Heinicke, M. P., Greenbaum, E., Jackman, T. R. & Bauer, A. M. Phylogeny of a trans‐Wallacean radiation (Squamata, Gekkonidae, Gehyra) supports a single early colonization of Australia. —Zoologica Scripta, 40, 584–602.
The genus Gehyra (34 species) is rare among squamate reptile radiations in spanning continents, extending from southeast Asia to Australia and Polynesia. Among the family Gekkonidae sensu stricto, Gehyra is the only genus that is species rich in Australia. We performed molecular phylogenetic, divergence timing, and ancestral area analyses to investigate the evolutionary and biogeographic history of Gehyra. Phylogenetic analyses resolve Hemiphyllodactylus as the closest relative of Gehyra. Some data also link Perochirus to this group, but previously suggested relationships with other morphologically similar genera of geckos are not supported. Within Gehyra, three geographically discrete clades are recovered, respectively, concentrated in Asia, the Pacific islands and Australia. Ancestral area analyses suggest that Gehyra originated in Asia, with a single colonization of Australia occurring in the mid‐Cenozoic. This date places the time of Gehyra colonization prior to those of other Australian gekkonid geckos, but after the near‐endemic pygopodoid geckos, a Gondwanan relictual group. Based on these dates, times of origin may best explain relative differences in species diversity among Australian gekkotans. In contrast, although originating earlier, Gehyra is less diverse in Asia than in Australia. This pattern may be explained by the long‐term presence of many competing, ecologically similar genera in Asia (e.g. Gekko, Hemidactylus, Lepidodactylus), whereas nearly all pygopodoids in Australia (the only gekkotans present at the time of colonization of Australia by Gehyra) are ecologically distinct.