A sister group of Neanderthals, the Denisovans, occupied the Tibetan Plateau long before Homo sapiens arrived in the region, concludes a team of scientists.

View of the virtual reconstruction of the Xiahe mandible after digital removal of the adhering carbonate crust. The mandible is so well preserved that it allows for a virtual reconstruction of the two sides of the mandible. Mirrored parts are in grey. Picture credit: Jean-Jacques Hublin, MPI-EVA, Leipzig

Discovery Likely Represents the Earliest Hominin Fossil on the “Roof of the World”

A sister group of Neanderthals, the Denisovans, occupied the Tibetan Plateau long before Homo sapiens arrived in the region, concludes a team of scientists in an analysis that appears in the journal Nature.

The work, which included NYU anthropologist Shara Bailey as well as researchers from the Institute of Tibetan Plateau Research, CAS, Lanzhou University, and the Max Planck Institute for Evolutionary Anthropology, analyzed a 160,000-year-old hominin mandible, or lower jaw bone, from Xiahe in China.

Using ancient protein analysis, the researchers found that the mandible’s owner belonged to a Denisovan population from Siberia. This population occupied the Tibetan Plateau—known as the “Roof of the World” because it rises three miles above sea level—and adapted to its low-oxygen terrain.

The Denisovans had already adapted to living in this high-altitude setting significantly prior to the appearance of Homo sapiens, the scientists note. Previous genetic studies found present-day Himalayan populations to carry the EPAS1 allele in their genome, passed on to them by Denisovans, which helps with adaptation to their specific environment.

Denisovans were discovered in 2010, when a research team led by Svante Pääbo from the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) sequenced the genome of a fossil finger bone found at Denisova Cave in Russia and showed that it belonged to a hominin group that was genetically distinct from Neanderthals.

“Traces of Denisovan DNA are found in present-day Asian, Australian, and Melanesian populations, suggesting that these ancient hominins may have once been widespread,” says Jean-Jacques Hublin, director of the Department of Human Evolution at the MPI-EVA and one of the paper’s co-authors. “Yet, so far, the only fossils representing this ancient hominin group were identified at Denisova Cave.”

In their new study, the researchers describe a hominin lower mandible that was found on the Tibetan Plateau in Baishiya Karst Cave in Xiahe, China. The fossil was originally discovered in 1980 by a local monk who donated it to the 6th Gung-Thang Living Buddha who then passed it on to Lanzhou University. Since 2010, researchers Fahu Chen and Dongju Zhang from Lanzhou University have been studying the area of the discovery and the cave site from where the mandible originated. In 2016, they initiated a collaboration with the Department of Human Evolution at the MPI-EVA and have since been jointly analyzing the fossil.

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Animation of the virtual reconstruction of the Xiahe mandible. Courtesy of Jean-Jacques Hublin, MPI-EVA, Leipzig

While the researchers could not find any traces of DNA preserved in this fossil, they managed to extract proteins from one of the molars, which they then examined by applying ancient protein analysis.

“Previous fossil remains of Denisovans were limited to some teeth and part of a pinkie bone,” notes Bailey. “Although we still do not know the shape and size of the Denisovan skull, now with a lower jaw we can start to piece together the puzzle of what they actually looked like.”

Additional Contacts:

Professor Jean-Jacques Hublin
Max Planck Institute for Evolutionary Anthropology, Germany
+49 341 3550-351
hublin@eva.mpg.de

Professor Fahu Chen
Institute of Tibetan Plateau Research, Chinese Academy of Sciences (CAS) & Lanzhou University, China
fhchen@itpcas.ac.cn

Dr. Dongju Zhang
Lanzhou University, China
djzhang@lzu.edu.cn

Dr. Frido Welker
Max Planck Institute for Evolutionary Anthropology, Germany &
University of Copenhagen
frido_welker@eva.mpg.de

Sandra Jacob
Press Officer
Max Planck Institute for Evolutionary Anthropology, Germany
+49 341 3550-122
jacob@eva.mpg.de