Abstract

A total of 168 specimens of 38 species of Australian native murid rodents and three species of nonnative rodents were screened electrophoretically at 20 loci. Genetic and phylogenetic relationships among species were assessed by means of Average Linkage Cluster and Wagner Analysis respectively. The major conclusions of the analysis are: the genera Melomys, Leggadina, Zyzomys, Notomys and Rattus ire each monophyletic, at least for the species we had; the genus Pseudomys is largely monophyletic; although it may be paraphyletic with respect to Mastacomys and Leporillus; the genus Pseudomys is nevertheless a genetically diverse group consisting of at least four groups, none of which correspond to the earlier genera Gyomys and Thetomys; the 'Old Endemics', the water rats, and the Uromys- Melomys groups are genetically more similar to each other than any is to Rattus. Within Rattus, the following groupings emerge: R. sordidus, R. colletti and R. villosissimus: R. t. tunneyi and R. t. culmorum; R. l. leucopus and R. l. cooktownensis; R. fuscipes coracius, R. f: assimilis and R. f. greyii.