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Biogeography And Systematics Of The Nerodia Clarkii/nerodia Fasciata Clade In Florida

Biogeography provides a window into the evolutionary history of populations, and helps explain the diversity and distribution of life through time. Viewed from a systematic perspective, biogeographic studies generate convincing arguments to explain the relationships among organisms and categorize them into useful taxonomies. When taxonomies do not reflect evolutionary histories, inaccurate representations of biodiversity confound future studies and conservation efforts. Two thamnophiine snakes, Nerodia clarkii and Nerodia fasciata, harbor unique morphological and ecological adaptations that obscured natural groupings, leading to controversial taxonomic delimitations. Additionally, population declines documented in N. clarkii compressicauda and N. clarkii taeniata led managers to list N. clarkii taeniata as threatened in 1977. I generated a baseline for continued biogeographic and systematic study of the Nerodia clarkii/fasciata clade. I used mitochondrial DNA to build a parsimony-based haplotype network, infer the phylogenetic relationships between the two species and their thamnophiine relatives, and estimate the divergence times of major N. clarkii/fasciata clades. With these data, I tested biogeographic and systematic hypotheses about the origin and distribution of diversity in this clade. I used principal components analyses to summarize morphological data and discuss ecological observations in search of characters that may unite genetic or taxonomic units. The analyses revealed a peninsular and a panhandle clade in Florida that appeared to iv diverge as a result of Pleistocene glacial fluctuations. I found no support genetically, morphologically, or ecologically for the current taxonomy, indicating a need for range-wide research to generate revised nomenclature. My results do not support the protection status of N. clarkii taeniata

Identiferoai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:etd-3823
Date01 January 2013
CreatorsTerrito, Gregory
PublisherSTARS
Source SetsUniversity of Central Florida
LanguageEnglish
Detected LanguageEnglish
Typetext
Formatapplication/pdf
SourceElectronic Theses and Dissertations

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