| Summary: | Electronic Thesis or Dissertation Exploring the factors that structure and limit species' ranges are of central importance to ecology, biogeography, and evolutionary biology because these factors are tied directly to understanding the distribution and abundance of species (ecology), the historical and ecological drivers of spatial distributions through time (biogeography), and the abiotic and biotic factors the influence the diversification of lineages and species (evolutionary biology). Testable biogeographic hypotheses, such as the abundant-center distribution (ACD) and the core-periphery hypothesis (CPH), provide the means for disentangling the factors that structure and limit species’ ranges. The ACD predicts a positive relationship between the abundance of a species and how close that population is to the center or core of the species’ range, while the CPH predicts that population abundance reflects the extent to which local sites satisfy the niche requirements of the species in that populations located at the geographic periphery of a species’ range increasingly experience unfavorable ecological (abiotic and/or biotic) conditions that lead to declines in population density and fitness. This dissertation focuses on the wood frog (Lithobates sylvaticus), which has the largest range of any amphibian in North America, spanning approximately 40 degrees in latitude (33 to 70 ). This wide range encompasses a broad spectrum of climate conditions, from extreme cold near the Arctic Circle to high heat and humidity in the south in Alabama. Within the aforementioned biogeographic framework, I examine the effects of geography, ecology, history, genetics, and life history (growth, development, survival, and behavior) on the structure of the wood frog’s range. These studies show support for predictions based on the ACD and the CPH. Populations in the core of the range have higher genetic diversity, faster developmental rates, highly active behavioral phenotypes, and have higher fitness compared to edge populations. ...
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