Cheng-Han Sun
Artistic concept of a denisovano hominid
A protein analysis allowed to determine that a jaw found in Taiwan belongs to a denisovan. This is the first time that a fossil of this human species, first found in Siberia, has been identified with confidence outside Central Asia.
A fossilized jaw found off the coast of Taiwan for over 20 years belonged to an ancient humans called denisovans, first identified in a Siberian cave.
The discovery, presented in a published last week in the magazine Scienceit is the result of a lengthy work to extract old proteins from this fossil, and widens the known geographical area of the group – From cold and high altitude regions for warmer climates.
“I am very enthusiastic about this,” he says Janet KelsoComputational Biologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, Ao.
The lower jaw, with four intact teeth, is called Penghu 1and it was Discovered in 2010 by fishing crews from the Penghu channel, 25 kilometers from the west coast of Taiwan.
Penghu 1 was donated to the Taiwan National Museum of Natural Sciences after the researchers recognized their importance as belonging to an ancient human relative. But the identity of this unknown relative remained a mystery, so far.
Ancient proteins
The investigators passed more than two years to improve Carefully techniques for extracting old proteins from animal bones taken from the canal. Then they used acid to isolate protein fragments from the surface of a penghu 1 molar tooth, and enzymes to extract them from the jaw.
The team identified several degraded fragments, two of which showed specific variations in the sequence of amino acids that correspond to those observed in the genetic sequences of a denisovan finger bone found in the Denisova cave in southern Siberia in 2008.
Investigators also managed to determine that the jaw belonged to a Male denisovano.
Is the second time that molecular evidence of antique proteins definitely connect fossil remains to denisovan. The first time was in 2019, when proteins from a jaw found in a cave in Tibetcall Xiaohe 1was determined as a denisovan fossil.
Determining the exact age of the PENGHU fossil is challenging because scientists have no samples of the sediment in which it was buried.
“It can only be said that it is over 50,000 years old,” he says Rainer greenGeochronologist at the Australian National University in Camberra, who dated the fossil in 2015 and later reanalized the data.
To jaw Xiahe 1 is at least 160,000 yearsand material from the Denisova cave indicates that the denisovans lived in Siberia between 200,000 and 50,000 years ago. At the time, sea levels were lower and mainland China was taiwan.
Multiple populations
Enrico CappelliniMolecular Biologist at the University of Copenhagen, says that the discovery of denisovan remains east than Tibet is not surprising.
Modern human populations throughout the Pacific houses denisovane genetic sequences resulting from the cross between denisovans and homo sapiens. In fact, one of the sequence variants that marked Penghu 1 as Denisovano is present in more than 20% of the modern population of the Philippines.
Kelso says traces of Denisovano DNISOs found in modern human populations suggest that there were multiple populations of this ancient hominid. The latest data also show slight differences in protein sequences between Denisovan fossils of Taiwan, Tibet and Siberia.
Future discoveries could widen the geographical area Known of the denisovans, says Cappellini.
It is not known if the denisovans They ever ventured west of the Altai mountains of Siberia, or south in the Indian subcontinent. Finding out this “is potentially extremely interesting,” says the biologist.
More bones would also clarify the appearance of the denisovans. There are several candidates for such bones. These include a northern laos tooth and a large skull – nicknamed the dragon man – found in Harbin, northern China.
