[ti:Scientists Use Ancient Genes to Estimate Contact Between Humans, Neanderthals]
[al:Science & Technology]
[ar:VOA]
[dt:2025-01-02]
[by:www.voase.cn]
[00:00.00]Scientists have used ancient genes to learn more details about contact between Neanderthals and humans tens of thousands of years ago.
[00:16.11]Results of two recent studies estimate the two groups likely met and began mating about 45,000 years ago.
[00:29.67]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.
[00:47.55]Scientists believe that at some point, they met and mated with Neanderthals. 
[00:56.16]The mixing of these groups had a major influence on humans' genetic code.
[01:04.82]However, scientists do not know exactly when or how the two groups interacted. 
[01:14.92]But the two new studies provide some additional details about the timing of this contact.
[01:24.96]One group of scientists examined genetic material from three female and three male Homo sapien individuals who lived around 45,000 years ago.
[01:41.97]Reuters news agency reported that research involved the oldest genes from Homo sapiens ever examined, or sequenced.
[01:55.86]Some of the genes came from bones found in a cave in the central German village of Ranis. 
[02:05.19]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.
[02:19.92]Researchers estimated the period of mixing between Neanderthals and humans at about 49,000 to 45,000 years ago.
[02:33.76]The findings were recently published in a study in Nature.
[02:39.85]A second group of researchers examined genetic material from 300 present-day and ancient Homo sapiens. 
[02:51.23]This included 59 individuals who lived between 2,000 and 45,000 years ago. 
[03:02.40]That study, published in the journal Science, estimated the period of mixing at about 50,500 to 43,500 years ago.
[03:18.38]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.
[03:33.60]They believe the contact continued over many generations.
[03:40.25]Priya Moorjani was co-writer of the study appearing in Science.
[03:46.90]She is an assistant professor of molecular and cell biology at the University of California, Berkeley.
[03:57.22]She told Reuters, "Genetic data from these samples really helps us paint a picture in more and more detail."
[04:09.96]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. 
[04:24.39]The researchers also could not confirm exactly where the mixing and mating happened.
[04:33.56]However, they believe it was most likely somewhere in the Middle East.
[04:40.70]The researchers noted most modern humans still have genetic material from Neanderthals that accounts for an estimated one to two percent of their DNA. 
[04:56.84]They said modern-day genetic traits linked to skin color, hair color and even nose shape can relate back to the Neanderthals. 
[05:09.62]Our genetic makeup also includes links to another group of human ancestors called Denisovans.
[05:19.39]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.
[05:38.64]"Some of their genes may have been beneficial to modern humans," she added.
[05:46.01]Rick Potts is director of the Smithsonian Institution's Human Origins program.
[05:53.14]He was not involved in the new research.
[05:57.70]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.
[06:13.99]He said, "Out of many really compelling areas of scientific investigation, one of them is: well, who are we?"
[06:26.65]I'm Caty Weaver.