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Dispersal, Gene Flow, And Adaptive Evolution During Invasion: Testing Range-Limit Theory With The Asian Tiger Mosquito, Kimberly Medley
Dispersal, Gene Flow, And Adaptive Evolution During Invasion: Testing Range-Limit Theory With The Asian Tiger Mosquito, Kimberly Medley
Electronic Theses and Dissertations
Understanding the factors that make non-native species successful invaders is an important step towards mitigating spread. At the same time, species invasions can serve as natural experiments to test range-limit theory. Range-limit theory postulates declines in local abundance (abundant center model) and genetic diversity (central-peripheral hypothesis) towards range edges because of underlying environmental gradients. Such declines constrain adaptation to marginal habitats via gene swamping. However, broader evolutionary theory predicts intermediate rates of immigration into range-edge populations can relieve genetic drift and improve adaptive potential. I tested hypotheses generated from theory while illuminating aspects affecting of the invasion of the Asian …
Beyond Building A Tree: Phylogeny Of Pitvipers And Exploration Of Evolutionary Patterns, Allyson Fenwick
Beyond Building A Tree: Phylogeny Of Pitvipers And Exploration Of Evolutionary Patterns, Allyson Fenwick
Electronic Theses and Dissertations
As generic and higher-scale evolutionary relationships are increasingly well understood, systematists move research in two directions: 1) understanding specieslevel relationships with dense taxon sampling, and 2) evaluating evolutionary patterns using phylogeny. In this study I address both foci of systematic research using pitvipers, subfamily Crotalinae. For direction one, I evaluate the relationships of 96% of pitvipers by combining independent sets of molecular and phenotypic data. I find the inclusion of species with low numbers of informative characters (i.e. less than 100) negatively impacts resolution of the phylogeny, and the addition of independent datasets has no effect on or a small …
Genetic And Phenotypic Evolution In The Ornate Chorus Frog (Pseudacris Ornata): Testing The Relative Roles Of Natural Selection,, Jacob Degner
Electronic Theses and Dissertations
Understanding how migration, genetic drift, and natural selection interact to maintain the genetic and phenotypic variation we observe in natural populations is a central goal of population genetics. Amphibians provide excellent model organisms for investigating the interplay between these evolutionary forces because amphibians are generally characterized by limited dispersal abilities, high philopatry, and are obligately associated with the areas around suitable habitats (e.g. breeding ponds). Thus, on relatively small geographic scales, the relative effects of all of these evolutionary forces can be studied together. Here, we study the interaction of migration, genetic drift, natural selection, and historical process in the …