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NEW YORK (AP) – Nearly 40 years after its discovery by a monk in a Chinese cave, a piece of fossilized jaw bone was revealed as coming from a mysterious Neanderthal parent.
Until now, the only known remains of these Denisovans were some remains of bones and teeth found in a Siberian cave. The DNA of these Siberian fossils showed a kinship with the Neanderthals. But the remains revealed little else.
The new discovery was made about 1,400 miles (2,300 kilometers) southeast of China's Gansu Province. The right half of the jaw with teeth is at least 160,000 years old, scientists said Wednesday in the journal Nature. No DNA could be found, but scientists recovered fragments of proteins that they compared to Siberian DNA. This showed that the fossil came from a Denisovan.
The discovery addresses several mysteries. One of the reasons why Siberian DNA has indicated that the Denisovans were adapted to life at high altitude when the Siberian cave is relatively close to sea level. The Chinese cave, on the other hand, is on the Tibetan plateau, at an altitude of about 3280 meters (10,800 feet).
"We now have an explanation," said Jean-Jacques Hublin of the Max Planck Institute of Evolutionary Anthropology in Leipzig, Germany, one of the authors of the journal.
In fact, "it's a big surprise" that any human parent can live in the cold climate and tunes of the plateau at that time, more than 100,000 years before our own species appeared there, did he told reporters.
Previous research had shown that the Denisovans must have lived elsewhere than in Siberia, as traces of their DNA are found in several present-day populations of Asia and Australia whose ancestors are probably not passed. by this region. The new discovery expands their known reach, although Hublin has stated that the place where the Denisovans appeared is still unclear. They bear the name of the cave Denisova, in Siberia, where the remains were found.
The new work has been long in coming. The monk who found the fossil in 1980 gave it to a Buddhist leader, who then passed it on to Lanzhou University in China. His study began in 2010.
The discovery also provides new anatomical details that can be compared to other fossils from China, some of which are "good candidates for being Chinese Denisovans," Hublin said.
Non-research experts agreed that the fossil could help identify other remains under the name of Denisovan.
"We have always assumed that Denisovans were distributed throughout Asia," said Bence Viola of the University of Toronto.
The Nature document points to similarities with a fossil jaw reported in 2015 that was allegedly dredged by a fishing net off Taiwan. So maybe the Denisovan range could be extended as far south, he said.
Such a fossil link could eventually reveal the shape and size of Denisovan's body, he said. Among the few known remains "I guess they were big guys, but it's hard to prove," said Viola.
In addition to anatomy, the study's approach of using bone or tooth proteins could also be used on fossils to look for evidence of identity from Denisovan, said Eric Delson of Lehman College in New York. Even if one discovers that a fossil is not Denisovan, the analysis could reveal details about how he fits into the evolutionary tree, he said. declared.
"The method potentially indicates a whole new way of looking at fossils," he said.
Katerina Harvati of the University of Tuebingen in Germany said the Denisovans' ability to adapt to the inhospitable climate of the Tibetan Plateau is remarkable. This adds to the growing evidence that our former parents were more capable than scientists thought, she said.
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The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute's Department of Science Education. The AP is solely responsible for all content.
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