Israeli scientists have been able to show the facial and skeletal structure of an extinct and little-known group of humans, despite an almost complete lack of bones.
Researchers at the Hebrew University of Jerusalem worked with peers at Stanford University in the US to offer new insights into Denisovans, who walked the earth with Neanderthals and modern humans’ ancestors until around 50,000 years ago.
Archaeologists only discovered the Denisovans in 2008, and only three teeth and the bone of a Denisovan’s small finger had been found by the time the team used genetic analysis to work out what this human group looked like.
Shortly after submitting their scientific paper, which followed three years studying the chemical changes in Denisovan DNA, a chance discovery showed they were right.
“One of the most exciting moments happened a few weeks after we sent our paper to peer-review,” said Professor Liran Carmel. “Scientists discovered a Denisovan jawbone! We compared it to our predictions and found it matched perfectly. Without even planning on it, we received independent confirmation of our ability to reconstruct whole anatomical profiles using DNA extracted from a single fingertip.”
Little is known about the Denisovans, who lived in Siberia and East Asia, but it is thought that their DNA helps today’s Tibetans live at high altitude. Studies have shown that around 6 percent of present-day Aboriginal Australians and Melanesians carry Denisovan DNA.
The Israeli-US team identified 56 Denisovan anatomical features in which Denisovans differ from modern humans and/or Neanderthals, 34 of them in the skull, and posted their findings in the journal Cell.
To get the results, the team mapped and compared the tiny chemical changes in genes in Denisovans, Neanderthals and chimpanzees. Then they worked out what those differences might mean for anatomical features, based on what is known about human disorders in which those same genes lose their function.
Thanks to their pain-staking genetic detective work, researchers now know that Denisovans had much wider skulls than modern humans, with a sloping forehead, long face, large dental arches, no chin and a large pelvis.
Scientists now hope that the discovery will help them understand more about the Denisovan lifestyle and how they survived the extreme cold of Siberia.