Genome sequencing study suggests that Aboriginal Australians are descended from early wave of modern humans who migrated out of Africa perhaps 62,000 - 75,000 years ago

Little did he know that giving a team of scientists a lock of his hair would provide answers to some profound questions about the origins of humankind in his native Australia. But that is exactly what happened when scientists sequenced his genome and found that he was descended from a very ancient wave of modern humanity out of Africa and eventually into Australia some 62,000 - 75,000 years ago.

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© Science/AAASReconstruction of early spread of modern humans outside Africa. The tree shows the divergence of the Aboriginal Australian (ABR) relative to the CEPH European (CEU) and the Han Chinese (HAN) with gene flow between aboriginal Australasians and Asian ancestors. Purple arrowshows early spread of the ancestors of Aboriginal Australians into eastern Asia ~62,000 to 75,000 years B.P. (ka BP), exchanging genes with Denisovans, and reaching Australia ~50,000 years B.P. Black arrow shows spread of East Asians ~25,000 to 38,000 years B.P. and admixing with remnants of the early dispersal (red arrow) some time before the split between Asians and Native American ancestors ~15,000 to 30,000 years B.P. YRI, Yoruba.
He is an Aboriginal Australian. The results of the genetic tests showed that modern humans migrated into Eastern Asia in more than one wave and that he, along with all of his fellow Aboriginal Australians, could claim direct heritage with a very early wave, perhaps even the first wave. This meant that his population constituted one of the oldest continuous populations outside of Africa.

The debate concerning how and when Eastern Asia was populated has been an ongoing one. Central to this has been the question regarding whether modern humans migrated into this part of the world in a single wave or in multiple waves. The origins of the Aboriginal Australians has been an integral part of the total debate.

Morten Rasmussen of the Natural History Museum of Denmark, Copenhagen, and his team of colleagues compared the Aboriginal genome sequence with no less than 79 other genome sequences from Africa, Asia and Europe, including genomes from three Han Chinese individuals. The results suggest that modern humans actually did migrate in more than one event or wave into East Asia, supporting the multiple event theory, and that the Aboriginal genome represented a very early or ancient migratory event, possibly as long ago as between 62,000 and 75,000 years ago, with their ancestors eventually arriving in Australia at around 50,000 B.P.

The suggested African exodus corresponds to a time when many scientists postulate that the first modern humans ventured out of Africa to populate Eurasia. It also suggests that the Aboriginal Australians were the earliest modern humans to occupy Australia. Moreover, their study indicated that most Asians today descend from an original population that migrated into East Asia around 24,000 to 50,000 years ago.

The paper detailing this study is published online by the journal Science at the Science Express website. It will also be published in the September 23 issue of Science, a publication of the American Association for the Advancement of Science (AAAS).

*"An Aboriginal Australian Genome Reveals Separate Human Dispersals into Asia," by M. Rasmussen; L. Orlando; M.C. Ávila-Arcos; J.V. Moreno-Mayar; M.T.P. Gilbert; A. Krogh; E. Willerslev; S. Lindgreen at Natural History Museum of Denmark in Copenhagen, Denmark.