Hebrew U. researchers win award for profile of extinct archaic humans

“Denise,” the first reconstructed anatomical profile of a Denisovan human was revealed in September by researchers at the Jerusalem-based University.

By JERUSALEM POST STAFF
Portrait of a female Denisovan teen (photo credit: MAAYAN HAREL)
Portrait of a female Denisovan teen
(photo credit: MAAYAN HAREL)
Hebrew University of Jerusalem researchers Professor Liran Carmel and David Gokhman, PhD have won the 2019 People's Choice for Breakthrough of the Year Award recreating the profile of the group of archaic humans known as the Denisovans, who lived over 100,000 years ago and then mysteriously vanish from existence.
“Denise,” the first reconstructed anatomical profile of a Denisovan human was revealed in September by researchers at the Jerusalem-based University.
Carmen and Gokhman's model ultimately prevailed over three other finalists to garner the award for their team. They were the only Israeli researchers nominated in the category.
“We are deeply moved by this honor and grateful to those who supported us. It’s amazing how scientific discoveries—even those relating to people who lived more than 100,000 years ago—still captivate the imagination of folks around the world," Carmel said.
With regard to the research model itself, the Denisovans lived in Siberia and Eastern Asia before going extinct approximately 50,000 years ago, Carmel explained. But exactly what Denisovans might have looked like had previously been anyone’s guess.
Researchers had only three fossils to work with to recreate "Denise" - a bone from the tip of “Denise’s” pinky finger, a few teeth and a recently found lower jaw bone.
The researchers were able to reconstruct the Denisovan profile over a three-year period by examining patterns of methylation in their ancient DNA. DNA methylation is a process by which methyl groups are added to the DNA molecule, thereby changing the activity of a segment of DNA.
By studying Denisovan DNA methylation maps and comparing them to those of Neanderthals – another group of archaic humans who went extinct in Europe about 40,000 years ago – and to those of ancient Homo sapiens, the team was able to understand what the differences might mean to Denisovan anatomical features, based on what is known about human disorders in which those genes lose their function.
“We got a prediction as to what skeletal parts are affected by differential regulation of each gene and in what direction that skeletal part would change – for example, a longer or shorter femur bone,” said Gokhman, now a postdoc at Stanford, who also worked on the project.
The team was able to prove their model to be about 85% accurate by using the same methodology to create anatomical models of Neanderthals and chimpanzees, which have known anatomical profiles.
“One of the most exciting moments happened a few weeks after we sent our paper to peer review,” Carmel said. “Scientists had discovered a Denisovan jawbone. We quickly compared this bone to our predictions and found that it matched perfectly. Without even planning it, we received independent confirmation of our ability to reconstruct whole anatomical profiles using DNA that we extracted from a single fingertip.”
The researchers found that Denisovans have strikingly similar methylation patterns to humans. They also found that there are 56 anatomical features in which Denisovans differ from modern humans and/or Neanderthals, 34 of them in the skull.
Maayan Jaffe-Hoffman contributed to this report.


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