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1
Sundberg, Nilas. "Quantifying Dental Morphological Variation in Lamniform Sharks." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-234749.
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Long, Gillian Mary. "Morphological and physiological variation in Brachypodium sylvaticum." Thesis, Cardiff University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254511.
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Dytham, Calvin. "Morphological and biochemical variation in rough periwinkles." Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277326.
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Owen, Joseph Thomas David. "Morphological variation in wild and domestic suids." Thesis, Durham University, 2013. http://etheses.dur.ac.uk/6950/.
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Pigs occupy a special place in the human psyche. They are kept both as stock domesticates, like cattle and sheep, and they are treated as companions and aids, like cats and dogs. There are currently nearly two billion (c.1,984,607,000) domesticated pigs in the world kept as stock animals bred for slaughter (Foreign Agricultural Service (FAS), 2012). Keeping pigs as pets has become increasingly popular in western society in recent years and commensalism with pigs is a long-held tradition in Island South East Asia (McDonald-Brown, 2009). Pigs are a key economic resource; however, they are also an animal that inspires strong emotions of attachment or revulsion; seen as loyal, intelligent, courageous and resourceful or unclean, licentious, gluttonous and ignorant (Albarella et al., 2007, Phillips, 2007). As such pigs and pig products are extensively referenced in classical literature and modern pop culture; examples include George Orwell’s Animal Farm, Circe, a minor Greek goddess who transforms Odysseus’ men into pigs when they feast at her table in Homer’s Odyssey; the warthog Pumba from the movie The Lion King, Miss Piggy from The Muppets and Spiderpig in the Simpsons; pigs continued popularity is a testament to their enduring importance. As a result of this unique dual positions of pet and produce, pigs have been intensively studied both as domestic and wild animals. The earliest studies of domestic pigs, their form and origins, come from Charles Darwin (1868) and Ludwig Rutimeyer (1860, 1864), whilst the first scientific description of wild Sus was by Karl Linnaeus (1740, 1758). Here I continue the investigation of the pig, particularly the evolution of wild and domestic pigs, through a geometric morphometric analysis of cranial form. Whist the original concept of this study was derived from a grant concerned with the spread of domestic pigs across Europe at the beginning of the Neolithic, this thesis encompasses wider studies. By applying geometric morphometrics to questions of suid evolution and variability and domestication, we can effect a deeper understanding of how pigs colonised Africa, how suid morphology is affected by climate and geography, that wild and domestic pig cranial morphologies are distinct enough to discriminate between. These have implications for evolutionary studies of the suid family, explaining apparent incongruence between morphological studies and genetics. There are significant implications for archaeological studies, especially those concerned with identifying the origins of domestication where inadequacies in the traditional methodology can be overcome through the application of geometric morphometrics. We also test and reject the traditional hypothesis of heterochrony as the causal mechanism for the development of the domestic morphotype. Methodologies to test this have recently been developed for geometric morphometrics (Mitteroecker et al., 2005), but had not been applied to stock domesticates before. What is seen in suid ontogeny is not explained by the traditional language of heterochrony, nor are domestic pigs paedomorphic wild pigs. This leaves the cause of morphological changes observed during domestication unexplained, which should be a focus of future work.
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Fulginiti, Laura Carr, and Laura Carr Fulginiti. "Discontinuous morphological variation at Grasshopper Pueblo, Arizona." Diss., The University of Arizona, 1993. http://hdl.handle.net/10150/186490.
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Cranial and post-cranial non-metric variants are used to examine 664 individuals from the Grasshopper Pueblo skeletal series. The pueblo was inhabited from the 12th to the 14th century A.D. A variety of statistical analyses are utilized to examine patterns of morphological variation which can be used to assess whether biological differences can be demonstrated on the basis of non-metric trait frequencies. All traits are examined for frequency of occurrence, and trait frequencies are then tested to determine if they vary by side of the body, sex, age, type of cranial deformation or association with one another. A series of skeletons are re-tested in order to test intra- and inter-observer reliability. A refined list of traits developed from these analyses is then used to examine trait frequency distributions among the three major room blocks at the site. The full battery of traits used in this study are found to be free of the effects of side of the body, sex, type of cranial deformation and associations with one another, but are affected slightly by age. Intra- and inter-rater reliability are low for this sample and battery of traits. The conclusion is that individuals from the Pueblo do not aggregate into groups which are distinguishable on the basis of non-metric traits.
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Hornsby, Angela D. "Molecular and morphological variation in Neotoma cinerea." abstract and full text PDF (UNR users only), 2009. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1467751.
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Wilson, Yvette. "Evolutionary relationships and morphological variation between Antirrhinum species." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/11591.
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Camp, Jessica Amber. "Morphological variation and disparity in Lystrosaurus (Therapsida: Dicynodontia)." Thesis, University of Iowa, 2010. https://ir.uiowa.edu/etd/650.
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The dicynodont genus Lystrosaurus, a relative of the Kannemeyerids, is one of few terrestrial vertebrate genera which can be found on both sides of the Permian-Triassic (P-T) boundary (Botha and Smith, 2006); indeed, a single species, Lystrosaurus curvatus, is known from both periods. In the Permian, Lystrosaurus was of average abundance relative to other genera. Shortly following the P-T extinction, it drastically increased in abundance until it dominated the faunas it was present in (Botha and Smith, 2006). To date, Lystrosaurus fossils have been found in South Africa, India, Antarctica, China, and Russia (Grine et al., 2006). Abundance, survivorship, and expansive geographic presence give Lystrosaurus extreme potential as a model organism for multiple questions involving ideas such as extinction survivorship, biogeography, and ecology; however, Lystrosaurus has been subject to the practice of an extreme version of "splitter" taxonomy in the past. Here I quantify Lystrosaurus morphology using geometric morphometrics. Chinese Lystrosaurus taxonomy has not been analyzed in light of this. My results show that they are different from Gondwanan Lystrosaurus and represent at least one if not two unique species.
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Trader, Brian Wayne. "Molecular and Morphological Investigation of Astilbe." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/28145.
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Astilbe (Saxifragaceae) is a genus of herbaceous perennials widely cultivated for their ornamental value. The genus is considered taxonomically complex because of its geographic distribution, variation within species, and the lack of adequate morphological characters to delineate taxa. To date, an inclusive investigation of the genus has not been conducted. This study was undertaken to (a) develop a well-resolved phylogeny of the genus Astilbe using an expanded morphological data set and sequences from the plastid gene matK, (b) use single nucleotide polymorphisms to determine the lineages of cultivated varieties, and (c) successfully culture Astilbe in vitro and evaluate potential somaclonal variation of resulting Astilbe microshoots.
Phylogenetic trees generated from a morphological character matrix of 28 character states divided Astilbe into three distinct clades. Relationships were well resolved among the taxa, though only a few branches had greater than 50% bootstrap support. There is evidence from the phylogeny that some described species may actually represent variation within populations of species. From our analysis I propose an Astilbe genus with 13 to 15 species and offer a key for distinguishing species and varieties.
There was little matK sequence variation among taxa of Astilbe. Phylogeny of Astilbe generated from the maximum parsimony and maximum likelihood analysis of matK sequences resulted in a polytomy of seven Astilbe species, with relationships within the genus poorly resolved. A second phylogeny of 21 taxa of Astilbe was more informative, aligning cultivated varieties near species from which they were derived. The matK sequence variation for Astilbe taxa was aligned to reveal DNA polymorphisms. Closely related taxa retained polymorphisms at the same sites within the gene sequence. These polymorphic sites could potentially be utilized to confirm the lineage of popular cultivated Astilbe varieties.
Propagation of Astilbe seedlings in tissue culture gave rise to various numbers of microshoots from each of 15 seedlings. Multivariate and cluster analysis of morphological characters from 138 plants derived from 15 seedlings revealed potential somaclonal variants. These variants were characterized by one or more of the following traits: dwarf habit, dark green leaves (high chlorophyll content), increased flowering, or larger plant size. Somaclonal variants with desirable phenotypes may be valuable for cultivar development.Ph. D.
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Gilkison, Victoria A. "Transcriptomic Insights into the Morphological Variation Present in Bromeliaceae." TopSCHOLAR®, 2015. http://digitalcommons.wku.edu/theses/1495.
