Plio-pleistocene diversification and connectivity between mainland and Tasmanian populations of Australian snakes (Drysdalia, Elapidae, Serpentes)

Abstract

The genus Drysdalia contains three recognised species of elapid (front-fanged) snakes, distributed across south-eastern Australia (including Tasmania). Here we aim to clarify the biogeography and phylogeographical relationships of this poorly documented region. We conducted molecular phylogenetic and dating analyses, using mitochondrial genes (ND4 and cyt-b). Our analyses suggest that divergence events among the three extant species, and among major lineages within those species, are congruent with Plio-pleistocene climatic variations. Two highly divergent genetic lineages within Drysdalia coronoides occur in Tasmania. Molecular dating suggests that these lineages were isolated from the mainland in the Pleistocene.