Scientists discover first ancient human DNA remarkably preserved from tropical Asia region – USA TODAY

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A group of scientists have uncovered a new chapter of the “human story” in Southeast Asia thanks to a partially preserved skeleton dating back approximately 7,200 years.

A new peer-reviewed study published in the journal Nature analyzes the first ancient human genome from Wallacea, an island region between the Sunda Shelf (which includes mainland southeast Asia and the islands of western Indonesia) and the Australia–New Guinea region. 

Scientists found and excavated the partially-preserved skeleton in 2015 from a limestone cave on the Indonesian island of Sulawesi. They were able to extract DNA from the petrous bone, a thick inner ear bone, and analysis revealed that the skeleton belonged to a female who was around 17-18 years old.

According to the study, recovering intact human remains from this region is uncommon because the tropical temperatures usually cause them to break down, making delicate structures like DNA unsalvageable. Adam Brumm, an archaeologist who co-wrote the study and a professor of archaeology at Griffith University, said the scientists were able to reconstruct about 2% of of the genome, which he said is a remarkable amount.

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He said the researchers have theories, but they are unsure exactly why the woman’s DNA was preserved.

“This [excavation] site is up in the highlands, so there’s obviously no snow or anything, but it’s higher up than what we work with down in the coastal plains, so maybe it was just cooler, the temperature, the climate,” Brumm told USA TODAY. “The petrous bone itself is remarkable; it’s like a rock. It’s the sort of place where, even in an unfit climate, DNA can survive.”

The skeleton was found to have about half of her DNA connected to Aboriginal Australian groups and the other half from Papua New Guineans. According to the study, her genome represents a previously undescribed ancestry profile that branched off around the time that Papuan and indigenous Australian groups split. The researchers said it is possible that she may carry a local ancestry that was present in Sulawesi before humans migrated to the Australian continent.

“It’s very early ancestral history, and it’s told us quite a bit more than we previously knew about patterns of early human migrations into that region,” Brumm said. “We can get indirect insights into from the archeology…but once you get DNA, that gives a more direct insight into the early human story, and that makes this quite an exciting discovery.”

Brumm said the archeologists at the excavation site also discovered sophisticated flint arrowheads and other tools that they believe were used for hunting and potentially for warfare with other tribal groups in the region. These artifacts led the archaeologists to conclude that the woman lived a hunter-gather lifestyle rather than an agriculture-based one.

Because of the COVID-19 pandemic, Brumm and his team have not been able to return to Indonesia for further excavations, but he said he has been able to connect with other archaeologists in the region and hopes to continue the study in the near future.

“My colleagues, some of the best archaeologists have ever worked with in my career, that’s their home and they’re still at work finding amazing things, so I think story will continue,” he said. “It’s just a matter time, and the bones are not going anywhere.”

Contact Emily Adams at eaadams@gannett.com or on Twitter @eaadams6.

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Scientists discover first ancient human DNA remarkably preserved from tropical Asia region – USA TODAY

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