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 85 for “"Genetic divergence"”.
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Genetic Divergence Among Subspecies of Basilarchia Arthemis
… and Jordan. The data suggest a greater level of divergence between arthemis and astyanax than between nominal species B. lorquini (Boisduval) and B. weidemeyerii (Edwards), and even more so between rubrofasciata and astyanax.
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DNA Methylation and Genetic Divergence Associated with an Inducible Defensive Response in Mimulus guttatus
… regions that exhibit statistically significant divergence in allele frequencies. This was tested on genome sequence data from an experiment involving artificial selection for increased trichome production. Results indicate that epigenetic inheritance of the damage response in a particular RIL is …
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Evolution in a fragmented world: Phenotypic and genetic divergence amongst neighbouring populations of the burying beetle Nicrophorus vespilloides
… I measured the extent of between population genetic differentiation. I found that the extent of genetic differentiation correlates strongly with the extent of dissimilarity in their community structures. These results suggest that the populations are undergoing divergent adaptation despite …
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Reproductive Isolation and Genetic Divergence in a Young "Species Flock" of Pupfishes (Cyprinodon sp.) from San Salvador Island, Bahamas
… contain many putative species and/or parallel divergences, such as many species flocks and species pairs, are extraordinary examples of divergence and therefore are critical to the understanding of the speciation process. A "miniature" species flock of pupfish (Cyprinodon variegatus) discovered …
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Scale dependent genetic structure of Idaho Giant salamanders (Dicamptodon aterrimus) in stream networks
… of life-history influences on population genetic structure may provide general insight. I examined how stream network structure affects gene flow and genetic structure of the facultatively paedomorphic Idaho Giant salamander, Dicamptodon aterrimus in Idaho and Montana, USA. I used …
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Scale dependent genetic structure of Idaho Giant salamanders (Dicamptodon aterrimus) in stream networks
… of life-history influences on population genetic structure may provide general insight. I examined how stream network structure affects gene flow and genetic structure of the facultatively paedomorphic Idaho Giant salamander, Dicamptodon aterrimus in Idaho and Montana, USA. I used …
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From Traditional Morphology to Genomes and Machine Learning: Navigating Taxonomic Uncertainties in Southeast Asian Agamids
… diagnose because phenotypic distinctiveness and genetic divergence do not align, as in the case of cryptic species, or when a group lacks considerable genetic divergence but exhibits variable morphology, as in polymorphic species. My dissertation provides an empirical example of delimiting …
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Comparative Phylogenetic Analysis in Populations of the Western Cottonmouth (Agkistrodon Piscivorus Leucostoma) Distributed in Three North American Drainage Basins
… American drainage basins. Using a molecular phylogenetic analysis, Knights et al. (1992) observed that western cottonmouths were highly divergent from both eastern and Florida cottonmouths yet the degree of divergence among populations of the western cottonmouth remains unexplored. During the …
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Parallel and Nonparallel Patterns of Genetic Co-Differentiation: Evidence for Host Associated Differentiation Among Trophic Levels of the Oak Gall Wasp System
… differentiation (HAD) in the form of genetic divergence and/or RI isolation across alternative host plants. In this work, we ask if HAD cascades to higher trophic levels in parasitoids of an insect herbivore that expresses HAD. Belonocnema treatae (Hymenoptera: Cynipidae) induces galls …
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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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Riverscape Community Genomics of Ozark Fishes: A Comparative Framework to Infer Ecological and Evolutionary Determinants of Genetic Diversity
<p>Genetic variation is a crucial component of biodiversity and represents the variability and spatial structure of alleles within and among organisms. Evolution modulates this variability over time through mutation, selection, gene flow, and genetic drift. However, our capacity to test …
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The cost of longevity: loss of sexual function in natural clones of Populus tremuloides
… leaves, branches. At the level of the genetic individual (clone or genet), they possess independent evolutionary and physiological units (ramets). These evolutionary units arise through the widespread phenomenon of clonal reproduction, achieved in a variety of ways including rhizomes, …
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Evolutionary Assembly of the Neotropical Montane Avifauna
… Second, I found weak support for simultaneous divergence between multiple population-pairs separated by the same barriers, suggesting temporal idiosyncrasies in differentiation. In the third chapter, I explored geographic patterns of evolutionary assembly using the same dataset. Overall, birds …
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Ecosystem engineering: beaver and the population structure of Columbia spotted frogs in western Montana
… distances larger than its dispersal ability. The genetic divergence seen within watersheds revealed that landscape configuration affected the fine scale population structure of Columbia spotted frogs. Landscape patterns of breeding sites were reflected in the presence and strength of isolation by …
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Ecosystem engineering: beaver and the population structure of Columbia spotted frogs in western Montana
… distances larger than its dispersal ability. The genetic divergence seen within watersheds revealed that landscape configuration affected the fine scale population structure of Columbia spotted frogs. Landscape patterns of breeding sites were reflected in the presence and strength of isolation by …
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Historical Land Fragmentation and its Effects on Genetic Diversity and Parasitism of Island Populations of Podarcis erhardii (Lacertidae, Reptilia)
… how island age, area and isolation affect genetic variation. My research focuses on the population genetics of the Aegean wall lizard Podarcis erhardii (Lacertidae, Reptilia), which because of its wide distribution, and poor dispersal abilities is a sensitive indicator of fragmentation …
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Phylogeography of Marine Meiofaunal Nemerteans of the Ototyphlonemertes Fila Species Complex
… and nuclear (ISSR) molecular markers. Deep genetic divergence (approximately 18% in cox3) was observed between sympatric mitochondrial lineages in Florida. This divergence was reflected in the nuclear marker as well, suggesting the presence of two cryptic species. The first contains Florida …
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Divergence of Threespine Stickleback That Differ in Nuptial Coloration
… to characterize within-species and among-morph genetic variation between the two morphs. We found substantial phenotypic and genetic divergence between color morphs, and patterns observed in a third, "mixed" morph that are likely due to hybridization between anadromous and freshwater …
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Population genetic structures and dispersal patterns of arthropods in New Zealand and the Ross Dependency, Antarctica
… of populations. This thesis assesses population genetic structures and dispersal patterns of arthropods in two geographic regions-Antarctica and New Zealand-using molecular techniques in conjunction with distributional data and dispersal experiments. Regional genetic divergence was revealed using …
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Population structure of the lizard Ecpleopus gaudichaudii coincides with a biogeographic barrier - the Doce River
<p>Intraspecific genetic variation is an integral component of diversification and the accumulation of biodiversity. The degree to which isolated populations of the same species are genetically structured in geographical space is impacted by a variety of mechanisms. In this study, I document …
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