In 1989, a femur and part of the skull were found in a cave in Yunnan province, southwest China.
Radiocarbon dating carried out in 2008 of the sediments where the fossils were found showed they were about 14,000 years old – meaning they date back to the time of Homo sapiens. modern humans) have migrated to many parts of the world.
However, the primitive features of the bones have made scientists wonder, who questioned which species the fossil belonged to.
The shape of the skull resembles that of Neanderthals – an ancient population that disappeared about 40,000 years ago – and it seems likely that the brains of modern humans would have been smaller.
As a result, some experts on human evolution suggest that the skull may belong to an ancient and modern hybrid population or perhaps a previously unknown human species that existed. with our humanity. The researchers named this group the Red Deer People after the cave in which the remains were found.
Now, Chinese scientists have extracted genetic material from the skull cap and sequenced the DNA. They discovered that the skull belonged to a female individual, who was most likely a direct ancestor of humanity – a member of Homo. sapiens – not a previously unknown type of person.
“Ancient DNA engineering is a really powerful tool,” said Bing Su, a professor at the Kunming Institute of Zoology. at the Chinese Academy of Sciences in Yunnan, who was involved in the study, in a press release. “It tells us quite clearly that the people of the Red Deer Cave are modern rather than an archaic species, such as Neanderthals or Denisovans, despite their unusual morphological features.”
Su and his colleagues shared their findings in a study published Thursday in the journal Current Biology. Their genome analysis showed that each individual bone belonged to had similar levels of Neanderthal and Denisovan ancestry to modern humans – suggesting that they were not part of a hybrid population that interbred.
The DNA of the Denisovans, a little known group of archaic humans, and the Neanderthals that inhabited some of today’s humans. That’s because our ancestors Homo sapiens long ago encountered these groups as they spread around the world and reproduced with them.
The researchers compared genomes extracted from ancient DNA with those of others around the world – both modern and ancient.
They discovered that the bones belonged to an individual closely related to East Asian Native American ancestry. Researchers believe this group of people traveled north to Siberia and then crossed the Bering Strait to become some of the first Americans.
“Her genome fills in a really important piece that’s missing from the overall story of how humans got to the Americas. A lot of work has been focused on the other branch of Native American ancestry – the Siberians. – but not many people knew about until this article about Native American ancestry in East Asia. It’s really important to understand this branch, as it makes up the majority of Native American ancestry!” Jennifer Raff, a geneticist and anthropologist at the University of Kansas and author of the book “Origin: The Genetic History of the Americas,” said by email.
“I find their results plausible and very interesting. We’re still trying to figure out the geographic location of the immediate First Man ancestry population, but this paper gives us what it takes. some additional clues,” said Raff, who was not involved in the study.
Features for sure
But what explains the unusual morphological features of the remains?
The researchers describe the genome as “low-coverage,” meaning it doesn’t contain enough detail to offer an explanation for why the bones look different from the others. modern human skeleton. The acidic soil and the warm, wet conditions where the skulls were found meant the scientists were only able to recover 11.3% of the genome. This is the first time DNA has been sequenced from a human fossil found in southern China.
The study notes that individual bones belong to there is a great deal of genetic diversity, suggesting that several different lineages of early modern humans must have coexisted in Southeast Asia at the end of the Stone Age. Presumably, research suggests that the area was once a refuge during the height of the Ice Age.
“I know these fossils better than anyone,” said Curnoe, who was not involved in the latest study.
“How do we reconcile that? Perhaps the anatomical form of humans in the past was – over time – very ‘plastic’ and reacted to the environment and lifestyle of these early humans. This might be something we’ve lost since we started farming.”
Analyzing the Red Deer Cave genome could also help build a more complete picture of ancient humans in East and Southeast Asia – an interesting site for paleontologists.
Next, the Chinese team hopes to add support to their findings by sequencing more ancient human DNA using fossils from Southeast Asia, especially those predated the Red Deer.