The identity of the Depuch Island rock-wallaby revealed through ancient DNA

Ancient DNA is becoming increasingly recognised as a tool in conservation biology to audit past biodiversity. The widespread loss of Australian biodiversity, especially endemic mammal populations, is of critical concern. An extreme example occurred onDepuch Island, situated off the north-west coast ofWestern Australia, where an unidentified species of rock-wallaby (Petrogale sp.) became extinct as a result of predation by red foxes. Two potential candidate species,Petrogale lateralis andP. rothschildi, both have ranges adjacent to Depuch Island, making identification based on geography difficult. A museum bone (one of the only surviving Depuch Island specimens) was subjected to standard ancient DNA analyses and procedures. Mitochondrial DNA cytochrome b and hypervariable control region were targeted for species identification. AncientDNAwas successfully recovered from the bone: 200base pairs (bp) of control region and975 bpof the cytochromeb gene. Bayesian phylogenetic analyses were employed to model the Depuch Island rock-wallaby DNA sequences together with sequences of other rock-wallaby taxa fromGenBank. Evidence suggests that of the two Petrogale lateralis subspecies proposed to have inhabitedDepuch Island,Petrogale lateralis lateraliswas identified as themost likely. The identification of theDepuch Island rock-wallaby populationmay assist in the reintroduction of an insurance population ofPetrogale lateralis lateralis, which is becoming increasingly threatened on mainland Australia. Additional keywords: Past biodiversity, Conservation. Received 21 November 2011, accepted 25 July 2012, published online 26 October 2012