tisthammer, Kaho H.; Richmond, Robert H.

2018-06-01

Due to their high morphological plasticity and complex evolutionary history, the species boundaries of many reef-building corals are poorly understood. The skeletal structures of corals have traditionally been used for species identification, but these structures can be highly variable, and currently we lack knowledge regarding the extent of morphological variation within species. Porites species are notorious for their taxonomic difficulties, both morphologically and genetically, and currently there are several unresolved species complexes in the Pacific. Despite its ubiquitous presence and broad use in coral research, Porites lobata belongs to one such unresolved species complex. To understand the degree of intraspecific variation in skeletal morphology, 120 corallites from the Hawaiian P. lobata were examined. A subset of samples from two genetically differentiated populations from contrasting high- and low-stress environments in Maunalua Bay, Hawaii, were then quantitatively analyzed using multivariate morphometrics. Our observations revealed high intraspecific variation in corallite morphology, as well as significant morphological differences between the two populations of P. lobata. Additionally, significant correlation was found between the morphological and genetic distances calculated from approximately 18,000 loci generated from restriction site-associated DNA sequencing. The unique morphological characters observed from the genetically differentiated population under environmental stress suggest that these characters may have adaptive values, but how such traits relate to fitness and how much plasticity they can exhibit remain to be determined by future studies. Relatively simple morphometric analyses used in our study can be useful in clarifying the existing ambiguity in skeletal architecture, thus contributing to resolving species issues in corals.

Differential Ecological Specificity of Protist and Bacterial Microbiomes across a Set of Termite Species

KAUST Repository

Waidele, Lena

2017-12-19

The gut microbiome of lower termites comprises protists and bacteria that help these insects to digest cellulose and to thrive on wood. The composition of the termite gut microbiome correlates with phylogenetic distance of the animal host and host ecology (diet) in termites collected from their natural environment. However, carryover of transient microbes from host collection sites are an experimental concern and might contribute to the ecological imprints on the termite gut microbiome. Here, we set out to test whether an ecological imprint on the termite gut microbiome remains, when focusing on the persistent microbiome. Therefore, we kept five termite species under strictly controlled dietary conditions and subsequently profiled their protist and bacterial gut microbial communities using 18S and 16S rRNA gene amplicon sequencing. The species differed in their ecology; while three of the investigated species were wood-dwellers that feed on the piece of wood they live in and never leave except for the mating flight, the other two species were foragers that regularly leave their nests to forage for food. Despite these prominent ecological differences, protist microbiome structure aligned with phylogenetic relatedness of termite host species. Conversely, bacterial communities seemed more flexible, suggesting that microbiome structure aligned more strongly with the foraging and wood-dwelling ecologies. Interestingly, protist and bacterial community alpha-diversity correlated, suggesting either putative interactions between protists and bacteria, or that both types of microbes in the termite gut follow shared structuring principles. Taken together, our results add to the notion that bacterial communities are more variable over evolutionary time than protist communities and might react more flexibly to changes in host ecology.

Differential Ecological Specificity of Protist and Bacterial Microbiomes across a Set of Termite Species

Directory of Open Access Journals (Sweden)

Lena Waidele

2017-12-01

Full Text Available The gut microbiome of lower termites comprises protists and bacteria that help these insects to digest cellulose and to thrive on wood. The composition of the termite gut microbiome correlates with phylogenetic distance of the animal host and host ecology (diet in termites collected from their natural environment. However, carryover of transient microbes from host collection sites are an experimental concern and might contribute to the ecological imprints on the termite gut microbiome. Here, we set out to test whether an ecological imprint on the termite gut microbiome remains, when focusing on the persistent microbiome. Therefore, we kept five termite species under strictly controlled dietary conditions and subsequently profiled their protist and bacterial gut microbial communities using 18S and 16S rRNA gene amplicon sequencing. The species differed in their ecology; while three of the investigated species were wood-dwellers that feed on the piece of wood they live in and never leave except for the mating flight, the other two species were foragers that regularly leave their nests to forage for food. Despite these prominent ecological differences, protist microbiome structure aligned with phylogenetic relatedness of termite host species. Conversely, bacterial communities seemed more flexible, suggesting that microbiome structure aligned more strongly with the foraging and wood-dwelling ecologies. Interestingly, protist and bacterial community alpha-diversity correlated, suggesting either putative interactions between protists and bacteria, or that both types of microbes in the termite gut follow shared structuring principles. Taken together, our results add to the notion that bacterial communities are more variable over evolutionary time than protist communities and might react more flexibly to changes in host ecology.

Manifold Shape: from Differential Geometry to Mathematical Morphology

OpenAIRE

Roerdink, J.B.T.M.

1994-01-01

Much progress has been made in extending Euclidean mathematical morphology to more complex structures such as complete lattices or spaces with a non-commutative symmetry group. Such generalizations are important for practical situations such as translation and rotation invariant pattern recognition or shape description of patterns on spherical surfaces. Also in computer vision much use is made of spherical mappings to describe the world as seen by a human or machine observer. Stimulated by th...

Morphology of leukaemias

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W. Ladines-Castro

2016-04-01

Full Text Available Acute leukaemias are characterised by uncontrolled proliferation of immature blood cells with lymphoid or myeloid lineage. Morphological classification is based on the identification of the leukaemia cell line and its stage of differentiation. The first microscopic descriptions dating from the 1930s pointed to 2 different types of leukaemia cells: lymphoid and myeloid. In 1976, the consensus that led to the French-American-British (FAB classification was achieved. This includes criteria for identifying myeloid and lymphoid leukaemias, and gives a list of morphological subtypes, describing how these affect the patient's prognosis. Today, despite new classifications based on sophisticated studies, FAB classification is widely used by experts due to its technical simplicity, good diagnostic reliability and cost-effectiveness.

Intraspecific ecological niche divergence and reproductive shifts foster cytotype displacement and provide ecological opportunity to polyploids.

Science.gov (United States)

Karunarathne, Piyal; Schedler, Mara; Martínez, Eric J; Honfi, Ana I; Novichkova, Anastasiia; Hojsgaard, Diego

2018-05-11

Niche divergence between polyploids and their lower ploidy progenitors is one of the primary mechanisms fostering polyploid establishment and adaptive divergence. However, within-species chromosomal and reproductive variability have usually been neglected in community ecology and biodiversity analyses even though they have been recognized to play a role in the adaptive diversification of lineages. We used Paspalum intermedium, a grass species with diverging genetic systems (diploidy vs. autopolyploidy, allogamy vs. autogamy and sexuality vs. apomixis), to recognize the causality of biogeographic patterns, adaptation and ecological flexibility of cytotypes. Chromosome counts and flow cytometry were used to characterize within-species genetic systems diversity. Environmental niche modelling was used to evaluate intraspecific ecological attributes associated with environmental and climatic factors and to assess correlations among ploidy, reproductive modes and ecological conditions ruling species' population dynamics, range expansion, adaptation and evolutionary history. Two dominant cytotypes non-randomly distributed along local and regional geographical scales displayed niche differentiation, a directional shift in niche optima and signs of disruptive selection on ploidy-related ecological aptitudes for the exploitation of environmental resources. Ecologically specialized allogamous sexual diploids were found in northern areas associated with higher temperature, humidity and productivity, while generalist autogamous apomictic tetraploids occurred in southern areas, occupying colder and less productive environments. Four localities with a documented shift in ploidy and four mixed populations in a zone of ecological transition revealed an uneven replacement between cytotypes. Polyploidy and contrasting reproductive traits between cytotypes have promoted shifts in niche optima, and increased ecological tolerance and niche divergence. Ecologically specialized diploids

Diatom species abundance and morphologically-based dissolution proxies in coastal Southern Ocean assemblages

Science.gov (United States)

Warnock, Jonathan P.; Scherer, Reed P.

2015-07-01

Taphonomic processes alter diatom assemblages in sediments, thus potentially negatively impacting paleoclimate records at various rates across space, time, and taxa. However, quantitative taphonomic data is rarely included in diatom-based paleoenvironmental reconstructions and no objective standard exists for comparing diatom dissolution in sediments recovered from marine depositional settings, including the Southern Ocean's opal belt. Furthermore, identifying changes to diatom dissolution through time can provide insight into the efficiency of both upper water column nutrient recycling and the biological pump. This is significant in that reactive metal proxies (e.g. Al, Ti) in the sediments only account for post-depositional dissolution, not the water column where the majority of dissolution occurs. In order to assess the range of variability of responses to dissolution in a typical Southern Ocean diatom community and provide a quantitative guideline for assessing taphonomic variability in diatoms recovered from core material, a sediment trap sample was subjected to controlled, serial dissolution. By evaluating dissolution-induced changes to diatom species' relative abundance, three preservational categories of diatoms have been identified: gracile, intermediate, and robust. The relative abundances of these categories can be used to establish a preservation grade for diatom assemblages. However, changes to the relative abundances of diatom species in sediment samples may reflect taphonomic or ecological factors. In order to address this complication, relative abundance changes have been tied to dissolution-induced morphological change to the areolae of Fragilariopsis curta, a significant sea-ice indicator in Southern Ocean sediments. This correlation allows differentiation between gracile species loss to dissolution versus ecological factors or sediment winnowing. These results mirror a similar morphological dissolution index from a parallel study utilizing

Relationships between morphology, diet and spatial distribution: testing the effects of intra and interspecific morphological variations on the patterns of resource use in two Neotropical Cichlids

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Ana Lúcia A. Sampaio

Full Text Available Considering th e morphology, diet and spatial distribution of Satanoperca pappaterraand Crenicichla britskii (Perciformes: Cichlidae in the Upper Paraná River floodplain (Brazil, the following questions were investigated: (1 Could the body shape predict the use of trophic resources and habitat by C. britskiiand S. pappaterra? (2 Could the relationship between morphology and use of trophic resources and habitat be also extended to the intraspecific scale? (3 What are the most important morphological traits used to predict the variation on diet and habitat occupation within and between species? We hypothesized that intra and interspecific differences in morphological patterns imply in different forms of resource exploitation and that the ecomorphological analysis enables the identification of trophic and spatial niche segregation. Fish samplings were performed in different types of habitats (rivers, secondary channels, connected and disconnected lagoons in the Upper Paraná River floodplain. Analyses of the stomach content was conducted to characterize the feeding patterns and twenty-two ecomorphological indices were calculated from linear morphological measurements and areas. A principal component analysis (PCA run with these indices evidenced the formation of two significant axes, revealing in the axis 1 an ecomorphological ordination according to the type of habitat, regardless the species. The individuals of both species exploiting lotic habitats tended to have morphological traits that enable rapid progressive and retrograde movements, braking and continuous swimming, whereas individuals found in lentic and semi-lotic habitats presented morphology adapted to a greater maneuverability and stabilization in deflections. On the other hand the axis 2 evidenced a segregation related to the feeding ecology, between S. pappaterra and C. britskii. The relationship between morphology and use of spatial and feeding resource was corroborated by the

Morphological and ecological variation of Gremmeniella abietina var. abietina in Pinus sylvestris, Pinus contorta and Picea abies sapling stands in northern Finland and the Kola Peninsula

Energy Technology Data Exchange (ETDEWEB)

Kaitera, Juha; Seitamaeki, Leena; Jalkanen, Risto [Finnish Forest Research Inst., Rovaniemi (Finland). Rovaniemi Research Station

2000-07-01

The morphological and ecological variation of two types of Gremmeniella abietina var. abietina causing scleroderris canker on conifers was investigated in Pinus spp. and Picea sp. sapling stands in northern Finland and the Kola Peninsula. Small-tree type (STT or B type) of G. abietina was detected alone in 13 Scots pine, three lodgepole pine and two Norway spruce sapling stands out of 26 stands investigated, both STT and large-tree type (LTT or A type) were observed in six Scots pine stands, and LTT was detected alone in two Scots pine stands. For the first time, G. abietina was found to injure Norway spruce saplings in a respective plantation in northern Fennoscandia. STT isolates produced statistically significantly more conidia in vitro than LTT isolates. Morphological variation in conidia septation revealed that STT produced conidia with more than five septa more frequently than did LTT. There was a greater range in variation in septation in STT than in LTT, with overlapping between the types. Isolates of both types were equally associated with cankers, coloured wood, pycnidia or apothecia in the infected saplings.

Cell type dependent morphological adaptation in polyelectrolyte hydrogels governs chondrogenic fate.

Science.gov (United States)

Raghothaman, Deepak; Leong, Meng Fatt; Lim, Tze Chiun; Wan, Andrew C A; Ser, Zheng; Lee, Eng Hin; Yang, Zheng

2016-04-04

Repair of critical-size articular cartilage defects typically involves delivery of cells in biodegradable, 3D matrices. Differences in the developmental status of mesenchymal stem cells (MSCs) and terminally differentiated mature chondrocytes might be a critical factor in engineering appropriate 3D matrices for articular cartilage tissue engineering. This study examined the relationship between material-driven early cell morphological adaptations and chondrogenic outcomes, by studying the influence of aligned collagen type I (Col I) presentation on chondrocytes and MSC in interfacial polyelectrolyte complexation (IPC)-based hydrogels. In the absence of Col I, both chondrocytes and MSCs adopted rounded cell morphology and formed clusters, with chondrocyte clusters favoring the maintenance of hyaline phenotype, while MSC clusters differentiated to fibro-superficial zone-like chondrocytes. Encapsulated chondrocytes in IPC-Col I hydrogel adopted a fibroblastic morphology forming fibro-superficial zone-like phenotype, which could be reversed by inhibiting actin polymerization using cytochalasin D (CytD). In contrast, adoption of fibroblastic morphology by encapsulated MSCs in IPC-Col I facilitated superior chondrogenesis, generating a mature, hyaline neocartilage tissue. CytD treatment abrogated the elongation of MSCs and brought about a single cell-like state, resulting in insignificant chondrogenic differentiation, underscoring the essential requirement of providing matrix environments that are amenable to cell-cell interactions for robust MSC chondrogenic differentiation. Our study demonstrates that MSCs and culture-expanded chondrocytes favour differential microenvironmental niches and emphasizes the importance of designing biomaterials that meet cell type-specific requirements, in adopting chondrocyte or MSC-based approaches for regenerating hyaline, articular cartilage.

Induction of morphological and functional differentiation of human ...

Indian Academy of Sciences (India)

Samaneh Sharif

2017-10-31

Oct 31, 2017 ... model of neuroblastoma cancer. Influence of miR-124 .... a more reliable marker for quantifying the expand of cell differentiation (Thiele et al. ..... results for children with high-risk neuroblastoma treated on a randomized trial of ...

The Ecological Dynamics of Natural Selection: Traits and the Coevolution of Community Structure.

Science.gov (United States)

McPeek, Mark A

2017-05-01

Natural selection has both genetic and ecological dynamics. The fitnesses of individuals change with their ecological context, and so the form and strength of selective agents change with abiotic factors and the phenotypes and abundances of interacting species. I use standard models of consumer-resource interactions to explore the ecological dynamics of natural selection and how various trait types influence these dynamics and the resulting structure of a community of coevolving species. Evolutionary optima favored by natural selection depend critically on the abundances of interacting species, and the traits of species can undergo dynamic cycling in limited areas of parameter space. The ecological dynamics of natural selection can also drive shifts from one adaptive peak to another, and these ecologically driven adaptive peak shifts are fundamental to the dynamics of niche differentiation. Moreover, this ecological differentiation is fostered in more productive and more benign environments where species interactions are stronger and where the selection gradients generated by species interactions are stronger. Finally, community structure resulting from coevolution depends fundamentally on the types of traits that underlie species interactions. The ecological dynamics of the process cannot be simplified, neglected, or ignored if we are to build a predictive theory of natural selection.

Identification of SACE_7040, a member of TetR family related to the morphological differentiation of Saccharopolyspora erythraea.

Science.gov (United States)

Han, Shu; Song, Ping; Ren, Ting; Huang, Xunduan; Cao, Cheng; Zhang, Buchang

2011-08-01

SACE_7040 is presumed to be a member of the TetR family of transcriptional regulators in Saccharopolyspora erythraea, but its biological function is unknown. It was shown that the SACE_7040 gene knockout mutant formed aerial mycelium earlier than its original strain, and this phenotype could be restored by complementation of a single copy of SACE_7040 gene, demonstrating that SACE_7040 is an important regulator of the morphological differentiation of Sac. erythraea. When SACE_7040 gene was disrupted in the bldD mutant, we intriguingly found that the defect in aerial development exhibited by the bldD mutant could be overcome, suggesting a crosstalk between SACE_7040 and BldD in Sac. erythraea morphogenesis. These findings provide novel insights toward the Sac. erythraea developmental biology.

The Genus Cladophora Kützing (Ulvophyceae) as a Globally Distributed Ecological Engineer.

Science.gov (United States)

Zulkifly, Shahrizim B; Graham, James M; Young, Erica B; Mayer, Robert J; Piotrowski, Michael J; Smith, Izak; Graham, Linda E

2013-02-01

The green algal genus Cladophora forms conspicuous nearshore populations in marine and freshwaters worldwide, commonly dominating peri-phyton communities. As the result of human activities, including the nutrient pollution of nearshore waters, Cladophora-dominated periphyton can form nuisance blooms. On the other hand, Cladophora has ecological functions that are beneficial, but less well appreciated. For example, Cladophora has previously been characterized as an ecological engineer because its complex structure fosters functional and taxonomic diversity of benthic microfauna. Here, we review classic and recent literature concerning taxonomy, cell biology, morphology, reproductive biology, and ecology of the genus Cladophora, to examine how this alga functions to modify habitats and influence littoral biogeochemistry. We review the evidence that Cladophora supports large, diverse populations of microalgal and bacterial epiphytes that influence the cycling of carbon and other key elements, and that the high production of cellulose and hydrocarbons by Cladophora-dominated periphyton has the potential for diverse technological applications, including wastewater remediation coupled to renewable biofuel production. We postulate that well-known aspects of Cladophora morphology, hydrodynamically stable and perennial holdfasts, distinctively branched architecture, unusually large cell and sporangial size and robust cell wall construction, are major factors contributing to the multiple roles of this organism as an ecological engineer. © 2013 Phycological Society of America.

