The Neanderthals and the Denisovans – both relatives of modern humans – were chamberlains, literally, for thousands of years in a remote Siberian cave, two new studies were found.
Back in antiquity, this cave would have been a paradise for the real estate agent; It is the only place in the world that Neanderthals, Denisovans and even modern humans lived together throughout history, researchers found.
The cave was so popular that hominins (a group that includes humans, our ancestors and our first evolutionaries as chimpanzees) lived almost continuously over the last 300,000 years, the researchers found. [In Photos: Bones from a Denisovan-Neanderthal Hybrid]
Through the analysis of fossils and DNA, researchers discovered that enigmatic Denisovans lived in the cave from at least 200,000 to 50,000 years ago, and Neanderthals lived between 190,000 and 100,000 years back.
It is not completely out of the blue that Neanderthals and Denisovans mix. In 2018, the researchers published a study in Nature on the bone fragment of a teenage girl who had a Neanderthal mother and father Denisovan, the first direct evidence that both hominin groups interred.
The new research shows that this girl, whose remains were found in the cave of Denisova, lived about 100,000 years ago, scientists said.
The researchers have been excavating the cave of Denisova, located on the foothills of the Altai mountains in Siberia, for the last 40 years.
In 2010, the cave received worldwide recognition when scientists announced that they had found the fingers of a previously unknown hominine and published their genome. They named the Denisovans hominins (deh-NEESE-so-vans), after the cave.
However, until now, the researchers had few artefacts to date, so they were not exactly sure when the cave dwellers lived there. Now, two new studies reveal a chronology for the inhabitants of the cave.
In a study, researchers from Australia and Russia used optical dating to determine the age of sediments in the cave. They could not use radiocarbon dating since they could reliably date organic objects 50,000 years ago. By contrast, optical dating allows scientists to discover when quartz and feldspar grain in the soil were exposed to sunlight.
In the other study, researchers from Germany, the United Kingdom, Australia, Russia and Canada analyzed the predictable decline of a radioactive carbon isotope (radiocarbon dating) to find out about the ages of # 39; bones, teeth and fragments of charcoal found in the upper layers of the site; and then they created a statistical model that included all the recently discovered dates of the cave.
"We had to invent some new methods to date the deepest and oldest deposits and build a solid chronology for the sediments of the Denisova cave," investigated co-researcher Bo Li, associate professor of the # 39 ; Earth, Atmospheric and Life Sciences School at Wollongong University in Australia, said in a statement.
In addition, the new statistical model helped "incorporate all available quotes tests for these small and isolated fossils, which could easily have been displaced after the deposition," investigated principal researcher Katerina Douka, 39; Max Planck Institute for Science Human history in Germany, said in the statement. [Denisovan Gallery: Tracing the Genetics of Human Ancestors]
Still, there are questions about the material dated from the cave. For example, "human fossils derive from human occupations or carnivorous activity, and have they been transported away from their original depositional location?" asked researcher Chris Stringer, a leading human-rights researcher at the Natural History Museum in London.
A sinking over the cave persists: did modern humans live? Our species (Homo sapiens) was present in other parts of Asia 50,000 years ago, but it is not clear if there is any H. Sapiens He interacted with the Denisovans in the cave. This is due to the fact that scientists have not yet found any fossil or genetic trace of modern humans in the cave, although researchers have found a man dating from between 50,000 and 46,000 years ago. The computer could not get any DNA from this one, so it is not clear what kind of species it belonged to.
In addition, it is possible that modern humans made some artifacts in the cave.
Another open question is whether Denisovans or modern humans did the oldest dots and personal ornaments [tooth pendants] which is in the cave, "said the professor of archeology at the University of Oxford, who worked in the radiocarbon study, told Tom Higham." With direct dates between 43,000 and 49,000 years ago, they are the first known artifacts from all of northern Eurasia. "
But Stringer said he would put his money in the first modern humans.
"The first modern humans can be mapped elsewhere in this date, for example at Ust & # 39; -Ishim in Siberia," Stringer told Live Science in an email. "But the authors of the [radiocarbon dating] The paper argues that, surprisingly, it is very parsimonious to suppose that the Denisovans were responsible, although Denisovans are still unknown as late as those in the sequence.
"Only more discoveries and more research can solve this issue satisfactorily," adds Stringer.
Both studies were published yesterday (January 30) in Nature magazine.
Originally posted on Live science.