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The Bromeliaceae family utilizes a wide range of adaptations to inhabit a variety of environments including dry ones. Many attribute the large adaptive radiation of Bromeliaceae throughout the Neotropics to three main features: absorptive trichomes, tank reservoirs, and CAM photosynthesis. Based on leaf morphology and arrangement, root type, and nutrient acquisition, Pittendrigh (1948) conservatively separated bromeliads into four main classes. These four main classes are designated Type I bromeliads, Type II bromeliads, Type III bromeliads and Type IV bromeliads. We used RNA-sequencing of leaf mRNA to investigate similarities and differences in gene expression which can be related back to the four distinct leaf morphologies in the Bromeliaceae family. We found several transcripts relating to the presence of a tank and absorptive trichomes. In addition, we found evidence of varying forms of carbohydrate synthesis for carbon storage during CAM photosynthesis. Lastly, transcriptomics differences indicate different drought survival strategies, with the most extreme differences occurring between Aechmea nudicaulis and Tillandsia gardneri. This study identified transcripts related to the morphological gradient and highlighted how each ecological type has a particular set of adaptations and strategies for survive in a particular regime.
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Estiandan, Monica. "MORPHOLOGICAL VARIATION IN THE MONARDELLA ODORATISSIMA – MONARDELLA VILLOSA COMPLEX." Scholarly Commons, 2017. https://scholarlycommons.pacific.edu/uop_etds/2969.
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In this study, morphological characters were investigated to better characterize the species boundaries between members of the Monardella odoratissima – M. villosa complex (Lamiaeceae). Traditionally, it has been very difficult to identify and separate members of this complex. Monardella linoides, M. purpurea, and M. sheltonii populations are distributed in the overlapping boundaries of these two species (M. odoratissima and M. villosa) and considered within the complex as well. Previous studies and floral manuals have found that the vegetative plant parts from these five Monardella species intergrade with the other taxa in the complex throughout their distribution in California and in the western United States. Many of these vegetative characters are used to differentiate the five species from one another. Furthermore, floral characters have not been studied as a tool for delimiting species in this genus. Univariate and multivariate statistical analyses (ANOVA, Kruskal-Wallis, Principal Components Analysis, Discriminant Analysis, Mantel Tests, and Cluster Analysis) of measurements of nine vegetative and 21 floral characters were used to gain a more accurate idea of relatedness between these five species of Monardella and help strengthen the argument for reclassification of the species’ taxonomic identities. Based on analysis of single characters among the five Monardella species, discontinuities among the taxa were not observed. The multivariate analyses performed in this study were unable to fully segregate Monardella species from one another and did not suggest clearly defined taxa. Overlap and intermingling between all species was seen in all analyses. This study was unable to define consistent floral combinations for detecting and delimiting taxa. In floral morphology, flower length characters were found to be weakly correlated with flower width characters. This study found there was little to no relationships between both morphological distance and geographic location. However, both morphological variation and elevation were found to be more strongly correlated. In general, species boundaries in this complex are difficult to identify.
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Townsend, Grant Clement. "Genetic studies of morphological variation in the human dentition /." Title page, contents, preface and overview only, 1994. http://web4.library.adelaide.edu.au/theses/09D/09dt748.pdf.
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Liu, Jianyang. "Morphological and genetic variation within perennial ryegrass (Lolium perenne l.)." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1127245394.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xiii, 123 p.; also includes graphics (some col.). Includes bibliographical references (p. 99-107). Available online via OhioLINK's ETD Center
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Brown, Jessica Lynn. "Morphological variation of the proximal femur in selected skeletal remains." Diss., Click here for available full-text of this thesis, 2006. http://library.wichita.edu/digitallibrary/etd/2006/t039.pdf.
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Svanbäck, Richard. "Ecology and Evolution of Adaptive Morphological Variation in Fish Populations." Doctoral thesis, Umeå University, Ecology and Environmental Science, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-196.
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The work in this thesis deals with the ecology and evolution of adaptive individual variation. Ecologists have long used niche theory to describe the ecology of a species as a whole, treating conspecific individuals as ecological equivalent. During recent years, research about individual variation in diet and morphology has gained interest in adaptive radiations and ecological speciation. Such variation among individual niche use may have important conservation implications as well as ecological and evolutionary implications. However, up to date we know very little about the extension of this phenomenon in natural populations and the mechanisms behind it.
The results in this thesis show that the extension of individual diet specialization is widely spread throughout the animal kingdom. The variation in diet is mainly correlated to morphological variation but not always. Furthermore, this variation in diet and morphology among individuals could be both genetically determined and environmentally induced and it mainly comes from trade-offs in foraging efficiency between different prey types.
The results from a number of studies of perch also show that individual perch differ in morphology and diet depending on habitat, where littoral perch has a deeper body compared to pelagic perch. This difference in morphology corresponds to functional expectations and is related to foraging efficiency trade-offs between foraging in the littoral and pelagic zone of a lake. The variation in morphology in perch is mainly due to phenotypic plasticity but there are also small genetic differences between the littoral and pelagic perch. Two separate studies show that both predation and competition may be important mechanism for the variation in morphology and diet in perch.
In conclusion, the results in this thesis show that individual variation in diet and habitat choice is a common phenomenon with lots of ecological and evolutionary implications. However, there are many mechanisms involved in this phenomenon on which we are just about to start learning more about, and only further research in this area will give us the full insight.
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Anders, Constance. "Morphological, Molecular, and Biogeographical Variation within the Imperiled Virginia Spiraea." TopSCHOLAR®, 2000. http://digitalcommons.wku.edu/theses/709.
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Spiraea virginiana Britton is a rare federally listed rhizomatous shrub endemic to the southern Blue Ridge and Appalachian Plateau physiographic provinces. Populations of S. virginiana are found restricted to scoured sections of high gradient streams within the Ohio River drainage. Present evidence indicates the species is reproducing asexually, most probably through the deposition of rhizomes from upstream populations forming new downstream ramets. Phenotypic variation was examined through a morphometric evaluation of 25 leaf measurements and analyzed using Principal Components Analysis (PCA) and discriminant function analysis. Identity and structure at the molecular level as examined with Randomly Amplified Polymorphic DNA (RAPDs) and band patterns were used to construct a cluster analysis. Past gene flow was identified by combining cluster analysis and biogeography data. Results support the current species delineation by affirming the S. virginiana/S. corymbosa species boundary. Patterns of variation found within S. virginiana indicate that there is some degree of relatedness along short reaches of a single river and that within a secondary drainage basin a downstream distribution of propagules from multiple tributaries results in a mix of phenotypes. Patterns of variation further indicate that past gene flow had occurred across drainages suggesting a pattern of migration during Pleistocene glaciation. Results place the S. virginiana ancestral population in the southern part of its range suggesting a southward migration followed by recolinization northward, concordant with the work of Delcourt and Delcourt (1981, 1984). Biogeographical patterns of variation within S. virginiana identify the Cumberland Plateau as a migratory route. In addition, evidence suggests that the deeply dissected Cumberland Plateau is the probable site of a Pleistocene refugium.
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Veldkornet, Dimitri Allastair. "Morphological variation and species diversity of South African Estuarine macrophytes." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1013001.
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Studies on morphological variation are important as it can depict the relationship with environmental factors clearly and convey an understanding of the manner, mechanism and factors influencing plant adaptation and evolution. Although many studies have been conducted on South African salt marsh plant physiology and phytosociology there are at present very few morphological studies on estuarine plants. The aim of this study was to compare the morphological variation of estuarine macrophytes in three different estuary types in the warm temperate biogeographic zone of South Africa and to compare characters used in the taxonomic descriptions of species with those measured in the field. Permanently open estuaries investigated were Ngqusi (WC), Kowie (KW) and Swartkops (SW) estuaries. The Knysna Estuary (KN) was the estuarine bay investigated and the temporarily open/ closed estuaries (TOCEs) were the East Kleinemonde (EK) and Great Brak (GB) estuaries. Macrophytes were morphologically different across different estuary types. This suggests that there were different factors operating between these estuary types that would directly influence the morphology of species. The variation of plant height with different estuary types can be attributed to the fact that smaller salt marshes also have smaller habitat ranges compared to larger ones. The variation in morphological characteristics such as plant height can also be attributed to biogeographical range. Most morphological characteristics measured in the field fall within previously published ranges, and so these characters are useful in delimiting species. There were significant relationships between phenotypic variables and multivariate environmental variables. The most important of these variables were soil electrical conductivity, soil organic content and soil water content. Specifically, plant height increased with water content and decreased with salinity, flower stalk length had strong significant positive correlations with moisture content, organic content and pH while there were strong significant correlations with redox potential and electrical conductivity. Salt marshes are considered ideal for studying variation of species due to the explicit environmental gradients and plants occurring in salt marshes are halophytes that exhibit a range of morphological traits that allows for growth and reproduction under the stressful and extreme conditions. Considering recent climate change predictions and the consequent effects on South African estuaries this study provides significant information with regard to the response of species to a changing environment. The study was also aimed at updating the existing botanical database for South African estuaries in terms of species occurrence in South African estuaries, taxonomic name changes of existing species, new species, common names and habitats. Species diversity indices were also calculated for different estuaries, estuary types and biogeographic zones and diagnostic descriptions of the dominant salt marsh species were developed. The objective of this was that these data should provide baseline information for determining habitat richness and plant species diversity of South African estuaries which in turn should be used in determining priority estuaries for conservation and management. The identification key, developed using the DELTA software, would also aid researchers, managers and laymen in identifying salt marsh species. Results showed that the total number of macrophyte species, including intraspecific taxa and macroalgae, was 242 in 53 estuaries that were updated . There was an increase in the number of taxa recorded in the database primarily due to 1) research focus and full taxonomic surveys on larger estuaries and the big research projects has led to the identification of more species, 2) the addition of species that are not characteristically known as estuarine species, 3) the addition of 50 macroalgal taxa and 4) minor changes due to taxonomic revisions of species and the addition of newly described species. The Shannon diversity index showed that greater species diversity was found in the Berg (Groot) Estuary (4.220) and the Uilkraals Estuary (4.025). The cool temperate bioregion was the most diverse in the number of taxa (58) with the highest Shannon index (4.736). Permanently open estuaries were the most diverse in the number of unique taxa (56) with the highest Shannon index (4.867). Estuarine managers need to be aware of the species diversity in different estuarine types as well as the associated impacts on them. Conservation planning must therefore include species. Diagnostic features of INTKEY indicated that all 57 taxa were distinguishable from each other. Contrary to expectations plant height and not floral morphology was the best diagnostic characteristic. Ecological information such as the estuarine habitat, where different life forms occur, was important in delimiting species.
