The information that was revealed included the idea that scientists may be wrong because Indigenous Australians may not be the oldest civilization on the planet.
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All non-Africans living today can trace the vast majority of their ancestry to a group of pioneers who left Africa in a single wave, tens of thousands of years ago.
“The genetic diversity among Indigenous Australians is wonderful”, said study first author Dr. Anna-Sapfo Malaspinas, from the SIB Swiss Institute of Bioinformatics, the Centre for GeoGenetics of Copenhagen and the University of Bern.
Significantly, the results also show that Indigenous ancestors migrated from Africa 72,000 years ago as part of a “single migration” of the world’s first people.
The third paper out today, which added almost 400 new genomes to an existing dataset, discovered something curious about Papuans: at least 2 percent of the modern Papuan genome comes from a population other than the one that left Africa to set up shop in Eurasia. They conclusively show that modern African hunter-gatherer populations split off from the group that became non-Africans around 130,000 years ago and from West Africans around 90,000 years ago. They even had common links with a radically different hominin cousin the exact nature of which remains unknown.
Did ancient humans move out of Africa in a single dispersion, or did the migration come in waves spread out throughout the course of thousands of years? This is prior to their split from each other around 29,000-55,000 years ago, and nearly immediately after the move out of Africa. “This study confirms our beliefs that we have ancient connections to our lands and have been here far longer than anyone else”, proclaimed Aubrey Lynch, an indigenous Australian elder, in a Guardian article. Although Australia is halfway around the world from our species’s accepted birthplace in Africa, the continent is nevertheless home to some of the earliest undisputed signs of modern humans outside Africa, and Aborigines have unique languages and cultural adaptations.
Genetic differences between Aboriginal populations were also exacerbated by the last ice age, which occurred about 20,000 to 30,000 years ago. This also indicates that all non-African people are descended from a single population movement out of the continent.
It shows ancient contact and gene flow between the ancestors of the First Australians and now extinct populations of Neanderthals and Denisovans.
“I don’t think this study will be the final word on this issue, as recent discoveries in places like China cast a big shadow over it”, Darren Curnoe, from the University of New South Wales (UNSW) in Australia, told Rae Johnston from Gizmodo.
Papuans and Aboriginals then split around 37,000 years ago, long before the continents were finally cut off from each other around 8000 years ago.
There has been considerable debate as to whether the First Australians took the northern route (through Papua and then down into Cape York) or a more southerly route, crossing from Timor into north-western Australia.
“As population geneticists, we could spend the next decade arguing about that 2 percent, but in practical terms it doesn’t matter”, Joshua Akey of the University of Washington, who wasn’t involved with the new studies, told Science magazine.
Co-author Dr Anna-Sapfo Malaspinas, from the Universities of Copenhagen and Bern, said: “The genetic diversity among aboriginal Australians is unbelievable”. What was their relationship to other groups?
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The study analysed the DNA of 483 people from 148 populations worldwide, including six Papuans. “We’re asking them what they want to find out, rather than the other way around, which is how most research is done on Aboriginal groups”, says project leader Alan Cooper at the University of Adelaide. Led by Luca Pagani, the scientists analyzed 483 human genomes from 148 populations and, like Willerslev’s team, found evidence for a mass migration out of Africa about 75,000 years ago.
