Conquering the Sahara and Arabian deserts: systematics and biogeography of Stenodactylus geckos (Reptilia: Gekkonidae)
1 Institute of Evolutionary Biology (CSIC-UPF), Passeig Marítim de la Barceloneta 37-49, 08003, Barcelona, Spain
2 The Natural History Museum, Cromwell Road, SW7 5BD, London, UK
3 CNRS-UMR 5175 Centre d'Ecologie Fontionnelle et Evolutive, 1919 Route de Mende, 34293, Montpellier cedex 5, France
4 EPHE-UMR, Centre d'Ecologie Fontionnelle et Evolutive, 1919 Route de Mende, 34293, Montpellier cedex 5, France
5 CIBIO/InBIO, 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
6 Natural History Museum of Crete, University of Crete, Knosou Av, P.O. Box 2208, 71409, Heraklion, Greece
7 Nature Conservation Sector, Egyptian Environmental Affairs Agency, 3 Abdalla El Katib, Apt. 3, Cairo, Dokki, Egypt
8 Museo Civico de Storia Naturale, via San Francesco di Sales 188, I-10022, Carmagnola, Italy
9 Sultan Qaboos University, Department of Biology, College of Science, Al-Khod, P.O. Box 36, Muscat, Sultanate of Oman
BMC Evolutionary Biology 2012, 12:258 doi:10.1186/1471-2148-12-258Published: 31 December 2012
The evolutionary history of the biota of North Africa and Arabia is inextricably tied to the complex geological and climatic evolution that gave rise to the prevalent deserts of these areas. Reptiles constitute an exemplary group in the study of the arid environments with numerous well-adapted members, while recent studies using reptiles as models have unveiled interesting biogeographical and diversification patterns. In this study, we include 207 specimens belonging to all 12 recognized species of the genus Stenodactylus. Molecular phylogenies inferred using two mitochondrial (12S rRNA and 16S rRNA) and two nuclear (c-mos and RAG-2) markers are employed to obtain a robust time-calibrated phylogeny, as the base to investigate the inter- and intraspecific relationships and to elucidate the biogeographical history of Stenodactylus, a genus with a large distribution range including the arid and hyper-arid areas of North Africa and Arabia.
The phylogenetic analyses of molecular data reveal the existence of three major clades within the genus Stenodactylus, which is supported by previous studies based on morphology. Estimated divergence times between clades and sub-clades are shown to correlate with major geological events of the region, the most important of which is the opening of the Red Sea, while climatic instability in the Miocene is hypothesized to have triggered diversification. High genetic variability is observed in some species, suggesting the existence of some undescribed species. The S. petrii - S. stenurus species complex is in need of a thorough taxonomic revision. New data is presented on the distribution of the sister species S. sthenodactylus and S. mauritanicus.
The phylogenetic hypothesis for the genus Stenodactylus presented in this work permits the reconstruction of the biogeographical history of these common desert dwellers and confirms the importance of the opening of the Red Sea and the climatic oscillations of the Miocene as major factors in the diversification of the biota of North Africa and Arabia. Moreover, this study traces the evolution of this widely distributed and highly specialized group, investigates the patterns of its high intraspecific diversity and elucidates its systematics.