Aboriginal Australians: First Explorers & First Peoples

ScienceDaily September 22, 2011

An international team of researchers has, for the first time, pieced together the human genome from an Aboriginal Australian.

The results, now to be published in the international journal Science, re-interpret the prehistory of our species.

By sequencing the genome, the researchers demonstrate that Aboriginal Australians descend directly from an early human expansion into Asia that took place some 70,000 years ago, at least 24,000 years before the population movements that gave rise to present-day Europeans and Asians. The results imply that modern day Aboriginal Australians are in fact the direct descendents of the first people who arrived in Australia as early as 50,000 years ago.

The study derived from a lock of hair donated to a British anthropologist by an Aboriginal man from the Goldfields region of Western Australia in the early 20th century. One hundred years later, researchers have isolated DNA from this same hair, using it to explore the genetics of the first Australians and to provide insights into how humans first dispersed across the globe.

Separation

The genome, shown to have no genetic input from modern European Australians, reveals that the ancestors of the Aboriginal man separated from the ancestors of other human populations some 64-75,000 years ago. Aboriginal Australians therefore descend directly from the earliest modern explorers, people who migrated into Asia before finally reaching Australia about 50,000 years ago. In showing this, the study establishes Aboriginal Australians as the population with the longest association with the land on which they live today. This research is presented with the full endorsement of the Goldfields Land and Sea Council, the organization that represents the Aboriginal traditional owners for the region.

New model for migration

The history of Aboriginal Australians plays a key role in understanding the dispersal of the first humans to leave Africa. Archaeological evidence establishes modern human presence in Australia by about 50,000 years ago, but this study re-writes the story of their journey there.

Previously, the most widely accepted theory was that all modern humans derive from a single out-of-Africa migration wave into Europe, Asia, and Australia. In that model, 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 private journey, the ancestors of Asians and Europeans had not yet differentiated from each other. Once they did, some 24,000 years after the first Australians had begun their explorations, Asians and remnants of the ancestral Australians intermixed for a period of time.

The first humans were explorers

Professor Eske Willerslev from the University of Copenhagen, who headed the study, explains: "Aboriginal Australians descend from the first human explorers. While the ancestors of Europeans and Asians were sitting somewhere in Africa or the Middle East, yet to explore their world further, the ancestors of Aboriginal Australians spread rapidly; the first modern humans traversing unknown territory in Asia and finally crossing the sea into Australia. It was a truly amazing journey that must have demanded exceptional survival skills and bravery."

The study has wide implications for understanding of how our human ancestors moved across the globe. 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. Through analysis of museum collections, and in collaboration with descendent groups, researchers can now study the genetic history of many indigenous populations worldwide, even where groups have recently moved about or intermingled.

Genes map Aborigines' arrival in Australia

Leigh Dayton and Stuart Rintou The Australian 23rd September 2011

A Lock of hair taken from an unknown young man near Kalgoorlie in the 1920s has provided solid genetic evidence that Aboriginal Australians are descended from the first modern humans to walk out of Africa nearly 75,000 years ago.

Detailed analysis of the Aborigine's genetic blueprint - his genome - by an international team on several continents supports the theory that humans migrated from Africa into eastern Asia in multiple waves, contrary to the theory of a single out-of-Africa migration wave.

The order, or sequence, of the genes in the young man's genome suggests his ancestors were "the first human explorers", leaving Africa before a second group migrated from Africa into eastern Asia, 25,000-38,000 years ago.

The first Aboriginal genome reinforces archeological evidence that people arrived on the Australian continent at least 50,000 years ago and that they share one of the oldest continuous cultures in the world.

Published today in the journal Science, the research was conducted by a Danish, Australian and British team led by evolutionary biologist Eske Willerslev, director of the Centre for Ancient Genetics at the University of Copenhagen.

"Aboriginal Australians descended from the first human explorers," he said.

"While the ancestors of Europeans and Asians were sitting somewhere in Africa or the Middle East, yet to explore their world further, the ancestors of Aboriginal Australians spread rapidly; the first modern humans traversing unknown territory in Asia and finally crossing the sea into Australia.

"It was a truly amazing journey that must have demanded exceptional survival skills and bravery."

