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 19 of 19 for “"Phenotypic divergence"”.
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Morphological Variation and Community Science in Orthoptera
<p>Patterns of morphological divergence across species’ ranges provide insight into local adaptation and speciation. Here, we compare phenotypic divergence among 4,221 crickets from 337 populations of two related species of field cricket, Gryllus firmus and G. pennsylvanicus and their hybrids. We …
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Evolutionary Genomics of Populus trichocarpa (Western Poplar)
… this study provide insights into the history of divergence and differentiation in P. trichocarpa populations and help us identify the functional genetic variants contributing to phenotypic divergence and fitness of the individuals in it.
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Evolutionary Trade-offs Between Antimicrobial Resistance and Virulence in Pseudomonas aeruginosa
… costs. PIT-resistant clones showed pronounced phenotypic heterogeneity, ranging from near–wild-type to strongly impaired phenotypes, reflecting diverse evolutionary trajectories. In contrast, STR-resistant clones largely maintained high growth and virulence despite strong resistance, suggesting …
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Improvement of common bean (Phaseolus vulgaris L.) for regional food systems in the northeastern United States
… material. Chapter III analyzes genotypic and phenotypic diversity of 18 seed sources of ‘Jacob’s Cattle’ dry bean across seed saver networks. Significant genotypic and phenotypic divergence was identified, indicating that North American seed saver networks are a significant repository of …
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Relationships between phenotype, diet, and individual specialization of threespine stickleback (Gasterosteus aculeatus) in Lake Mývatn, Iceland
… prey consumption and their tendency towards both phenotypic and genetic adaptations in response to different habitats and prey. Using stickleback in Lake Mývatn, it is possible to study diet diversity, individual specialization, and phenotypic variation among sites. Clear connection with sites may …
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The genetic and developmental bases of male genital organ size evolution
… provides insights into the cis-regulation of phenotypic divergence, and given that trn functions as a cell affinity molecule, this may represent a novel mechanism for the developmental regulation of organ size.
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Chromosomal inversions as a mechanism for sympatric differentiation in common quails
Chromosomal inversions are key drivers of phenotypic divergence, local adaptation and early reproductive isolation, but their effects in highly mobile species remain poorly understood. In the common quail Coturnix coturnix, a large inversion on chromosome 1 spans about 12% of the genome and defines …
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Impacts And Implications Of Polytypism On The Evolution Of Aposematic Coloration
… that gene flow plays in promoting or limiting phenotypic divergence. By using model, naïve predators for learning experiments, I found that the hue color component influences predators’ abilities to learn to avoid an aposematic signal. I provide the first among-population characterization of …
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Foraging ecology, sexual selection, and divergence in sunfish (Lepomis spp.)
… and how these mechanisms interact to shape the phenotypic diversification of natural populations. Using bluegill (Lepomis macrochirus) and pumpkinseed sunfish (Lepomis gibbosus), I examined three major questions: 1) how are diet and morphological variation related to alternative reproductive …
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The genetic mechanisms that coordinate the development and morphological divergence of Drosophila genital structures
… to some extent, the genetic differences causing phenotypic divergence are not well understood. Drosophila simulans and D. mauritiana exhibit striking morphological differences in the size, shape, and bristle composition of the male periphallic genitalia, despite only diverging 240,000 years ago. …
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Testing the Urban Dulling Hypothesis in an Iridescent Passerine Bird
… new setting. Novel urban ecosystems have led to phenotypic divergence between urban and rural populations. There is a rich body of literature on how songbirds are affected by urbanization, however divergent signaling behaviors are less well understood. Urban color homogenization is …
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The individual and collective behavior of social organisms across environments
… in collective behavior and its role in phenotypic divergence. Addressing these gaps could help us predict the effects of environmental changes on behavioral evolution. In this thesis, I address these questions through the use of two organisms; three-spined stickleback fish (Gasterosteus …
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Geographic variation in the phenotype of an African horseshoe bat species, Rhinolophus damarensis, (Chiroptera: Rhinolophidae)
… full species status on the basis of genetic and phenotypic differences between it and R. darlingi darlingi. Rhinolophus damarensis is itself made up of two ecologically separated genetic lineages. A total of 106 individuals of R. damarensis were sampled from seven localities across its …
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Colouration evo-devo: the developmental basis of intra-specific variation in cichlid pigmentation
… limits our understanding of the evolution of phenotypic diversity. Classical evo-devo tends to comprise comparative developmental biology between phylogenetically distant model organisms, while population genetics and evolutionary ecology studies often consider development as a ‘black-box’ …
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Mechanism of Rare Variant In Acta2, P.Arg149Cys, Driving Diverse Vascular Disease
… increases the risk for CAD, mirroring the phenotypic divergence observed in mutation carriers.</p> <p>Single cell RNA sequencing (scRNA-Seq) identified phenotypically modulated SMCs (mSMCs) characterized by upregulation of macrophage, fibroblast, and chrondrocyte markers that appear with …
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Studies of the genome and regulatory processes of Vibrio parahaemolyticus
… is interesting because it exhibits a spontaneous phenotypic switch in colony morphology due to the loss of a functional OpaR; this also influences virulence. OpaR is the major quorum-sensing regulator in V. parahaemolyticus homologous to LuxR from V. harveyi. When opaR is removed from the …
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The Role of Polyploidy in Phenotypic and Genomic Evolution in the Shy Monkeyflower, <i>Mimulus sookensis<i>
… and genomic evolution in polyploids affect phenotypic evolution? I use the shy monkeyflower, <italic>Mimulus sookensis</italic>, a tetraploid of hybrid origin between <italic>Mimulus guttatus</italic> and <italic>Mimulus nasutus</italic>, to address these focal questions. In order to develop …
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The evolution of gene regulatory landscapes in mammalian tissues
… evolution is paramount to gaining insight into phenotypic divergence across species. Although gene expression programs are broadly maintained during mammalian evolution, the collection of cis-regulatory elements and transcription factor (TF) binding events has diverged at different rates. In …
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Divergence of Threespine Stickleback That Differ in Nuptial Coloration
… locations following glacial retreat. We measured phenotypic variation in a suite of traits and used next generation sequencing to characterize within-species and among-morph genetic variation between the two morphs. We found substantial phenotypic and genetic divergence between color morphs, and …