The prestigious scientific journal Science announced Thursday that Israeli scientists’ reconstruction of the face of an ancient girl, an elusive cousin to modern humans and Neanderthals, has won the “People’s Choice” category of its Breakthrough of the Year contest.
Hebrew University researchers Prof. Liran Carmel and Dr. David Gokhman used DNA from excavated remains to give a face to humanity’s “newest” ancient relative, the Denisovans, and produced from the likeness of a teenage girl who likely lived around 70,000 years ago.
In a final round of voting that closed at midnight Monday, the Israeli research won 49 percent of the 34,000 online votes beating the three other candidates. It was named among four finalists including the discovery of new Ebola drugs, a technique that made a black hole “visible,” and a new cystic fibrosis drug
The imaging of black holes won Science Magazine’s Breakthrough of the Year title.
“We are deeply moved by this honor and grateful to those who supported us,” Carmel said in a statement from the Hebrew University. “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.”
First discovered in a Siberian cave in 2008, the Denisovans coexisted with Neanderthals and modern Homo sapiens some 100,000 years ago. However, unlike their Neanderthal relatives, the paucity of verified Denisovan remains — and their highly fragmented state — has until now made it impossible to create an anatomical picture of this early man.
The groundbreaking Israeli technique picked by Science readers, which was first published in the prestigious journal Cell in mid-September, helped to finally lift the veil.
Carmel’s and Gokhman’s model “gave the world a glimpse of this nearly unknown ancestor of modern-day humans,” the university said.
They discovered a method of reconstructing what our long-ago relatives may have looked like by using open-source sequencing of ancient Denisovan DNA taken from a single bone fragment. Professors Eran Meshorer from the Hebrew University, Yoel Rak from Tel Aviv University, and Tomas Marques-Bonet from Barcelona’s Institute of Evolutionary Biology (UPF-CSIC) also contributed to the study.
“The Denisovans have haunted human evolution researchers for 10 years,” Science Magazine wrote on its webpage about the research.
By reconstructing the girl’s face the researchers “concluded that she would have looked a lot like a Neanderthal, with a wide pelvis, sloping forehead, and protruding lower jaw,” the magazine wrote. “But she also had a wider face than modern humans or Neanderthals, and a longer arch of teeth along her jaw bone.”
After some 40 years of excavation in Siberia’s Anui River Valley, scientists in 2008 discovered the remains of a previously unknown form of ancient human. At the time, only a microscopic bone fragment, which underwent DNA analysis in Germany together with the rest of the findings from the cave, turned out to be from a human who was neither Neanderthal nor Homo sapiens.
After that first tiny fragment, which was part of a pinkie finger, scant other clearly determined Denisovan bone fragments were discovered, including a few teeth and recently a jawbone in Tibet. But the DNA of the Denisovans is still around in modern humans, including some six percent of aboriginal Australians, Malaysians and some other Southeast Asian populations. It may be part of the remarkable genetic differences seen in Inuits and Tibetans that allows their bodies to better handle extreme cold and high altitudes, the Israeli researchers have said.
According to Carmel, speaking at a September announcement of the findings, DNA analysis alone would not have allowed scientists to reconstruct physical characteristics of ancient humans, beyond vague information on their features, which included medium to dark hair, eyes, and skin.
Instead, the Israeli researchers had to reconstruct the ways those genes would express themselves in the living organism.
To arrive at how a skeleton is influenced by the methylation switch of certain genes, the team of scientists cross-checked physical characteristics with a database of single-gene diseases, as some “monogenic” disorders can point to changes in bone structure such as a small pelvis.
Over a three-year study, the team tested its theory by drawing up physical characteristics of Neanderthals, Homo sapiens and chimpanzees based on their methylation patterns. Their predictions had an 85% accuracy.
The team then applied the methylation methodology to the Denisovans and found 56 anatomical traits which were different from modern humans and Neanderthals, 34 of which were in the skull, and probably included a longer dental arch, no chin and very wide skulls.