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Researchers Find Human Ancestor That Lived in Oxygen-Deprived Tibet 160,000 Years Ago

A mandible discovered by a monk in 1980 shows that ancient human ancestors lived in oxygen-deprived altitudes more than 160,000 years ago.

As noted by the researchers, the first hominins inhabiting the Tibetan Plateau were Denisovans, and they lived there, more than 3,300 meters above sea level around 160,000 years ago.

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A Denisovan mandible likely represents the earliest hominin fossil on the Tibetan Plateau. This mysterious human species was known from a small collection of ancient fossils discovered from the Denisova Cave in Siberia.

But that’s about it when it comes to Denisovans.

Now, a new study led by researchers from the Institute of Tibetan Plateau, Lanzhou University and the Max Planck Institute for Evolutionary Anthropology, reveals a 160,000-year-old mandible from Xiage in China.

An ancient mandible discovered by a monk

Virtual reconstruction of the mandible found in Xiahe, China. Image Credit: Jean-Jacques Hublin, MPI-EVA, Leipzig.
Virtual reconstruction of the mandible found in Xiahe, China. Image Credit: Jean-Jacques Hublin, MPI-EVA, Leipzig.

Scientists discovered that the owner of the mandible was closely related to the Denisovans from Siberia. This population of ancient humans occupied the Tibetan Plateau in the Middle Pleistocene and was adapted to this low-oxygen environment long before Homo sapiens arrived in the region, reveals a statement from the Max Planck Institute for Evolutionary Anthropology.

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The study detailing the discovery was published in the journal Nature.

And researchers reveal it is the first evidence of this species found outside the Denisova Caves, in Siberia.

The fossil was discovered in 1980 by a local monk inside the Baishiya Karst Cave at an altitude of 10,760 feet (3,280 meters). But only now scientists have managed to perform the analysis of an ancient protein extracted from the fossil and identify the species.

“The ancient proteins in the mandible are highly degraded and clearly distinguishable from modern proteins that may contaminate a sample,” explains Frido Welker of the MPI-EVA and the University of Copenhagen.

“Our protein analysis shows that the Xiahe mandible belonged to a hominin population that was closely related to the Denisovans from Denisova Cave.”

Extreme Heights

The mandible is considered the oldest hominin fossil ever discovered in the high altitudes of the Himalayan Region.

“Archaic hominins occupied the Tibetan plateau in the Middle Pleistocene and successfully adapted to high-altitude, low oxygen environments long before the regional arrival of modern Homo sapiens,” revealed Dr. Dongju Zhang, from Lanzhou University.

The mandible means that human ancestors had adapted to life in an environment of high altitude and low oxygen, long before Homo sapiens reached the region.

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The fossil was dated to 160,000 years thanks to a ‘thick’ carbonate crust covering it.

Curiously, the oldest Denisovan specimens of Siberia are from a similar time period.

But the greatest difference is perhaps the altitude where the fossils were discovered.

Denisova Genes live on

The Denisova cave in Siberia is located at an altitude of 700 meters above sea level, while the mandible recently analyzed by experts was found at an altitude of 3,280 meters.

Interestingly, genes from this archaic species have been found in some modern-day people, such as the Sherpas. Their ancestry has given them the necessary biological tools that allow them to thrive at high altitudes.

It was previously s scientific mystery how some natives of Tibet are able to survive and thrive at such altitudes, where oxygen levels can be up to 40 percent less than at sea level.

Via
MPG.de
Source
Nature