The history of indigenous Australians is thought to have spanned forty thousand to forty-five thousand years, although some estimates have put the figure at up to seventy thousand years before European settlement.
A genetic study of one hundred and eleven Aboriginal Australians, published in the journal Nature on March 8, 2017 (Aboriginal mitogenomes reveal 50,000 years of regionalism in Australia), implies that "the settlement of Australia comprised a single, rapid migration along the east and west coasts that reached southern Australia by 49–45 ka. After continent-wide colonization, strong regional patterns developed and these have survived despite substantial climatic and cultural change during the late Pleistocene and Holocene epochs. Remarkably, we find evidence for the continuous presence of populations in discrete geographic areas dating back to around 50 ka, in agreement with the notable Aboriginal Australian cultural attachment to their country.”
For most of this time, the Indigenous Australians lived as nomads and as hunter-gatherers with a strong dependence on the land and their agriculture for survival.
Only Africa has older physical evidence of habitation by modern humans.
There is also evidence of a change in fire regimes in Australia, drawn from reef deposits in Queensland, between seventy thousand years and one hundred thousand years years ago, and the integration of human genomic evidence from various parts of the world supports a date of before sixty thousand years for the arrival of Australian Aboriginal people in the continent.
Modern humans reach Australia by at least 58,000 BCE.
In 1990, a date of sixty thousand years was suggested for a rock shelter in the Northern Territory, but the finding, based on the use of a recently developed technique called thermoluminescence, is still being evaluated.
The first settlement would have occurred during an era of lowered sea levels, when there was an almost continuous land bridge between Asia and Australia, but watercraft must have been used at some points.