- Petra Zivic
- BBC World Service
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Sex with Homo sapiens may have caused the extinction of Neanderthals
The intersection with A wise man may have played a key role in the extinction of Neanderthals, according to a published study recently in the scientific journal Paleo Anthropology.
This interbreeding may have reduced the number of Neanderthals reproducing with each other, which may have had the effect of driving the species to extinction.
“For a long time, the dominant theory has been that there is a lot of competition for resources among the A wise man and Neanderthals,” Lucile Crete, co-author of the study with Professor Chris Stringer, lead researcher at the Natural History Museum in London, told the BBC.
However, says the researcher, the new study analyzed evidence that it was not violence between species that caused the extinction, but a mixture of populations that weakened the gene pool of Neanderthals.
“We propose that this behavior could have led to the extinction of Neanderthals if they had regularly reproduced with the A wise manthat could have eroded their population until they disappeared,” said Professor Stringer after the study was published.
Neanderthal DNA can be found in all humans alive today, including people of African descent whose ancestors did not come into direct contact with this group.
Neanderthals and A wise man it evolved in different areas of the world after the species arose from a common ancestor about 600,000 years ago.
While the A wise man evolved in Africa, the homo neanderthalensis emerged in Europe and Asia.
“Recent discoveries show that the A wise man it was in Europe 50,000 or 60,000 years ago, which means they were in Europe at the same time as the Neanderthals for much longer than we previously thought,” Crete explains.
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Scientists believe that communication between Neanderthals and Homo sapiens was not easy
reproduction
Neanderthal genomes have been traced back to the genome of A wise manbut not vice versa, suggests the study.
“There appears to be gene swapping, but only in one direction,” Crete says
The knowledge that the two species interbred is not new. On average, a person born outside Africa has about 2% of their genome derived from Neanderthals.
But Crete and Stringer dug deeper, analyzing what is known about the 32 Neanderthal genomes that have been discovered and sequenced to date. The two scientists suggest that the success of the cross depended on the exact pair that was reproducing.
“But we don’t know how to explain it. It could be due to the available data that we have, or the way hybridization (the process of mixing two species) worked,” Crete says. “For some bird and mammal species, hybridization sometimes doesn’t work both ways. It can be difficult for one species to produce fertile offspring.”
He hopes that more Neanderthal fossils can be found and analyzed in the future.
“The more we can sequence and analyze, the more we will be able to test these theories,” he says.
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It is still unclear how different male and female Neanderthals were.
rape
Another theory Crete and Stringer put forward in their study is that it is probable that not all couplings were consensual.
“Perhaps Homo sapiens was going in search of female Neanderthals, or the other way around, and force was used to fertilize fertile representatives of the other group,” says Crete.
He explains that this type of behavior can also be observed in some chimpanzees. “If the males don’t have enough reproductive females in their group, they can go to the other group and steal them to keep expanding.”
Very little is known about interspecies sex. Scientists believe that it was not easy for Neanderthals and the A wise man communicate, because they were very different.
“They probably wouldn’t be able to produce the same kind of sound, they didn’t have the same kind of articulate speech, their brains were structured differently,” Crete explains.
Even his physical appearance was different. “Neanderthals were quite stocky, heavily built, with shorter arms and legs and a distinctive bulge on the forehead above the eyes,” Crete explains.
It is still unclear how different male and female Neanderthals were.
“Skeletons are often fragmented and broken, and we don’t have many basins to compare and see the difference between the two,” Crete says.
But despite many unknowns, the researcher is excited about possible future discoveries.
“New methods have made possible some discoveries that we could not have imagined before,” he says. “It’s like a giant jigsaw puzzle. It gets bigger and bigger with new discoveries as we change the way we think.”
