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We know what Neanderthals looked like. Now, thanks to an old DNA, Israeli scientists have unveiled the appearance of another of our former parents.
There is very little evidence about the life of the Denisovans – Neanderthal cousins - who died about 50,000 years ago: three teeth, one pink bone and one lower jaw.
But this was enough for researchers from the Hebrew University of Jerusalem to draw conclusions about their appearance.
The mission was difficult, according to Professor Liran Carmel, one of two scientists who lead the study.
"It's very difficult to start from a DNA sequence to end up with an anatomical profile," he said.
If that were so easy, police around the world would extract DNA from crime scenes and profile the suspects, he added.
Instead, he and his team reconstructed the appearance of the Denisovans after three years spent examining the characteristics of chemical changes in their old DNA.
They then compared these motifs to those of Neanderthals' DNA and modern humans.
Using knowledge of human disorders in which genes lose their function in favor of anatomical features, they explored the meaning of these differences.
Using this method – described by Carmel as "85% reliable" -, they highlighted 56 differences between Denisovan and modern humans and / or Neanderthals.
"The Denisovan looks more like Neanderthal than us because they are closer in terms of evolution," he said.
The study revealed that Denisovan's skulls were probably wider than those of modern humans or Neanderthals, and that they probably had no chin.
Scientists hope that this new technique will allow them to identify skulls discovered in China a few years ago and whose width seems to indicate that they might be Denisovans.
Contemporary Neanderthals, the Denisovans were first discovered a decade ago.
A finger bone was discovered a decade ago in a cave called Denisova, in southern Siberia, near the Mongolian border.
The little bone "belonged to a 13-year-old girl Denisovan, who died in the cave" about 70,000 years ago, Carmel explained.
"This pink bone has reopened a whole new chapter in the evolution of man," he said.
The Denisovans and Neanderthals branched out about 400,000 to 500,000 years ago into two distinct branches, distinct from the Homo Sapiens branch of modern man.
While Neanderthals traveled from Africa to Europe and West Asia, the Denisovans were present in East Asia.
Scientists do not know why these human parents have disappeared, but believe they have left part of their genome to modern men.
According to the Hebrew University, up to six percent of Melanesians and current indigenous Australians own Denisovan's DNA.
It is also believed that they transmitted a gene to Tibetans allowing them to breathe at high altitude.
The fossilized jaw of a Denisovan found in the Tibetan mountains proves that they adapted to live at high altitudes at least 160,000 years ago.
Denisovans may have made tools and even jewelry, according to a new study published in January.
Neanderthals emigrated to areas where the Denisovans lived, said Erella Hovers, professor of prehistoric archeology at the Hebrew University.
Scientists have even found a bone fragment of a girl born to a Denisovian father and a Neanderthal mother, she said.
But, she added, cultural relations between branches of the human family remain unclear.
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