Aboriginal Australians descend from one of the earliest groups of modern humans to leave Africa, arriving on the Australian continent at least 65,000 years ago. Genomic evidence shows their ancestors split from other Eurasian populations between 62,000 and 75,000 years ago, making them part of a migration wave that occurred long before the ancestors of modern Europeans and East Asians diverged from each other. This makes Aboriginal Australians one of the oldest continuous populations outside of Africa.
An Early Wave Out of Africa
All humans trace their origins to Africa, and Aboriginal Australians are no exception. What makes their story distinctive is timing. Genome sequencing, including a landmark study published in Science, shows that the ancestors of Aboriginal Australians were part of an early dispersal into eastern Asia roughly 62,000 to 75,000 years ago. This was a separate migration from the one that later produced modern East Asian and European populations, which diverged from each other only about 25,000 to 38,000 years ago.
This finding supports what researchers call the “multiple-dispersal model”: rather than one single wave of humans spreading out of Africa and populating the rest of the world, there were at least two major waves into Asia. The first carried the ancestors of Aboriginal Australians and related populations eastward. The second, tens of thousands of years later, gave rise to the populations that eventually settled across the rest of Asia and into Europe.
The Route to Australia
Getting to Australia required crossing a chain of islands and open water, even during ice ages when sea levels were far lower than today. During those periods, much of Southeast Asia was connected in a massive landmass called Sunda (covering present-day Malaysia, Indonesia’s western islands, and Borneo), and Australia was joined to New Guinea and Tasmania in a supercontinent called Sahul. But between Sunda and Sahul lay a scattered archipelago called Wallacea, where deep ocean channels meant the land was never fully connected.
Researchers have identified two plausible routes through Wallacea. A northern route ran through Sulawesi and into New Guinea. A southern route went from Bali through Timor and onto the expanded northwestern shelf of Australia. Both routes required multiple ocean crossings. At minimum, one open-water crossing of about 100 kilometers was necessary, along with several shorter hops of 20 to 30 kilometers. Even the earliest segments involved crossings: getting from Bali to Lombok, for instance, required navigating several short stretches of open sea.
The fact that people successfully made these crossings 65,000 years ago tells us something important. These were not accidental drifters washing ashore on rafts. A study published in Scientific Reports concluded that the settlement of Sahul “was not an accident,” and the ocean crossings serve as direct evidence that these early humans possessed advanced cognitive and technological abilities, likely including some form of watercraft and the navigational knowledge to use them.
The Earliest Archaeological Evidence
The oldest confirmed site of human occupation in Australia is Madjedbebe, a rock shelter in the Northern Territory. Excavations there recovered stone tools and grinding stones dated to 65,000 years ago using a technique called optically stimulated luminescence, which measures the last time mineral grains were exposed to sunlight. The grinding stone record at Madjedbebe spans the entire 65,000-year period continuously, making it one of the longest such records anywhere on Earth.
Other key sites push the story further inland. At Lake Mungo in New South Wales, the remains of two individuals, known as Mungo Lady and Mungo Man, have been dated to between 40,000 and 42,000 years ago. These are the oldest human remains found in Australia. Mungo Lady had been cremated, and Mungo Man was ceremonially buried on his back with his hands crossed and his body dusted with red ochre. These are among the earliest known examples of cremation and ritual burial anywhere in the world, pointing to complex cultural practices already well established by that time. Researchers believe humans reached Lake Mungo by following a river system inland from the coast.
Denisovan DNA and the Journey Through Asia
As Aboriginal ancestors traveled through Southeast Asia, they encountered and interbred with Denisovans, a now-extinct human species closely related to Neanderthals. Today, Indigenous peoples of Australia and Island Southeast Asia carry up to 5% Denisovan DNA in their genomes. By comparison, most people of European or East Asian descent carry little to no Denisovan ancestry.
This Denisovan genetic inheritance wasn’t just a footnote. Research published in PLOS Genetics found that Denisovan DNA variants strongly influence immune system function in present-day Papuan populations. Specific inherited gene variants affect how immune cells respond to pathogens, including genes involved in fighting viral infections. This suggests the interbreeding may have helped early humans adapt to the diseases and environments they encountered as they moved through tropical Asia and into Sahul.
Divergence Within Sahul
Once people reached Sahul, they spread across the combined landmass of Australia and New Guinea. But they didn’t remain a single population for long. Genomic analysis published in Nature estimates that the ancestors of Aboriginal Australians and Papuans (the Indigenous peoples of New Guinea) diverged roughly 37,000 years ago, with a confidence range of 25,000 to 40,000 years. That split happened well before the land bridge between Australia and New Guinea was submerged by rising seas, which occurred between 7,000 and 14,500 years ago. In other words, the two populations became genetically distinct not because the ocean separated them, but because of distance, geography, and the sheer size of the Sahul continent creating natural barriers to contact.
Within Australia itself, populations diversified further. The Pama-Nyungan language family, which covers roughly 90% of the Australian continent today, originated in the Gulf Plains region of northern Australia during the mid-Holocene (roughly 4,000 to 6,000 years ago) and expanded rapidly, replacing earlier non-Pama-Nyungan languages across most of the landmass. This linguistic pattern suggests significant internal population movement and cultural change long after the initial settlement.
Tens of Thousands of Years of Isolation
After the initial settlement, Aboriginal Australians remained largely isolated from the rest of the world for an extraordinary stretch of time. The ancestors of Aboriginal Australians split from other Eurasian populations 62,000 to 75,000 years ago and reached Australia by around 50,000 to 65,000 years ago. As sea levels rose at the end of the last ice age, the land connections through Southeast Asia became increasingly difficult to traverse, and the ocean gaps widened. This created one of the longest periods of genetic isolation for any human population on Earth, spanning roughly 50,000 years before European contact in the 18th century.
That isolation, combined with the vast and varied Australian landscape, produced remarkable cultural and genetic diversity. Despite sometimes being spoken of as a single group, Aboriginal Australians encompass hundreds of distinct nations and language groups, each adapted to environments ranging from tropical rainforests to arid deserts. Their deep roots on the continent, stretching back at least 65,000 years, make them the custodians of the oldest continuous cultures in the world.