Denis cave in the Altai mountains of Siberia has been a hot feature today – at least for the ancient people who have called it home for more than 200,000 years.
This is, according to researchers, who dated artifacts, fossils and sediments dug from the pit in the cave floor to collectively collect housing records.
In nature, today, Denisovans, an extinct species whose genome was reported in 2011, has cast a cave roughly from 287,000 to 50,000 years ago.
This overlapped with the Neanderthals who also lived here, but for a shorter time: about 193,000 and 91,000 years ago.
Until a timeline was established, archaeologists did not know when the Denis arrived in the cave, said Bert Roberts, a geologist at the University of Wollongong and co-author of both papers.
"They could have been millions of years ago or 100,000 years ago," said Professor Roberts.
We do not know whether the denizens and neanderthals are classmates living in the cave at the same time.
Recent studies, however, suggest that both groups live in the region, meet and – occasionally – have joined together for about 150,000 years, "said the researchers.
Fossil deep freezing
No much is known about mysterious Denis.
Their remains were found only in one place – Denis cave, their moniker, and then the fossils contained finger bones and several teeth from four different individuals and a hybrid child.
"We know little about them," Professor Roberts said.
"We do not even know what they look like."
This is because they were first identified not by skeleton or skull, but by their DNA, scratched by the precious finger of a young girl.
The use of genetic material is possible because the cave that is in the Siberian mountains is like a large freezer, protecting DNA that normally breaks down in a warmer, wetter environment.
Russian scientists knew about 40 years and dug the floor of the cave, looking for bones and artifacts as tools and pendants.
But for the reconstruction of the housing timeline it is necessary to give sediments.
Layers of dirt work as an archive of what happened in the cave at the time they were laid.
The idea is, the deeper you dig, the more you see in the time you see.
And because cave sediments last for at least 300,000 years, scientists in one post had to use a variety of dating techniques.
They included radiocarbon dating, which is about 50,000 years old and optically stimulated luminescence, which measured when the quartz and feldspar minerals were last exposed to sunlight.
Optically stimulated luminescence along with some clever modeling can be taken by archaeologists for about 300,000 years, says Zenobia Jacobs, also from the University of Wollongong and co-author of articles.
In a separate work, scientists used radiocarbon dating to find out the age of denizens fossils, along with the remains of three Neanderthals and a hybrid child.
They estimated that the oldest and youngest fossil Denisovana was 194,400 years old and 51,600 years old.
Neanderthals were over 90,900 to 147,300 years old, and the Neanderthal / Denisovan child aged between 79,300 and 118,100 years, which is within a wide range of dates determined by sediment analysis.
Question of artifacts
Between the branches in Denis Cave, carvings were carved from teeth and bone spears dated between 43,000 and 49,000 years ago.
So were they made Denis?
The idea was overwhelmed by researchers, but Darren Curnoe, a paleoanthropologist at New South Wales, who did not work, is not convinced.
Although there are still no signs that modern humans – Homo sapiens – lived in Denis Cave until later, "they were not too far at the same time," he said.
Complex behaviors such as carving jewelery are typical of modern people.
"And now we have claims in southern China, where modern people have been more than 100,000 years ago," said Dr. Curnoe.
"If it is right, modern people have been in the neighborhood [of Siberia] about 50,000 years. "
Professor Jacobs said that the attribution of artifacts to the Denizens would undoubtedly be controversial.
"As Western scientists, we can immediately assume that Homo sapiens can be produced by looking at such artifacts.
"But we have coworkers who feel very strongly that the evidence for Homo sapiens is not in the cave, there are no fossils or DNA, except for later periods."
Denied DNA in Australia
Native Australians and Papua New Guinea populations have a relatively high percentage of denied DNA that their ancestors have raised in Asia prior to their arrival in Australia.
Recent genetic analyzes have suggested that crossbreeding occurred after Altai Denisovans released the cave, said Joao Teixeira, a genetics scientist at the University of Adelaide who recently dealt with.
So even if there is no trace of the Denisans about 50,000 years ago in the cave – or elsewhere, it is very unlikely that a certain population was the last of their kind.
"Not only is their geographic distribution likely to be wider than Altai … but also the nature of Denisovan's DNA shows that it points to various Denis populations, which probably reflects geographic isolation, which would then lead to a slight accumulation of genetic differences," said Teixeira.