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This distinct human line has never been found anywhere else in the world, according to new research.
“We have discovered the first ancient human DNA in the island region between Asia and Australia, known as ‘Wallacea’, providing new insight into the genetic diversity and population history of early humans. modern in this little-understood part of the world, ”said study co-author Adam Brumm, professor of archeology at Griffith University’s Australian Research Center for Human Evolution, via email.
Early modern humans used the Wallacea Islands, primarily the Indonesian islands that include Sulawesi, Lombok and Flores, during their passage from Eurasia to mainland Australia more than 50,000 years ago, the researchers say. The exact route or how they sailed this crossing, however, is unknown.
“They had to do this using relatively sophisticated boats, as there were no land bridges between the islands, even during the ice peaks of the last ice age, when world sea level was as high as ‘140 meters (459 feet) lower than they are today, ”Brumm said.
Tools and cave paintings have suggested humans lived on these islands 47,000 years ago, but fossil records are scarce and ancient DNA degrades faster in the tropical climate.
However, researchers found the skeleton of a woman aged 17 to 18 in a cave in Sulawesi in 2015. Her remains were buried in the cave 7,200 years ago. It was part of Toalean culture, which can only be found in a pocket of the southwestern Sulawesi peninsula. The cave is part of an archaeological site called Leang Panninge.
“The” Toaleans “is the name archaeologists have given to a rather enigmatic culture of prehistoric hunter-gatherers who lived in the wooded plains and mountains of South Sulawesi about 8,000 years ago until about the fifth century afterwards. JC, ”Brumm said via email. “They were making very distinctive stone tools (including tiny, intricately crafted arrowheads known as ‘Maros points’) that are not found anywhere else on the island or throughout the whole of it. ‘Indonesia.”
The young hunter-gatherer is the first largely complete and well-preserved skeleton associated with Toalean culture, Brumm said.
Lead author of the study, Selina Carlhoff, was able to recover DNA from the wedge-shaped petrous bone at the base of the skull.
“This was a major challenge, as the remains had been severely degraded by the tropical climate,” Carlhoff, also a doctoral student at the Max Planck Institute for the Science of Human History in Jena, Germany, said in a statement. .
Secrets hidden in DNA
The work to retrieve the genetic information was well worth it.
The DNA of the young woman has shown that she descended from the first wave of modern humans to enter Wallacea 50,000 years ago. It was part of the initial settlement of “Greater Australia”, or the combined Ice Age landmass of Australia and New Guinea. These are the ancestors of today’s native Australians and Papuans, said Brumm.
And it turns out that the oldest genome found in the Wallacea Islands has revealed something else: ancient humans previously unknown.
She also shares ancestors with a separate and distinct group from Asia that likely arrived after the colonization of Greater Australia – because Indigenous Australians and modern Papuans do not share ancestry with this group, Brumm said.
“Previously, it was believed that the first time people with Asian genes entered Wallacea was around 3,500 years ago, when Austronesian-speaking farmers from the Neolithic era of Taiwan invaded the Philippines and Indonesia. “, did he declare.
“This suggests that there might have been a distinct group of modern humans in this region that we really had no idea of until now, as archaeological sites are so rare in Wallacea and ancient skeletal remains are rare. . “
There are no descendants of this line left.
His genome included another trace of an enigmatic and extinct group of humans: the Denisovans. The handful of fossils signifying these earliest humans ever existed come largely from Siberia and Tibet.
“The fact that their genes are found in Leang Panninge’s hunter-gatherers supports our earlier hypothesis that the Denisovans occupied a much larger geographic area” than previously thought, the study co-author said. Johannes Krause, professor of archeogenetics at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, in a statement.
But when his DNA was compared to that of other hunter-gatherers who lived west of Wallacea around the same time, their DNA contained no trace of Denisovan DNA.
“The geographic distribution of Denisovans and modern humans may have overlapped in the Wallacea region. It may well be the key location where the Denisovans and ancestors of native Australians and Papuans crossed paths,” said study co-author Cosimo Posth, a professor at the University of The Senckenberg Tübingen Center for Human Evolution and the Paleoenvironment in Frankfurt, Germany, in a statement.
Researchers don’t know what happened to Toalean culture, and this latest discovery is part of the puzzle as they attempt to understand the ancient genetic history of humans in Southeast Asia. Brumm hopes that the older DNA of the Toalean people can be recovered to reveal their diversity “and their broader ancestral history.”
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