Phylogeographic variation in the quokka, Setonix brachyurus (Marsupialia :Macropodidae): implications for conservation

Allozyme electrophoresis and mitochondrial DNA sequences were used to asses s genetic variation in a small macropod marsupial, the quokka (Setonix brac hyurus). Setonix brachyurus is restricted to the southwest corner of Wester n Australia. Its habitat has been fragmented at least since the late Pleist ocene by rising sea levels, creating two island populations, and more recen tly through anthropomorphic modification of the mainland habitat. Genetic a nalyses showed low levels of variation for allozymes (two polymorphic loci) , although there was significant heterogeneity among populations (overall F -ST = 0.362). Nucleotide sequence diversity was low (pi = 0.028) while hapl otype diversity was high (H = 1.0). Overall, the patterns of genetic variat ion reflect a shallow history, but with restricted gene flow across the spe cies' range.