Doctor of Philosophy, Miami University, 2024, Biology

This dissertation is structured into five chapters. Chapter I: I provide a general introduction to my dissertation, primarily introducing the different influences on intraspecific variation and providing a background on local adaptation. Chapter II: I investigate the effects of environmental conditions and demographic history on populations of desert horned lizards (Phrynosoma platyrhinos). I evaluate the demographic history of P. platyrhinos and identify signatures of selection associated with climate, which may be indicative of local adaptation. I then link signatures of selection to genes and functional genomic elements. Chapter III: I explore the influence of environmental heterogeneity on intraspecific variation of the chisel-toothed kangaroo rat (Dipodomys microps). I discover signals of selection associated with both climate and vegetation. I also find evidence that selective pressures likely vary across the species distribution and develop a permutation test to identify populations that possess more putatively adaptive alleles than expected by chance. I also link signals of selection to genes and biological functions that may be related to previously identified morphological differences between populations. Chapter IV: I perform a meta-analysis to understand general patterns of putative local adaptation in terrestrial chordates. I use previously published datasets and analyze them using a common framework to test theoretical predictions regarding the relationship between environmental and demographic factors and signals of selection. I find that signals of selection follow theoretical predictions, and, importantly, find that constant variation is an important driver of signals of selection. Chapter V: I provide conclusions and future directions from my results.

Committee: Tereza Jezkova (Advisor); David Berg (Committee Member); Donghyung Lee (Committee Member); Richard Moore (Committee Member); Susan Hoffmann (Committee Member) Subjects: Bioinformatics; Biology; Climate Change; Evolution and Development