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Svanbäck, Richard. "Ecology and evolution of adaptive morphological variation in fish populations /." Umeå : Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-196.
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Quinney, Patrick S. "Taxonomic implications of morphological variation in Middle Pleistocene archaic Homo." Thesis, University of Liverpool, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402331.
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Riga, Alessandro <1984>. "Environmental influence on the phenotype: Morphological variation in human dentition." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6416/1/riga_alessandro_tesi.pdf.
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This work is about the role that environment plays in the production of evolutionary significant variations. It starts with an historical introduction about the concept of variation and the role of environment in its production. Then, I show how a lack of attention to these topics may lead to serious mistakes in data interpretation. A statistical re-analysis of published data on the effects of malnutrition on dental eruption, shows that what has been interpreted as an increase in the mean value, is actually linked to increase of variability. In Chapter 3 I present the topic of development as a link between variability and environmental influence, giving a review of the possible mechanisms by which development influences evolutionary dynamics. Chapter 4 is the core chapter of the thesis; I investigated the role of environment in the development of dental morphology. I used dental hypoplasia as a marker of stress, characterizing two groups. Comparing the morphology of upper molars in the two groups, three major results came out: (i) there is a significant effect of environmental stressors on the overall morphology of upper molars; (ii) the developmental response increases morphological variability of the stressed population; (iii) increase of variability is directional: stressed individuals have increased cusps dimensions and number. I also hypothesized the molecular mechanisms that could be responsible of the observed effects. In Chapter 5, I present future perspectives for developing this research. The direction of dental development response is the same direction of the trend in mammalian dental evolution. Since malnutrition triggers the developmental response, and this particular kind of stressor must have been very common in our class evolutionary history, I propose the possibility that environmental stress actively influenced mammals evolution. Moreover, I discuss the possibility of reconsidering the role of natural selection in the evolution of dental morphology.
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Riga, Alessandro <1984>. "Environmental influence on the phenotype: Morphological variation in human dentition." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6416/.
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This work is about the role that environment plays in the production of evolutionary significant variations. It starts with an historical introduction about the concept of variation and the role of environment in its production. Then, I show how a lack of attention to these topics may lead to serious mistakes in data interpretation. A statistical re-analysis of published data on the effects of malnutrition on dental eruption, shows that what has been interpreted as an increase in the mean value, is actually linked to increase of variability. In Chapter 3 I present the topic of development as a link between variability and environmental influence, giving a review of the possible mechanisms by which development influences evolutionary dynamics. Chapter 4 is the core chapter of the thesis; I investigated the role of environment in the development of dental morphology. I used dental hypoplasia as a marker of stress, characterizing two groups. Comparing the morphology of upper molars in the two groups, three major results came out: (i) there is a significant effect of environmental stressors on the overall morphology of upper molars; (ii) the developmental response increases morphological variability of the stressed population; (iii) increase of variability is directional: stressed individuals have increased cusps dimensions and number. I also hypothesized the molecular mechanisms that could be responsible of the observed effects. In Chapter 5, I present future perspectives for developing this research. The direction of dental development response is the same direction of the trend in mammalian dental evolution. Since malnutrition triggers the developmental response, and this particular kind of stressor must have been very common in our class evolutionary history, I propose the possibility that environmental stress actively influenced mammals evolution. Moreover, I discuss the possibility of reconsidering the role of natural selection in the evolution of dental morphology.
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Leguizamón, Sergio David Bolívar. "Morphological variation and taxonomy of Lepidocolaptes angustirostris (Vieillot, 1818) (Passeriformes: Furnariidae)." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/38/38131/tde-14012015-155408/.
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Lepidocolaptes angustirostris (Narrow-billed Woodcreeper) is a South American woodcreeper that inhabits predominantly open lowlands such as the Cerrado, Chaco and Caatinga. This species exhibits highly variable morphology and vocalization throughout its range. The taxonomic position of L. angustirostris is doubtful; it can be located in at the root or within the Lepidocolaptes genus radiation, depending on the author. Two main groups are recognized within the species, a northern clade distributed in the lowlands of northern Bolivia and central and northern Brazil, and a southern group, which inhabits northern and central Argentina, Uruguay and the state of Rio Grande do Sul, in Brazil. Eight subspecies are currently recognized based on plumage and geographical distribution patterns. However, a more detailed morphological analysis and taxonomic revision have not been conducted in this species. Based on the above information, the objective of this project is to conduct a taxonomic revision of L. angustirostris using morphometrical, plumage, and vocal characters. Second, with the aim to test the existence of phenotypic gradients associated to geographical and climatic variations in the taxon, a clinal and GLM analyses were performed. Finally, a distributional pattern was elaborated using geo-referenced records of examined individuals of the Narrow-billed Woodcreeper. The phenotypic analyses allowed us to identify six main plumage types; however, we also found a high level of intergradation among all of these populations. The PCA analyses show certain levels of morphological differentiation among the populations, with a first component correlated with bill characters (bill length, exposed and total culmen), and a second one that reflects the bill width and the tarsus-metatarsus length. These two components could explain 70.88% of the morphological variation described. Evidence of a latitudinal morphological variation was found, summarized in a series of clines partially overlapped on a region localized from the southern Cerrado and Pantanal ecoregions through the Humid and Dry Chaco and the Paraná Flooded Savanna, to the Espinal and Humid Pampas ecoregions. Some climatic variables explain the geographical variation in the taxon, mainly, temperature seasonality, annual precipitation, and minimum temperature of the coldest month. The ecogeographic rules of Bergmann and Gloger are consistent with this variation, as well as the Allens rule, but more narrowly. Thus, the populations of the Narrow-billed Woodcreeper tend to be larger to the south of the distribution. Due the intergradation of all populations found, with no clear diagnosable population, we propose here that Lepidocolaptes angustirostris be treated as a unique species with no subordinate taxa. Any evidence collected here did not support the taxonomic validity of the proposed subspecies in the Narrow-billed Woodcreeper. Despite colour-polymorphism identified in the plumage patterns, the high level of intergradation, the poor resolution of geographical boundaries, and the existence of clinal variation with a plausible introgression among populations not support the splitting of this species in several taxonomic subunits.Lepidocolaptes angustirostris (arapaçu-do-cerrado) habita principalmente regiões abertas como a Caatinga, Cerrado e Chaco. Esta espécie apresenta morfologia e vocalização muito variáveis em toda a sua distribuição geográfica. A posição taxonômica de Lepidocolaptes angustirostris não é clara, sendo localizado na raiz ou dentro da radiação do gênero Lepidocolaptes. Dois grupos principais são reconhecidos: um grupo do norte que habita as terras baixas do norte da Bolivia e da região central do Brasil para o norte, e um grupo do sul das regiões do norte ao centro-norte da Argentina, Uruguai, e no Estado do Rio Grande do Sul, sul do Brazil. Oito subespécies são atualmente reconhecidas baseadas em padrões da plumagem e distribuição geográfica. Uma análise morfológica e uma revisão taxonômica nunca foram realizadas nesta espécie. Com base nas informações acima, o objetivo deste projeto é desenvolver uma revisão taxonômica de Lepidocolaptes angustirostris usando caracteres morfológicos e vocais. Além disso, para testar a existência da variação geográfica no táxon, uma análise clinal foi realizada. Finalmente, análises de (GLM) foram feitas para identificar variáveis ambientais que possam explicar esta variação, e um mapa de distribuição geográfica foi elaborado usando os registros geográficos dos indivíduos examinados L. angustirostris. Os resultados indicam que as diferentes populações do complexo Lepidocolaptes angustirostris que habitam as areas abertas da Caatinga, Cerrado e Chaco (mais as populações amazônicas) não têm um nível significativo de diferenciação morfológica nem da plumagem para serem consideradas como espécies válidas. As análise do PCA apresentaram baixos níveis de diferenciação morfológica entre os grupos propostos, com um primeiro componente formado por caracteres do bico (comprimento, cúlmen exposto e cúlmen total), e um segundo componente formado por largura do bico e comprimento do tarso, explicando 70,88% da variação identificada. Igualmente, há evidência de uma variação morfológica latitudinal nos dados analisados, apresentado em uma série de clinas parcialmente sobrepostas sobre uma região localizada desde o sul do Cerrado e Pantanal através das ecoregiões do Chaco Úmido e Seco e a savana inundada do Paraná, até as ecoregiões do Espinal e dos Pampas Úmidos. Nas análises do GLM, algumas variáveis climáticas explicaram a variação geográfica no táxon; principalmente a sazonalidade térmica, a precipitação anual, e a temperatura minima do mês mais frio. As leis ecogeográficas de Bergmann e Gloger podem ser aplicadas nesta variação, assim como a lei de Allen, mas de forma restrita. Assim, as populações do Arapaçu-do-cerrado tendem a ser maiores ao sul da distribuição. A proposta apresentada aqui é de manter o status taxonômico de Lepidocolaptes angustirostris como uma espécie única, e propor evitar a utilização das denominações subespecíficas para este taxon. A validade taxonômica das subespécies no Arapaçu-do-cerrado não foi suportada por quaisquer das evidências coletada aqui. A pesar do polimorfismo de cores identificado nos padrões da plumagem, o elevado nível de intergradação, a baixa resolução dos limites geográficos entre as populações, e a presença de uma variação clinal com um nível considerável de introgressão entre populações não suportam a divisão de uma única espécie em várias sub-unidades taxonômicas.