Bioinformatic and Biometric Methods in Plant Morphology

Directory of Open Access Journals (Sweden)

Surangi W. Punyasena

2014-08-01

Full Text Available Recent advances in microscopy, imaging, and data analyses have permitted both the greater application of quantitative methods and the collection of large data sets that can be used to investigate plant morphology. This special issue, the first for Applications in Plant Sciences, presents a collection of papers highlighting recent methods in the quantitative study of plant form. These emerging biometric and bioinformatic approaches to plant sciences are critical for better understanding how morphology relates to ecology, physiology, genotype, and evolutionary and phylogenetic history. From microscopic pollen grains and charcoal particles, to macroscopic leaves and whole root systems, the methods presented include automated classification and identification, geometric morphometrics, and skeleton networks, as well as tests of the limits of human assessment. All demonstrate a clear need for these computational and morphometric approaches in order to increase the consistency, objectivity, and throughput of plant morphological studies.

The species concept in a marine diatom: LSU rDNA–based phylogenetic differentiation in Skeletonema marinoi/dohrnii (Bacillariophyceae) is not reflected in morphology

DEFF Research Database (Denmark)

Ellegaard, Marianne; Godhe, Anna; Härnström, Karolina

2008-01-01

and Canada) included in the study showed differences in LSU rDNA sequence within the morphospecies, with differences seen even among clones established from a single plankton net sample. Morphologically, all clones were indistinguishable from each other and from the closely related species Skeletonema...... dohrnii. In the original description of these two species, they were differentiated by the structure of the girdle bands. However, the girdle band types of both species were found within single samples of almost all clones of S. marinoi in this study. The LSU-based phylogeny is consistent with the split...... into two species, and there may be a difference in their biogeographical distribution. We therefore do not at present suggest that the two species be merged. Questions regarding species delimitation and cryptic species within protists often arise from such studies that include data from both morphological...

Ecological diversification associated with the benthic-to-pelagic transition by North American minnows.

Science.gov (United States)

Burress, E D; Holcomb, J M; Tan, M; Armbruster, J W

2017-03-01

Ecological opportunity is often regarded as a key factor that explains why diversity is unevenly distributed across life. Colonization of novel environments or adaptive zones may promote diversification. North American minnows exhibit an ancestral benthic-to-pelagic habitat shift that coincided with a burst in diversification. Here, we evaluate the phenotypic and ecological implications of this habitat shift by assessing craniofacial and dietary traits among 34 species and testing for morphology-diet covariation, convergence and adaptive optima. There were several instances of morphology-diet covariation such as correlations between mouth angle and the consumption of terrestrial insects and between relative gut length and the consumption of algae. After accounting for size and phylogenetic nonindependence, benthic species had longer heads, longer snouts, eyes positioned higher on their head, smaller mouth angles and longer digestive tracts than pelagic minnows. Benthic minnows also consumed more algae but less terrestrial insects, by volume, than pelagic minnows. Lastly, there were three distinct evolutionary regimes and more convergence in morphology and dietary characteristics than expected under a Brownian motion model of evolution. These findings indicate that colonization of the pelagic zone by minnows involved myriad phenotypic and dietary changes associated with exploitation of terrestrial subsidies. Thus, minnows exhibit phenotype-dietary covariation, an expansion of ecological roles and a burst in diversification rates in response to the ecological opportunity afforded by the colonization of a novel habitat. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

[Ecology and ecologies].

Science.gov (United States)

Valera, Luca

2011-01-01

Ecology (from the Greek words οιχοσ, "house" and λογια "study of") is the science of the "house", since it studies the environments where we live. There are three main ways of thinking about Ecology: Ecology as the study of interactions (between humans and the environment, between humans and living beings, between all living beings, etc.), Ecology as the statistical study of interactions, Ecology as a faith, or rather as a science that requires a metaphysical view. The history of Ecology shows us how this view was released by the label of "folk sense" to gain the epistemological status of science, a science that strives to be interdisciplinary. So, the aim of Ecology is to study, through a scientific methodology, the whole natural world, answering to very different questions, that arise from several fields (Economics, Biology, Sociology, Philosophy, etc.). The plurality of issues that Ecology has to face led, during the Twentieth-century, to branch off in several different "ecologies". As a result, each one of these new approaches chose as its own field a more limited and specific portion of reality.

Poorly-differentiated colorectal neuroendocrine tumour: CT differentiation from well-differentiated neuroendocrine tumour and poorly-differentiated adenocarcinomas

Energy Technology Data Exchange (ETDEWEB)

Kang, Ji Hee [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Kim, Se Hyung [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Han, Joon Koo [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of)

2017-09-15

The differentiation of poorly-differentiated neuroendocrine tumours (PD-NETs), well-differentiated NETs (WD-NETs), and adenocarcinomas (ADCs) is important due to different management options and prognoses. This study is to find the differential CT features of colorectal PD-NETs from WD-NETs and ADCs. CT features of 25 colorectal WD-NETs, 36 PD-NETs, and 36 ADCs were retrospectively reviewed. Significant variables were assessed using univariate and multivariate analyses. Receiver operating characteristics analysis determined the optimal cut-off value of tumour and lymph node (LN) size. Large size, rectum location, ulceroinfiltrative morphology without intact overlying mucosa, heterogeneous attenuation with necrosis, presence of ≥3 enlarged LNs, and metastasis were significant variables to differentiate PD-NETs from WD-NETs (P < 0.05). High attenuation on arterial phase, persistently high enhancement pattern, presence of ≥6 enlarged LNs, large LN size, and wash-in/wash-out enhancement pattern of liver metastasis were significant variables to differentiate PD-NETs from ADCs (P < 0.05). Compared to WD-NETs, colorectal PD-NETs are usually large, heterogeneous, and ulceroinfiltrative mass without intact overlying mucosa involving enlarged LNs and metastasis. High attenuation on arterial phase, presence of enlarged LNs with larger size and greater number, and wash-in/wash-out enhancement pattern of liver metastasis can be useful CT discriminators of PD-NETs from ADCs. (orig.)

MRI and MRS on preserved samples as a tool in fish ecology.

Science.gov (United States)

Bock, Christian; Wermter, Felizitas C; Mintenbeck, Katja

2017-05-01

Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopy (MRS) gain increasing attention and importance as a tool in marine ecology. So far, studies were largely limited to morphological studies, e.g. for the creation of digital libraries. Here, the utility of MRI and MRS for ecologists is tested and exemplified using formalin preserved samples of the Antarctic silverfish, Pleuragramma antarctica. As this species lacks a swim bladder, buoyancy is attained by the deposition of large amounts of lipids that are mainly stored in subcutaneous and intermuscular lipid sacs. In this study MRI and MRS are not only used to study internal morphology, but additionally to investigate functional morphology and to measure parameters of high ecological interest. The data are compared with literature data obtained by means of traditional ecological methods. The results from this study show that MR scans are not only an alternative to histological sections (as shown before), but even allow the visualization of particular features in delicate soft tissues, such as Pleuragramma's lipid sacs. 3D rendering techniques proved to be a useful tool to study organ volumes and lipid content, which usually requires laborious chemical lipid extraction and analysis. Moreover, the application of MRS even allows for an analysis of lipids and fatty acids within lipid sacs, which wouldn't be possible using destructive methods. MRI and MRS, in particular when used in combination, have the capacity to provide useful data on parameters of high ecological relevance and thus have proven to be a highly valuable addition, if not alternative, to the classical methods. Copyright © 2016 Elsevier Inc. All rights reserved.

Differentiation in the microbial ecology and activity of suspended and attached bacteria in a nitritation-anammox process.

Science.gov (United States)

Park, Hongkeun; Sundar, Suneethi; Ma, Yiwei; Chandran, Kartik

2015-02-01

A directed differentiation between the biofilm and suspension was observed in the molecular microbial ecology and gene expression of different bacteria in a biofilm nitritation-anammox process operated at varying hydraulic residence times (HRT) and nitrogen loading rates (NLR). The highest degree of enrichment observed in the biofilm was of anaerobic ammonia-oxidizing bacteria (AMX) followed by that of Nitrospira spp. related nitrite-oxidizing bacteria (NOB). For AMX, a major shift from Candidatus "Brocadia fulgida" to Candidatus "Kuenenia stuttgartiensis" in both suspension and biofilm was observed with progressively shorter HRT, using discriminatory biomarkers targeting the hydrazine synthase (hzsA) gene. In parallel, expression of the hydrazine oxidoreductase gene (hzo), a functional biomarker for AMX energy metabolism, became progressively prominent in the biofilm. A marginal but statistically significant enrichment in the biofilm was observed for Nitrosomonas europaea related ammonia-oxidizing bacteria (AOB). In direct contrast to AMX, the gene expression of ammonia monooxygenase subunit A (amoA), a functional biomarker for AOB energy metabolism, progressively increased in suspension. Using gene expression and biomass concentration measures in conjunction, it was determined that signatures of AOB metabolism were primarily present in the biofilm throughout the study. On the other hand, AMX metabolism gradually shifted from being uniformly distributed in both the biofilm and suspension to primarily the biofilm at shorter HRTs and higher NLRs. These results therefore highlight the complexity and key differences in the microbial ecology, gene expression and activity between the biofilm and suspension of a nitritation-anammox process and the biokinetic and metabolic drivers for such niche segregation. © 2014 Wiley Periodicals, Inc.

Shape up or ship out: migratory behaviour predicts morphology across spatial scale in a freshwater fish.

Science.gov (United States)

Chapman, Ben B; Hulthén, Kaj; Brönmark, Christer; Nilsson, P Anders; Skov, Christian; Hansson, Lars-Anders; Brodersen, Jakob

2015-09-01

1. Migration is a widespread phenomenon, with powerful ecological and evolutionary consequences. Morphological adaptations to reduce the energetic costs associated with migratory transport are commonly documented for migratory species. However, few studies have investigated whether variation in body morphology can be explained by variation in migratory strategy within a species. 2. We address this question in roach Rutilus rutilus, a partially migratory freshwater fish that migrates from lakes into streams during winter. We both compare body shape between populations that differ in migratory opportunity (open vs. closed lakes), and between individuals from a single population that vary in migratory propensity (migrants and residents from a partially migratory population). Following hydrodynamic theory, we posit that migrants should have a more shallow body depth, to reduce the costs associated with migrating into streams with higher flow conditions than the lakes the residents occupy all year round. 3. We find evidence both across and within populations to support our prediction, with individuals from open lakes and migrants from the partially migratory population having a more slender, shallow-bodied morphology than fish from closed lakes and all-year residents. 4. Our data suggest that a shallow body morphology is beneficial to migratory individuals and our study is one of the first to link migratory strategy and intraspecific variation in body shape. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Biophysical subsets of embryonic stem cells display distinct phenotypic and morphological signatures.

Directory of Open Access Journals (Sweden)

Tom Bongiorno

Full Text Available The highly proliferative and pluripotent characteristics of embryonic stem cells engender great promise for tissue engineering and regenerative medicine, but the rapid identification and isolation of target cell phenotypes remains challenging. Therefore, the objectives of this study were to characterize cell mechanics as a function of differentiation and to employ differences in cell stiffness to select population subsets with distinct mechanical, morphological, and biological properties. Biomechanical analysis with atomic force microscopy revealed that embryonic stem cells stiffened within one day of differentiation induced by leukemia inhibitory factor removal, with a lagging but pronounced change from spherical to spindle-shaped cell morphology. A microfluidic device was then employed to sort a differentially labeled mixture of pluripotent and differentiating cells based on stiffness, resulting in pluripotent cell enrichment in the soft device outlet. Furthermore, sorting an unlabeled population of partially differentiated cells produced a subset of "soft" cells that was enriched for the pluripotent phenotype, as assessed by post-sort characterization of cell mechanics, morphology, and gene expression. The results of this study indicate that intrinsic cell mechanical properties might serve as a basis for efficient, high-throughput, and label-free isolation of pluripotent stem cells, which will facilitate a greater biological understanding of pluripotency and advance the potential of pluripotent stem cell differentiated progeny as cell sources for tissue engineering and regenerative medicine.

Impulsive differential inclusions a fixed point approach

CERN Document Server

Ouahab, Abdelghani; Henderson, Johnny

2013-01-01

Impulsive differential equations have been developed in modeling impulsive problems in physics, population dynamics, ecology, biotechnology, industrial robotics, pharmacokinetics, optimal control, etc. The questions of existence and stability of solutions for different classes of initial values problems for impulsive differential equations and inclusions with fixed and variable moments are considered in detail. Attention is also given to boundary value problems and relative questions concerning differential equations. This monograph addresses a variety of side issues that arise from its simple

Individual-based modeling of ecological and evolutionary processes

NARCIS (Netherlands)

DeAngelis, D.L.; Mooij, W.M.

2005-01-01

Individual-based models (IBMs) allow the explicit inclusion of individual variation in greater detail than do classical differential and difference equation models. Inclusion of such variation is important for continued progress in ecological and evolutionary theory. We provide a conceptual basis

Large-scale pattern of genetic differentiation within African rainforest trees: insights on the roles of ecological gradients and past climate changes on the evolution of Erythrophleum spp (Fabaceae).

Science.gov (United States)

Duminil, Jerome; Brown, Richard P; Ewédjè, Eben-Ezer B K; Mardulyn, Patrick; Doucet, Jean-Louis; Hardy, Olivier J

2013-09-12

The evolutionary events that have shaped biodiversity patterns in the African rainforests are still poorly documented. Past forest fragmentation and ecological gradients have been advocated as important drivers of genetic differentiation but their respective roles remain unclear. Using nuclear microsatellites (nSSRs) and chloroplast non-coding sequences (pDNA), we characterised the spatial genetic structure of Erythrophleum (Fabaceae) forest trees in West and Central Africa (Guinea Region, GR). This widespread genus displays a wide ecological amplitude and taxonomists recognize two forest tree species, E. ivorense and E. suaveolens, which are difficult to distinguish in the field and often confused. Bayesian-clustering applied on nSSRs of a blind sample of 648 specimens identified three major gene pools showing no or very limited introgression. They present parapatric distributions correlated to rainfall gradients and forest types. One gene pool is restricted to coastal evergreen forests and corresponds to E. ivorense; a second one is found in gallery forests from the dry forest zone of West Africa and North-West Cameroon and corresponds to West-African E. suaveolens; the third gene pool occurs in semi-evergreen forests and corresponds to Central African E. suaveolens. These gene pools have mostly unique pDNA haplotypes but they do not form reciprocally monophyletic clades. Nevertheless, pDNA molecular dating indicates that the divergence between E. ivorense and Central African E. suaveolens predates the Pleistocene. Further Bayesian-clustering applied within each major gene pool identified diffuse genetic discontinuities (minor gene pools displaying substantial introgression) at a latitude between 0 and 2°N in Central Africa for both species, and at a longitude between 5° and 8°E for E. ivorense. Moreover, we detected evidence of past population declines which are consistent with historical habitat fragmentation induced by Pleistocene climate changes. Overall

Morphology, Reproduction and Diet in Australian and Papuan Death Adders (Acanthophis, Elapidae)

OpenAIRE

Shine, Richard; Spencer, Carol L.; Keogh, J. Scott

2014-01-01

Death adders (genus Acanthophis) differ from most other elapid snakes, and resemble many viperid snakes, in their thickset morphology and ambush foraging mode. Although these snakes are widely distributed through Australia and Papua New Guinea, their basic biology remains poorly known. We report morphological and ecological data based upon dissection of >750 museum specimens drawn from most of the range of the genus. Female death adders grow larger than conspecific males, to about the same ex...

Why are tropical mountain passes "low" for some species? Genetic and stable-isotope tests for differentiation, migration and expansion in elevational generalist songbirds.

Science.gov (United States)

Gadek, Chauncey R; Newsome, Seth D; Beckman, Elizabeth J; Chavez, Andrea N; Galen, Spencer C; Bautista, Emil; Witt, Christopher C

2018-05-01

Most tropical bird species have narrow elevational ranges, likely reflecting climatic specialization. This is consistent with Janzen's Rule, the tendency for mountain passes to be effectively "higher" in the tropics. Hence, those few tropical species that occur across broad elevational gradients (elevational generalists) represent a contradiction to Janzen's Rule. Here, we aim to address the following questions. Are elevational generalists being sundered by diversifying selection along the gradient? Does elevational movement cause these species to resist diversification or specialization? Have they recently expanded, suggesting that elevational generalism is short-lived in geological time? To answer these questions, we tested for differentiation, movement and expansion in four elevational generalist songbird species on the Andean west slope. We used morphology and mtDNA to test for genetic differentiation between high- and low-elevation populations. To test for elevational movements, we measured hydrogen isotope (δ 2 H) values of metabolically inert feathers and metabolically active liver. Morphology differed for House Wren (Troglodytes aedon) and Hooded Siskin (Spinus magellanicus), but not for Cinereous Conebill (Conirostrum cinereum) and Rufous-collared Sparrow (Zonotrichia capensis) respectively. mtDNA was structured by elevation only in Z. capensis. δ 2 H data indicated elevational movements by two tree- and shrub-foraging species with moderate-to-high vagility (C. cinereum and S. magellanicus), and sedentary behaviour by two terrestrial-foraging species with low-to-moderate vagility (T. aedon and Z. capensis). In S. magellanicus, elevational movements and lack of mtDNA structure contrast with striking morphological divergence, suggesting strong diversifying selection on body proportions across the c. 50 km gradient. All species except C. cinereum exhibited mtDNA haplotype variation consistent with recent population expansion across the elevational

Genetic Determinism vs. Phenotypic Plasticity in Protist Morphology.

