All non-Africans trace their ancestry to a single intrepid population that probably took a “beachcomber” route along the SE Asian coast sometime between 80,000 and 60,000 years ago. Evidence is building that our ancestors made it to Australia as early as 60,000 years ago.
Even though sea levels were much lower then, they still had to have the means to cross 37 miles of open ocean. Several earlier human dispersals from Africa apparently failed, although some of these seem to have left genetic traces in the other human species (Neanderthals, Denisovans, and perhaps Homo erectus) with whom they interbred.
An ancient Aboriginal rock painting of a wallaby in Kakadu National Park in Northern Australia (photo by PanBK).