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Hopper, Garrett W. "Ecological and morphological variation of darters among assemblages in Oklahoma streams." Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/20116.
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Master of ScienceBiology
Michael Tobler
Environmental variation can shape phenotypic variation in organisms. Most evidence for trait differentiation along environmental gradients comes from analyses of dichotomous habitat types that differ in only one or few environmental factors. In reality, however, environmental variation is often more subtle, gradual, and multifarious. I investigated geographic variation in body shape, trophic resource use, and individual diet specialization in two species of darters (Etheostoma spectabile and E. flabellare; Percidae) that occur along river gradients. I explicitly tested how abiotic and biotic environmental factors shape trait variation within and between species. Results indicated significant among population variation in the body shape of both species. Population differences in body shape were correlated with variation in substrate composition. Although body shape analyses revealed a small but significant signal of convergent evolution of body shape when both species occur in sympatry, E. spectabile and E. flabellare mostly exhibited unique responses to shared sources of selection. The analyses of darter trophic resource use uncovered significant resource partitioning between the two species and geographic variation in diets that is likely driven by differences in resource availability. Furthermore, the majority of populations exhibited significant individual specialization. Variation in individual specialization in populations of E. flabellare was related to invertebrate density and competitor richness, and in E. spectabile to the combined effects of invertebrate density and invertebrate diversity. My results indicate substantial variation in trophic resource use among individuals, populations, and species of small-bodied fishes that are typically assumed to be generalist insectivores. Variation in diet specialization may be more widespread than previously considered, and ecological opportunity is an important factor in shaping trophic resource use of individuals and populations. Overall, the results indicate that even subtle and gradual environmental variation can induce substantial variation in phenotypes on a relatively small spatial scale.
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Sorrentino, Rita <1989>. "Exploring morphological variation in hominid talar bones using geometric morphometric approaches." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amsdottorato.unibo.it/8876/1/Rita%20Sorrentino_PhD_thesis.pdf.
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This thesis focused on the exploration of morphological variation in extinct and extant hominid talar bones through (semi)landmark-based geometric morphometric methods.
The first section of this project analyzes sexual dimorphism in three modern human groups for which the sex is known from cemetery and municipal records. Shape, form and size variables have been investigated. Results shown that changes in size have the higher power in driving sexual differences in modern humans.
The second section aims to evaluate both external and internal (trabecular bone) architecture of modern human tali related to populations with different lifestyle (nomadic vs. sedentary) and subsistence strategy. The goal is to determine changes related to different loadings during bipedal locomotion using both geometric morphometric and biomechanical methods. Overall, the results show differences between hunter-gatherers and sedentary groups, indicating that different locomotor behaviors of modern humans affect both internal and the external talar morphology.
The third section investigate the morphological variability of extinct and extant hominid tali. The evolutionary timing and appearance of modern human-like features and their contributions to bipedal locomotion were evaluated on the talus as a whole, each articular facet separately, and multiple combinations of talar facets. We trace the evolutionary emergence of talar features in the human lineage that are linked to the biomechanical demands of bipedalism. We show that a more everted foot and stable medial midtarsal region are early adaptive modifications that coincide with the emergence of bipedalism, while a high medial longitudinal arch emerges comparatively more recently in the human evolutionary lineage
In conclusion, this research points out that the talar morphology could be informative of intra- and inter specific anatomical variability in hominid taxa.
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Makhasi, Ntuthuzelo. "Morphological and genetic variation in samango monkeys (Cercopithecus albogularis) in Southern Africa." Thesis, University of Fort Hare, 2013. http://hdl.handle.net/10353/d1018580.
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My aim was to resolve the taxonomy of the South African forms of Cercopithecus albogularis by exploring morphological and genetic variation in the two samango subspecies described for the region: C. a. erythrarchus and C. a. labiatus. In addition, I estimated their geographic distributions and habitat requirements from the provenance data I collected during my study of museum specimens. My analysis has shown clear morphological differences between C. a. labiatus and C. a. erythrarchus. The two subspecies differ in pelage coloration, but also in cranial shape and tail lengths. Furthermore, C. a. labiatus is slightly smaller, shorter-tailed and stocky compared with the long-tailed slender northern forms of C. albogularis, which may be adaptations to cold environments like montane forest. The northern C. albogularis subspecies are distinguishable from the southern taxa with a high degree of reliability (98.5%), suggesting that C. albogularis consists of more than one species. The most appropriate name for the southern species is C. labiatus. My genetic study did not detect variation among the 10 animals sampled in Hogsback; while it clustered the different taxa, it could not resolve relationships between them, with the exception of the outgroup. The lack of resolution of the deeper nodes could be a result of the fact that our sequence was very short (274 bp). The mt 12S rRNA gene was not an ideal gene for this study, which should have involved a less conserved section of the mtDNA molecule, like the rapidly evolving D-loop. More genetic work is clearly needed to resolve the phylogenetic relationships within the C. mitis supergroup. However, preliminary genetic data indicate that the southern samangos are distinct from the C. mitis of West Africa, while my morphometric study suggests they may also be distinct from C. albogularis in East Africa. Molecular and karyological studies comparing the genomes of Hogsback “C. a. labiatus” with the neighbouring “C. a. erythrarchus” and Zanzibar C. albogularis would be extremely enlightening.
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Florin, Ann-Britt. "Bottlenecks and blowflies : Speciation, reproduction and morphological variation in Lucilia." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-5133-0/.
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Fu, Wing-kan, and 傅詠芹. "Population dynamics, diet and morphological variation of the Hong Kongnewt (Paramesotriton hongkongensis)." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44676372.
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El, Salman Mahmoud Ahmad Moh'd Said. "Phonological and morphological variation in the speech of Fallahis in Karak (Jordan)." Thesis, Durham University, 2003. http://etheses.dur.ac.uk/1072/.