Science.gov (United States)

Mulot, Matthieu; Marcisz, Katarzyna; Grandgirard, Lara; Lara, Enrique; Kosakyan, Anush; Robroek, Bjorn J M; Lamentowicz, Mariusz; Payne, Richard J; Mitchell, Edward A D

2017-11-01

Untangling the relationships between morphology and phylogeny is key to building a reliable taxonomy, but is especially challenging for protists, where the existence of cryptic or pseudocryptic species makes finding relevant discriminant traits difficult. Here we use Hyalosphenia papilio (a testate amoeba) as a model species to investigate the contribution of phylogeny and phenotypic plasticity in its morphology. We study the response of H. papilio morphology (shape and pores number) to environmental variables in (i) a manipulative experiment with controlled conditions (water level), (ii) an observational study of a within-site natural ecological gradient (water level), and (iii) an observational study across 37 European peatlands (climate). We showed that H. papilio morphology is correlated to environmental conditions (climate and water depth) as well as geography, while no relationship between morphology and phylogeny was brought to light. The relative contribution of genetic inheritance and phenotypic plasticity in shaping morphology varies depending on the taxonomic group and the trait under consideration. Thus, our data call for a reassessment of taxonomy based on morphology alone. This clearly calls for a substantial increase in taxonomic research on these globally still under-studied organisms leading to a reassessment of estimates of global microbial eukaryotic diversity. © 2017 The Author(s) Journal of Eukaryotic Microbiology © 2017 International Society of Protistologists.

QUANTITATIVE GENETICS OF MORPHOLOGICAL DIFFERENTIATION IN PEROMYSCUS. II. ANALYSIS OF SELECTION AND DRIFT.

Science.gov (United States)

Lofsvold, David

1988-01-01

The hypothesis that the morphological divergence of local populations of Peromyscus is due to random genetic drift was evaluated by testing the proportionality of the among-locality covariance matrix, L, and the additive genetic covariance matrix, G. Overall, significant proportionality of L̂ and Ĝ was not observed, indicating the evolutionary divergence of local populations does not result from random genetic drift. The forces of selection needed to differentiate three taxa of Peromyscus were reconstructed to examine the divergence of species and subspecies. The selection gradients obtained illustrate the inadequacy of univariate analyses of selection by finding that some characters evolve in the direction opposite to the force of selection acting directly on them. A retrospective selection index was constructed using the estimated selection gradients, and truncation selection on this index was used to estimate the minimum selective mortality per generation required to produce the observed change. On any of the time scales used, the proportion of the population that would need to be culled was quite low, the greatest being of the same order of magnitude as the selective intensities observed in extant natural populations. Thus, entirely plausible intensities of directional natural selection can produce species-level differences in a period of time too short to be resolved in the fossil record. © 1988 The Society for the Study of Evolution.

Synergistic selection between ecological niche and mate preference primes diversification.

Science.gov (United States)

Boughman, Janette W; Svanbäck, Richard

2017-01-01

The ecological niche and mate preferences have independently been shown to be important for the process of speciation. Here, we articulate a novel mechanism by which ecological niche use and mate preference can be linked to promote speciation. The degree to which individual niches are narrow and clustered affects the strength of divergent natural selection and population splitting. Similarly, the degree to which individual mate preferences are narrow and clustered affects the strength of divergent sexual selection and assortative mating between diverging forms. This novel perspective is inspired by the literature on ecological niches; it also explores mate preferences and how they may contribute to speciation. Unlike much comparative work, we do not search for evolutionary patterns using proxies for adaptation and sexual selection, but rather we elucidate how ideas from niche theory relate to mate preference, and how this relationship can foster speciation. Recognizing that individual and population niches are conceptually and ecologically linked to individual and population mate preference functions will significantly increase our understanding of rapid evolutionary diversification in nature. It has potential to help solve the difficult challenge of testing the role of sexual selection in the speciation process. We also identify ecological factors that are likely to affect individual niche and individual mate preference in synergistic ways and as a consequence to promote speciation. The ecological niche an individual occupies can directly affect its mate preference. Clusters of individuals with narrow, differentiated niches are likely to have narrow, differentiated mate preference functions. Our approach integrates ecological and sexual selection research to further our understanding of diversification processes. Such integration may be necessary for progress because these processes seem inextricably linked in the natural world. © 2016 The Author(s). Evolution �

Ecological model of the interprise danger of gas

International Nuclear Information System (INIS)

Sadygov, A.B.

2009-01-01

It has been looked into the basic problems for establishment of ecological model of the enterprise danger of gas. There have been established mathematical model in the base of equation of Novye-Stoks which consists of private reproductive second row differential equation system of three

Ecology of the coexisting copepod species in Cochin backwaters

Digital Repository Service at National Institute of Oceanography (India)

Madhupratap, M.

of the high saline species. The degree of ecological differentiation between them was not very clear. Probably the peculiarities of the estuarine system allowed them to survive as competitors, since it is conceivable that the competing species expand...

Reliable molecular differentiation of Trichuris ovis and Trichuris discolor from sheep (Ovis orientalis aries) and roe deer (Capreolus capreolus) and morphological characterisation of their females: morphology does not work sufficiently.

Science.gov (United States)

Vejl, Pavel; Nechybová, Stanislava; Peřinková, Pavla; Melounová, Martina; Sedláková, Vladimíra; Vašek, Jakub; Čílová, Daniela; Rylková, Kateřina; Jankovská, Ivana; Vadlejch, Jaroslav; Langrová, Iva

2017-08-01

The main aim of the study was to evaluate associations between morphological variability of Trichuris females from sheep and roe deer and their rDNA polymorphism in whipworm populations from the Czech Republic. The results introduced the use of new molecular markers based on the internal transcribed spacer (ITS)1-5.8S RNA-ITS2 region polymorphisms, as useful tools for the unambiguous differentiation of congeners Trichuris ovis and Trichuris discolor. These markers revealed both parasites in roe deer and in sheep; however, T. ovis females predominated in sheep while T. discolor females occurred mostly in roe deer. Additional analysis of ITS1-5.8 rRNA-ITS2 discovered the genetic uniformity of the analysed T. discolor but high haplotype variation of T. ovis. Simultaneously, molecularly designated female individuals of both species were categorised into four morphotypes (MT) on the basis of morphology of genital pore area. MT1 and MT4 (vulvar opening on everted vaginal appendage/on visible cuticular bulge) occurred only in T. ovis, MT2 (uneverted vagina-vulvar opening without any elevation) was identified only in T. discolor and MT3 (transient type of vulvar opening on a small swelling) was observed in both species. Statistical analysis of biometric data confirmed that morphology of vulva is not a reliable marker for the species determination. On the basis of the ITS1-5.8S RNA-ITS2 region variability, we carried out a phylogenetic analysis (maximum likelihood method, Hasegawa-Kishino-Yano model) which showed that T. ovis haplotypes from the Czech Republic and Ireland and T. discolor haplotypes from the Czech Republic, Spain, Iran and Japan are sister OTUs.

Disentangling the phylogenetic and ecological components of spider phenotypic variation.

Science.gov (United States)

Gonçalves-Souza, Thiago; Diniz-Filho, José Alexandre Felizola; Romero, Gustavo Quevedo

2014-01-01

An understanding of how the degree of phylogenetic relatedness influences the ecological similarity among species is crucial to inferring the mechanisms governing the assembly of communities. We evaluated the relative importance of spider phylogenetic relationships and ecological niche (plant morphological variables) to the variation in spider body size and shape by comparing spiders at different scales: (i) between bromeliads and dicot plants (i.e., habitat scale) and (ii) among bromeliads with distinct architectural features (i.e., microhabitat scale). We partitioned the interspecific variation in body size and shape into phylogenetic (that express trait values as expected by phylogenetic relationships among species) and ecological components (that express trait values independent of phylogenetic relationships). At the habitat scale, bromeliad spiders were larger and flatter than spiders associated with the surrounding dicots. At this scale, plant morphology sorted out close related spiders. Our results showed that spider flatness is phylogenetically clustered at the habitat scale, whereas it is phylogenetically overdispersed at the microhabitat scale, although phylogenic signal is present in both scales. Taken together, these results suggest that whereas at the habitat scale selective colonization affect spider body size and shape, at fine scales both selective colonization and adaptive evolution determine spider body shape. By partitioning the phylogenetic and ecological components of phenotypic variation, we were able to disentangle the evolutionary history of distinct spider traits and show that plant architecture plays a role in the evolution of spider body size and shape. We also discussed the relevance in considering multiple scales when studying phylogenetic community structure.

Identification of differentially expressed sequences in bud ...

African Journals Online (AJOL)

The developmental process of lily flower bud differentiation has been studied in morphology thoroughly, but the mechanism in molecular biology is still ambiguous and few studies on genetic expression have been carried out. Little is known about the physiological responses of flower bud differentiation in Oriental hybrid lily ...

Ecological stability of landscape - ecological infrastructure - ecological management

International Nuclear Information System (INIS)

1992-01-01

The Field Workshop 'Ecological Stability of Landscape - Ecological Infrastructure - Ecological Management' was held within a State Environmental Programme financed by the Federal Committee for the Environment. The objectives of the workshop were to present Czech and Slovak approaches to the ecological stability of the landscape by means of examples of some case studies in the field, and to exchange ideas, theoretical knowledge and practical experience on implementing the concept of ecological infrastructure in landscape management. Out of 19 papers contained in the proceedings, 3 items were inputted to the INIS system. (Z.S.)

Morphological and genetic divergence between Agave inaequidens, A. cupreata and the domesticated A. hookeri. Analysis of their evolutionary relationships.

Directory of Open Access Journals (Sweden)

Carmen J Figueredo-Urbina

Full Text Available Agave inaequidens and A. cupreata are wild species with some populations under incipient management, while A. hookeri is exclusively cultivated, used for producing the fermented beverage pulque. These species are closely related and sympatric members of the Crenatae group, but taxonomists have previously hypothesized that A. inaequidens is the most probable ancestor of A. hookeri. Our study aims at evaluating patterns of morphological and genetic divergence among populations of the three species, in order to analyze their ecological and possible evolutionary relationships. We studied 24 agave populations, 16 of them of Agave inaequidens, four of A. cupreata and four of A. hookeri. Population morphometric and genetics studies were performed using 39 morphological characters and 10 nuclear microsatellites, respectively. We estimated levels of morphological and genetic diversity and dissimilarity, as well as genetic structure and gene flow among populations and species. The three species were clearly differentiated by general plant size, lateral teeth, terminal spines, flowers and fruit size. The largest plants were those of A. hookeri followed by A. inaequidens and the smallest were A. cupreata. Multivariate analyses indicated greater morphological similarity between A. hookeri and cultivated A. inaequidens, while A. cupreata consistently appeared as a separate group. We identified similar levels of morphological diversity index (MDI in the three species, but higher genetic diversity in A. inaequidens (MDI = 0.401-0.435; HE = 0.704-0.733, than in A. cupreata (MDI = 0.455-0.523; HE = 0.480-0.510 and the predominantly vegetative propagated crop A. hookeri (MDI = 0.335-0.688; HE = 0.450-0.567, a pattern consistent with our expectations. The morphological and genetic similarities between cultivated A. inaequidens and A. hookeri support the hypothetical evolutionary relationships among these species, but studies with cpDNA and SNPs, and including other

Morphological and genetic divergence between Agave inaequidens, A. cupreata and the domesticated A. hookeri. Analysis of their evolutionary relationships.

Science.gov (United States)

Figueredo-Urbina, Carmen J; Casas, Alejandro; Torres-García, Ignacio

2017-01-01

Agave inaequidens and A. cupreata are wild species with some populations under incipient management, while A. hookeri is exclusively cultivated, used for producing the fermented beverage pulque. These species are closely related and sympatric members of the Crenatae group, but taxonomists have previously hypothesized that A. inaequidens is the most probable ancestor of A. hookeri. Our study aims at evaluating patterns of morphological and genetic divergence among populations of the three species, in order to analyze their ecological and possible evolutionary relationships. We studied 24 agave populations, 16 of them of Agave inaequidens, four of A. cupreata and four of A. hookeri. Population morphometric and genetics studies were performed using 39 morphological characters and 10 nuclear microsatellites, respectively. We estimated levels of morphological and genetic diversity and dissimilarity, as well as genetic structure and gene flow among populations and species. The three species were clearly differentiated by general plant size, lateral teeth, terminal spines, flowers and fruit size. The largest plants were those of A. hookeri followed by A. inaequidens and the smallest were A. cupreata. Multivariate analyses indicated greater morphological similarity between A. hookeri and cultivated A. inaequidens, while A. cupreata consistently appeared as a separate group. We identified similar levels of morphological diversity index (MDI) in the three species, but higher genetic diversity in A. inaequidens (MDI = 0.401-0.435; HE = 0.704-0.733), than in A. cupreata (MDI = 0.455-0.523; HE = 0.480-0.510) and the predominantly vegetative propagated crop A. hookeri (MDI = 0.335-0.688; HE = 0.450-0.567), a pattern consistent with our expectations. The morphological and genetic similarities between cultivated A. inaequidens and A. hookeri support the hypothetical evolutionary relationships among these species, but studies with cpDNA and SNPs, and including other member of the

Prenatal uterine environment and sexual differentiation of rats

NARCIS (Netherlands)

E.J. Houtsmuller (Elisabeth Judith)

1993-01-01

textabstractprenatal factors relevant to hormonal environment on the sexual differentiation of behavior, morphology and central nervous system in rats. The effects of such factors as prenatal sex composition of the litter and position in utero on the sexual differentiation of normally developed

Morphology and rDNA phylogeny of a Mediterranean Coolia monotis (Dinophyceae strain from Greece

Directory of Open Access Journals (Sweden)

Nicolas P. Dolapsakis

2006-03-01

Full Text Available Sequences of LSU and SSU ribosomal RNA genes and phylogeny have not been widely investigated for the dinoflagellate Coolia monotis Meunier, and no information is available on the small and large rDNA subunits of Mediterranean strains. A strain isolated from the Thermaikos Gulf in northern Greece was identified as C. monotis—a new record for the Greek algal flora—using thecal morphology by light, epifluorescence and scanning electron microscopy. The small subunit and partial (D1/D2 large subunit sequences were analyzed and compared to other strains of C. monotis and dinoflagellates from various regions. Thecal architecture showed that the Greek strain of C. monotis was phenotypically similar, but not identical, to other strains reported in literature. The partial LSU sequence (700 bp was found to vary by 113 bp positions (16% from the C. monotis strain from New Zealand, whereas the SSU (1757 bp had 15 bp differences (0.85% from the strain from Norway. Phylogenetic tree construction showed that the Greek strain fell within the Coolia clade and had a close relationship with the families Ostreopsidaceae and Goniodomaceae of the order Gonyaulacales. Preliminary findings suggest the existence of different genotype strains of C. monotis with large intraspecific genetic variability and minimal morphological differentiation (similar phenotypes. Certain ecological and evolutionary implications of these findings are discussed.

RELATIONSHIP BETWEEN EXPRESSION OF MATRIX METALLOPROTEINASES AND MORPHOLOGICAL HETEROGENEITY, TUMOR DIFFERENTIATION AND LYMPHOGENOUS METASTASIS OF SQUAMOUS CELL LARYNGEAL CARCINOMA

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О. V. Savenkova

2015-01-01

Full Text Available The study included 58 patients with stage Т1–3N0–3M0–1 squamous cell laryngeal carcinoma. The age range was from 31 to 77 years. Patients received no cancer treatment before surgery. The expression of metalloproteinases (ММP-1, -2, -9, their inhibitors (TIMP-1, -2 and inductor of metalloproteinase expression (CD147 were determined in tumor cells of different structures of squamous cell carcinoma using immunohistochemical method. Results were compared with the presence of lymphogenous metastases. Results. Five morphological structures of squamous cell carcinomas were studied: with keratinization (type 1, with cells of basaloid and acanthocyte types without kartinization (type 2, with cells of basaloid type (type 3, with pronounced cellular polymorphism (type 4 and single tumor cells (type 5. With regard to combination of these structures, tumors were divided into high-grade, low-grade and mixed tumor structures. In tumors without lymphogenous metastases, the increased expression of ММP-1, -2, and-9 was only revealed in discrete cells. In tumors with lymphogenic metastases, the increased MMP-9 expression was observed in more differentiated structures of 1, 2 and 3 types. Less frequent lymphogenous metastasis of vocal cord carcinomas was associated only with tumors of mixed structure, in which the expression of TIMP1 was reduced.  Conclusion. To assess the histological differentiation of squamous cell carcinoma of the larynx, it should be considered a combination of high and low-grade tumor structures. The expression of metalloproteinases should be studied considering morphological heterogeneity of squamous cell carcinomas. The frequency of lymphogenous metastasis of high-or low-grade squamous cell carcinoma of the vocal cords did not differ from that of squamous cell carcinoma of the supra-glottal area. The frequency of lymphogenous metastasis was significantly lower in mixed squamous cell carcinomas of the vocal cords than in similar

[Research advances in heavy metals pollution ecology of diatom].

