title: The genus Atheris (Serpentes: Viperidae) in East Africa: phylogeny and the role of rifting and climate in shaping the current pattern of species diversity.
abstract: Past climatic and tectonic events are believed to have strongly influenced species diversity in the Eastern Afromontane Biodiversity Hotspot. We investigated the phylogenetic relationships and historical biogeography of the East African genus Atheris (Serpentes: Viperidae), and explored temporal and spatial relationships between Atheris species across Africa, and the impact of palaeoclimatic fluctuations and tectonic movements on cladogenesis of the genus. Using mitochondrial sequence data, the phylogeny of East African species of Atheris shows congruent temporal patterns that link diversification to major tectonic and aridification events within East Africa over the last 15million years (my). Our results are consistent with a scenario of a delayed direct west-east colonisation of the Eastern Arc Mountains of Atheris by the formation of the western rift. Based on the phylogenetic patterns, this terrestrial, forest-associated genus has dispersed into East Africa across a divided route, on both west-southeasterly and west-northeasterly directions (a C-shaped route). Cladogenesis in the Eastern Arc Mountains and Southern Highlands of Tanzania corresponds to late Miocene and Plio-Pleistocene climatic shifts. Taxonomically, our data confirmed the monophyly of Atheris as currently defined, and reveal four major East African clades, three of which occur in discrete mountain ranges. Possible cryptic taxa are identified in the Atheris rungweensis and A. ceratophora clades.
authors: Tropical Biodiversity Section, MUSE, The Science Museum of Trento, Trento, Italy; Division of Biology & Conservation Ecology, School of Science & the Environment, Manchester Metropolitan University, Manchester, UK. Electronic address: michele.menegon@muse.it.
authors: M
authors: M
authors: Menegon
authors: Department of Environmental Sciences, Biogeography Research Group, University of Basel, Basel, Switzerland.
authors: S P
authors: SP
authors: Loader
authors: Division of Biology & Conservation Ecology, School of Science & the Environment, Manchester Metropolitan University, Manchester, UK.
authors: S J
authors: SJ
authors: Marsden
authors: Department of Zoology, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031, South Africa.
authors: W R
authors: WR
authors: Branch
authors: Wildlife Conservation Society, P.O. Box 922, Zanzibar, Tanzania.
authors: T R B
authors: TR
authors: Davenport
authors: Department of Environmental Sciences, Section of Conservation Biology, University of Basel, Basel, Switzerland.
authors: S
authors: S
authors: Ursenbacher
mesh_terms: D000351:Africa, Eastern; D000818:Animals; D002980:Climate; D004272:DNA, Mitochondrial / Q000235:genetics; D065928:Forests; D049810:Genetic Speciation; D008957:Models, Genetic; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017819:Viperidae / Q000145:classification*
chemical_list: D004272:DNA, Mitochondrial
keywords: Biogeography; East Africa colonisation; Forest species; Viper