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This study is conducted in the Karak area (Jordan) to investigate linguistic variation in the speech of the Fallahis who migrated to the area in 1948. Three variables are considered to investigate this variation. These are the (Q), (Vki) and (K). The study shows that young Fallahis have abandoned the variants of their native dialect in favour of the local variants, or sometimes the urban variant. Young Fallahis have abandoned the [k] variant of the variable (Q) in favour of the local variant [g] or [?] and the [ik] variant of the variable (Vki) in favour of the local variant [ki]. They also appear to have abandoned the variant [C] of the variable (K) in favour of the [k] variant. The study also shows that while none of the young males abandon the non-local variant [k] in favour of the urban variant [?], a considerable proportion (50%) of young females appear to have abandoned the non-local [k] variant in favour of the urban variant [?]. The young, thus, appear to prefer the local variants of the investigated variables whether this variable is stereotype like (Q) or a marker like (Vki). A considerable proportion of the middle age-group also show a tendency to accommodate to the local variant [g] as well as the local variant [ki). The old appear to preserve the variant [k] and the variant [ik] of their native dialect. The variant [C] of the variable (K) is categorically abandoned by the young and used in a very low ratio by the middle-age group (6%), but rather more frequently by the old age group (430/0). In this regard, we can report a sound change which is near completion in the Karak area in the speech of the Fallahis.
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Roussos, Athanasios. "Morphological variation, population genetics and genetic relatedness in three species of Callopora." Thesis, Swansea University, 2007. https://cronfa.swan.ac.uk/Record/cronfa42590.
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The genus Callopora is typical of a very large number of encrusting neocheilostomate genera and can be used to demonstrate the range of autozooid morphology seen in the group. Morphometric analyses of zooid length (ZL), zooid width (ZW), ovicell length (OL) and ovicell width (OW) were conducted in order to study morphological variation in different populations of Callopora dumerilii, Callopora lineata and CaUopora rylandi and to partition the morphological variation within and between sites and colonies for each species using a nested analysis of variance and a principal component analysis approach. In addition, the genetic structure in populations of these three Callopora species using the mitochondrial DNA COI gene was examined to test hypotheses concerning levels of population differentiation and intrapopulation variation. The relationships of mtDNA lineages within and between species was also investigated to clarify the phylogenetic relationships of the three species and to search for possible phylogenetic subdivisions within species. The morphological characters zooid length and zooid width were significantly different between different sites for Callopora lineata and Callopora dumerilii, but not for Callopora rylandi. However, major differences for these two morphological variables appeared in all three species in between colony within site comparisons. When comparing the ovicell length variable between different sites, noteworthy differences appeared only for Callopora rylandi, whereas considerable differences appeared in all three sites for between colonies within site comparisons. On the other hand, non-significant differences appeared for all three species when comparing ovicell width between different sites whereas highly significant differences appeared for between colony within site comparisons. The results of principal component analysis together with the results from nested ANOVA revealed that for factor 1, which defines aspects of the overall size of the zooid, there were significant differences between sites, as well as between colonies within sites for Callopora rylandi. For Callopora dumerilii and Callopora lineata, it appeared that there were no significant differences between different sites whereas there were notable differences between different colonies within sites. For factor 2, which defines aspects of the shape of the organism, there were significant differences between sites as well as between colonies within sites for both Callopora rylandi and Callopora dumerilii, while for Callopora lineata it emerged that there were no significant differences between sites, but there were important differences between colonies within sites. Analysis of the mitochondrial DNA population structure in these three species based on either haplotype frequencies or sequence divergence showed a large percentage of genetic variation within populations and a much smaller percentage of genetic variation among populations. However, for haplotype frequencies the among populations P values were significant for all species whereas when sequence divergence was taken into account only the P value for Callopora rylandi was significant. Overall nucleotide diversity was similar for Callopora dumerilii and Callopora lineata and higher than that of Callopora rylandi, whereas overall haplotype diversity was similar in all three species. Tajima's D and Fu's Fs test statistic appeared more negative in Callopora rylandi than the other species suggesting greater purifying selection or a recent population expansion. Comparisons based on dn/ds ratio suggested purifying selection as well. Reconstruction of phylogenetic relationships showed three major lineages which are mixed in all three species. Tests of neutrality in these lineages, which do not correspond to species, also suggested the existence of purifying selection.
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Hasnain, Hashim. "Is there a relationship between morphological variation and genetic variation of enzyme and blood group loci in human populations?" Thesis, Loughborough University, 1991. https://dspace.lboro.ac.uk/2134/25401.
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The relationship between variability in 27 morphological traits and genetic variation at three enzyme loci (EsD, PGM-1 and AP) and three blood group loci (MN, ABO and Rhesus) was studied in two Caucasian populations. No difference was noted in the mean values of the homozygous and heterozygous classes at the loci studied in both populations. Neither was there any difference in the percentage of 'Modal' individuals among the homozygous and heterozygous classes in the two populations. However, at the EsD, PGM-1, AP and MN loci, a negative correlation was observed between morphological variance and heterozygosity in both populations. These results are in agreement with Lerner's prediction of 'Genetic Homeostasis'. Lerner's understanding of the correlation was that heterozygosity at the individual or population level was advantageous as it provided the organism with a greater buffering ability to withstand environmental change and, therefore, a greater chance of survival and reproduction. In the English population no significant departures from Hardy Weinberg expectations were observed for the three enzyme loci AP, EsD and PGM-1 and the blood group locus MN, hence it can be assumed that a random mating population was sampled. However, in the Gujarati Indian population significant departures from Hardy Weinberg expectations were noted at the EsD and AP enzyme loci, due to an excess of homozygotes and a deficiency of heterozygotes. A number of possible reasons can be given to explain this, although it is most likely due to inbreeding. On comparing the gene frequencies of the biochemical systems in this study with those recorded by other researchers, a close agreement was noted. This indicates that the population sample studied is representative of the parent population. On comparing the results of the anthropometric data in the English population with that in the Gujarati population, differences are noted in human morphology. The Gujaratis tend to be shorter in stature, have a lower body mass and less subcutaneous fat tissue. This is partially due to hereditable differences between the two populations but the possibility of some environmental effect still exists. Several theories explaining the negative correlation between morphological variation and heterozygosity have been put forward. They basically fall into two categories, those that attribute the correlation to the scored loci themselves (mostly enzyme loci), and those that consider the scored loci as markers for genetic conditions that are not detectable by the assay method involved but are, nevertheless, the causative agents of the morphological variation in individuals. The theory of additive allelic effects was directly addressed in this study. This theory implies that the observation within a population. that the least phenotypic variation exists among the most heterozygous individuals can be explained by genotype pooling. In this study the homozygote genotypes were both pooled and then separated to look for any differences in variance of the traits in the two situations. No reduction in morphological variation was noted when the homozygous genotypes were treated separately instead of pooled, hence no evidence to support the theory of additive allelic effects. At present there is no consensus about the genetic mechanism underlying the morphological variance/heterozygosity correlation or any other correlation of heterozygosity with a phenotypic trait. This is not because one cannot choose among competing hypotheses that can explain the observations but rather because it is difficult to arrive at a hypothesis that will be consistent with all (or even the bulk) of the results to date. The observed negative correlation between morphological variation and heterozygosity was more pronounced in the English population than the Gujarati population suggesting that hypotheses that place a stronger emphasis on the structure of the population than on the scored loci e.g. associative overdominance, are more likely to explain those findings.
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Banerjee, Satindranath Mishtu. "The ontogeny of morphological variation : an example from yellow-cedar [Chamaecyparis nootkatensis (D. Don Sprach)]." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28893.
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The papers in this thesis represent a series of attempts — empirical and theoretical — to integrate developmental biology with population level studies of variation; to initiate a "developmental population biology" which would complement the well established fields of population ecology and population genetics. The introductory chapter traces the development of the conceptual ideas from the context of the maturation of a single research group.
There follow three empirical chapters based on population studies of yellow cedar (Chamaecyparis nootkatensis). The first of these chapters examines the interdependency of progeny growth variation on parentage and stand structure and argues that parentage, developmental history and environmental contingencies can interact in complex ways to structure the variation observed in natural stands. The second chapter examines time related changes in patterns of variation for mainstem growth and needle initiation data of seedlings, and finds that the majority of the increase in variation with time results from differentiation among individual seedlings. The third chapter examines the nature of intra-individual variation in needle (from seedlings) and scale (from mature trees) data from the perspective of the concept of morphological integration, the amount and structure of covariation within an individual. The results of this chapter demonstrate that the nature of morphological integration changes during the course of development, and that variation in morphological integration — that is the pattern of variable relationships or covariance structure — distinguishes individuals.
The final chapter is more theoretically oriented, and demonstrates how the patterns of increasing variation with time, and changing covariation with development (Chapters 2, 3) may be unified and explained in the context of developmental trajectories, where such trajectories represent the development of the form of individual organs through time in terms of point trajectories through a multivariate space. The nature of such developmental trajectories is ultimately a manifestation of cell division and elongation in various planes, resulting in the external form of the organs. Three increasingly complex graphical models of developmental trajectories are presented and it is argued that when developmental trajectories diverge from each other in a nonlinear manner, changes can occur in both correlation and covariance structures, coincident with changes in size. The relation between developmental trajectories and the production of variation within populations is further elaborated from the context of dynamical systems theory.Science, Faculty of
Botany, Department of
Graduate
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Dawson, Hope C. "Morphological variation and change in the Rigveda: The Case of -au vs. -ā:." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1110469087.