Science.gov (United States)

Ding, Teng-Da; Ni, Wan-Min; Zhang, Jian-Ying

2012-03-01

Diatom, due to its high sensitivity to environmental change, is one of the bio-indicators of aquatic ecosystem health, and some typical diatom species have been applied to indicate the heavy metals pollution of water body. With the focus on the surface water heavy metals pollution, this paper reviewed the research advances in the toxic effect of heavy metals pollution on diatom, biosorption and bioaccumulation of heavy metals by diatom, ecological adaptation mechanisms of diatom to heavy metals pollution, and roles of diatom as bio-indicator and in ecological restoration of heavy metals pollution. The growth tendency of diatom and the morphological change of frustule under heavy metals pollution as well as the differences in heavy metals biosorption and bioaccumulation by diatom, the ecological adaptation mechanisms of diatom on heavy metals surface complexation and ion exchange, and the roles of diatom as bio-indicator and in ecological restoration of heavy metals polluted water body were also discussed. This review could provide scientific evidences for the prevention of aquatic ecosystems heavy metals pollution and related early warning techniques.

Human Mesenchymal Stem Cell Morphology and Migration on Micro-Textured Titanium

Directory of Open Access Journals (Sweden)

Brittany eBanik

2016-05-01

Full Text Available The implant used in spinal fusion procedures is an essential component to achieving successful arthrodesis. At the cellular level, the implant impacts healing and fusion through a series of steps: first, mesenchymal stem cells (MSCs need to adhere and proliferate to cover the implant; second, the MSCs must differentiate into osteoblasts; third, the osteoid matrix produced by the osteoblasts needs to generate new bone tissue, thoroughly integrating the implant with the vertebrate above and below. Previous research has demonstrated that micro-textured titanium is advantageous over smooth titanium and PEEK implants for both promoting osteogenic differentiation and integrating with host bone tissue; however, no investigation to date has examined the early morphology and migration of MSCs on these surfaces. This study details cell spreading and morphology changes over 24 hours, rate and directionality of migration 6 to 18 hours post seeding, differentiation markers at 10 days, and the long term morphology of MSCs at 7 days, on micro-textured, acid-etched titanium (Endoskeleton, smooth titanium, and smooth PEEK surfaces. The results demonstrate in all metrics, the two titanium surfaces outperformed the PEEK surface. Furthermore, the rough acid-etched titanium surface presented the most favorable overall results, demonstrating the random migration needed to efficiently cover a surface in addition to morphologies consistent with osteoblasts and preosteoblasts.

X-radiation-induced differentiation of xenotransplanted human undifferentiated rhabdomyosarcoma

International Nuclear Information System (INIS)

Takizawa, T.; Matsui, T.; Maeda, Y.

1989-01-01

A serially xenotransplantable strain of undifferentiated embryonal rhabdomyosarcoma originating from the nasal cavity of a 42-year-old woman has been established in our laboratory. After radiotherapy for the tumor donor, distinct rhabdomyoblastic differentiation of the undifferentiated sarcoma cells appeared in the primary lesion, and it is a reasonable assumption that X-irradiation has a certain potentiality to induce morphologic differentiation of tumor cells. To study this possibility, tissue fragments of undifferentiated embryonal rhabdomyosarcoma that had grown to more than 10 mm after being transplanted to nude mice were selectively irradiated in situ. The degree of rhabdomyoblastic differentiation according to radiation dose was evaluated by light and electron microscopy and by immunostainability for myoglobin, creatine phosphokinase-MM, and desmin. Distinct morphologic differentiation of undifferentiated sarcoma cells could be induced by repeated X-irradiations at several-week intervals

Primate dental ecology: How teeth respond to the environment.

Science.gov (United States)

Cuozzo, Frank P; Ungar, Peter S; Sauther, Michelle L

2012-06-01

Teeth are central for the study of ecology, as teeth are at the direct interface between an organism and its environment. Recent years have witnessed a rapid growth in the use of teeth to understand a broad range of topics in living and fossil primate biology. This in part reflects new techniques for assessing ways in which teeth respond to, and interact with, an organism's environment. Long-term studies of wild primate populations that integrate dental analyses have also provided a new context for understanding primate interactions with their environments. These new techniques and long-term field studies have allowed the development of a new perspective-dental ecology. We define dental ecology as the broad study of how teeth respond to, or interact with, the environment. This includes identifying patterns of dental pathology and tooth use-wear, as they reflect feeding ecology, behavior, and habitat variation, including areas impacted by anthropogenic disturbance, and how dental development can reflect environmental change and/or stress. The dental ecology approach, built on collaboration between dental experts and ecologists, holds the potential to provide an important theoretical and practical framework for inferring ecology and behavior of fossil forms, for assessing environmental change in living populations, and for understanding ways in which habitat impacts primate growth and development. This symposium issue brings together experts on dental morphology, growth and development, tooth wear and health, primate ecology, and paleontology, to explore the broad application of dental ecology to questions of how living and fossil primates interact with their environments. Copyright © 2012 Wiley Periodicals, Inc.

Gamma ray induced chlorophyll and morphological mutants in grasspea

International Nuclear Information System (INIS)

Das, P.K.; Kundagrami, S.

2000-01-01

Higher dose of gamma ray treatment such as 30 kR promoted larger chlorophyll as well as morphological mutation frequency and spectrum. In both M 1 and M 2 generation marginata significantly out numbered other types of chlorophyll mutations. On the other hand, along morphological mutations stunted growth types were recovered more frequently. Both the genotypes Nirmal and P-24 differed greatly for their mutagenic specificity. In both M 1 and M 2 generation Nirmal recorded higher chlorophyll and morphological mutation frequency and spectrum indicating differential genotype response to different dosages of gamma ray treatment. (author)

New Insights on the Morphology of Adult Mouse Penis1

Science.gov (United States)

Rodriguez, Esequiel; Weiss, Dana A.; Yang, Jennifer H.; Menshenina, Julia; Ferretti, Max; Cunha, Tristan J.; Barcellos, Dale; Chan, Lok Yun; Risbridger, Gail; Cunha, Gerald R.; Baskin, Laurence S.

2011-01-01

ABSTRACT The adult mouse penis represents the end point of masculine sex differentiation of the embryonic genital tubercle and contains bone, cartilage, the urethra, erectile bodies, several types of epithelium, and many individual cell types arrayed into specific anatomical structures. Using contemporary high-resolution imaging techniques, we sought to provide new insights to the current description of adult mouse penile morphology to enable understanding of penile abnormalities, including hypospadias. Examination of serial transverse and longitudinal sections, scanning electron microscopy, and three-dimensional (3D) reconstruction provided a new appreciation of the individual structures in the adult mouse penis and their 3D interrelationships. In so doing, we discovered novel paired erectile bodies, the male urogenital mating protuberance (MUMP), and more accurately described the urethral meatus. These morphological observations were quantified by morphometric analysis and now provide accurate morphological end points of sex differentiation of mouse penis that will be the foundation of future studies to identify normal and abnormal penile development. PMID:21918128

Divergence in morphology, but not habitat use, despite low genetic differentiation among insular populations of the lizard Anolis lemurinus in Honduras

Science.gov (United States)

Logan, M.L.; Montgomery, Chad E.; Boback, Scott M.; Reed, R.N.; Campbell, J.A.

2012-01-01

Studies of recently isolated populations are useful because observed differences can often be attributed to current environmental variation. Two populations of the lizard Anolis lemurinus have been isolated on the islands of Cayo Menor and Cayo Mayor in the Cayos Cochinos Archipelago of Honduras for less than 15 000 y. We measured 12 morphometric and 10 habitat-use variables on 220 lizards across these islands in 2 y, 2008 and 2009. The goals of our study were (1) to explore patterns of sexual dimorphism, and (2) to test the hypothesis that differences in environment among islands may have driven divergence in morphology and habitat use despite genetic homogeneity among populations. Although we found no differences among sexes in habitat use, males had narrower pelvic girdles and longer toe pads on both islands. Between islands, males differed in morphology, but neither males nor females differed in habitat use. Our data suggest that either recent selection has operated differentially on males despite low genetic dill'erentiation, or that they display phenotypic plasticity in response to environmental variation. We suggest that patterns may be driven by variation in intrapopulation density or differences in predator diversity among islands.

Optimizing sampling approaches along ecological gradients

DEFF Research Database (Denmark)

Schweiger, Andreas; Irl, Severin D. H.; Steinbauer, Manuel

2016-01-01

1. Natural scientists and especially ecologists use manipulative experiments or field observations along gradients to differentiate patterns driven by processes from those caused by random noise. A well-conceived sampling design is essential for identifying, analysing and reporting underlying...... patterns in a statistically solid and reproducible manner, given the normal restrictions in labour, time and money. However, a technical guideline about an adequate sampling design to maximize prediction success under restricted resources is lacking. This study aims at developing such a solid...... and reproducible guideline for sampling along gradients in all fields of ecology and science in general. 2. We conducted simulations with artificial data for five common response types known in ecology, each represented by a simple function (no response, linear, exponential, symmetric unimodal and asymmetric...

Tendinous framework of anurans reveals an all-purpose morphology.

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Fratani, Jéssica; Ponssa, María Laura; Abdala, Virginia

2018-02-01

Tendons are directly associated with movement, amplifying power and reducing muscular work. Taking into account habitat and locomotor challenges faced by anurans, we identify the more conspicuous superficial tendons of a neotropical anuran group and investigate their relation to the former factors. We show that tendons can be visualized as an anatomical framework connected through muscles and/or fascia, and describe the most superficial tendinous layer of the postcranium of Leptodactylus latinasus. To analyze the relation between tendon morphology and ecological characters, we test the relative length ratio of 10 tendon-muscle (t-m) elements in 45 leptodactylid species while taking phylogeny into account. We identify the evolutionary model that best explains our variables. Additionally, we optimize t-m ratio values, and the shape of the longissimus dorsi insertion onto a selected phylogeny of the species. Our data show the existence of an all-purpose morphology that seems to have evolved independently of ecology and functional requirements. This is indicated by no significant relation between morphometric data of the analyzed tendons and habitat use or locomotion, a strong phylogenetic component to most of the analyzed variables, and a generalized pattern of intermediate values for ancestral states. Ornstein-Uhlenbeck is the model that best explains most t-m variables, indicating that stabilizing selection or selective optima might be driving shifts in tendon length within Leptodactylidae. Herein, we show the substantial influence that phylogeny has on tendon morphology, demonstrating that a generalized and stable morphological configuration of tendons is adequate to enable versatile locomotor modes and habitat use. This is an attempt to present the tendinous system as a framework to body support in vertebrates, and can be considered a starting point for further ecomorphological research of this anatomical system in anurans. Copyright © 2017 Elsevier GmbH. All

Geo-ecological spatial pattern analysis of the island of Fogo (Cape Verde)

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Olehowski, C.; Naumann, S.; Fischer, D.; Siegmund, A.

2008-12-01

With its small-scale climatic, floristic and geo-ecological differentiation, the island of Fogo is an optimal research area for understanding semi-arid island ecosystems in the marginal tropics. Because of the high variability in precipitation, the archipelago of Cape Verde has a potentially high ecological vulnerability, which is caused mainly by population growth, intensification of agricultural land use and increasing tourism. In this context, a geo-ecological spatial pattern analysis has been conducted for Fogo, including several types of geo-ecological layers like vegetation, elevation, aspect, soil and geology. The different kinds of spatial patterns that are detected can be used as a first tool to display distinctive levels of ecological vulnerability. These levels could constitute a base for sustainable land use planning and the redevelopment of agricultural strategies.

Morphology, taxonomy and ecology of Thraustochytrids and Labyrinthulids, the marine counterparts of zoosporic fungi

Digital Repository Service at National Institute of Oceanography (India)

RaghuKumar, S.

ecology and the fact that mycologists have traditionally studied these unique organisms, their inclusion in the discipline of mycology is well justified. In this, followed are the arguments put forth by Barr (1992) for including the Chytridiomycota...

The Iberian genus Paraphaenops Jeannel, 1916 (Coleoptera: Carabidae: Trechini): Morphology, phylogeny and geographical distribution

DEFF Research Database (Denmark)

Ortuño, Vicente M.; Sendra, Alberto; P. S. Reboleira, Ana Sofia

2017-01-01

) and one nuclear (LSU) gene fragments evidenced a strong divergence for all markers considered between P. breuilianus and the new species P. fadriquei sp. nov. The strong genetic differences between the two taxa contrast singularly with the extreme morphological homogeneity of the genus. The ecological......The species Paraphaenops breuilianus (Jeannel, 1916) is an Iberian iconic cave beetle with “aphaenopsian” facies, monospecific until now. An extensive field work over the last years allowed the revision of this peculiar genus using the combinations of morphological, molecular and ecological...... approaches and led to the description of new taxa Paraphaenops fadriquei Ortuño and Faille sp. nov., Paraphaenops breuilianus espanoli Ortuño and Faille ssp. nov. and the full larval diagnosis of the third larval instar of the type species. The sequencing of two mitochondrial (cox1, rrnl + tRNA-Leu + nad1...

Sexual dimorphism in bite performance drives morphological variation in chameleons.

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da Silva, Jessica M; Herrel, Anthony; Measey, G John; Tolley, Krystal A

2014-01-01

Phenotypic performance in different environments is central to understanding the evolutionary and ecological processes that drive adaptive divergence and, ultimately, speciation. Because habitat structure can affect an animal's foraging behaviour, anti-predator defences, and communication behaviour, it can influence both natural and sexual selection pressures. These selective pressures, in turn, act upon morphological traits to maximize an animal's performance. For performance traits involved in both social and ecological activities, such as bite force, natural and sexual selection often interact in complex ways, providing an opportunity to understand the adaptive significance of morphological variation with respect to habitat. Dwarf chameleons within the Bradypodion melanocephalum-Bradypodion thamnobates species complex have multiple phenotypic forms, each with a specific head morphology that could reflect its use of either open- or closed-canopy habitats. To determine whether these morphological differences represent adaptations to their habitats, we tested for differences in both absolute and relative bite performance. Only absolute differences were found between forms, with the closed-canopy forms biting harder than their open-canopy counterparts. In contrast, sexual dimorphism was found for both absolute and relative bite force, but the relative differences were limited to the closed-canopy forms. These results indicate that both natural and sexual selection are acting within both habitat types, but to varying degrees. Sexual selection seems to be the predominant force within the closed-canopy habitats, which are more protected from aerial predators, enabling chameleons to invest more in ornamentation for communication. In contrast, natural selection is likely to be the predominant force in the open-canopy habitats, inhibiting the development of conspicuous secondary sexual characteristics and, ultimately, enforcing their overall diminutive body size and

Non-instantaneous impulses in differential equations

CERN Document Server

Agarwal, Ravi; O'Regan, Donal

2017-01-01

This monograph is the first published book devoted to the theory of differential equations with non-instantaneous impulses. It aims to equip the reader with mathematical models and theory behind real life processes in physics, biology, population dynamics, ecology and pharmacokinetics. The authors examine a wide scope of differential equations with non-instantaneous impulses through three comprehensive chapters, providing an all-rounded and unique presentation on the topic, including: - Ordinary differential equations with non-instantaneous impulses (scalar and n-dimensional case) - Fractional differential equa tions with non-instantaneous impulses (with Caputo fractional derivatives of order q ϵ (0, 1)) - Ordinary differential equations with non-instantaneous impulses occurring at random moments (with exponential, Erlang, or Gamma distribution) Each chapter focuses on theory, proofs and examples, and contains numerous graphs to enrich the reader’s understanding. Additionally, a carefully selected bibliogr...

Why do different oceanic archipelagos harbour contrasting levels of species diversity? The macaronesian endemic genus Pericallis (Asteraceae) provides insight into explaining the 'Azores diversity Enigma'.

Science.gov (United States)

Jones, K E; Pérez-Espona, S; Reyes-Betancort, J A; Pattinson, D; Caujapé-Castells, J; Hiscock, S J; Carine, M A

2016-10-08

Oceanic archipelagos typically harbour extensive radiations of flowering plants and a high proportion of endemics, many of which are restricted to a single island (Single Island Endemics; SIEs). The Azores represents an anomaly as overall levels of endemism are low; there are few SIEs and few documented cases of intra-archipelago radiations. The distinctiveness of the flora was first recognized by Darwin and has been referred to as the 'Azores Diversity Enigma' (ADE). Diversity patterns in the Macaronesian endemic genus Pericallis (Asteraceae) exemplify the ADE. In this study we used morphometric, Amplified Length Polymorphisms, and bioclimatic data for herbaceous Pericallis lineages endemic to the Azores and the Canaries, to test two key hypotheses proposed to explain the ADE: i) that it is a taxonomic artefact or Linnean shortfall, ie. the under description of taxa in the Azores or the over-splitting of taxa in the Canaries and (ii) that it reflects the greater ecological homogeneity of the Azores, which results in limited opportunity for ecological diversification compared to the Canaries. In both the Azores and the Canaries, morphological patterns were generally consistent with current taxonomic classifications. However, the AFLP data showed no genetic differentiation between the two currently recognized Azorean subspecies that are ecologically differentiated. Instead, genetic diversity in the Azores was structured geographically across the archipelago. In contrast, in the Canaries genetic differentiation was mostly consistent with morphology and current taxonomic treatments. Both Azorean and Canarian lineages exhibited ecological differentiation between currently recognized taxa. Neither a Linnean shortfall nor the perceived ecological homogeneity of the Azores fully explained the ADE-like pattern observed in Pericallis. Whilst variation in genetic data and morphological data in the Canaries were largely congruent, this was not the case in the Azores, where

Ecological, morphological and genetic divergence of sympatric North Atlantic killer whale populations

DEFF Research Database (Denmark)

Foote, Andrew D; Newton, Jason; Piertney, Stuart B

2009-01-01

promoting divergence. Here we use morphological traits, nitrogen stable isotope ratios and tooth wear to characterize two disparate types of North Atlantic killer whale. We find a highly specialist type, which reaches up to 8.5 m in length and a generalist type which reaches up to 6.6 m in length...

