Phylogenetic relationships among members of the Pachydactylus capensis group of southern African geckos
The Pachydactylus capensis group is a phenetically-defined assemblage of five small-bodied geckos broadly distributed in eastern southern Africa. Several additional small-bodied Pachydactylus have been historically considered subspecies of P. capensis or members of this group. To assess evolutionary relationships among these taxa, we conducted a molecular phylogenetic analysis of the members of the P. capensis group using sequence data from the mitochondrial cytochrome b and 16S ribosomal RNA genes (1081 nt). Maximum parsimony and maximum likelihood analyses recovered a well-supported clade comprising all five species of the currently-recognized P. capensis group. This clade is clearly separate from the P. rugosus group and P. labialis, both of which were formerly included in P. capensis. Sequence data thus corroborate patterns of affinity based on phenetic analysis of scale features (Broadley 1977). Within the P. capensis clade, Pachydactylus tigrinus and P. oshaughnessyi form a tropical lineage, whereas P. capensis (P. affinis + P. vansoni) represent a more temperate, southern assemblage. Cladogenesis within the group appears coincident with Tertiary events affecting the Zambezi River, Kalahari and Great Escarpment.
Key words: Gekkonidae, Pachydactylus capensis, systematics, molecular phylogeny, zoogeography.