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Nguyen, Huy Thong. "Genotypic, physiological and morphological variation for rice grown under a raised bed system /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19049.pdf.
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Gíslason, Davíd. "Genetic and morphological variation in polymorphic Arctic charr, Salvelinus alpinus, from Icelandic lakes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ33225.pdf.
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Lima, Rodrigo. "Morphological variation in red-backed voles (Myodes gapperi) in Québec and Western Labrador." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114592.
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Environmental heterogeneity has long been associated with morphological variation in small mammals. Studies of ecotypic variation across time and space provide valuable information about the way organisms' phenotypes respond to changing environmental conditions and the major factors influencing morphological changes, providing insight into the mechanisms that promote adaptation. In this thesis, I quantified morphological variation among 12 populations of the widespread and abundant southern red-backed vole, and examined the degree to which climate, primary productivity and ecozones explained variation in the morphological traits. Teeth and skulls of voles collected in several locations along a 1,000 km latitudinal gradient in Québec and Western Labrador were studied using geometric morphometric methods, and the relations between morphology and environmental and spatial variables were examined. Most of the spatial variation in morphology was correlated with environmental gradients. The morphological differentiation among populations could be explained by the environmental differences between their habitats, and precipitation and ecozone were the environmental variables mostly correlated with morphological variation.L'hétérogénéité de l'environnement a depuis longtemps été associée à la variation morphologique chez les petits mammifères. Les études de la variation écotypique dans le temps et dans l'espace fournissent des informations utiles sur la réponse du phénotype des organismes aux variations des conditions environnementales, sur les principaux facteurs qui influencent les changements morphologiques, et sur les mécanismes qui favorisent l'adaptation. Cette étude examine les réponses morphologiques d'un mammifère généraliste et abondant, le campagnol a dos roux de Gapper, à la variation du climat, de la productivité, et des écozones. Les dents et les crânes de campagnols échantillonnés à plusieurs sites le long d'un gradient de 1000 km de latitude au Québec et a l'Ouest du Labrador ont été étudiés en utilisant des méthodes de morphométrie géométrique, et les relations entre la morphologie et les variables environnementales et spatiales ont été examinées. La plupart de la variation spatiale de la morphologie est corrélée avec les variations de l'environnement. Les précipitations et les écozones sont les variables environnementales le plus fortement corrélées avec la variation morphologique, et la différenciation morphologique entre les populations peut être expliquée par la variation de l'environnement entre leurs habitats.
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Porteous, Robert. "Evolution in the genus Arum : a comparative analysis of morphological and genetic variation." Thesis, Bournemouth University, 2005. http://eprints.bournemouth.ac.uk/10556/.
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Testing the correlation of morphological and genetic marker variation enables the investigation of evolutionary processes. Knowledge of evolutionary processes can be used to identify those morphological characters that could be used to produce evolutionary meaningful taxonomies. This thesis aims to test the correlation between morphological and genetic marker variation to further understand the evolution of species within the genus Arum and identify those morphological characters that correspond with evolutionary groups. The investigation is carried out at the intraspecific level, intrageneric level and in a putative hybrid zone. At the intraspecific level, genetic (ISSR) and morphological variation was quantified in populations of the morphologically similar species A. maculatum and A. italicum. Populations of A. maculatum showed evidence of isolation by distance, presumably a result of pollinator behaviour and seed dispersal. Leaf patterning in A. maculatum did not correspond to evolutionary lineages. However, similar leaf patterning characters in A. italicum are used to classify the two subspecies neglectum and italicum and the ISSR analysis confirmed that these taxa are genetically distinct. These two subspecies were shown to be interbreeding in sympatric populations. The interbreeding has created a morphological and genetic difference between subsp. neglectum in sympatric populations compared with allopatric populations. At the intrageneric level, a phylogenetic analysis of Arum (using trnL and ITS 1 sequences) indicated that both vegetative and reproductive characters are convergent within the genus. The apparent convergent evolution of reproductive and vegetative characters indicates that both have been important during the diversification of the genus. These convergent characters are not useful for producing classifications that reflect evolutionary groups as the groups they produce are polyphyletic. In the putative hybrid zone, ISSR markers confirmed the presence of A. creticum and A. idaeum hybrids. There appears to be introgression of the A. idaeum genome into A. creticum; this could have implications for the future genetic integrity of A. creticum. Within this hybrid zone, continuous characters were found to be representative of genetic variation, however categorical characters were not. In conclusion, this thesis has shown that even within a single genus, the correlation between morphological and genetic marker variation is influenced by both the taxa being studied and the nature of the morphological trait. In particular, if morphological characters are found to be adaptively important, their correspondence to genetic groups should be tested before their use in taxonomies. The findings of this thesis also suggest there is great value in the complementary use of genetic and morphological analysis for taxonomic studies as well as evolutionary studies. For example, the importance of reproductive characters in the diversification of Arum species has produced a wide range of morphological variation, with limited taxonomic utility due to a tendency for homoplasy. Vegetative characters were also found to need careful testing before use in taxonomies as leaf patterning was found to correspond to sub-species status for one species of Arum but not another. Finally, this thesis has shown that, if closely related taxa are hybridising, variation of continuous reproductive characters may be used as an indicator of hybridisation, even if the morphological characters are potentially polygenic.
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Thomson, George. "Enzyme variation at morphological boundaries in Maniola and related genera (Lepidoptera: Nymphalidae: Satyrinae)." Thesis, University of Stirling, 1987. http://hdl.handle.net/1893/12198.
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The evolutionary biology of 14 species of Maniolini (Nymphalidae: Satyrinae) was studied. Electrophoretic analysis of 35 enzyme loci identified a larger number of alleles than an1 levels of polymorphism similar to those found in other Lepidoptera. In Maniola jurtina, some populations exhibited a massive heterozygote deficit and sex associated allele frequency differentiation at the GOT-l locus. Allele frequencies in pre- and post-aestivation jurtina from southern Europe were significantly different. At some loci, significant annual differences in allele frequencies were noted. A significant correlation between geographic and genetic distance in allele frequencies was observed, but no correlation was detected between heterozygosity and land area in insular populations. Cluster analysis and nonmetric multidimensional scaling per~ormed on electrophoretic data from populations of Maniola jurtina revealed a dichotomy between 'Eastern' and 'Western' subspecies groups. The analysis of Manioline species fitted existing taxonomies. Genetic differences between Maniola species were much smaller than those between Pyronia and Hyponephele species. Ultrastructural studies of the Maniola Jullien organs revealed a species-specific tooth pattern on the inner surfaces. It is suggested that these structures may be sound production mechanisms of great evolutionary significance to the species. Maniolini ova were studied and it is suggested that their form and chorionic sculpturing owe much to selection induced by oviposition strategy. Chaetotaxy of first instar larvae was undertaken and morphometric analysis of setal lengths was found to be useful, but not unambiguous. Multivariate analysis of chaetotaxy data showed a significant correlation with electrophoretic data. viii The evolution and zoogeography of Maniola is discussed. It is suggested that disjunction, founder effect, rapid post-glacial colonisation and bottlenecking have played a major roles in effecting rapid speciation. It is further suggested that all Maniola species are very recent, perhaps having evolved within the last 50,000 years, and some species almost certainly have evolved in postglacial times •
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McIntosh, Douglas. "Studies on bacterial fish pathogens : with emphasis on morphological variation in Aeromonas salmonicida." Thesis, Heriot-Watt University, 1990. http://hdl.handle.net/10399/1479.
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DeWoody, Jennifer. "Evolutionary and genetic basis of morphological variation in Populus nigra (European black poplar)." Thesis, University of Southampton, 2011. https://eprints.soton.ac.uk/203957/.
