DNA evidence shows the ancestors of modern Australian Aboriginals separated from other populations some 64,000 to 75,000 years ago.
DNA sequencing of a 100-year-old lock of hair has established that Aboriginal Australians have a longer continuous association with the land than any other race of people.
Sequencing of a West Australian Aboriginal man’s hair shows he was directly descended from a migration out of Africa into Asia that took place about 70,000 years ago.
The finding, published today in Science , rewrites the history of the human species by confirming humans moved out of Africa in waves of migrations rather than one single out-of-Africa diaspora.
The study is based on a lock of hair donated to British anthropologist Alfred Haddon by an Aboriginal man from the Goldfields region of Western Australia in the early 20th century.
The genome, shown to have no genetic input from modern European Australians, reveals the ancestors of the Aboriginal man separated from the ancestors of other human populations some 64,000 to 75,000 years ago.
Aboriginal Australians therefore descend directly from the earliest modern explorers — people who migrated into Asia before finally reaching Australia.
Co-author Dr Joe Dortch, an archaeologist at the University of Western Australia, says the work is significant because it shows the timeline for people in Australia is more than 50,000 years.
“So far there are no [archaeological] sites that are over 50,000 years old so it puts a time limit on that and focuses our future efforts,” he says.
Dortch believes the finding will foster a sense of pride in modern Australian Aborigines.
“It shows Aboriginal Australians have the longest branch of history in one particular place of anyone in the world.
“No one else in the world can say ‘I am descended from people who have been here 75,000 years’.”
Dortch says there has been debate among researchers as to whether there was a single migration wave out of Africa into Europe, Asia, and Australia.
Under that view, the first Australians would have branched off from an Asian population already separated from the ancestors of Europeans.
However, this study shows that when ancestral Aboriginal Australians began their journey, the ancestors of Asians and Europeans had not yet differentiated from each other and were still in Africa or the Middle East.
Dortch says the study shows a high level of sophistication among these early explorers.
“Their arrival in Australia required an incredible degree of planning and foresight,” he says.
“You can’t see Australia from Indonesia, you have to infer it is there. This was a colonisation journey and that is modern behaviour happening more than 50,000 years ago.”
Fellow co-author David Lambert, a professor of evolutionary biology at Griffith University, agrees.
“Aboriginal people were in Australia before people got to Europe and already had very complex societies by that time,” Lambert says.
He says the closest populations to Australian Aborigines from that first early dispersal migration can be found today in the Highlands of Papua New Guinea and the Aeta people of The Philippines.
Lambert says the “landmark paper” breaks new ground in its approach in consulting and working in partnership with indigenous groups.
“We know this hair sample was taken voluntarily and that an Aboriginal man gave his consent in 1923, and the people that represent the area he was from in 2011 have given their consent,” says GLSC research manager Dr Craig Muller.
Muller says the Goldfields people are proud the research highlights the longevity of Aboriginal Australian occupation of the land.
“The Aboriginal people of the Goldfields area knew that anyway, but they like the fact the broader community is being reminded of [the length of our connection],” he says.
Muller says the people of the region have also told him they are eager to collaborate on further research.
Creating a genetic road map
Murdoch University’s ancient DNA expert Dr Michael Bunce and hair analysis expert Silvana Tridico also contributed to the project.
“It really is remarkable the recent advances in technology that now enable us to convert an old lock of hair into a complete genome – the information encoded in the DNA can tell us a lot about how humans explored the globe,” says Bunce.
“The great news is that there is so much more we can discover both from this sample.”
Tridico says the sample not only yielded information on the donor’s ancestry, but also his own personal history.
“I was able to see features like ochre still attached to the hair shafts and weathering from the harsh outback conditions,” Tridico says.
So far the only ancient human genomes have been obtained from hair preserved under frozen conditions.
The researchers have now shown that hair preserved in much less ideal conditions can be used for genome sequencing without risk of modern human contamination that is typical in ancient bones and teeth.
[GR1]he Aboriginal people of the Goldfields region have been looking after and managing their traditional country for over 60,000 years. GLSC has developed a Goldfields Ranger Program over the last ten years, drawing on this accumulated wealth of knowledge and experience and applying it in a context that provides an opportunity for employment on country for the local Aboriginal community.