Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 157 for “"Genetic differentiation"”.
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Genetic differentiation of the parasitoid, Cotesia congregata (Say), based on host-plant complex
… systems and thus, drive diversification. Genetic differentiation was estimated for Cotesia congregata (Say) collected from two distinct host-plant complexes, Manduca sexta L. on tobacco (Nicotiana tabacum L.) and Ceratomia catalpae, (Haworth) on catalpa (Catalpa bignonioides Walker), in …
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A Comparison of Genetic Differentiation and Gene Flow Among Populations of Two Species of Mice (Peromyscus)
… variable in P. leucopus. Results indicate that genetic similarities and differences among populations of P. attwateri are not affected by gene flow. Populations of P. leucopus tend to show genetic differences due more to isolation by distance.
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Genetic differentiation of a sympatric lake-resident/anadromous species pair of threespine stickleback in Mud Lake, Alaska
… used to study speciation. Many morphological and genetically divergent forms within this complex have adapted to freshwater conditions. Studying the mechanisms that allow stickleback to adapt to freshwater conditions has provided much insight into the process of speciation. Here, we present the …
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Relationships Between Genetic and Ecological Variables in Nine Populations of Phlox Drummondii Hook (Niche, Allozymes, Genetic Differentiation)
… a correlation between niche breadth and level of genetic variation, was tested using nine populations of the annual plant, Phlox drummondii, from south central Texas. Niche breadth was measured as population response along controlled environmental gradients. Statistically significant differences …
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Spatial Ecology of a Vulnerable Species: Home Range Dynamics, Resource Use, and Genetic Differentiation of Eastern Spotted Skunks in Central Appalachia
… ofwith spotted skunk habitat selection and genetic differentiation. I assessed first-order habitat selection by conducting an analysis of predicted occurrence at the landscape scale. Next, I assessed second- and third-order selection using resource utilization functions to determine habitat …
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Genetic variability and differentiation in niche components of marine phytoplankton species
… The data were used to determine the amount of genetic variability and the spatial patterns of genetic differentiation in these species. None of the species examined exist purely as clones in nature. Statistically significant genetic variability is found even among clones isolated from single …
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Genetic Structure of Yonahlossee Salamander Populations.
… to be rare and local throughout their range. Genetic differentiation among populations of any species is usually attributable to long-standing, extrinsic barriers to gene flow. Because of their disjunct population structure and some observed morphological variation, genetic differentiation …
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Population and Conservation Genetics of Crawfish Frogs, Lithobates areolatus, at their Northeastern Range Limits
… range limits to (1) assess the level of genetic diversity within populations (2) estimate fine-scale genetic structure, and (3) estimate genetic differentiation between populations at the state level. Crawfish Frogs breed in temporary pools and wetlands, and have high breeding-pond …
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Effects of habitat degradation on the evolutionary dynamics of populations in a rainforest cycad (Gymnospermae)
… persistence, including effects on ecological and genetic processes beyond decreased demographic viability and the loss of genetic variation. Particularly interesting is the potential for evolutionary changes and adaptation to degraded habitats, that can affect population viability even in the …
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Genetic population structure and dispersal of two North American woodpeckers in ephemeral habitats
… patches. In this research, I used patterns of genetic variation to estimate the dispersal dynamics of black-backed woodpeckers (Picoides arcticus), a fire specialist, and compared these patterns to hairy woodpeckers (Picoides villosus), a generalist. I then examined how frequent colonization of …
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Genetic population structure and dispersal of two North American woodpeckers in ephemeral habitats
… patches. In this research, I used patterns of genetic variation to estimate the dispersal dynamics of black-backed woodpeckers (Picoides arcticus), a fire specialist, and compared these patterns to hairy woodpeckers (Picoides villosus), a generalist. I then examined how frequent colonization of …
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Population substructuring in Schreibers' long-fingered bat (Miniopterus schreibersii) in South Africa
… gene flow among colonies, resulting in genetically distinct breeding subpopulations. The population structure of M. schreibersii in South Africa was investigated using microsatellites and mitochondrial DNA (mtDNA), with the aim of determining the degree of genetic differentiation among …
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Gene Flow and Dispersal Among Populations of the Stonefly <i>Peltoperla tarteri</i> (Plecoptera: Peltoperlidae) in the Southern Appalachians
… directly using traditional means; however, genetic markers provide an ideal method for estimating stream insect dispersal. In this study, the control region of mitochondrial DNA was used to study gene flow and dispersal among populations of the stonefly <i>Peltoperla tarteri</i> in the …
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The Population Genetics Of The Wood Frog, Rana Sylvatica, Across Its Geographic Range
<p>This study aimed to determine the level of genetic variation across the continental-wide range of the wood frog, Rana sylvatica. Levels of genetic differentiation between sampled populations were investigated as was the possible locations of glacial refugia for this species. DNA microsatellites …
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Genetic Variation Among Geographically Disparate Yellow Perch Broodstock Populations
… and future marker assisted selection, genetic variation revealed by microsatellite DNA was evaluated in yellow perch, Perca flavescens, from four wild North American populations collected in 2003-2004 (Maine, ME; New York, NY; North Carolina, NC; and Pennsylvania, PA), and two captive …
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The Evolutionary History and Conservation of Speyeria Idalia (Lepidoptera: Nymphalidae)
… in the Great Plains, in the form of increased genetic differentiation and lower levels of within population genetic variation.
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An Assessment of Population Genetic Structure in Guillemots (Cepphus)
… how evolutionary forces shape population genetic structure is a principal goal of evolutionary geneticists. Guillemots (Aves: Charadriiformes: Alcidae: Cepphus) provide useful systems for investigating population genetic differentiation in a genus with a wide geographic range that …
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MATING COSTS, MALE CHOICE DISPLACEMENT, AND THE EFFECTS ON HYBRIDIZATION AND SPECIATION IN THE HAWAIIAN CRICKET LAUPALA (SUBFAMILY:TRIGONIDIINAE)
… alternatives will occur depends on the degree of genetic differentiation and behavioral isolation between the species. If there is significant and non-combinable genetic variation between species, but behavioral isolation between the two incipient taxa is incomplete and allows hybrid offspring to …
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