New York — It is likely that the Neanderthals and humans mixed and interacted during a short time 45,000 years agoscientists reported Thursday.
The researchers analyzed ancient genes to pin down the period, which is slightly more recent than pre-mating estimates.
Modern humans emerged in Africa hundreds of thousands of years ago and then spread across Europe, Asia and beyond. At some point along their journey, they encountered and mated with Neanderthals, leaving a lasting imprint on our genetic code.
Scientists don’t know exactly when or how the two groups intertwined. But ancient bone fragments and genes are helping them figure it out.
“The genetic data from these samples really helps us paint a picture in more and more detail,” said study co-author Priya Moorjani of the University of California, Berkeley.
The research was published Thursday in scientific journals Science and Nature.
To pin down the chronology, researchers examined some of the oldest human genes found in the skull of a woman named Zlatý kůň, or Golden Horse, on a hill in the Czech Republic where it was found. They also examined bone fragments from an early human population in Ranis, Germany, about 140 miles away. They found fragments of Neanderthal DNA that placed mating around 45,000 years ago.
In another study, researchers traced Neanderthal signs in our genetic code from more than 50,000 years ago. They found Neanderthal genes related to immunity and metabolism that could have helped early humans survive and thrive outside of Africa.
We still carry the legacy of the Neanderthals in our DNA. Modern genetic quirks related to skin color, hair color, and even nose shape can be traced back to our ancient extinct neighbors. And our genetic code also contains echoes of another group of extinct human cousins called “Denisovans” or “Denisova Man.”
Future genetic studies can help scientists unravel exactly what — and who — we are made of, said Rick Potts, director of the Smithsonian’s Human Origins program, who was not involved in the new research.
“Of so many really fascinating areas of scientific research, one of them is, well, who are we?” Potts said.