Award Date


Degree Type


Degree Name

Master of Science in Biological Sciences


Life Sciences

First Committee Member

Brett R. Riddle, Co-Chair

Second Committee Member

Jef R. Jaeger, Co-Chair

Third Committee Member

David F. Bradford

Graduate Faculty Representative

Stephen M. Rowland

Number of Pages



I investigate the phylogeography of the relict and lowland leopard frogs (Rana onca; R. yavapaiensis) inhabiting the Mojave and Sonoran deserts. In Chapter 1, I summarize literature describing taxonomy, phylogenetics, and the possible effects of Quaternary climate change on distribution. Examples of phylogeographic patterns from generally co-distributed organisms are provided to develop background for interpreting the structure. In Chapter 2, I investigate the phylogeography of these frogs using mitochondrial DNA data. The analysis supports a previously determined phylogenetic break between taxa however further dividing R. yavapaiensis into two lineages. I estimate a possible Early Pleistocene divergence of R. onca and R. yavapaiensis, followed by a Middle Pleistocene separation of the western Grand Canyon population of R. yavapaiensis from the main R. yavapaiensis clade. Demographic/network analyses indicate population/range expansion for R. yavapaiensis. Species distribution models suggest that these frogs may not have greatly shifted ranges since the last glacial maximum.


Biogeography; Divergence (Biology); Leopard frogs; Mitochondrial DNA; North America – Sonoran Desert; Phylogeography; Rana onca; Rana yavapaiensis; North America – Sonoran Desert; United States – Mojave Desert


Biology | Desert Ecology | Evolution