So the case definitely isn’t closed on how humans first ventured out of Africa and populated the rest of our planet, but if nothing else, this new research serves as an important confirmation that Indigenous Australians really were the first to inhabit the continent – something that has, in the past, had doubt cast on it. Some scientists believe that all non-Africans today can trace their ancestry back to a single migrant population, while others argue that there were several different waves of migration out of Africa. In 2011, Willerslev’s analysis of a single, 100-year-old lock of hair from an Australian Aboriginal man detected enough genetic differences from modern Asian populations that the researchers concluded Sahul must have been populated by a group of ancient humans who left Africa in an earlier wave, traveling south through India to eventually reach it.
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New research suggests that the genetic ancestry of people living outside Africa can be traced nearly completely to a single exodus of humans from that continent long ago.
Dr Westaway said this could be connected to the last Ice Age around 30,000 to 20,000 years ago.
Genome sequencing of remote peoples of the Pacific and Australia is shedding light on how early humans moved out of Africa and spread across the world, New Zealand scientists said Thursday.
The new research also suggests the splintering of the human tree began earlier than experts had suspected.
Genetic traces of the mysterious early humans, whose fossil remains have never been found, are still carried by Australian aboriginal people.
Australian aboriginals come from a massive migration from Africa.
Co-author Dr Anna-Sapfo Malaspinas, from the Universities of Copenhagen and Bern, said: “The genetic diversity among aboriginal Australians is unbelievable”. However, scientists have long debated when and how the modern human lineage spread out of Africa to almost every corner of the globe.
Prof Lambert said what the DNA could not explain to researchers was why a stream of early humans walked out of Africa, through Asia and down into Australia thousands of years later.
The genetic analyses revealed the genomes of present-day aboriginal Australians might harbor evidence of ancient interbreeding with an unknown human lineage. But in the Aboriginal DNA is an ancient story of migration into this continent, far deeper in time than any other population group has so far revealed.
Overall, the evidence shows that the vast majority of modern human ancestry outside of Africa comes from a single exit from Africa, said David Reich of Harvard Medical School, an author of the 142-population paper.
“The importance of this study for me is to have some proof of how long we [Aboriginals] have been in Australia”, Colleen Wall, an Aboriginal elder and Senior Woman of the Dauwa Kau’bvai Nation, told CNN.
But using large-scale genome data from Australians and Papuans we estimate the time of divergence between the two groups to be 37,000 years ago.
Crucially, because the ancestors of modern-day Europeans and Asians hadn’t split in two at this point, we think that they must have still been somewhere in western Eurasia at this point.
The authors sequenced the complete genomes of 83 Indigenous Australians (speakers of Pama-Nyungan languages) and 25 Papuans from the New Guinea Highlands. Scientists are still trying to reconstruct that expansion.
Researchers managed to trace the Papuan and Australian groups’ progress. Importantly, they are also a huge resource of over 600 new and diverse human genomes that provide the genomics community with the opportunity for further understanding of the paths our ancestors took towards the Anthropocene.
Examining their data separately, all three groups came to the same conclusion: People everywhere descend from a single migration of early humans from Africa.
So although these studies fill in some missing pieces in the puzzle of human history, many fascinating questions remain to fully retrace the steps taken by our ancestors as they explored the world.
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But the present study finds no evidence of this.
