Scientists have used ancient genes to learn more details about contact between Neanderthals and humans tens of thousands of years ago.
Results of two recent studies estimate the two groups likely met and began mating about 45,000 years ago.
Modern humans – also known as Homo sapiens – began in Africa hundreds of thousands of years ago and later started spreading to Europe, Asia and other places. Scientists believe that at some point, they met and mated with Neanderthals. The mixing of these groups had a major influence on humans’ genetic code.
However, scientists do not know exactly when or how the two groups interacted. But the two new studies provide some additional details about the timing of this contact.
One group of scientists examined genetic material from three female and three male Homo sapiens individuals who lived around 45,000 years ago. Reuters news agency reported that research involved the oldest genes from Homo sapiens ever examined, or sequenced.
Some of the genes came from bones found in a cave in the central German village of Ranis. Other material came from a woman believed to have lived at around the same time in a cave in a mountainous area of what is now the Czech Republic.
Researchers estimated the period of mixing between Neanderthals and humans at about 49,000 to 45,000 years ago. The findings were recently published in a study in Nature.
A second group of researchers examined genetic material from 300 present-day and ancient Homo sapiens. This included 59 individuals who lived between 2,000 and 45,000 years ago. That study, published in the journal Science, estimated the period of mixing at about 50,500 to 43,500 years ago.
The scientists said their new findings on the mixing and mating of the groups suggested the activities happened a little more recently than thought in the past. They believe the contact continued over many generations.
Priya Moorjani was co-writer of the study appearing in Science. She is an assistant professor of molecular and cell biology at the University of California, Berkeley. She told Reuters, “Genetic data from these samples really helps us paint a picture in more and more detail.”
The team noted that it is difficult to know the exact nature of the interactions between Homo sapiens and Neanderthals based on the examined data. The researchers also could not confirm exactly where the mixing and mating happened. However, they believe it was most likely somewhere in the Middle East.
The researchers noted most modern humans still have genetic material from Neanderthals that accounts for an estimated one to two percent of their DNA. They said modern-day genetic traits linked to skin color, hair color and even nose shape can relate back to the Neanderthals. Our genetic makeup also includes links to another group of human ancestors called Denisovans.
Moorjani noted that the history of Neanderthals living outside Africa for thousands of years likely gave them a greater ability to deal with climate and diseases in new environments. “Some of their genes may have been beneficial to modern humans,” she added.
Rick Potts is director of the Smithsonian Institution’s Human Origins program. He was not involved in the new research. Potts told The Associated Press he hopes future genetic studies can help scientists learn even more details about the interactions of Neanderthals and modern humans.
He said, “Out of many really compelling areas of scientific investigation, one of them is: well, who are we?”
I’m Caty Weaver.
Bryan Lynn wrote this story for VOA Learning English, based on reports from The Associated Press, Reuters and Nature.
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Words in This Story
genetic code – n. information from DNA or RNA that is used to create an organism's proteins
cave – n. a large hole in the side of a mountain or underground
sample – n. a small amount of something that gives you information about the thing it was taken from
trait – n. a quality, good or bad, in someone’s character
beneficial – adj. helpful or useful
compelling – adj. demanding attention
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