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Historical Biogeography Of North American Nightsnakes And Their Relationships Among The Dipsadines: Evidence For Vicariance Associated With Miocene Formations Of Northwestern Mexico, Daniel G. Mulcahy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I used a hierarchical approach to study historical biogeography in a group of colubrid snakes found in western North America. I combined small regions of mtDNA sequence data from a large number of individuals, with complete mt-genomic data. First, I investigated the relationships among leptodeirines—a presumed subgroup of dipsadines, including nightsnakes (Pseudoleptodeira, Eridiphas, and Hypsiglena)—using ~1.5 kb of data (cob and nad4). The relationships differed among parsimony, likelihood, and Bayesian analyses. All analyses supported the monophyly of the nightsnakes; however, none supported the monophyly of the leptodeirines. Instead, these data supported a new hypothesis …