The Goldfields Land and Sea Council, which covers the area where the man lived, has endorsed the research, marking a break with past tensions over scientific research. In Kalgoorlie, council chairwoman Dianne Logan said the findings were

"exciting". The project further proved the ancient Aboriginal connection to the land, and Aborigines felt "exonerated in showing the broader community that they are by far the oldest continuous civilisation in the world".

Adelaide-based DNA expert Alan Cooper, head of the Australian Centre for Ancient DNA, who was not part of the research team, agreed the genome strongly supported the idea Aborigines were an early and separate wave of human expansion out of Africa, before the subsequent wave that established Europeans and Asians.

Along with Mike Bunce, head of the Ancient DNA Research Laboratory at Perth's Murdoch University, who co-ordinated the Australian contribution to the program, Professor Willerslev and geneticists in Britain and Denmark concluded that, after the first wave of migration, a second wave of people left Africa 25,000-38,000 years ago.

The team estimated the timing of the first and second migrations using the known rate at which DNA changes, or mutates, over time. Because they had had quality data on 60 per cent of the Aboriginal genome, they had plenty of data to calibrate the "molecular clock".

Then as both waves of immigrants moved into the Middle East and onwards, they swapped genes with archaic people such as the Neanderthals and the Denisovans, and with one another.

A second report this week in the American Journal of Human Genetics by another team - headed by geneticist Mark Stoneking at Germany's Max Planck Institute for Evolutionary Anthropology in Leipzig - details the extent of intermingling by the various groups, and bolsters the Science team's finding of multiple waves of early human movement out of Africa.

Professor Cooper said Professor Stoneking's work showed there was not a single wave of migration out of Africa through to Australia. "There's a whole patchwork of interactions in Asia before the Aboriginal people get to Australia," he said.

The Aboriginal hair sample was collected at a long-gone train station at Golden Ridge, near Kalgoorlie, in 1923, by Cambridge anthropologist and ethnologist Alfred Haddon, who like many anthropologists of the time, believed Aboriginal people were a dying race.

Craig Muller, research manager at the Goldfields Land and Sea Council, said Haddon was in Australia in 1923 to attend a conference in Sydney and Melbourne, but travelled to Western Australia on the Trans-Australia. The train would have stopped for about 40 minutes at Golden Ridge, now just "scrub and gravel". Aboriginal people traded artefacts with passengers along the line, although he "likes to imagine the young man was rather surprised when he was asked to give up some of his hair".

With little provenance other than Haddon's name and the label "Golden Ridge", the sample remained at Cambridge, at the Duckworth Laboratory, devoted to the study of human evolution and variation, until about a year ago when Professor Willerslev learned of its existence.

Initial tests confirmed DNA could be extracted from it. Dr Bunce noted: "That's when Eske got on a plane and came straight over. He's acutely aware that this is a politically charged area."

In particular, the 2005 US Genographic Project aroused much anger among indigenous communities in Australia and the US. The project was denounced as a clone of the Human Genome Diversity Project, which was condemned by the US-based Indigenous Peoples Council on Biocolonialism as an "unconscionable attempt" by genetic scientists "to pirate our DNA for their own purposes".

Dubbed the Vampire Project, the Human Genome Diversity Project was condemned in 1993 by the Central Australian Aboriginal Congress. "The Vampire scientists are planning to take and to own what belongs to indigenous people," it said.

Dr Bunce said "times have moved on" and scientists and indigenous communities had learned how to work together.

Mr Muller said the project had raised several ethical issues for the Goldfields Land and Sea Council, but he was satisfied the sample was obtained ethically, rather than in a way "we would now find distasteful".

In June, Professor Willerslev spoke to the Land and Sea Council to explain his research and gain Aboriginal endorsement.

The council last night said it was excited by the study, which "establishes Aboriginal Australians as the population with the longest association with the land on which they still live today".

"Aboriginal people, in the Goldfields, as elsewhere, always feel secure in their connection to this country, and the research does not alter this fact."

One of the council's directors, Wongatha elder Cyril Barnes, said the genome project was "just a whitefella story" and he would continue to believe in the Wati Kutjara desert creation story, just as other people in Kalgoorlie were Bible-belt creationists.