Phylogenetic and biogeographic analyses of Palearctic naked-toed geckos and Prosymna snakes

The study of systematics is a framework for the understanding of the natural world by generating units of biodiversity and relatedness between and among groups. My project focused on two studies: resolving the hierarchical placement and diversity of Palearctic naked-toed geckos and Prosymna snakes. To achieve these goals, I used molecular and computational analyses to generate a robust and accurate phylogeny and biogeographic analyses of both groups. These projects work in conjunction by leveraging two faunal systems that persist in Africa: an endemic sub-Saharan fauna and Palearctic fauna in the north. Palearctic Naked-toed geckos are not endemic to Africa. Instead this group ranges as far East as western China. Contrary to this, Prosymna snakes are an endemic group in sub-Saharan Africa with high species richness within the genus. Relationships among Palearctic naked-toed geckos constituent genera remain incompletely resolved, and the monophyly of key genera remains unverified. I used both mitochondrial (ND2) and nuclear genes (RAG1, PDC) to study relationships among representatives. Our data confirms the previous identification of a Saharo-Arabian clade. Tropiocolotes and Microgecko, formerly treated as congeneric, exhibit extensive osteological differences, which agrees with the phylogenetic assessment in this study. The divergence between Cyrtodactylus and the Palearctic naked-toed gecko clade predates the initial collision of the Indian and Eurasian plates, but deeper divergences within both groups are consistent with mountain building in the Himalayas and adjacent ranges, which could have promoted cladogenic events. Miocene divergences within Tenuidactylus are consistent with vicariant speciation caused by uplift events in the Iranian and Trans-Caspian regions.;Prosymna is a genus of African snakes whose phylogenetic relationships are not well understood. Higher order affinities of Prosymna are controversial and previously been placed in the families Elapidae, Colubridae, and Lamprophiidae, or have been assigned familial rank as the sole member of the Prosymnidae. To date there has been no explicit phylogeny for the genus, and until recently, sequence data was only available for five species of sixteen. We investigated relationships among eleven species in the genus using mitochondrial (Cyt B, ND2, and 16s) and nuclear markers (RAG1, C-MOS, and ENC1). The monophyly of the genus has high support. Intraspecific relations find a northern radiation consisting of P. meleagris and P. greigerti and a southern radiation of all other snakes. This southern group divides into two distinct clades: P. janii and P. stuhlmannii form a clade in the eastern portion of South Africa and P. bivittata, P. lineata, P. sundevallii and P. visseri form a broad-ranging clade across the southern portion Africa. The radiation of the genus coincides with the rapid uplift of the African escarpment around 20 mya. From these data, I affirm Prosymna as part of the family Lamprophiidae.