Framework for analyzing ecological trait-based models in multidimensional niche spaces

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Biancalani, Tommaso; DeVille, Lee; Goldenfeld, Nigel

2015-05-01

We develop a theoretical framework for analyzing ecological models with a multidimensional niche space. Our approach relies on the fact that ecological niches are described by sequences of symbols, which allows us to include multiple phenotypic traits. Ecological drivers, such as competitive exclusion, are modeled by introducing the Hamming distance between two sequences. We show that a suitable transform diagonalizes the community interaction matrix of these models, making it possible to predict the conditions for niche differentiation and, close to the instability onset, the asymptotically long time population distributions of niches. We exemplify our method using the Lotka-Volterra equations with an exponential competition kernel.

Ecological niche partitioning between Anopheles gambiae molecular forms in Cameroon: the ecological side of speciation

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Fotsing Jean-Marie

2009-05-01

Full Text Available Abstract Background Speciation among members of the Anopheles gambiae complex is thought to be promoted by disruptive selection and ecological divergence acting on sets of adaptation genes protected from recombination by polymorphic paracentric chromosomal inversions. However, shared chromosomal polymorphisms between the M and S molecular forms of An. gambiae and insufficient information about their relationship with ecological divergence challenge this view. We used Geographic Information Systems, Ecological Niche Factor Analysis, and Bayesian multilocus genetic clustering to explore the nature and extent of ecological and chromosomal differentiation of M and S across all the biogeographic domains of Cameroon in Central Africa, in order to understand the role of chromosomal arrangements in ecological specialisation within and among molecular forms. Results Species distribution modelling with presence-only data revealed differences in the ecological niche of both molecular forms and the sibling species, An. arabiensis. The fundamental environmental envelope of the two molecular forms, however, overlapped to a large extent in the rainforest, where they occurred in sympatry. The S form had the greatest niche breadth of all three taxa, whereas An. arabiensis and the M form had the smallest niche overlap. Correspondence analysis of M and S karyotypes confirmed that molecular forms shared similar combinations of chromosomal inversion arrangements in response to the eco-climatic gradient defining the main biogeographic domains occurring across Cameroon. Savanna karyotypes of M and S, however, segregated along the smaller-scale environmental gradient defined by the second ordination axis. Population structure analysis identified three chromosomal clusters, each containing a mixture of M and S specimens. In both M and S, alternative karyotypes were segregating in contrasted environments, in agreement with a strong ecological adaptive value of

Aspectos morfológicos de folhas na diferenciação de variedades de carambola Morphological aspects of leaves in differentiation of varieties of star fruit

Directory of Open Access Journals (Sweden)

Renata Aparecida de Andrade

2007-08-01

Full Text Available Em certas espécies vegetais, a distinção entre variedades pode ser realizada com base em aspectos morfológicos das folhas, o que permite a diferenciação mesmo quando não apresentam flores e/ou frutos. O presente trabalho foi realizado objetivando a distinção entre variedades de caramboleira (Averrhoa carambola L. através de aspectos foliares. Foram avaliadas quatro variedades de caramboleira: Arkin, B-10, Golden Star e Hart, com quatro repetições de 10 folhas cada. Pelos resultados obtidos no presente trabalho, conclui-se que há diferenças morfológicas foliares entre as variedades de caramboleira, permitindo a sua distinção, especialmente em condições de viveiro.In some vegetable species, the distinction among varieties can be done based on morphological aspects of the leaves that allow the differentiation even when they do not have flowers and/or fruits. The aim of this work was to differentiate the varieties of star fruit (Averrhoa carambola L. by foliar aspects. It was evaluated four varieties of star fruit: Arkin, B-10, Golden Star and Hart, with four replications containing 10 leaves in each one. The results obtained showed that exist morphological foliar differences among the varieties of star fruit, being permitted the distinction, especially in nursery conditions.

Ecological response of a multi-purpose river development project using macro-invertebrates richness and fish habitat value

International Nuclear Information System (INIS)

Pellaud, M.

2007-05-01

It has been acknowledged that river morphology and hydrology have been intensively altered due to the anthropic demands in floodplain land use and management, flood protection, promotion of navigability or energy production. Rivers were transformed in water highways, having lost contact with their surrounding floodplain as well as the plethora of ecological processes and occupants once thriving in these ecotonal zones. The identification of this emerging threat of morphological and hydrological alteration on ecological integrity adds further complexity in the exploitation of hydrosystem resources. These resources are heavily coveted and guarded by different lobbies each having strategic views on future project development. Stakeholders may want to promote hydro-electricity, ecologists a natural reserve, communes may wish to have an increased flood protection and leisure promoters a nautical center. As a result, the proposition of a river development project is certain to face opposition of one party or the other. The motivations of this dissertation are anchored in this context, where various and sometimes conflicting potentials for hydrosystem exploitation remain. This works aims at contributing scientifically to an innovative approach at the conception phase of a multi-purpose river development project by developing the ecological module to be implemented in the general project's optimizer. The SYNERGIE project hypothesis is that it should be possible to identify a synergetic pattern joining the interests of ecological integrity, flood safety, energy production and leisure development. Such a multi-objective river development project would stand more chance of acceptance. This dissertation focuses on the ecological aspects of such a river development project and an application on the regulated Swiss Upper Rhone River. Is expected an ecological answer to a river development project design / management which has to be compatible with Heller's Heller (2007) general

Integrating a DNA barcoding project with an ecological survey: a case study on temperate intertidal polychaete communities in Qingdao, China

Science.gov (United States)

Zhou, Hong; Zhang, Zhinan; Chen, Haiyan; Sun, Renhua; Wang, Hui; Guo, Lei; Pan, Haijian

2010-07-01

In this study, we integrated a DNA barcoding project with an ecological survey on intertidal polychaete communities and investigated the utility of CO1 gene sequence as a DNA barcode for the classification of the intertidal polychaetes. Using 16S rDNA as a complementary marker and combining morphological and ecological characterization, some of dominant and common polychaete species from Chinese coasts were assessed for their taxonomic status. We obtained 22 haplotype gene sequences of 13 taxa, including 10 CO1 sequences and 12 16S rDNA sequences. Based on intra- and inter-specific distances, we built phylogenetic trees using the neighbor-joining method. Our study suggested that the mitochondrial CO1 gene was a valid DNA barcoding marker for species identification in polychaetes, but other genes, such as 16S rDNA, could be used as a complementary genetic marker. For more accurate species identification and effective testing of species hypothesis, DNA barcoding should be incorporated with morphological, ecological, biogeographical, and phylogenetic information. The application of DNA barcoding and molecular identification in the ecological survey on the intertidal polychaete communities demonstrated the feasibility of integrating DNA taxonomy and ecology.

Three-dimensional geometric morphometric analysis of talar morphology in extant gorilla taxa from highland and lowland habitats.

Science.gov (United States)

Knigge, Ryan P; Tocheri, Matthew W; Orr, Caley M; Mcnulty, Kieran P

2015-01-01

Western gorillas (Gorilla gorilla) are known to climb significantly more often than eastern gorillas (Gorilla beringei), a behavioral distinction attributable to major differences in their respective habitats (i.e., highland vs. lowland). Genetic evidence suggests that the lineages leading to these taxa began diverging from one another between approximately 1 and 3 million years ago. Thus, gorillas offer a special opportunity to examine the degree to which morphology of recently diverged taxa may be "fine-tuned" to differing ecological requirements. Using three-dimensional (3D) geometric morphometrics, we compared talar morphology in a sample of 87 specimens including western (lowland), mountain (highland), and grauer gorillas (lowland and highland populations). Talar shape was captured with a series of landmarks and semilandmarks superimposed by generalized Procrustes analysis. A between-group principal components analysis of overall talar shape separates gorillas by ecological habitat and by taxon. An analysis of only the trochlea and lateral malleolar facet identifies subtle variations in trochlear shape between western lowland and lowland grauer gorillas, potentially indicative of convergent evolution of arboreal adaptations in the talus. Lastly, talar shape scales differently with centroid size for highland and lowland gorillas, suggesting that ankle morphology may track body-size mediated variation in arboreal behaviors differently depending on ecological setting. Several of the observed shape differences are linked biomechanically to the facilitation of climbing in lowland gorillas and to stability and load-bearing on terrestrial substrates in the highland taxa, providing an important comparative model for studying morphological variation in groups known only from fossils (e.g., early hominins). © 2014 Wiley Periodicals, Inc.

Depth-related trends in morphological and functional diversity of demersal fish assemblages in the western Mediterranean Sea

Science.gov (United States)

Farré, Marc; Tuset, Víctor M.; Cartes, Joan E.; Massutí, Enric; Lombarte, Antoni

2016-09-01

The morphological and functional traits of fishes are key factors defining the ecological and biological habits of species within ecosystems. However, little is known about how the depth gradient affects these factors. In the present study, several demersal fish assemblages from the Balearic Islands (western Mediterranean Sea) along a wide depth range (40-2200 m) were morphologically, functionally and ecologically described. The morphological characterization of communities was performed using geometric morphometric methods, while the functional structures were obtained by the functional categorization of species and the application of principal coordinates analysis (PCoA). The results revealed that morphospaces presented less richness of body forms as depth increases, although they showed a progressive spreading of species toward the periphery, with a proliferation of more extreme body traits, demonstrating lower morphological redundancy. In addition, a trend toward the elongation of body shape was also observed with depth. Moreover, functional diversity increased with bathymetry up to 1400 m, where it sharply decreased downwards. This decrease was parallel to a progressive fall of H‧ (ecological diversity) up to 2200 m. Functional redundancy progressively decreased until the deepest assemblage (more constantly in the deeper levels), which was almost exclusively dominated by benthopelagic wandering species feeding on suprabenthos. Redundancy analysis (RDA) demonstrated that both morphological and functional spaces showed high variation along the bathymetric range. Mantel test indicated that the majority of species presented similar spatial distribution within the morphospace and functional space, although in the functional space the more abundant species were always located at the periphery. These results demonstrate that the assessment of the morpho-functional variation between marine communities helps to understand the processes that affect the structure and

Solutions manual to accompany Ordinary differential equations

CERN Document Server

Greenberg, Michael D

2014-01-01

Features a balance between theory, proofs, and examples and provides applications across diverse fields of study Ordinary Differential Equations presents a thorough discussion of first-order differential equations and progresses to equations of higher order. The book transitions smoothly from first-order to higher-order equations, allowing readers to develop a complete understanding of the related theory. Featuring diverse and interesting applications from engineering, bioengineering, ecology, and biology, the book anticipates potential difficulties in understanding the various solution steps

Morphology and phylogeny of Triadinium polyedricum (Pouchet) Dodge (Dinophyceae) from Korean coastal waters

Science.gov (United States)

Shin, Hyeon Ho; Li, Zhun; Kim, Eun Song; Youn, Joo Yeon; Jeon, Seul Gi; Oh, Seok Jin; Lim, Weol-Ae

2016-12-01

To identify features that can be used to differentiate Triadinium polyedricum from other related species, such as Fukuyoa paulensis and Alexandrium species, the detailed morphology and phylogeny of T. polyedricum collected from Korean coastal waters were investigated. The cells had a plate formula of Po, 3', 7″, 5‴, 1p and 2″″, which is consistent with morphological descriptions in previous reports. Large subunit ribosomal DNA sequences also revealed that T. polyedricum from Korean coastal waters is identical to previously recorded isolates. T. polyedricum is morphologically characterized by a ventral pore in the 1″ plate that is comparable to F. paulensis and Alexandrium species. This result indicates that the location and presence of this ventral pore seems suitable for differentiating T. polyedricum from other related species.

Middle ear cavity morphology is consistent with an aquatic origin for testudines

DEFF Research Database (Denmark)

Willis, Katie L; Christensen-Dalsgaard, Jakob; Ketten, Darlene R

2013-01-01

The position of testudines in vertebrate phylogeny is being re-evaluated. At present, testudine morphological and molecular data conflict when reconstructing phylogenetic relationships. Complicating matters, the ecological niche of stem testudines is ambiguous. To understand how turtles have...... evolved to hear in different environments, we examined middle ear morphology and scaling in most extant families, as well as some extinct species, using 3-dimensional reconstructions from micro magnetic resonance (MR) and submillimeter computed tomography (CT) scans. All families of testudines exhibited...... volume resonating in an underwater sound field, the calculated resonances for the volumes of the middle ear cavities largely fell within testudine hearing ranges. Although there were some differences in morphology, there were no statistically significant differences in the scaling of the volume...

Morphology and function in the empirical analysis of reading adjustment

Directory of Open Access Journals (Sweden)

Carpio, Claudio

2010-06-01

Full Text Available The present study evaluated the effects of varying the criterion and the morphology of the percentage of correct response upon reading adjustment tasks. Participants were 20 voluntary students, distributed in four groups, which were differentiated by the certainty - variability of the criterion and the certainty - variability of the morphology of response to satisfy the criterion. All participants were exposed to a first evaluation, training and finally a second evaluation similar to the first one was applied. Results question the role of morphology as a comprehension strategy independent of a functional criterion, domain and of the text itself

Analysis of Genetic Diversity of Two Mangrove Species with Morphological Alterations in a Natural Environment

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Catarina Fonseca Lira-Medeiros

2015-04-01

Full Text Available Mangrove is an ecosystem subjected to tide, salinity and nutrient variations. These conditions are stressful to most plants, except to mangrove plants that are well-adapted. However, many mangrove areas have extremely stressful conditions, such as salt marshes, and the plants nearby usually present morphological alterations. In Sepetiba Bay, two species of mangrove plants, Avicennia schaueriana and Laguncularia racemosa, have poor development near a salt marsh (SM compared to plants at the riverside (RS, which is considered a favorable habitat in mangroves. The level of genetic diversity and its possible correlation with the morphological divergence of SM and RS plants of both species were assessed by AFLP molecular markers. We found moderate genetic differentiation between A. schaueriana plants from SM and RS areas and depleted genetic diversity on SM plants. On the other hand, Laguncularia racemosa plants had no genetic differentiation between areas. It is possible that a limited gene flow among the studied areas might be acting more intensely on A. schaueriana plants, resulting in the observed genetic differentiation. The populations of Laguncularia racemosa appear to be well connected, as genetic differentiation was not significant between the SM and RS populations. Gene flow and genetic drift are acting on neutral genetic diversity of these two mangrove species in the studied areas, and the observed genetic differentiation of A. schaueriana plants might be correlated with its morphological variation. For L. racemosa, morphological alterations could be related to epigenetic phenomena or adaptive loci polymorphism that should be further investigated.

Available data support protection of the Southwestern Willow Flycatcher under the Endangered Species Act

Science.gov (United States)

Theimer, Tad C.; Smith, Aaron D.; Mahoney, Sean M.; Ironside, Kirsten E.

2016-01-01

Zink (2015) argued there was no evidence for genetic, morphological, or ecological differentiation between the federally endangered Southwestern Willow Flycatcher (Empidonax traillii extimus) and other Willow Flycatcher subspecies. Using the same data, we show there is a step-cline in both the frequency of a mtDNA haplotype and in plumage variation roughly concordant with the currently recognized boundary between E. t. extimus and E. t adastus, the subspecies with which it shares the longest common boundary. The geographical pattern of plumage variation is also concordant with previous song analyses differentiating those 2 subspecies and identified birds in one low-latitude, high-elevation site in Arizona as the northern subspecies. We also demonstrate that the ecological niche modeling approach used by Zink yields the same result whether applied to the 2 flycatcher subspecies or to 2 unrelated species, E. t. extimus and Yellow Warbler (Setophaga petechia). As a result, any interpretation of those results as evidence for lack of ecological niche differentiation among Willow Flycatcher subspecies would also indicate no differentiation among recognized species and would therefore be an inappropriate standard for delineating subspecies. We agree that many analytical techniques now available to examine genetic, morphological, and ecological differentiation would improve our understanding of the distinctness (or lack thereof) of Willow Flycatcher subspecies, but we argue that currently available evidence supports protection of the Southwestern Willow Flycatcher under the Endangered Species Act.

The Impact of Organismal Innovation on Functional and Ecological Diversification.

Science.gov (United States)

Wainwright, Peter C; Price, Samantha A

2016-09-01

Innovations in organismal functional morphology are thought to be a major force in shaping evolutionary patterns, with the potential to drive adaptive radiation and influence the evolutionary prospects for lineages. But the evolutionary consequences of innovation are diverse and usually do not result in adaptive radiation. What factors shape the macroevolutionary impact of innovations? We assert that little is known in general about the macroevolutionary outcomes associated with functional innovations and we discuss a framework for studying biological innovations in an evolutionary context. Innovations are novel functional mechanisms that enhance organismal performance. The ubiquity of trade-offs in functional systems means that enhanced performance on one axis often occurs at the expense of performance on another axis, such that many innovations result in an exchange of performance capabilities, rather than an expansion. Innovations may open up new resources for exploitation but their consequences for functional and ecological diversification depend heavily on the adaptive landscape around these novel resources. As an example of a broader program that we imagine, we survey five feeding innovations in labrid fishes, an exceptionally successful and ecologically diverse group of reef fishes, and explore their impact on the rate of evolution of jaw functional morphology. All of the innovations provide performance enhancements and result in changes in patterns of resource use, but most are not associated with subsequent functional diversification or substantial ecological diversification. Because selection acts on a specific performance enhancement and not on the evolutionary potential of an innovation, the enhancement of diversity may be highly serendipitous. The macroevolutionary potential of innovations depends critically on the interaction between the performance enhancement and the ecological opportunity that is exposed. © The Author 2016. Published by Oxford

Delineating ecological boundaries of Hanuman langur species complex in peninsular India using MaxEnt modeling approach.

