Phylogeny and Biogeography of Malagasy Dwarf Geckos, Lygodactylus Gray, 1864: Preliminary Data from Mitochondrial DNA Sequences (Squamata: Gekkonidae)

Abstract

Dwarf geckos, Lygodactylus, are small, secondarily diurnal lizards that occur in Africa, South America and Madagascar. Identification of many species is based on scale features only, and is therefore extremely difficult in the field due to their small size. Based on DNA sequences of a fragment of the mitochondrial 16S rRNA gene we studied the relationships among the Malagasy taxa and their differentiation relative to some African Lygodactylus. The results do not contradict a division of Malagasy Lygodactylus into three main lineages, which had been defined as Oriental, Occidental and Meridional clades. However, while the Oriental lineage (subgenus Domerguella) was very strongly corroborated by our analysis, no significant support was found for the other groupings. No evidence for a monophyletic group of the Malagasy taxa, or for a monophyletic Lygodactylus to the exclusion of Microscalabotes was found. The genetic divergences among Malagasy Lygodactylus were surprisingly large, indicating a relatively old age of most species and especially of the major lineages.