title: Conquering the Sahara and Arabian deserts: systematics and biogeography of Stenodactylus geckos (Reptilia: Gekkonidae).
abstract: BACKGROUND
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Institute of Evolutionary Biology (CSIC-UPF), Passeig Marítim de la Barceloneta 37-49, 08003, Barcelona, Spain.
authors.forename: Margarita
authors.initials: M
authors.lastname: Metallinou
authors.forename: Edwin Nicholas
authors.initials: EN
authors.lastname: Arnold
authors.forename: Pierre-André
authors.initials: PA
authors.lastname: Crochet
authors.forename: Philippe
authors.initials: P
authors.lastname: Geniez
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Brito
authors.forename: Petros
authors.initials: P
authors.lastname: Lymberakis
authors.forename: Sherif
authors.initials: S
authors.lastname: Baha El Din
authors.forename: Roberto
authors.initials: R
authors.lastname: Sindaco
authors.forename: Michael
authors.initials: M
authors.lastname: Robinson
authors.forename: Salvador
authors.initials: S
authors.lastname: Carranza
mesh_terms: D000352:Africa, Northern; D000818:Animals; D001499:Bayes Theorem; D002467:Cell Nucleus / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D003889:Desert Climate; D019143:Evolution, Molecular; D005843:Geography; D016013:Likelihood Functions; D008116:Lizards / Q000145:classification* / Q000235:genetics; D008957:Models, Genetic; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial; D012335:RNA, Ribosomal; D012336:RNA, Ribosomal, 16S; C075526:RNA, ribosomal, 12S