Ancient DNA Of Teen Hunter-Gatherer Uncovers New Unknown Group Of Humans
Image via Carlhoff, et al (CC By 4.0)
Researchers have published a new study involving the bones of a teenage hunter-gatherer who died more than 7,000 years ago. The ancient DNA could give scientists insight to a distinct human lineage that hasn’t been found anywhere else in the world.
“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 modern humans in this little understood part of the world,” the study’s co-author Adam Brumm, a professor of archaeology at Griffith University’s Australian Research Centre for Human Evolution, told CNN.
It is believed that early modern humans from more than 50,000 years ago used the Wallacea islands—comprising the Indonesia islands Sulawesi, Lombok, and Flores—to cross from Eurasia to the Australian continent.
Earlier researchers had come across tools and cave paintings that point to humans living on the islands about 47,000 years ago, though the tropical climate has led to fewer fossils and DNA records surviving, as they degrade more rapidly in the heat.
In 2015, a team has discovered the skeleton of a female, aged between 17 and 18, in a cave on Sulawesi island. She was confirmed to be the first complete and well-preserved skeleton belonging to the Toalean culture, which has only been found in the island’s southwestern peninsula.
“The ‘Toaleans’ is the name archaeologists have given to a rather enigmatic culture of prehistoric hunter-gatherers that lived in the forested plains and mountains of South Sulawesi between around 8,000 years ago until roughly the fifth century AD,” Brumm explained.
Image via Carlhoff, et al (CC By 4.0)
The study’s lead author, Selina Carlhoff, was then able to extract DNA from the base of the skeleton’s skull. The ancient DNA showed that the teen had descended from the first group of modern humans who made it to Wallacea. These people would have been the great ancestors of Indigenous Australians and Papuans today.
Interestingly, the DNA revealed that the teen had also shared ancestry with a separate group of humans that came from Asia. This find suggested that researchers had uncovered a distinct group of early humans that weren’t known of till now, considering how rare skeletal remains are in the region.
Image via Carlhoff, et al (CC By 4.0)
Apart from these two groups of humans, the teen’s DNA also included traces of another extinct group: the Denisovans. Only a handful of fossils of this group have been found, and they suggest that they were from Siberia and Tibet. Researchers said this could mean the Denisovans traversed a greater area than originally thought.
“The geographic distribution of Denisovans and modern humans may have overlapped in the Wallacea region. It may well be the key place where Denisova people and the ancestors of indigenous Australians and Papuans interbred,” said Cosmio Posth, a professor at the University of Tübingen’s Senckenberg Centre for Human Evolution and Palaeoenvironment in Frankfurt, Germany, who co-authored the study.
While it’s still unclear what happened to the Toaleans and how they eventually died out, this discovery could be a large piece to the puzzle of ancient humans’ genetic history in Southeast Asia. Going forward, the researchers hope more Toalean DNA will be uncovered, so as to reveal a bigger picture of our early ancestors.
[via CNN, images via Carlhoff, et al]
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