Life Sciences Commons^™

Integrating, Developing, And Testing Methods To Generate More Cohesive Approaches To Biogeographic Inference, Mallory Elizabeth Eckstut

UNLV Theses, Dissertations, Professional Papers, and Capstones

As a fundamental component of the developing discipline of conservation biogeography, broadscale analyses of biotic assembly and disassembly across multiple temporal and spatial scales provide an enhanced understanding of how geologic transformations and climate oscillations have shaped extant patterns of biodiversity. As with any scientific field, there are limitations in the case of biogeographic historical reconstructions. Historical reconstructions are only as robust as the theoretical underpinnings of the methods of reconstruction (including data collection, quality, analysis, and interpretation). Nevertheless, historical reconstructions of species distributions can help inform our understanding of how species respond to environmental change.

My dissertation takes a …

From The Valleys To The Mountains: The Biographic History Of Antelope Squirrels, Bats, And Chipmunks In Western North America, Stacy James Mantooth

UNLV Theses, Dissertations, Professional Papers, and Capstones

Genetic differentiation within and between species often coincides with significant geological or climatic changes that have shaped the sizes and locations of their geographic ranges and altered the connectivity between populations over time. Across western North America, many endemic taxa experienced high levels of initial divergence associated with geological transformations of the Neogene, with subsequent diversification and geographic structuring of populations associated with climatic changes during the Quaternary. As such, we can use a combination of molecular markers and genetic analyses to effectively examine the evolutionary and biogeographic histories of populations, species, and regional biotas whose signatures of differentiation are …

Molecular Systematics And Phylogeography Of The Genus Richardsonius, Derek Dee Houston

UNLV Theses, Dissertations, Professional Papers, and Capstones

The complex geological and climatic events that significantly altered the landscape throughout the Cenozoic Era impacted the diversification of many North American taxa, including freshwater fishes. Here, I employ an array of phylogenetic analyses using a multiple gene tree approach to address several questions regarding the phylogenetic relationships of the North American cyprinid genus Richardsonius and two other closely related genera, Clinostomus and Iotichthys. I also use divergence time estimates generated using fossil calibrations to qualitatively assess the phylogeographic implications of evolution within and among these three genera. Mitochondrial and nuclear DNA sequences show a sister relationship between Iotichthys and …