We Aussies were the original pickpockets and thieves, with plenty of genetic diversity because of our 'common' (ironic) social status, as opposed to the inbreeding gentry. Combine that with the fact that we don't have all that nasty gravity stuff weighing us down because we live upside down, means that of course we look different. Local habitat, such as drop bears, giant wombats, bunyips, snakes and spiders meant that we needed to diversify genetically pretty quickly too! ;-)