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Nag, Chetan; Chetan, Nag; Karanth, K Praveen; Praveen, Karanth K; Gururaja, Kotambylu Vasudeva; Vasudeva, Gururaja Kotambylu

2014-01-01

Hanuman langur is one of the widely distributed and extensively studied non-human diurnal primates in India. Until recently it was believed to be a single species - Semnopithecus entellus. Recent molecular and morphological studies suggest that the Hanuman langurs consists of at least three species S. entellus, S. hypoleucos and S. priam. Furthermore, morphological studies suggested that both S. hypoleucos and S. priam have at least three subspecies in each. We explored the use of ecological niche modeling (ENM) to confirm the validity of these seven taxa and an additional taxon S. johnii belonging to the same genus. MaxEnt modeling tool was used with 19 bioclimatic, 12 vegetation and 6 hydrological environmental layers. We reduced total environmental variables to 14 layers after testing for collinearity and an independent test for model prediction was done using ENMTools. A total of 196 non-overlapping data points from primary and secondary sources were used as inputs for ENM. Results showed eight distinct ecological boundaries, corroborating the eight taxa mentioned above thereby confirming validity of these eight taxa. The study, for the first time provided ecological variables that determined the ecological requirements and distribution of members of the Hanuman langur species complex in the Indian peninsula.

Ecological strategies shapes the insurance potential of biodiversity

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Miguel eMatias

2013-01-01

Full Text Available Biodiversity is thought to provide insurance for ecosystem functioning under heterogeneous environments, however, such insurance potential is under serious threat following unprecedented loss of biodiversity. One of the key mechanism underlying ecological insurance is that niche differentiation allows asynchronous responses to fluctuating environments; although, the role of different ecological strategies (e.g. specialists vs generalists has yet to be formally evaluated. We combine here a simple model and experimental study to illustrate how different specialization-performance strategies shape the biodiversity-insurance relationship. We assembled microcosm of generalists and specialist bacteria over a gradient of salinity and found that, bacterial communities made up of generalists were more productive and more stable over time under environmental fluctuations. We argue that beyond species richness itself, it is essential to incorporate the distribution of ecological strategies across relevant environmental gradients as predictors of the insurance potential of biodiversity in natural ecosystems.

Sexual Dimorphism in Bite Performance Drives Morphological Variation in Chameleons

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da Silva, Jessica M.; Herrel, Anthony; Measey, G. John; Tolley, Krystal A.

2014-01-01

Phenotypic performance in different environments is central to understanding the evolutionary and ecological processes that drive adaptive divergence and, ultimately, speciation. Because habitat structure can affect an animal’s foraging behaviour, anti-predator defences, and communication behaviour, it can influence both natural and sexual selection pressures. These selective pressures, in turn, act upon morphological traits to maximize an animal’s performance. For performance traits involved in both social and ecological activities, such as bite force, natural and sexual selection often interact in complex ways, providing an opportunity to understand the adaptive significance of morphological variation with respect to habitat. Dwarf chameleons within the Bradypodion melanocephalum-Bradypodion thamnobates species complex have multiple phenotypic forms, each with a specific head morphology that could reflect its use of either open- or closed-canopy habitats. To determine whether these morphological differences represent adaptations to their habitats, we tested for differences in both absolute and relative bite performance. Only absolute differences were found between forms, with the closed-canopy forms biting harder than their open-canopy counterparts. In contrast, sexual dimorphism was found for both absolute and relative bite force, but the relative differences were limited to the closed-canopy forms. These results indicate that both natural and sexual selection are acting within both habitat types, but to varying degrees. Sexual selection seems to be the predominant force within the closed-canopy habitats, which are more protected from aerial predators, enabling chameleons to invest more in ornamentation for communication. In contrast, natural selection is likely to be the predominant force in the open-canopy habitats, inhibiting the development of conspicuous secondary sexual characteristics and, ultimately, enforcing their overall diminutive body size and

Sexual dimorphism in bite performance drives morphological variation in chameleons.

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Jessica M da Silva

Full Text Available Phenotypic performance in different environments is central to understanding the evolutionary and ecological processes that drive adaptive divergence and, ultimately, speciation. Because habitat structure can affect an animal's foraging behaviour, anti-predator defences, and communication behaviour, it can influence both natural and sexual selection pressures. These selective pressures, in turn, act upon morphological traits to maximize an animal's performance. For performance traits involved in both social and ecological activities, such as bite force, natural and sexual selection often interact in complex ways, providing an opportunity to understand the adaptive significance of morphological variation with respect to habitat. Dwarf chameleons within the Bradypodion melanocephalum-Bradypodion thamnobates species complex have multiple phenotypic forms, each with a specific head morphology that could reflect its use of either open- or closed-canopy habitats. To determine whether these morphological differences represent adaptations to their habitats, we tested for differences in both absolute and relative bite performance. Only absolute differences were found between forms, with the closed-canopy forms biting harder than their open-canopy counterparts. In contrast, sexual dimorphism was found for both absolute and relative bite force, but the relative differences were limited to the closed-canopy forms. These results indicate that both natural and sexual selection are acting within both habitat types, but to varying degrees. Sexual selection seems to be the predominant force within the closed-canopy habitats, which are more protected from aerial predators, enabling chameleons to invest more in ornamentation for communication. In contrast, natural selection is likely to be the predominant force in the open-canopy habitats, inhibiting the development of conspicuous secondary sexual characteristics and, ultimately, enforcing their overall diminutive

MORPHOLOGICAL ANALYSIS OF THE LEAVES OF Anacardium occidentale L.

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Glenda Quaresma Ramos

2016-03-01

Full Text Available In morphological studies are analyzed various parameters, ranging from macro scale through the micro scale to the nanometer scale, which contribute to the study of taxonomy, pharmacognosy, ecology, among others. Among the structures found in plants, the leaves are most organs analyzed. This study aimed to analyze morphological features of the leaves of the cashew tree, which is a plant of great commercial importance in Brazil. In this work we observed sinuous epidermal cells in the adaxial and abaxial, characterize their stomata in paracytic surrounded subsidiaries cells. On the abaxial surface the presence of glandular trichomes was observed; and cross-sectional analysis showed a single-layered epidermis with compact mesophyll and several layers of parenchyma cells. Keywords: leaf anatomy; cashew tree; optical microscopy.

Functional morphology of the bovid astragalus in relation to habitat: controlling phylogenetic signal in ecomorphology.

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Barr, W Andrew

2014-11-01

Bovid astragali are one of the most commonly preserved bones in the fossil record. Accordingly, astragali are an important target for studies seeking to predict the habitat preferences of fossil bovids based on bony anatomy. However, previous work has not tested functional hypotheses linking astragalar morphology with habitat while controlling for body size and phylogenetic signal. This article presents a functional framework relating the morphology of the bovid astragalus to habitat-specific locomotor ecology and tests four hypotheses emanating from this framework. Highly cursorial bovids living in structurally open habitats are hypothesized to differ from their less cursorial closed-habitat dwelling relatives in having (1) relatively short astragali to maintain rotational speed throughout the camming motion of the rotating astragalus, (2) a greater range of angular excursion at the hock, (3) relatively larger joint surface areas, and (4) a more pronounced "spline-and-groove" morphology promoting lateral joint stability. A diverse sample of 181 astragali from 50 extant species was scanned using a Next Engine laser scanner. Species were assigned to one of four habitat categories based on the published ecological literature. A series of 11 linear measurements and three joint surface areas were measured on each astragalus. A geometric mean body size proxy was used to size-correct the measurement data. Phylogenetic generalized least squares (PGLS) was used to test for differences between habitat categories while controlling for body size differences and phylogenetic signal. Statistically significant PGLS results support Hypotheses 1 and 2 (which are not mutually exclusive) as well as Hypothesis 3. No support was found for Hypothesis 4. These findings confirm that the morphology of the bovid astragalus is related to habitat-specific locomotor ecology, and that this relationship is statistically significant after controlling for body size and phylogeny. Thus, this study

Community genetics reveal elevated levels of sympatric gene flow among morphologically similar but not among morphologically dissimilar species of Lake Victoria cichlid fish

NARCIS (Netherlands)

Konijnendijk, N.; Joyce, D.A.; Mrosso, H.D.J.; Egas, M.; Seehausen, O.

2011-01-01

We examined genetic structure among five species of Lake Victoria haplochromine cichlids in four island communities, using a full factorial sampling design that compared genetic differentiation between pairs of species and populations of varying morphological similarity and geographical proximity.

Functional Morphology of Eunicidan (Polychaeta) Jaws

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Clemo, W. C.; Dorgan, K. M.

2016-02-01

Polychaetes exhibit diverse feeding strategies and diets, with some species possessing hardened teeth or jaws of varying complexity. Species in the order Eunicida have complex, rigidly articulated jaws consisting of multiple pairs of maxillae and a pair of mandibles. While all Eunicida possess this general jaw structure, a number of characteristics of the jaw parts vary considerably among families. These differences, described for fossilized and extant species' jaws, were used to infer evolutionary relationships, but current phylogeny shows that jaw structures that are similar among several families are convergent. Little has been done, however, to relate jaw functional morphology and feeding behavior to diet. To explore these relationships, we compared the jaw kinematics of two taxa with similar but evolutionarily convergent jaw structures: Diopatra (Onuphidae) and Lumbrineris (Lumbrineridae). Diopatra species are tube-dwelling and predominantly herbivorous, whereas Lumbrineris species are burrowing carnivores. Jaw kinematics were observed and analyzed by filming individuals biting or feeding and tracking tooth movements in videos. Differences in jaw structure and kinematics between Diopatra and Lumbrineris can be interpreted to be consistent with their differences in diet. Relating jaw morphology to diet would provide insight into early annelid communities by linking fossil teeth (scolecodonts) to the ecological roles of extant species with similar morphologies.

Are sympatrically speciating Midas cichlid fish special? Patterns of morphological and genetic variation in the closely related species Archocentrus centrarchus.

Science.gov (United States)

Fruciano, Carmelo; Franchini, Paolo; Raffini, Francesca; Fan, Shaohua; Meyer, Axel

2016-06-01

Established empirical cases of sympatric speciation are scarce, although there is an increasing consensus that sympatric speciation might be more common than previously thought. Midas cichlid fish are one of the few substantiated cases of sympatric speciation, and they formed repeated radiations in crater lakes. In contrast, in the same environment, such radiation patterns have not been observed in other species of cichlids and other families of fish. We analyze morphological and genetic variation in a cichlid species (Archocentrus centrarchus) that co-inhabits several crater lakes with the Midas species complex. In particular, we analyze variation in body and pharyngeal jaw shape (two ecologically important traits in sympatrically divergent Midas cichlids) and relate that to genetic variation in mitochondrial control region and microsatellites. Using these four datasets, we analyze variation between and within two Nicaraguan lakes: a crater lake where multiple Midas cichlids have been described and a lake where the source population lives. We do not observe any within-lake clustering consistent across morphological traits and genetic markers, suggesting the absence of sympatric divergence in A. centrarchus. Genetic differentiation between lakes was low and morphological divergence absent. Such morphological similarity between lakes is found not only in average morphology, but also when analyzing covariation between traits and degree of morphospace occupation. A combined analysis of the mitochondrial control region in A. centrarchus and Midas cichlids suggests that a difference between lineages in the timing of crater lake colonization cannot be invoked as an explanation for the difference in their levels of diversification. In light of our results, A. centrarchus represents the ideal candidate to study the genomic differences between these two lineages that might explain why some lineages are more likely to speciate and diverge in sympatry than others.

Morphology of Thermoplastic Elastomers:Stereoblock Polypropylene

Energy Technology Data Exchange (ETDEWEB)

Pople, John A

2002-08-06

The morphologies of low-density (0.86 g/cm{sup 3}), elastomeric polypropylene (ePP) derived from bis(2-arylindenyl) hafnium dichloride were investigated using a combination of polarized optical microscopy (OM), differential scanning calorimetry (DSC), wide angle X-ray scattering (WAXS), Fourier transform infrared (FT-IR) spectroscopy, and tapping mode atomic force microscopy (TMAFM). These low-crystallinity polypropylenes, when crystallized isothermally from the melt, exhibit morphologies reminiscent of classical semi-crystalline polymers. The presence of lamellae, cross-hatching, hedrites, and spherulites was revealed by high resolution TM-AFM. These elastomeric polypropylenes can be fractionated into components of different average tacticities and crystallinities, but similar molecular mass. The analysis of the morphologies of all of the fractions revealed both large hierarchical structures and cross-hatching typical of the {alpha}-modification of crystalline isotactic polypropylene for all but the lowest crystalline ether soluble fraction. Evidence for high-melting crystals in all of the fractions are most consistent with a stereoblock microstructure of atactic and isotactic sequences.

Diversity Of Mandibular Morphology In Some Carnivorans

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Rahmat S. J.

2015-06-01

Full Text Available Comparison of mandibular morphology of some aquatic (seals, walruses, and sea otters and terrestrial (hyenas and pandas carnivorans demonstrates a rather general pattern correlating size of condyloid angle, size of gape, and diet. Structural differences of carnivoran jaws reveal morphological and ecological adaptations that are directly correlated with availability of prey, diving depth, feeding competition and specialized feeding methods. Specifically, the inclination of the condyloid process relative to the axis of the alveolar row (= condyloid angle can be used to determine dietary preferences, including size of prey. Generally, carnivorans with a large condyloid angle feed on larger prey, while a low condyloid angle suggests feeding on small prey or can be an advantageous feeding mechanism. Mirounga angustirostris (Northern elephant seal displays sex-specific characters in cranial and postcranial elements. Likewise, significant sexually dimorphic differences in the size of condyloid angle imply that deeper-diving male Northern elephant seals have a feeding niche dissimilar to that of females. Morphological assessment of male M. angustirostris suggests they are bottom-feeding seals that utilize a suction-feeding mechanism to capture small prey and crush shells with their teeth, which become weaker as they age.

Missing ecology: integrating ecological perspectives with the social-ecological system framework

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Graham Epstein

2013-08-01

Full Text Available The social-ecological systems framework was designed to provide a common research tool for interdisciplinary investigations of social-ecological systems. However, its origin in institutional studies of the commons belies its interdisciplinary ambitions and highlights its relatively limited attention to ecology and natural scientific knowledge. This paper considers the biophysical components of the framework and its epistemological foundations as it relates to the incorporation of knowledge from the natural sciences. It finds that the mixture of inductive and deductive reasoning associated with socially-oriented investigations of these systems is lacking on the ecological side, which relies upon induction alone. As a result the paper proposes the addition of a seventh core sub-system to the social-ecological systems framework, ecological rules, which would allow scholars to explicitly incorporate knowledge from the natural sciences for deductive reasoning. The paper shows, through an instructive case study, how the addition of ecological rules can provide a more nuanced description of the factors that contribute to outcomes in social-ecological systems.

Host Diet Affects the Morphology of Monarch Butterfly Parasites.

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Hoang, Kevin; Tao, Leiling; Hunter, Mark D; de Roode, Jacobus C

2017-06-01

Understanding host-parasite interactions is essential for ecological research, wildlife conservation, and health management. While most studies focus on numerical traits of parasite groups, such as changes in parasite load, less focus is placed on the traits of individual parasites such as parasite size and shape (parasite morphology). Parasite morphology has significant effects on parasite fitness such as initial colonization of hosts, avoidance of host immune defenses, and the availability of resources for parasite replication. As such, understanding factors that affect parasite morphology is important in predicting the consequences of host-parasite interactions. Here, we studied how host diet affected the spore morphology of a protozoan parasite ( Ophryocystis elektroscirrha ), a specialist parasite of the monarch butterfly ( Danaus plexippus ). We found that different host plant species (milkweeds; Asclepias spp.) significantly affected parasite spore size. Previous studies have found that cardenolides, secondary chemicals in host plants of monarchs, can reduce parasite loads and increase the lifespan of infected butterflies. Adding to this benefit of high cardenolide milkweeds, we found that infected monarchs reared on milkweeds of higher cardenolide concentrations yielded smaller parasites, a potentially hidden characteristic of cardenolides that may have important implications for monarch-parasite interactions.

Magadi tilapia ecological specialization: filling the early gap in the speciation continuum.

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Pinho, Catarina; Faria, Rui

2016-04-01

Cichlid fish are well known for their high speciation rates, which are usually accompanied by spectacular and rapid diversification in eco-morphological and secondary sexual traits. This is best illustrated by the famous repeated explosive radiations in the African Great Lakes Tanganyika, Malawi and Victoria, each lake harbouring several hundreds of mostly endemic species. Correspondingly, cichlids diversified very rapidly in many other lakes across their range. Although the larger radiations, unparalleled in vertebrates, are certainly the most intriguing, they are also the most intricate and difficult to address because of their complex nature. This is where smaller, simpler systems may prove to be the most useful. In this issue of Molecular Ecology, Kavembe et al. (2016) report very recent genetic diversification accompanied by ecological specialization in cichlids of the small and ecologically extreme Lake Magadi, in Kenya. Combining geometric morphometrics, stable isotope analysis, population genomics using RADSeq data and coalescent-based modelling techniques, the authors characterize the eco-morphological differences between genetically distinct populations of Magadi tilapia (Alcolapia grahami), which are consistent with the different environmental conditions they experience, and infer their history of divergence. The simplicity of the focal system and the use of a multidisciplinary approach make this work particularly important for our understanding of the early stages of speciation, in both cichlids and other organisms. © 2016 John Wiley & Sons Ltd.

