Centro de Investigação em Biodiversidade e Recursos Genéticos da Universidade do Porto Instituto de Ciências Agrárias de Vairão.
R. Padre Armando Quintas, 4485-661 Vairão, Portugal
Institute of Evolutionary Biology (CSIC-UPF)
Passeig Marítim de la Barceloneta
CEFE UMR 5175CNRS Université de Montpellier - Université Paul-Valéry Montpellier – EPHE 1919 route de Mende, 34293 Montpellier cedex 5, France
Carrera de San Agustín
24, 18300 Loja
Brito, José *
Departamento de Biologia Faculdade de Ciências da Universidade do Porto Rua Campo Alegre 4169-007 Porto, Portugal
Pleistocene climatic oscillations have influenced biogeographical patterns of species worldwide, affecting distributional ranges and shaping genetic diversity. The Sahara and Arabian deserts are outstanding regions to study the influence of climate in the genetic structure and variability of species given their accentuated and dynamic climatic history, and the diverse life history and habitat traits of taxa inhabiting such extreme regions. This study aims to address the role of Pleistocene climatic oscillations in the evolutionary histories of the three Cerastes viper species (Viperinae): C. cerastes and C. vipera from the Sahara Desert, and C. gasperetti from deserts of the Arabian Peninsula. Phylogenetic structure was inferred using Bayesian inference over sequences (68 samples mostly covering species ranges) for one mtDNA (COI) and three nuDNA (PRLR, NT3, VIM) gene markers. Paleoclimatic models combined 318 occurrences and five climatic variables in Maxent to infer climatic suitability for current and past (mid Holocene, Last Glacial Maximum and Last Inter Glacial) events, and stability over time. Mitochondrial inferences show C. cerastes and C. gasperetti as sister taxa, while C. vipera is identified as a phylogenetically more distant species. Further levels of mtDNA structure within the three species were originated along the middle and late Pleistocene. Nuclear inferences, however, resulted in important discordances to mtDNA patterns. Paleoclimatic models identified warm events as major drivers of range reduction and isolation for the three species we studied. Areas of high climatic stability across the Sahara and Arabian deserts likely acted as Pleistocene climatic refugia for species and lineages.