New research suggests that the title of world's oldest civilization goes to the indigenous populations of Australia and Papua New Guinea. Scientists say the DNA of these people can be traced back to an original wave of settlers from Africa more than 50,000 years ago, reports the Guardian. “They are probably the oldest group in the world that you can link to one particular place,” says the University of Copenhagen's Eske Willerslev, lead author of a new study in Nature. It finds that the ancestors of these indigenous populations arrived on Sahul—a supercontinent that once included New Guinea, Australia, and Tasmania, per the Telegraph—between 51,000 and 72,000 years ago. In fact, the study suggests they were the first people to cross an ocean.
"Now we know their relatives are the guys who were the first real human explorers," says Willerslev. "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.” At some point, they seem to have interbred with an unspecified early human relative whose DNA has left a small mark on their modern genetic makeup—it accounts for about 4% of it. The study, based on analysis of 83 indigenous Australians and 25 Papuans, found that the group remained largely isolated until about 4,000 years ago, when they encountered populations from Asia and then Europe. (A related study found that almost everyone is descended from a single wave of African migrants.)