Multigene phylogenetic analysis of Lygodactylus dwarf geckos (Squamata: Gekkonidae)

The genus Lygodactylus is a group of small, diurnal geckos distributed mainly in Africa and Madagascar. A closely related, monotypic genus is Microscalabotes from Madagascar. We examined fragments of two moderate- to slow-evolving nuclear genes (RAG-1, RAG-2) and of two fast-evolving mitochondrial genes (16SrRNA, cytochrome b) to estimate phylogenetic relationships among 28 (of about 60) species (including Microscalabotes). Since cytochrome b provided little resolution for analysis of interspecific relationships in Lygodactylus, it was excluded from the concatenated Bayesian analysis. Our well-resolved Bayesian inference tree and its resulting clades confirm many previously suggested relationships among dwarf geckos based mainly on morphological characters, while several novel relationships lead us to regroup some species and to synonymize the genus Microscalabotes with the genus Lygodactylus. Our phylogenetic analysis well supports the monophyly of Lygodactylus (including Microscalabotes). However, it rejects monophyly of the Madagascan Lygodactylus. On the other hand, the data do not reject monophyly of the African forms. Though Africa is currently the main centre of diversity of Lygodactylus, our data suggest that the most parsimonious scenario would be a Madagascan origin, one dispersal to Africa, and one back to Madagascar.