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Changes in precipitation over the next century may impact the distribution of species, particularly in southern Europe, where droughts are predicted to increase in frequency. In forest trees, intraspecific variation in leaf size, branching architecture, and growth rate among populations are considered adaptive and likely related to climatic differences between sites. A previous common garden study of Populus nigra L. showed morphological variation to be highly heritable and significantly differentiated among populations, indicating phenotypic differences may be adaptive. This project studied the evolutionary processes that have contributed to the morphological differentiation observed in P. nigra. Examining scales ranging from landscape-level patterns of variation to cellular differences within developing leaves identified historic and developmental processes contributing to the phenotypic differences in this species. Both isolation by distance, where migrants do not move equally across the landscape, and isolation by adaptation, where genetically divergence varies with morphological differences, have influenced differentiation among populations of P. nigra in western Europe. These patterns broadly correspond to the recolonization routes following the most recent glacial event, indicating that historic vicariance and not just adaptive divergence influence phenotypic variation. Identification of quantitative trait loci (QTL) for insect herbivory in a common garden study of hybrid poplar indicated that leaf morphology might also be influenced by insect preference. Among individuals, differences in leaf size corresponded to variation in cell number and not cell size, indicating natural selection may have influenced the regulation of cell division. Further, variation in gene regulation across the developing leaf identified differences across the leaf lamina. Finally, simulations of demographic, genetic, and adaptive processes among populations revealed that a lack of correspondence between the optimal phenotype of colonists and the optimal phenotype and newly colonized populations significantly affects levels of phenotypic differentiation among populations. In addition, changes in phenotypic optima, as may occur due to climate change, impacted the level of genetic variance, and thus the future adaptive potential of populations. Together, these results provide insight into the evolution of phenotype in P. nigra, and contribute information for management efforts in the context of a changing climate.
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Robarts, Daniel William Howard. "Investigations of morphological and molecular variation in wild and cultivated violets (Viola; Violaceae)." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1385555287.
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Dawson, Hope C. "Morphological variation and change in the Rigveda the case of -au vs. -a: /." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1110469087.
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Thesis (Ph. D.)--Ohio State University, 2005.Document formatted into pages; contains 359 p. Includes bibliographical references. Abstract available online via OhioLINK's ETD Center; full text release delayed at author's request until 2008 Mar. 10.
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Tojo, Bunji. "Heterochronic morphological variation and predatory drillholes on the shells of Vicarya yokoyamai (Gastropoda)." 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/149998.
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Ros, Petra. "Pollinator-driven floral variation in Tritoniopsis revoluta." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4198.
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Thesis (MSc (Botany and Zoology))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: It is thought that a large proportion of the great variety of floral structures in flowering plants reflect adaptations to different biotic pollen vectors. Divergence in flower traits and pollinators is linked to speciation. Pollinator-driven speciation is thought to have played a large role in the spectacular floral diversity found in South African Iridaceae and the genus Tritoniopsis is a particularly good example of this. This study focuses on Tritoniopsis revoluta, a pink irid occurring in the Swartberg and Langeberg Mountains, as well as Potberg Mountain. I tested the hypothesis that variation in flower tube-lengths of Tritoniopsis revoluta are related to the geographic distribution of pollinators and the variation of their tongue lengths. It was determined that this species is highly variable in respect to corolla tube-length and is pollinated by different fly species across its range. Also, the tongue-lengths of the fly pollinators corresponded almost exactly with the tube-length of the flowers they were pollinating in each population. In some populations, where long-proboscid flies were absent, bees were observed visiting T. revoluta flowers. This presents evidence for pollinator-driven floral variation within a single plant species, and most of this vast diversification in floral morphology has probably been driven by morphological variation found within a single fly family. In one population I found variable tube-lengths which appeared to exhibit a bimodal distribution of corolla tubelengths. I hypothesized that the two Tritoniopsis revoluta ecotypes at this population are pollinated by two different pollinators, leading to assortative mating, and ultimately strong inter-ecotype incompatibility. Tritoniopsis revoluta is self-incompatible and exists as two discrete entities (morphotypes) at the Gysmanshoek Pass site, and these entities differ in tubelength, color, nectar volume and sugar content. These morphotypes were not pollinated by long-proboscid flies, but seems to represent a recent shift to pollination by Amegilla bees. However, ecotypes are not reproductively isolated as short and long flowers can produce offspring, rather tube-length differences are possibly maintained through spatial separation. To compliment the correlatory data between flower tube-lengths and pollinator tongue-lengths, I used molecular tools (chloroplast markers and AFLPs) to elucidate the patterns of tube-length evolution in Tritoniopsis revoluta. I aimed to determine the directionality and frequency of transitions between tube-length categories. Tube-length transitions would be suggestive of flower morphology being labile, and together with the tube-tongue length correlation it suggests pollinator shifts may drive the changes in tube length. Character state reconstructions using tube-length as character determined that four evolutionary transitions to shorter tube-length categories and two transitions to longer categories occurred. I also tested whether morphological divergence between populations corresponds to patterns of divergence from neutral genetic markers. Population genetic structure in this system showed that the different populations of T. revoluta are vicariant and tube-length differences between them could have evolved through selection.
AFRIKAANSE OPSOMMING: Dit is ‘n algemene gedagte dat die groot verskeidenheid blom strukture in die angiosperme dui op aanpassings tot verskillende biotiese stuifmeel draers. Die diverse blom strukture in baie van die groot Kaapse genera kan verduidelik word deur aanpassings tot veranderinge in bestuiwings-sisteme. ‘n Aantal studies hieroor stel voor dat bestuiwers nie net die veranderinge in blom morfologie bewerkstellig nie, maar ook ‘n rol speel in die aanpassende uiteenlopendheid van blomplant kenmerke. Spesiasie bewerkstellig deur bestuiwers het moontlik ‘n groot rol gespeel in die blom-diversiteit wat gevind word in die Suid-Afrikaanse Iridaceae familie, en die genus Tritoniopsis is ‘n baie goeie voorbeeld hiervan. Hierdie studie fokus spesifiek op Tritoniopsis revoluta, ‘n pienk iris wat voorkom in die Swart- en Langeberge, asook by Potberg. Die hipotese dat die variasie in buis-lengtes van T. revoluta verwant is aan die geografiese verspreiding van bestuiwers en die variasie in hul tong-lengtes is hier getoets. Dit is bepaal dat hierdie spesie groot variasie toon in terme van buis-lengtes en bestuif word deur verskillende vlieg spesies regoor sy verspreiding. Die tong-lengtes van hierdie vlieë korrespondeer ook met die buis-lengtes van die blomme wat hul bestuif in elkeen van die T. revoluta populasies. In sommige van die populasies, waar lang-tong vlieë afwesig was, is bye wat die T. revoluta blomme besoek, opgemerk. Hierdie resultate lewer bewyse vir die hipotese dat bestuiwers blom morfologie kan beïnvloed; die interessante hiervan is dat die variasie in buis-lengtes in hierdie spesie heel moontlik te danke is aan die morfologies variasie wat gevind word in ‘n enkele lang-tong vlieg familie. In een van die populasies het ek ‘n bimodale verspreiding van buis-lengtes gevind. ‘n Logiese afleiding is dat hierdie twee verskillende buislengtes – ekotipes – deur twee verskillende bestuiwers besoek word, en dat dit lei tot sterk onversoenbaarheid tussen ekotipes. Tritoniopsis revoluta is nie instaat tot self-bestuiwing nie en die twee ekotipes verskil in terme van buis-lengtes, kleur, nektar volume en suiker inhoud. Kort- en lang-buis blomme word nie eksklusief bestuif deur lang-tong vlieë in die Gysmanshoek Pas nie, maar word in die algemeen ook bestuif deur bye van die genus Amegilla. Die twee ekotipes is in staat om te reproduseer met mekaar, so die buis-lengte verskille word moontlik in stand gehou deur hul geografiese skeiding. Om die korrelasie analise tussen blom buislengtes en vlieg tong-lengtes te komplimenteer, het ek molekulêre tegnieke (chloroplast merkers en AFLPs) gebruik om die patrone van buis-lengte evolusie in Tritoniopsis revoluta duidelik te maak. Ten eerste het ek bepaal of verkortings en verlengings van buis-lengtes een keer in die verlede gebeur het, of as meermalige gebeurtenisse. Meermalige veranderinge in buis-lengtes kan moontlik dui op verskuiwings tussen verskillende bestuiwers, asook taksonomiese verdelings wat korrespondeer met bestuiwer veranderinge. Ek het ook bepaal of die buis-lengte verskille in die verskillende populasies toegeskryf kan word aan seleksie prosesse. Deur buis-lengte as karakter te gebruik, het ek karakter-status rekonstruksies gedoen en bepaal dat vier ewolutionêre transisies na korter buis-lengte kategorieë, en twee transisies na langer kategorieë plaasgevind het. Populasie genetiese struktuur in die sisteem dui daarop dat T. revoluta populasies geïsoleer is deur afstand. Die konklusie wat ek trek gebasseer op hierdie resultate is dat verskille in buis-lengtes in hierdie sisteem moontlik ontstaan het as gevolg van die verskillende bestuiwers wat aktief is in die verskillende T. revoluta populasies, en dat natuurlike prosesse nie die hoofrol spelers in hierdie sisteem is ten opsigte van buis-lengte evolusie nie.
