Graduation Semester and Year

2012

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Quantitative Biology

Department

Biology

First Advisor

Eric N Smith

Abstract

Comparing phylogeographic patterns among vertebrates can give insight into the landscape and ecological determinants of phylogenetic diversity. However, in certain taxonomic groups (e.g., birds and mammals) natural history traits can be more influential in structuring phylogeographic patterns than historical interactions with the landscape. In contrast, groups like anurans (6132+ species) with poor dispersal capability and strict ecological requirements often display patterns of genetic diversification consonant with the geological and climatic characteristics of a landscape. The patterns resulting from these interactions can be used to elucidate the temporal dynamics of ecological differentiation, historical biogeography, and morphological evolution. The study of anurans is also timely since they have recently experienced globally distributed declines in biodiversity and are a conservation priority. A large proportion of remaining anuran diversity in the New World tropics is dominated by direct-developing frogs of the mega-diverse group Terrarana. In the northern Neotropics, frogs of the genus Craugastor are by far the most abundant terraranan group. Although they are relatively common and species rich, the phylogeographic relationships within many Craugastor lineages are not well characterized. Herein I examine phylogeography in several poorly known Craugastor groups found north of the Nicaraguan depression using mitochondrial and nuclear DNA. Specifically, I examined (1) phylogenetic relationships in the genus Craugastor, (2) the subgenus Hylactophryne (C. augusti and C. bocourti species series), (3) the C. mexicanus species series, and (4) the C. rhodopis species series. Using this research, I address several longstanding nomenclatural issues and identify several hitherto unnamed lineages. I then use these data to discuss ecological diversification, nucleotide substitution rate variation, and biogeography. Collectively, my data indicate that the Craugastor groups I examined are extremely diverse and an important faunal component of Mexico and northern Central America. Given this diversity, I suspect that the patterns of molecular diversity observed in northern Craugastor will play an important future role in understanding the evolution of biodiversity across this dynamic region.

Disciplines

Biology | Life Sciences

Comments

Degree granted by The University of Texas at Arlington

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