'Completely mind-blowing' discovery of a hybrid of two extinct human species
About 60,000 years ago, a Neanderthal woman and a Denisovan man met, mated, and produced a hybrid child. Researchers announced this week that they'd found a bone fragment that contains the DNA of that child, which represents a unique historical snapshot in the history of human evolution.
The bone was found in Denisova Cave, in the Altai mountains in southern Siberia. This cave has been a treasure trove for anthropologists because it has been inhabited more than a hundred thousand years by different human groups — Denisovans, Neanderthals and modern humans. The remains of all three species have been found in the cave.
Understanding the mysterious Denisovans — and who they mated with
In fact, Denisova Cave contains the only evidence of the mysterious Denisovan people. In DNA from a bone discovered there in 2008 was the first evidence we had for the Denisovan people. These would have been cousins to the Neanderthals and modern humans as their DNA suggests they split from the Neanderthals between two and three hundred thousand years ago. The ancestors of modern humans and the common ancestor of Neanderthals and Denisovans split about 400,000 years before that.
The species didn't stay apart, however. Ancient DNA analysis in recent years has suggested that Neanderthals, Denisovans and modern humans all interbred with each other in Eurasia — modern humans carry both Neanderthal and Denisovan genes.
A hybrid child whose genes might still be with us today
The discovery of the hybrid child is a concrete example of that interbreeding. Analysis of the DNA in the tiny bone fragment shows the child was a female, with a Neanderthal mother and Denisovan father.
Dr. Bence Viola, a physical anthropologist at the University of Toronto, was part of the team that made the discovery. His work helped clarify the age of the girl/woman. He determined that the thickness of the bone fragment meant it came from someone at least 13 years old, though she could have been older.
This raises the intriguing possibility that this hybrid human might have been the mother of later generations of hybrids — perhaps even contributing her genes to the modern human gene pool.