For centuries, Aboriginal Australians have said they belonged to the oldest sustained civilization on the face of the Earth, citing their culture and history of oral storytelling that stretches back tens of thousands of years. Now, one of the most extensive analyses of Indigenous Australian DNA to date suggests that they've been right all along.
The ancestors to modern humans first arose in Africa, but the question of where and when they began spreading out from the continent has long plagued scientists and archeologists alike. While Homo sapiens are far from the first human species to begin exploring other parts of the planet (other, older species like the Neanderthals and Denisovans made it out first), the question has long been whether the ancestors of modern non-Africans left in waves or all at once, Emily Benson reports for the New Scientist.
Nailing down the approximate times that one’s ancestors left Africa is tricky business. Previous research has shown that humans began splitting into different genetic groups about 200,000 years ago, long before they first began exploring other continents. By analyzing DNA from 787 people from 270 modern cultures spread across the world, a group of scientists identified and tracked ancient genetic mutations that they believe mark when different ethnicities diverged as their ancestors settled across the world, Benson reports.
Using this genetic tracing, the researchers suggest that the first Homo sapiens began leaving Africa between 51,000 and 72,000 years ago. And the ancestors of Indigenous Australians were the first group to split off from that migration. While the ancestors of European and Asian people diverged about 42,000 years ago, the precursors to today’s Indigenous Australians and Papuans diverged 58,000 years ago to head east, George Dvorsky reports for Gizmodo.
“This story has been missing for a long time in science,” Eske Willerslev, an evolutionary geneticist at the University of Copenhagen, tells Hannah Devlin for The Guardian. “Now we know their relatives are the guys who were the first real human explorers. Our ancestors were sitting being kind of scared of the world while they set out on this exceptional journey across Asia and across the sea.”
These humans eventually made their way to an ancient supercontinent, which was eventually split into Australia, New Zealand and Papua New Guinea by rising tides. While that isolated them genetically from the rest of the world, their culture was strong and vibrant enough to develop new languages and traditions as they made their way across the continent, Devlin reports.
“This study confirms our beliefs that we have ancient connections to our lands and have been here far longer than anyone else,” Aubrey Lynch, an Indigenous elder from Australia's Goldfields region, tells Devlin.
While the study appears to seal the deal on the world’s oldest society, it raises new questions. The genetic analysis also showed that the ancestors of Indigenous Australians and Papuans may have mated with a previously-unknown human species, just like ancient Europeans interbred with Neanderthals. Though scientists are just now getting hints at who these mysterious human species were, further genetic analysis could shed light on another ancient relative.