The Neanderthals and Denisovs may have lived on their shoulders by dozens of thousands of years, scientists say in two papers Nature1.2.
The long-awaited studies are based on the analysis of bones, artifacts and sediments from the Denis cave in southern Siberia, which is strewn with antique human remains. They provide the first detailed history of 300,000 years of occupation of various groups of ancient people.
"We can now tell the whole story of the entire cave, not just parts," says Zenobia Jacobs, a geocronologist from Wollongong University, Australia, who led one of the studies.
Ancient human hot spot
The Soviet archaeologists began to reveal the story of Denis Cave, at the foot of the Altai Mountain, at the beginning of the eighties. Since then, scientists have discovered fragmentary remains of nearly a dozen ancient people in that place. The cave became world famous in 2010 after DNA analysis of a small bony fingers of hominine, which revealed that the creature was different from modern humans and neanderthals.3, He belonged to the once unknown group of hominine, later called Denisovans.
In addition, DNA sequencing in cemetary remains revealed that the Denisovans were a nursing group of neanderthals, and that they might have lived in Asia – where they crossed the precincts of some people who now live there4.
Last year, another spectacular discovery emerged: DNA analysis of long bone fragments revealed the first known "hybrid" of two ancient human groups, a woman – nicknamed Denny – whose mother was a neanderthal, and father Denisovan5.
Most of the remains of the cave are older than the 50,000-year limitations of radiocarbon dating techniques used on organic materials, and efforts to use other methods to date sediments where the remains were buried were prevented by the lack of a good map. geological layers of the cave. Many scientists are concerned that cavernous disorders, such as animal weeds, mixed its contents so that the remains and artifacts are no longer in sediments of a similar age.
In order to overcome these challenges, Jacobs and Wollongong Geohronologist Richard Roberts researchers have used dating techniques that determine when certain soil grains are last exposed to light1, Which allowed them to identify regions of caves where the soil was disturbed so that adjacent grains returned wildly different dates. They could then leave these areas when they consist of sediments in the same geological layer as hominine remains and tools.
The first signs that some ancient human species occupied the cave were stone tools – excavated at the beginning of the eighties – which were about 300,000 years old. But the researchers could not determine whether they were made by Denisovani or Neanderthals. Denis's remains from the cave (including some ground-fed DNAs) date 200,000 years ago and 55,000 years ago, while the oldest Neanderthal remains are about 190,000 years old, and the youngest were about 100,000 years ago.
Researchers can not find out exactly when groups have lived together or have ever shared a cave. But the existence of a hybrid person – who lived 100,000 years ago – meant that the groups had to live close enough to meet each other to meet at that time. Moreover, Denny's father gave the rest of Neanderthal origin, suggesting that his ancestors had previously crossed the Neanderthals.
Who was here?
Homo sapiens perhaps they lived in the cave, researchers suggested. Bones and tools pins – similar to those made by early modern people in Europe – from the younger layers in the cave are between 49,000 and 43,000 years old, reports team led by archaeologist Katerine Douka at the Max Planck Institute for Humanities History in Jena, Germany, and Tom Higham at Oxford University, United Kingdom, in the second Nature paper2.
Researchers dated an hominine bone about 46,000 to 50,000 years ago, but could not find DNA to investigate the type of cancer they belong to.
No one else H. sapiens the remnants of that period, known as the initial upper Palaeolithic, were found in Denis cave or in the wider Alta area. For this reason, Russian archaeologists who led the excavation of this site claimed that Denisovani had made artefacts more sophisticated than old stone tools at the site. But High would like to see more evidence before linking artifacts with any group. "It is possible that Denisovani could make the upper Palaeolithic. It is possible that the Russians are right. At this point, with the evidence we have, we can not really be sure, "he says.
Dunny-like hybrids are still one suspect, says Robin Dennell, an archeologist from Exeter University, UK, and the author of the accompanying study essay6.
It is also possible that those who made the artifacts affected the contact H. sapiens, he says. "I would be very surprised if the Denise's or Neanderthals' initial Denisian Upper Palaeolithic were made without any contribution from our species."
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