Sensory Evolution and Ecology of Early Turtles Revealed by Digital Endocranial Reconstructions

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Stephan Lautenschlager

2018-02-01

Full Text Available In the past few years, new fossil finds and novel methodological approaches have prompted intensive discussions about the phylogenetic affinities of turtles and rekindled the debate on their ecological origin, with very distinct scenarios, such as fossoriality and aquatic habitat occupation, proposed for the earliest stem-turtles. While research has focused largely on the origin of the anapsid skull and unique postcranial anatomy, little is known about the endocranial anatomy of turtles. Here, we provide 3D digital reconstructions and comparative descriptions of the brain, nasal cavity, neurovascular structures and endosseous labyrinth of Proganochelys quenstedti, one of the earliest stem-turtles, as well as other turtle taxa. Our results demonstrate that P. quenstedti retained a simple tube-like brain morphology with poorly differentiated regions and mediocre hearing and vision, but a well-developed olfactory sense. Endocast shape analysis indicates that an increase in size and regionalization of the brain took place in the course of turtle evolution, achieving an endocast diversity comparable to other amniote groups. Based on the new evidence presented herein, we further conclude that P. quenstedti was a highly terrestrial, but most likely not fossorial, taxon.

Feeding kinematics and performance of Hawaiian stream gobies, Awaous guamensis and Lentipes concolor: linkage of functional morphology and ecology.

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Maie, Takashi; Wilson, Megan P; Schoenfuss, Heiko L; Blob, Richard W

2009-03-01

Distributions of Hawaiian stream fishes are typically interrupted by waterfalls that divide streams into multiple segments. Larvae hatch upstream, are flushed into the ocean, and must climb these waterfalls to reach adult habitats when returning back to freshwater as part of an amphidromous life cycle. Stream surveys and studies of climbing performance show that Lentipes concolor Gill can reach fast-flowing upper stream segments but that Awaous guamensis Valenciennes reaches only slower, lower stream segments. Gut content analyses for these two species indicate considerable overlap in diet, suggesting that feeding kinematics and performance of these two species might be comparable. Alternatively, feeding kinematics and performance of these species might be expected to differ in relation to the different flow regimes in their habitat (feeding in faster stream currents for L. concolor versus in slower currents for A. guamensis). To test these alternative hypotheses, we compared food capturing kinematics and performance during suction feeding behaviors of A. guamensis and L. concolor using morphological data and high-speed video. Lentipes concolor showed both a significantly larger gape angle and faster jaw opening than A. guamensis. Geometric models calculated that despite the inverse relationship of gape size and suction pressure generation, the fast jaw motions of L. concolor allow it to achieve higher pressure differentials than A. guamensis. Such elevated suction pressure would enhance the ability of L. concolor to successfully capture food in the fast stream reaches it typically inhabits. Differences in jaw morphology may contribute to these differences in performance, as the lever ratio for jaw opening is about 10% lower in L. concolor compared with A. guamensis, suiting the jaws of L. concolor better for fast opening. Copyright 2008 Wiley-Liss, Inc.

Cranial morphological variation in Peromyscus maniculatus over nearly a century of environmental change in three areas of California.

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Holmes, Michael W; Boykins, Genevieve K R; Bowie, Rauri C K; Lacey, Eileen A

2016-01-01

Determining how species respond to prolonged environmental change is critical to understanding both their evolutionary biology and their conservation needs. In general, organisms can respond to changing environmental conditions by moving, by adapting in situ, or by going locally or globally extinct. Morphological changes, whether plastic or adaptive, are one way that species may respond in situ to local environmental change. Because cranial morphology is influenced by selective pressures arising from an organism's abiotic and biotic environments, including aspects of thermal physiology, diet, and sensory ecology, studies of cranial morphology may generate important insights into how species are responding to environmental change. To assess potential response of deer mice (Peromyscus maniculatus) to changing conditions in the Sierra Nevada Mountains of California, we quantified cranial variation in museum specimens of this species collected approximately 100 years apart. Specifically, we examined how cranial morphology varies in three populations of this geographically widespread, ecological generalist over elevation and time. Our analyses indicate that cranial morphology does not differ with elevation within either modern or historical samples but does vary between time periods, suggesting that in situ responses to environmental change have occurred. Contrary to predictions based on Bergmann's rule, we found no consistent relationship between body size and either elevation or time, suggesting that morphological differences detected between historic and modern specimens are specific to factors influencing cranial structure. Collectively, these analyses demonstrate the potential importance of in situ changes in morphology as a response to changing environmental conditions. © 2015 Wiley Periodicals, Inc.

Individual-based modeling of ecological and evolutionary processes

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DeAngelis, Donald L.; Mooij, Wolf M.

2005-01-01

Individual-based models (IBMs) allow the explicit inclusion of individual variation in greater detail than do classical differential-equation and difference-equation models. Inclusion of such variation is important for continued progress in ecological and evolutionary theory. We provide a conceptual basis for IBMs by describing five major types of individual variation in IBMs: spatial, ontogenetic, phenotypic, cognitive, and genetic. IBMs are now used in almost all subfields of ecology and evolutionary biology. We map those subfields and look more closely at selected key papers on fish recruitment, forest dynamics, sympatric speciation, metapopulation dynamics, maintenance of diversity, and species conservation. Theorists are currently divided on whether IBMs represent only a practical tool for extending classical theory to more complex situations, or whether individual-based theory represents a radically new research program. We feel that the tension between these two poles of thinking can be a source of creativity in ecology and evolutionary theory.

Ecological niche models reveal the importance of climate variability for the biogeography of protosteloid amoebae.

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Aguilar, María; Lado, Carlos

2012-08-01

Habitat availability and environmental preferences of species are among the most important factors in determining the success of dispersal processes and therefore in shaping the distribution of protists. We explored the differences in fundamental niches and potential distributions of an ecological guild of slime moulds-protosteloid amoebae-in the Iberian Peninsula. A large set of samples collected in a north-east to south-west transect of approximately 1000 km along the peninsula was used to test the hypothesis that, together with the existence of suitable microhabitats, climate conditions may determine the probability of survival of species. Although protosteloid amoebae share similar morphologies and life history strategies, canonical correspondence analyses showed that they have varied ecological optima, and that climate conditions have an important effect in niche differentiation. Maxent environmental niche models provided consistent predictions of the probability of presence of the species based on climate data, and they were used to generate maps of potential distribution in an 'everything is everywhere' scenario. The most important climatic factors were, in both analyses, variables that measure changes in conditions throughout the year, confirming that the alternation of fruiting bodies, cysts and amoeboid stages in the life cycles of protosteloid amoebae constitutes an advantage for surviving in a changing environment. Microhabitat affinity seems to be influenced by climatic conditions, which suggests that the micro-environment may vary at a local scale and change together with the external climate at a larger scale.

Effects of extreme habitat conditions on otolith morphology: a case study on extremophile live bearing fishes (Poecilia mexicana, P. sulphuraria).

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Schulz-Mirbach, Tanja; Riesch, Rüdiger; García de León, Francisco J; Plath, Martin

2011-12-01

Our study was designed to evaluate if, and to what extent, restrictive environmental conditions affect otolith morphology. As a model, we chose two extremophile livebearing fishes: (i) Poecilia mexicana, a widespread species in various Mexican freshwater habitats, with locally adapted populations thriving in habitats characterized by the presence of one (or both) of the natural stressors hydrogen sulphide and darkness, and (ii) the closely related Poecilia sulphuraria living in a highly sulphidic habitat (Baños del Azufre). All three otolith types (lapilli, sagittae, and asterisci) of P. mexicana showed a decrease in size ranging from the non-sulphidic cave habitat (Cueva Luna Azufre), to non-sulphidic surface habitats, to the sulphidic cave (Cueva del Azufre), to sulphidic surface habitats (El Azufre), to P. sulphuraria. Although we found a distinct differentiation between ecotypes with respect to their otolith morphology, no clear-cut pattern of trait evolution along the two ecological gradients was discernible. Otoliths from extremophiles captured in the wild revealed only slight similarities to aberrant otoliths found in captive-bred fish. We therefore hypothesize that extremophile fishes have developed coping mechanisms enabling them to avoid aberrant otolith growth - an otherwise common phenomenon in fishes reared under stressful conditions. Copyright © 2011 Elsevier GmbH. All rights reserved.

The Diatom Anorthoneis dulcis Hein from Southern Brazil: Morphology and Ecology

International Nuclear Information System (INIS)

Marines, G.; Marciana, T.D.

2007-01-01

A new geographic locality for Anorthoneis dulcis is reported. The paper describes the distribution and relative abundance of A. dulcis in Lagoa dos Patos lagoon (a lagoon in Rio Grande do Sul state, Brazil) from samples collected between 2004 and 2005, and shows that this rare species is present all year round. This study extends the species distribution to South America indicating that the species can thrive on sand grains in lentic estuarine, and freshwater areas. It widens the range of tolerance to environmental parameters. The valve fine structure, morphology, and dimensions are in agreement with the original diagnosis.

Species delimitation in the Stenocereus griseus (Cactaceae) species complex reveals a new species, S. huastecorum.

Science.gov (United States)

Alvarado-Sizzo, Hernán; Casas, Alejandro; Parra, Fabiola; Arreola-Nava, Hilda Julieta; Terrazas, Teresa; Sánchez, Cristian

2018-01-01

The Stenocereus griseus species complex (SGSC) has long been considered taxonomically challenging because the number of taxa belonging to the complex and their geographical boundaries remain poorly understood. Bayesian clustering and genetic distance-based methods were used based on nine microsatellite loci in 377 individuals of three main putative species of the complex. The resulting genetic clusters were assessed for ecological niche divergence and areolar morphology, particularly spination patterns. We based our species boundaries on concordance between genetic, ecological, and morphological data, and were able to resolve four species, three of them corresponding to S. pruinosus from central Mexico, S. laevigatus from southern Mexico, and S. griseus from northern South America. A fourth species, previously considered to be S. griseus and commonly misidentified as S. pruinosus in northern Mexico showed significant genetic, ecological, and morphological differentiation suggesting that it should be considered a new species, S. huastecorum, which we describe here. We show that population genetic analyses, ecological niche modeling, and morphological studies are complementary approaches for delimiting species in taxonomically challenging plant groups such as the SGSC.

Species delimitation in the Stenocereus griseus (Cactaceae species complex reveals a new species, S. huastecorum.

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Hernán Alvarado-Sizzo

Full Text Available The Stenocereus griseus species complex (SGSC has long been considered taxonomically challenging because the number of taxa belonging to the complex and their geographical boundaries remain poorly understood. Bayesian clustering and genetic distance-based methods were used based on nine microsatellite loci in 377 individuals of three main putative species of the complex. The resulting genetic clusters were assessed for ecological niche divergence and areolar morphology, particularly spination patterns. We based our species boundaries on concordance between genetic, ecological, and morphological data, and were able to resolve four species, three of them corresponding to S. pruinosus from central Mexico, S. laevigatus from southern Mexico, and S. griseus from northern South America. A fourth species, previously considered to be S. griseus and commonly misidentified as S. pruinosus in northern Mexico showed significant genetic, ecological, and morphological differentiation suggesting that it should be considered a new species, S. huastecorum, which we describe here. We show that population genetic analyses, ecological niche modeling, and morphological studies are complementary approaches for delimiting species in taxonomically challenging plant groups such as the SGSC.

Morphological differentiation of severe aplastic anaemia from hypocellular refractory cytopenia of childhood

DEFF Research Database (Denmark)

Baumann, Irith; Führer, Monika; Behrendt, Sonja

2012-01-01

To evaluate the reproducibility and reliability of the histomorphological criteria differentiating severe aplastic anaemia (SAA) and hypoplastic refractory cytopenia of childhood (RCC), the most frequently acquired hypocellular bone marrow conditions of childhood.......To evaluate the reproducibility and reliability of the histomorphological criteria differentiating severe aplastic anaemia (SAA) and hypoplastic refractory cytopenia of childhood (RCC), the most frequently acquired hypocellular bone marrow conditions of childhood....

Oestradiol and progesterone differentially alter cytoskeletal protein expression and flame cell morphology in Taenia crassiceps.

Science.gov (United States)

Ambrosio, Javier R; Ostoa-Saloma, Pedro; Palacios-Arreola, M Isabel; Ruíz-Rosado, Azucena; Sánchez-Orellana, Pedro L; Reynoso-Ducoing, Olivia; Nava-Castro, Karen E; Martínez-Velázquez, Nancy; Escobedo, Galileo; Ibarra-Coronado, Elizabeth G; Valverde-Islas, Laura; Morales-Montor, Jorge

2014-09-01

We examined the effects of oestradiol (E2) and progesterone (P4) on cytoskeletal protein expression in the helminth Taenia crassiceps - specifically actin, tubulin and myosin. These proteins assemble into flame cells, which constitute the parasite excretory system. Total protein extracts were obtained from E2- and P4-treated T. crassiceps cysticerci and untreated controls, and analysed by one- and two-dimensional protein electrophoresis, flow cytometry, immunofluorescence and videomicroscopy. Exposure of T. crassiceps cysticerci to E2 and P4 induced differential protein expression patterns compared with untreated controls. Changes in actin, tubulin and myosin expression were confirmed by flow cytometry of parasite cells and immunofluorescence. In addition, parasite morphology was altered in response to E2 and P4 versus controls. Flame cells were primarily affected at the level of the ciliary tuft, in association with the changes in actin, tubulin and myosin. We conclude that oestradiol and progesterone act directly on T. crassiceps cysticerci, altering actin, tubulin and myosin expression and thus affecting the assembly and function of flame cells. Our results increase our understanding of several aspects of the molecular crosstalk between host and parasite, which might be useful in designing anthelmintic drugs that exclusively impair parasitic proteins which mediate cell signaling and pathogenic reproduction and establishment. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Physiological differentiation within a single-species biofilm fueled by serpentinization.

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Brazelton, William J; Mehta, Mausmi P; Kelley, Deborah S; Baross, John A

2011-01-01

Carbonate chimneys at the Lost City hydrothermal field are coated in biofilms dominated by a single phylotype of archaea known as Lost City Methanosarcinales. In this study, we have detected surprising physiological complexity in single-species biofilms, which is typically indicative of multispecies biofilm communities. Multiple cell morphologies were visible within the biofilms by transmission electron microscopy, and some cells contained intracellular membranes that may facilitate methane oxidation. Both methane production and oxidation were detected at 70 to 80°C and pH 9 to 10 in samples containing the single-species biofilms. Both processes were stimulated by the presence of hydrogen (H(2)), indicating that methane production and oxidation are part of a syntrophic interaction. Metagenomic data included a sequence encoding AMP-forming acetyl coenzyme A synthetase, indicating that acetate may play a role in the methane-cycling syntrophy. A wide range of nitrogen fixation genes were also identified, many of which were likely acquired via lateral gene transfer (LGT). Our results indicate that cells within these single-species biofilms may have differentiated into multiple physiological roles to form multicellular communities linked by metabolic interactions and LGT. Communities similar to these Lost City biofilms are likely to have existed early in the evolution of life, and we discuss how the multicellular characteristics of ancient hydrogen-fueled biofilm communities could have stimulated ecological diversification, as well as unity of biochemistry, during the earliest stages of cellular evolution. Our previous work at the Lost City hydrothermal field has shown that its carbonate chimneys host microbial biofilms dominated by a single uncultivated "species" of archaea. In this paper, we integrate evidence from these previous studies with new data on the metabolic activity and cellular morphology of these archaeal biofilms. We conclude that the archaeal biofilm

Does the Morphology of the Forelimb Flexor Muscles Differ Between Lizards Using Different Habitats?

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Lowie, Aurélien; Herrel, Anthony; Abdala, Virginia; Manzano, Adriana S; Fabre, Anne-Claire

2018-03-01

Lizards are an interesting group to study how habitat use impacts the morphology of the forelimb because they occupy a great diversity of ecological niches. In this study, we specifically investigated whether habitat use impacts the morphology of the forelimb flexor muscles in lizards. To do so, we performed dissections and quantified the physiological cross sectional area (PCSA), the fiber length, and the mass of four flexor muscles in 21 different species of lizards. Our results show that only the PCSA of the m. flexor carpi radialis is different among lizards with different ecologies (arboreal versus non-arboreal). This difference disappeared, however, when taking phylogeny into account. Arboreal species have a higher m. flexor carpi radialis cross sectional area likely allowing them to flex the wrist more forcefully which may allow them climb and hold on to branches better. In contrast, other muscles are not different between arboreal and non-arboreal species. Further studies focusing on additional anatomical features of the lizard forelimb as well as studies documenting how lizards use the arboreal niche are needed to fully understand how an arboreal life style may constrain limb morphology in lizards. Anat Rec, 301:424-433, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Ecological response of a multi-purpose river development project using macro-invertebrates richness and fish habitat value[Dissertation 3807

Energy Technology Data Exchange (ETDEWEB)

Pellaud, M.

