Award Date

5-2011

Degree Type

Dissertation

Degree Name

Doctor of Philosophy in Biological Sciences

Department

Life Sciences

First Committee Member

Brett Riddle, Chair

Second Committee Member

Dave J. Hafner

Third Committee Member

John Klicka

Fourth Committee Member

Dan Thompson

Graduate Faculty Representative

Chad L. Cross

Number of Pages

134

Abstract

Revealing how communities are shaped by abiotic and biotic factors plays a central role in biogeographic and comparative phylogeographic studies. The biogeography of North American arid grasslands is explored using nuclear and mitochondrial DNA from three groups of heteromyid rodents that are broadly sympatric in aridlands across western North America. Phylogenetic and molecular clock analyses are used to estimate the timing of divergences within each group. A general pattern of late Miocene divergence and expansion of lineages in each of the groups that is coincident with the rapid expansion of arid grasslands at the time. The initial divergence is followed by temporally and spatially concordant geographic diversification in recognized biogeographic and physiographic regions that corresponds to major climatic and tectonic events during the Pliocene and Pleistocene. The similarities and differences in the response of each taxon to proposed phylogeographic barriers are discussed.

Keywords

Biogeography; Biotic communities; Grasslands; Heteromyidae; North America; Phylogeography; Rodents

Disciplines

Biology | Desert Ecology | Ecology and Evolutionary Biology

Language

English


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