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Shaw, Kate. "An analysis of morphological variation within and between stream populations of Gasterosteus aculeatus Linnaeus." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24918.
Full textAbstract:
Two small streams on Vancouver Island, British Columbia, were examined
for patterns of morphological variation in Gasterosteus aculeatus. A progressive analysis beginning with Principle Components Analysis, followed by Nested and Partially Nested Multiple Analysis of Variance and then Duncan's Multiple Range Test was used for pattern determination. This new technique allows the researcher to sequentially isolate the pattern of variation at different levels of generality from species to individual organisms. The pattern of variation for G. aculeatus in Bonsall Creek and Nunns Creek can be summarized as follows: The largest amount of variation accounted for by the analysis is interpreted
as individual variation. Populations also account for a large amount of variation and show consistent, fully nested patterns of variation
at each of the analysed geographic and microgeographic levels. These populations are probably genealogical units. The so-called "leiurus" and "trachurus" forms on the Pacific coast of North America do not appear to be evolutionary entities, but to be historical artifacts
that are best viewed as labels for the extremes of a continuum of variation. In areas where distinct populations meet, different clines are documented in the two stream systems. In Nunns Creek there is a smooth cline between populations, whereas in Bonsall Creek there is a step cline.Science, Faculty of
Zoology, Department of
Graduate
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Olsson, Jens. "Interplay Between Environment and Genes on Morphological Variation in Perch – Implications for Resource Polymorphisms." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7212.
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Edwards, Shelley. "Phylogeographic variation of the Karoo bush rat, Otomys unisulcatus : a molecular and morphological perspective." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/2108.
Full textAbstract:
Thesis (MSc (Botany and Zoology))--Unkiversity of Stellenbosch, 2009.Phylogeographic genetic structure has been documented for a number of southern African terrestrial taxa. Information regarding geographic population genetic structuring in multiple taxa, with differing life histories, can provide insights into abiotic processes such as vicariance. A fragment of the cytochrome b mitochondrial DNA gene of a plains-dwelling species, Otomys unisulcatus, was sequenced and analysed. Two closely related geographic assemblages were found. The first assemblage (lowland group) contains populations from both the eastern and western parts of the species range, and the second comprises populations from the Little Karoo (central group). The lowland group was shown to be in a state of population expansion after a relatively recent mitochondrial DNA (mtDNA) coalescence, while the genetic signature of the central assemblage was characterized by more genetic diversity indicative of an older lineage/genetic refuge. Areas of higher elevation (namely mountain ranges) appeared to be the main factor limiting gene flow between these two groups. Aridification cycles due to glacial maximum periods probably resulted in increased dispersal leading to the widespread distribution of common haplotypes throughout the lowland group. Morphological variation in skull shape and size has been shown to follow environmental clines in some rodents. Geometric morphometric analyses on the ventral and dorsal views of the craniums of O. unisulcatus were utilised to test whether the population groupings obtained in the genetic analyses would be recovered by morphometric analyses. In addition, it was also investigated which of the environmental factors investigated influenced skull shape and size. The genetic groupings were not recovered for either the cranial shape or size. Size variation in the females correlated positively with annual rainfall, and so by proxy with habitat productivity, indicating that females which inhabited areas with lower rainfall would be larger. The significant relationship between females’ centroid sizes and rainfall was thought to be as a result of the increased nutrient requirement by this gender in the production of offspring. The males did not show a significant correlation between any of the environmental variables and centroid size. There was a significant difference between the skull shapes of the genders, further verifying the sexual dimorphism in the species. Three major clusters were found (according to cranium shape) using a Two-Block Partial Least Squares Analysis (2B-PLS), which relate to the biome boundaries within the species’ range. Variations in shape were attributed to the varying needs for strong masticatory muscles resulting from differing diets. The skull shapes of specimens occurring along the escarpment were intermediate between the first two clusters. Cranial shape in the male dorsal view dataset was significantly correlated with the environmental variables block, possibly due to the much lower minimum temperature in the Sutherland population (a population which was not included in the female analyses). It was concluded that differing diets of individuals in the respective biomes influenced the shape of the cranium of both genders. The sexual dimorphism in the cranium shapes may be as a result of the females digging tunnels (using their teeth) underneath the stick nests. Otomys unisulcatus show high levels of phenotypic plasticity throughout the range and it thus appears that the species can adapt fast to the different environmental variables.
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Sithole, Yonela. "Morphological and genetic variation of Gymnothorax undulatus (Anguilliformes: Muraenidae) in the Western Indian Ocean." Thesis, Rhodes University, 2018. http://hdl.handle.net/10962/63722.
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Briceño, M. Jorge. "Morphological variation and ecological status of Hydrilla verticillata (L.f.) Royle in Gatun Lake, Panama." Thesis, University of North Texas, 1990. https://digital.library.unt.edu/ark:/67531/metadc798208/.
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Research provides biological and ecological information on Hydrilla Verticillata (L. f.) Royle in Gatun Lake, Panama for an ongoing management program of aquatic weeds in the Panama Canal. Morphological and genetic variation, standing crop and life cycle were determined.
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Twentyman, Jones Vanessa. "Morphological variation and its taxonomic implications for insular populations of Pseudocrenilabrus philander (Pisces: Cichlidae)." Thesis, Rhodes University, 1993. http://hdl.handle.net/10962/d1005146.
Full textAbstract:
The cichlid fish Pseudocrenilabrus philander is widely distributed in southern Africa. Many of the populations occur in small, insular, geographically isolated water bodies, some of which are in arid areas. These small allopatric populations have been isolated for thousands of years and gene flow between them is non-existent or severely restricted. Populations were found to be different in terms of coloration, size of individuals, sexual dimorphism and behaviour. This thesis involved the determination of the taxonomic status of these isolated populations, from a morphological point of view. This has been part of a larger project, involving genetic and behavioural studies, to determine whether the different populations are geographic races of a single species, or whether they are species. Heritability of the observed differences was tested by breeding through three generations under uniform laboratory conditions. The populations from which wild-caught individuals were drawn could be identified on the basis of colour. There were some differences in anatomy between populations, but none of these were entirely distinctive for a particular population. When bred under laboratory conditions, populations did not show a tendency towards uniformity, as would be expected if morphological differences were environmentally induced. However, there were slight changes in the oral and pharyngeal bone form which may be diet related. Although there are morphological differences between populations and between wild-caught and laboratory-bred populations, it is suggested that the populations of P. philander are not fully differentiated and thus in the stages of incipient speciation. other studies on P. philander have introduced an element of uncertainty in that they show different results. Behavioural work suggests that different populations would behave as different species if they were to become sympatric. Karyological and mitochondrial studies showed that there were no differences between populations. Protein electrophoresis showed that populations were genetically unique. Since the various species and subspecies of Pseudocrenilabrus have been based on morphological criteria, the approach and conclusions in this study are based entirely on morphological criteria. These studies have practical implications for conservation, as some of the small populations are threatened with extinction. If the differences between the populations were ecophenotypic (i.e. related to their environment), then threats to some populations would not affect the conservation status of the species as a whole. If, however, such differences were genetic (i.e. the populations have evolved separately), then the extinction of small, isolated populations could mean the loss of actual species. This study strongly suggests that populations are incipient species and thus should be conserved.
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ROCCHIA, EMANUEL. "Temporal variation of species distribution and species morphological traits along altitude in the Alps." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2016. http://hdl.handle.net/10281/131144.
Full textAbstract:
Many species have shown recent shifts in their distribution in response to environmental changes, in particular to climate change, mostly moving towards higher latitudes and/or altitudes. In this framework, it’s crucial to determine temporal variation in species occurrence or abundance along altitudinal gradients in order to detect changes in altitudinal shifts and to assess sensitivity of mountain species to land use and climate change.
The main purpose of the research was to detect temporal changes in species distribution along altitudinal gradients in the Alps at different levels of ecological organization. The Phd thesis is divided into four different chapters: 1) Detecting range altitudinal shifts of mountain birds in time: a comparison between two alpine areas, 2) To shift or not to shift? The role of climate and land-use changes in shaping the altitudinal distribution of birds in time, 3) Multi taxa distribution along altitude: 5 years data from the Western Alps, 4) Morphometric variation of ground beetles along an altitudinal gradient.
For the first study we investigated how birds species distributions changed in time between two different alpine areas. The second chapter focused on understanding which was the major driver between land cover and temperature changes in determining birds altitudinal shifts. The third part was based on a multi taxa approach in order to detect and compare temporal changes in species elevational distribution of three faunistic groups: ground beetles, butterflies and birds. The aim of the last chapter consisted in detecting changes of 11 morphometric variables of 5 ground beetles species along an altitudinal gradient starting from 1200 m to 2700 m asl.