2007-05-15

It has been acknowledged that river morphology and hydrology have been intensively altered due to the anthropic demands in floodplain land use and management, flood protection, promotion of navigability or energy production. Rivers were transformed in water highways, having lost contact with their surrounding floodplain as well as the plethora of ecological processes and occupants once thriving in these ecotonal zones. The identification of this emerging threat of morphological and hydrological alteration on ecological integrity adds further complexity in the exploitation of hydrosystem resources. These resources are heavily coveted and guarded by different lobbies each having strategic views on future project development. Stakeholders may want to promote hydro-electricity, ecologists a natural reserve, communes may wish to have an increased flood protection and leisure promoters a nautical center. As a result, the proposition of a river development project is certain to face opposition of one party or the other. The motivations of this dissertation are anchored in this context, where various and sometimes conflicting potentials for hydrosystem exploitation remain. This works aims at contributing scientifically to an innovative approach at the conception phase of a multi-purpose river development project by developing the ecological module to be implemented in the general project's optimizer. The SYNERGIE project hypothesis is that it should be possible to identify a synergetic pattern joining the interests of ecological integrity, flood safety, energy production and leisure development. Such a multi-objective river development project would stand more chance of acceptance. This dissertation focuses on the ecological aspects of such a river development project and an application on the regulated Swiss Upper Rhone River. Is expected an ecological answer to a river development project design / management which has to be compatible with Heller's Heller (2007

Resilience, political ecology, and well-being: an interdisciplinary approach to understanding social-ecological change in coastal Bangladesh

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Sonia F. Hoque

2017-06-01

Full Text Available The commodification of peasant livelihoods through export-oriented aquaculture has brought about significant social-ecological changes in low-lying coastal areas in many parts of Asia. A better understanding of the underlying drivers and distributional effects of these changes requires integration of social and ecological approaches that often have different epistemological origins. Resilience thinking has gained increased traction in social-ecological systems research because it provides a dynamic analysis of the cross-scalar interactions between multiple conditions and processes. However, the system-oriented perspective inherent in resilience thinking fails to acknowledge the heterogeneous values, interests, and power of social actors and their roles in navigating social-ecological change. Incorporation of political ecology and well-being perspectives can provide an actor-oriented analysis of the trade-offs associated with change and help to determine which state is desirable for whom. However, empirical demonstrations of such interdisciplinary approaches remain scarce. Here, we explore the combined application of resilience, political ecology, and well-being in investigating the root causes of social-ecological change and identifying the winners and losers of system transformation through empirical analysis of the differential changes in farming systems in two villages in coastal Bangladesh. Using the adaptive cycle as a structuring model, we examine the evolution of the shrimp aquaculture system over the past few decades, particularly looking at the power dynamics between households of different wealth classes. We found that although asymmetric land ownership and political ties enabled the wealthier households to reach their desired farming system in one village, social resilience achieved through memory, leadership, and crisis empowered poorer households to exercise their agency in another village. Material dimensions such as improved

Urban ecological systems: scientific foundations and a decade of progress.

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Pickett, S T A; Cadenasso, M L; Grove, J M; Boone, Christopher G; Groffman, Peter M; Irwin, Elena; Kaushal, Sujay S; Marshall, Victoria; McGrath, Brian P; Nilon, C H; Pouyat, R V; Szlavecz, Katalin; Troy, Austin; Warren, Paige

2011-03-01

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs. Copyright © 2010 Elsevier Ltd. All rights reserved.

In Vitro Morphological Characteristics of Pyrenophora tritici-repentis Isolates from Several Algerian Agro-Ecological Zones

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Hamida Benslimane

2017-04-01

Full Text Available Tan spot caused by the fungus Pyrenophora triticirepentis is a serious disease of wheat, which is on increase in recent years in Mediterranean region. In the field this fungus produces a diamond-shaped necrotic lesions with a yellow halo on wheat foliage. The objective of this study was to characterize and compare several monospore isolates of P. tritici-repentis collected from different infected wheat fields in various locations of Algeria, and find the morphological differences between them, if any. The results revealed wide morphologically variation among the isolates based on colony colors and texture, mycelial radial growth and conidial size.

Impact of Geography and Climate on the Genetic Differentiation of the Subtropical Pine Pinus yunnanensis.

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Wang, Baosheng; Mao, Jian-Feng; Zhao, Wei; Wang, Xiao-Ru

2013-01-01

Southwest China is a biodiversity hotspot characterized by complex topography, heterogeneous regional climates and rich flora. The processes and driving factors underlying this hotspot remain to be explicitly tested across taxa to gain a general understanding of the evolution of biodiversity and speciation in the region. In this study, we examined the role played by historically neutral processes, geography and environment in producing the current genetic diversity of the subtropical pine Pinus yunnanensis. We used genetic and ecological methods to investigate the patterns of genetic differentiation and ecological niche divergence across the distribution range of this species. We found both continuous genetic differentiation over the majority of its range, and discrete isolated local clusters. The discrete differentiation between two genetic groups in the west and east peripheries is consistent with niche divergence and geographical isolation of these groups. In the central area of the species' range, population structure was shaped mainly by neutral processes and geography rather than by ecological selection. These results show that geographical and environmental factors together created stronger and more discrete genetic differentiation than isolation by distance alone, and illustrate the importance of ecological factors in forming or maintaining genetic divergence across a complex landscape. Our findings differ from other phylogenetic studies that identified the historical drainage system in the region as the primary factor shaping population structure, and highlight the heterogeneous contributions that geography and environment have made to genetic diversity among taxa in southwest China.

Laryngotracheal morphology of Afro-Madagascan geckos: a comparative survey.

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Russell, A P; Rittenhouse, D R; Bauer, A M

2000-09-01

The structural variation of the gekkonid larynx and trachea is examined within a representative subset of 17 species of Afro-Madagascan gekkonines to determine if there are underlying morphological correlates of vocalization. The documented morphology is compared to that of the tokay (Gekko gecko), which has previously been described. Data were obtained from gross anatomical observations, scanning electron microscopy, histological examinations and computer-generated, three-dimensional, skeletal reconstructions. Although there is limited variation among most Afro-Malagasy gekkonids, the larynges of Ptenopus garrulus and Uroplatus fimbriatus exhibit marked degrees of differentiation, suggesting that laryngeal and tracheal morphology may account for the documented vocal variability of gekkonid lizards. Cladistic analyses indicated that parallel adaptive trends characterize the laryngeal morphology of the examined taxa. Alternate designs and refinements to a model of gekkonid phonation are presented, and the evolution of acoustic communication in the Gekkonidae is considered. Copyright 2000 Wiley-Liss, Inc.

Ecological changes in Coyotes (Canis latrans in response to the ice age megafaunal extinctions.

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Julie A Meachen

Full Text Available Coyotes (Canis latrans are an important species in human-inhabited areas. They control pests and are the apex predators in many ecosystems. Because of their importance it is imperative to understand how environmental change will affect this species. The end of the Pleistocene Ice Age brought with it many ecological changes for coyotes and here we statistically determine the changes that occurred in coyotes, when these changes occurred, and what the ecological consequences were of these changes. We examined the mandibles of three coyote populations: Pleistocene Rancho La Brean (13-29 Ka, earliest Holocene Rancho La Brean (8-10 Ka, and Recent from North America, using 2D geometric morphometrics to determine the morphological differences among them. Our results show that these three populations were morphologically distinct. The Pleistocene coyotes had an overall robust mandible with an increased shearing arcade and a decreased grinding arcade, adapted for carnivory and killing larger prey; whereas the modern populations show a gracile morphology with a tendency toward omnivory or grinding. The earliest Holocene populations are intermediate in morphology and smallest in size. These findings indicate that a niche shift occurred in coyotes at the Pleistocene/Holocene boundary - from a hunter of large prey to a small prey/more omnivorous animal. Species interactions between Canis were the most likely cause of this transition. This study shows that the Pleistocene extinction event affected species that did not go extinct as well as those that did.

Morphology and cardiac physiology are differentially affected by temperature in developing larvae of the marine fish mahi-mahi (Coryphaena hippurus

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Prescilla Perrichon

2017-06-01

Full Text Available Cardiovascular performance is altered by temperature in larval fishes, but how acute versus chronic temperature exposures independently affect cardiac morphology and physiology in the growing larva is poorly understood. Consequently, we investigated the influence of water temperature on cardiac plasticity in developing mahi-mahi. Morphological (e.g. standard length, heart angle and physiological cardiac variables (e.g. heart rate fH, stroke volume, cardiac output were recorded under two conditions by imaging: (i under acute temperature exposure where embryos were reared at 25°C up to 128 h post-fertilization (hpf and then acutely exposed to 25 (rearing temperature, 27 and 30°C; and (ii at two rearing (chronic temperatures of 26 and 30°C and performed at 32 and 56 hpf. Chronic elevated temperature improved developmental time in mahi-mahi. Heart rates were 1.2–1.4-fold higher under exposure of elevated acute temperatures across development (Q10≥2.0. Q10 for heart rate in acute exposure was 1.8-fold higher compared to chronic exposure at 56 hpf. At same stage, stroke volume was temperature independent (Q10∼1.0. However, larvae displayed higher stroke volume later in stage. Cardiac output in developing mahi-mahi is mainly dictated by chronotropic rather than inotropic modulation, is differentially affected by temperature during development and is not linked to metabolic changes.

Ecology and evolution of mammalian biodiversity.

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Jones, Kate E; Safi, Kamran

2011-09-12

Mammals have incredible biological diversity, showing extreme flexibility in eco-morphology, physiology, life history and behaviour across their evolutionary history. Undoubtedly, mammals play an important role in ecosystems by providing essential services such as regulating insect populations, seed dispersal and pollination and act as indicators of general ecosystem health. However, the macroecological and macroevolutionary processes underpinning past and present biodiversity patterns are only beginning to be explored on a global scale. It is also particularly important, in the face of the global extinction crisis, to understand these processes in order to be able to use this knowledge to prevent future biodiversity loss and loss of ecosystem services. Unfortunately, efforts to understand mammalian biodiversity have been hampered by a lack of data. New data compilations on current species' distributions, ecologies and evolutionary histories now allow an integrated approach to understand this biodiversity. We review and synthesize these new studies, exploring the past and present ecology and evolution of mammalian biodiversity, and use these findings to speculate about the mammals of our future.

Ecology and evolution of mammalian biodiversity

Science.gov (United States)

Jones, Kate E.; Safi, Kamran

2011-01-01

Mammals have incredible biological diversity, showing extreme flexibility in eco-morphology, physiology, life history and behaviour across their evolutionary history. Undoubtedly, mammals play an important role in ecosystems by providing essential services such as regulating insect populations, seed dispersal and pollination and act as indicators of general ecosystem health. However, the macroecological and macroevolutionary processes underpinning past and present biodiversity patterns are only beginning to be explored on a global scale. It is also particularly important, in the face of the global extinction crisis, to understand these processes in order to be able to use this knowledge to prevent future biodiversity loss and loss of ecosystem services. Unfortunately, efforts to understand mammalian biodiversity have been hampered by a lack of data. New data compilations on current species' distributions, ecologies and evolutionary histories now allow an integrated approach to understand this biodiversity. We review and synthesize these new studies, exploring the past and present ecology and evolution of mammalian biodiversity, and use these findings to speculate about the mammals of our future. PMID:21807728

Scrambled eggs: mechanical forces as ecological factors in early development.

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Moore, Steven W

2003-01-01

Many ecological interactions involve, at some level, mechanical forces and the movements or structural deformations they produce. Although the most familiar examples involve the functional morphology of adult structures, all life history stages (not just the adults) are subject to the laws of physics. Moreover, the success of every lineage depends on the success of every life history stage (again, not just the adults). Therefore, insights gained by using mechanical engineering principles and techniques to study ecological interactions between gametes, embryos, larvae, and their environment are essential to a well-rounded understanding of development, ecology, and evolution. Here I draw on examples from the literature and my own research to illustrate ways in which mechanical forces in the environment shape development. These include mechanical forces acting as selective factors (e.g., when coral gamete size and shape interact with turbulent water flow to determine fertilization success) and as developmental cues (e.g., when plant growth responds to gravity or bone growth responds to mechanical loading). I also examine the opposite cause-and-effect relationship by considering examples in which the development of organisms impacts ecologically relevant mechanical forces. Finally, I discuss the potential for ecological pattern formation as a result of feedback loops created by such bidirectional interactions between developmental processes and mechanical forces in the environment.

Adult renal cell carcinoma with rhabdoid morphology represents a neoplastic dedifferentiation analogous to sarcomatoid carcinoma.

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Chapman-Fredricks, Jennifer R; Herrera, Loren; Bracho, Jorge; Gomez-Fernandez, Carmen; Leveillee, Raymond; Rey, Luis; Jorda, Merce

2011-10-01

Renal cell carcinoma (RCC) with rhabdoid morphology (RCC-RM) is a recently described variant of RCC, which has an aggressive biologic behavior and poor prognosis, akin to sarcomatoid RCC. The current World Health Organization classification of RCC does not include the rhabdoid phenotype as a distinct histologic entity. The aim of this study is to investigate whether RCC-RM represents a dedifferentiation of a classifiable-type World Health Organization RCC or a carcinosarcoma with muscle differentiation. We reviewed 168 cases of RCC obtained between 2003 and 2008. From these cases, 10 (6%) were found to have areas of classic rhabdoid morphology. Immunohistochemistry for cytokeratin, epithelial membrane antigen, desmin, CD10, and CD117 was performed in each case using the labeled streptavidin-biotin method. Rhabdoid differentiation was identified in association with conventional-type RCC (9) and with unclassifiable-type RCC with spindle cell morphology (1). In all cases, both the rhabdoid and nonrhabdoid tumoral areas were positive for cytokeratin and epithelial membrane antigen and negative for desmin. Cytokeratin positivity in the rhabdoid areas was focal. In cases associated with conventional-type RCC, CD10 was positive in both the rhabdoid and nonrhabdoid foci. CD117 was negative in these tumors. The unclassifiable-type RCC with spindle cell morphology was negative for both CD10 and CD117. The similar immunophenotype between the rhabdoid and nonrhabdoid tumoral foci supports the origin of the rhabdoid cells from the classifiable-type RCC. Areas of rhabdoid morphology do not represent muscle metaplastic differentiation. Renal cell carcinoma with rhabdoid morphology may represent a dedifferentiation of a classifiable-type RCC, similar to that of sarcomatoid differentiation. The recognition of RCC-RM is important as it allows for the inclusion of these high-grade malignancies into a category associated with poor prognosis despite lacking the spindle cell component

Division of labor in biofilms : The ecology of cell differentiation

NARCIS (Netherlands)

van Gestel, Jordi; Vlamakis, Hera; Kolter, Roberto

The dense aggregation of cells on a surface, as seen in biofilms, inevitably results in both environmental and cellular heterogeneity. For example, nutrient gradients can trigger cells to differentiate into various phenotypic states. Not only do cells adapt physiologically to the local environmental

Molecular Ecological Insights into Neotropical Bird-Tick Interactions.

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Matthew J Miller

Full Text Available In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In contrast, immature Neotropical ticks are often found on wild birds, yet difficulties in identifying immatures hinder studies of birds' role in tropical tick ecology and tick-borne disease transmission. In Panama, we found immature ticks on 227 out of 3,498 individually-sampled birds representing 93 host species (24% of the bird species sampled, and 13% of the Panamanian land bird fauna. Tick parasitism rates did not vary with rainfall or temperature, but did vary significantly with several host ecological traits. Likewise, Neotropical-Nearctic migratory birds were significantly less likely to be infested than resident species. Using a molecular library developed from morphologically-identified adult ticks specifically for this study, we identified eleven tick species parasitizing birds, indicating that a substantial portion of the Panamanian avian species pool is parasitized by a diversity of tick species. Tick species that most commonly parasitized birds had the widest diversity of avian hosts, suggesting that immature tick species are opportunistic bird parasites. Although certain avian ecological traits are positively associated with parasitism, we found no evidence that individual tick species show specificity to particular avian host ecological traits. Finally, our data suggest that the four principal vectors of Rocky Mountain Spotted Fever in the Neotropics rarely, if ever, parasitize Panamanian birds. However, other tick species that harbor newly-discovered rickettsial parasites of unknown pathogenicity are frequently found on these birds. Given our discovery of broad interaction between Panamanian tick and avian biodiversity, future work on tick ecology

Molecular Ecological Insights into Neotropical Bird-Tick Interactions.

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Miller, Matthew J; Esser, Helen J; Loaiza, Jose R; Herre, Edward Allen; Aguilar, Celestino; Quintero, Diomedes; Alvarez, Eric; Bermingham, Eldredge

2016-01-01

In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In contrast, immature Neotropical ticks are often found on wild birds, yet difficulties in identifying immatures hinder studies of birds' role in tropical tick ecology and tick-borne disease transmission. In Panama, we found immature ticks on 227 out of 3,498 individually-sampled birds representing 93 host species (24% of the bird species sampled, and 13% of the Panamanian land bird fauna). Tick parasitism rates did not vary with rainfall or temperature, but did vary significantly with several host ecological traits. Likewise, Neotropical-Nearctic migratory birds were significantly less likely to be infested than resident species. Using a molecular library developed from morphologically-identified adult ticks specifically for this study, we identified eleven tick species parasitizing birds, indicating that a substantial portion of the Panamanian avian species pool is parasitized by a diversity of tick species. Tick species that most commonly parasitized birds had the widest diversity of avian hosts, suggesting that immature tick species are opportunistic bird parasites. Although certain avian ecological traits are positively associated with parasitism, we found no evidence that individual tick species show specificity to particular avian host ecological traits. Finally, our data suggest that the four principal vectors of Rocky Mountain Spotted Fever in the Neotropics rarely, if ever, parasitize Panamanian birds. However, other tick species that harbor newly-discovered rickettsial parasites of unknown pathogenicity are frequently found on these birds. Given our discovery of broad interaction between Panamanian tick and avian biodiversity, future work on tick ecology and the dynamics of

Validating DNA barcodes: A non-destructive extraction protocol enables simultaneous vouchering of DNA and morphological vouchers

Science.gov (United States)

Morphology-based keys support accurate identification of many taxa. However, identification can be difficult for taxa that are not well studied, very small, members of cryptic species complexes, or represented by immature stages. For such cases, DNA barcodes may provide diagnostic characters. Ecolog...

Ecological characterization of surface waters in the province of Overijssel, The Netherlands

NARCIS (Netherlands)

Verdonschot, P.F.M.

1990-01-01

Nowadays many surface waters in The Netherlands tend to become ecologically uniform with the same mediocre quality. A differentiated approach to water management is necessary to stop this process of impoverishment of aquatic ecosystems. In The Netherlands the provincial