Award Date

8-2011

Degree Type

Dissertation

Degree Name

Doctor of Philosophy in Biological Sciences

Department

Life Sciences

First Committee Member

Brett R. Riddle, Chair

Second Committee Member

John Klicka

Third Committee Member

Brian Hedlund

Graduate Faculty Representative

Stephen M. Roland

Number of Pages

115

Abstract

The Mexican highlands consist of four major mountain ranges spanning most of mainland Mexico. The evolutionary history of the Mexican highlands has been shaped by various geological and climatic events over the past several million years. The relative impacts of these historical events on diversification in montane taxa, however, remains uncertain. I used mitochondrial DNA data from three widely distributed species complexes of lizards as a model system to exemplify the potential roles of Neogene mountain formation and Quaternary climate change on timing and tempo of diversification across the Mexican highlands. My results suggested strong geographic partitioning of genetic variation across Mexico in all three lizard groups. There appeared to be a generalizable anchor of diversification across taxa centered around the development of the Transvolcanic Belt. Diversification across the rest of the Mexican highlands was largely idiosyncratic, but filter barriers such as river drainages likely subdivided lineages differentially through time. Diversification patterns observed in my three focal groups of lizards provide additional insight into the mechanisms that impacted differentiation of highland taxa across the complex Mexican highlands.

Keywords

Biogeography; Lizards – Evolution; Lizards – Geographical distribution; Mexico; Mountain animals; Paleobiogeography; Uplands

Disciplines

Biodiversity | Climate | Ecology and Evolutionary Biology | Evolution | Population Biology

Language

English


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