Australian Aboriginals led the way out of Africa

Aboriginal Australians may be descendants of the very first people to leave Africa more than 60,000 years ago, DNA evidence suggests.

The analysis of hair collected from an aboriginal man in southwestern Australia in 1923 supports the theory that there were two separate waves of migration from Africa, the place where humans first evolved, and that most Europeans and Asians came from the second migration.

The research was published this week in Science.

The researchers picked the 88-year-old hair sample, collected by British anthropologist Alfred Haddon in southwestern Australia, because they wanted to find someone who was of purely aboriginal descent, said Rasmus Nielsen, co-author of the study in an interview with Quirks & Quarks set to air on CBC Radio on Saturday.

"It turns out that if you take hair and just leave it on a desk for a hundred years, there's still enough DNA preserved in the hair to actually sequence the genome," added Nielsen, an evolutionary genomics researcher at the University of California, Berkeley.

The sequencing and comparison with the genomes of people from other populations around the world found far more similarity between Europeans and Asians and Asians and Australians, suggesting they had come from two separate waves of migration.

Scientists estimate the first wave took place about 60,000 to 70,000 years ago and the second took place 30,000 to 40,000 years ago.

Fossil evidence had suggested that modern humans were in Australia 50,000 years ago, Nielsen said, but there has been a lot of debate about whether modern-day aboriginals are descended from that original group or from a later migration.

He added that the new DNA evidence means "it's possible that the modern aboriginal Australians are in fact descendents of these very first individuals that came to Australia."

It's likely the early migrants travelled out from the Middle East, through India and Asia to Australia, Nielsen said.

The researchers are now interested in seeing if they can find evidence in Asia of that first group of migrants, who are believed to have been largely displaced by the second wave of migrants.