Views 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)
Views 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)

Our ancient Denisovan ancestors travelled much further than we thought

Embargoed until: Publicly released:

A 160,000-year-old Denisovan jawbone found in a cave on the Tibetan Plateau is the first reported evidence of this ancient human group outside the Denisova cave in Siberia. This jawbone is also the earliest known hominin fossil found on the Tibetan Plateau. The discovery indicates that Denisovans - a sister group of Neanderthals - adapted to high-altitude, low-oxygen environments much earlier than the regional arrival of modern humans.

Journal/conference: Nature

Link to research (DOI): 10.1038/s41586-019-1139-x

Organisation/s: Institute of Tibetan Plateau Research | Max Planck Institute for Evolutionary Anthropology, Germany | Lanzhou University, China

Funder: We received support from the Strategic Priority Research Program of Chinese Academy of Sciences, Pan-Third Pole Environment Study for a Green Silk Road and National Natural Science Foundation of China. D.J.Z. received support from National Natural Science Foundation of China. Fieldwork in 2018 was supported by the Second Tibetan Plateau Scientific Expedition (Project no. 4). U–Th dating was supported by the Science Vanguard Research Program of the Ministry of Science and Technology and the Higher Education Sprout Project of the Ministry of Education, Taiwan (107L901001). J.-J.H. and F.W. thank the Max Planck Society for providing financial support.

Media Release

From: Max Planck Institute for Evolutionary Anthropology

First hominins on the Tibetan Plateau were Denisovans

Denisovan mandible likely represents the earliest hominin fossil on the Tibetan Plateau

So far Denisovans were only known from a small collection of fossil fragments from Denisova Cave in Siberia. A research team led by Fahu Chen from the Institute of Tibetan Plateau Research, CAS, Dongju Zhang from Lanzhou University and Jean-Jacques Hublin from the Max Planck Institute for Evolutionary Anthropology now describes a 160,000-year-old hominin mandible from Xiahe in China. Using ancient protein analysis the researchers found that the mandible’s owner belonged to a population that was closely related to the Denisovans from Siberia. This population occupied the Tibetan Plateau in the Middle Pleistocene and was adapted to this low-oxygen environment long before Homo sapiens arrived in the region.

Denisovans – an extinct sister group of Neandertals - 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 Neandertals. “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. “Yet so far the only fossils representing this ancient hominin group were identified at Denisova Cave.”

In their new study, the researchers now 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 analysing the fossil.

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 analysed applying ancient protein analysis. “The ancient proteins in the mandible are highly degraded and clearly distinguishable from modern proteins that may contaminate a sample,” says 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.”

The researchers found the mandible to be well-preserved. Its robust primitive shape and the very large molars still attached to it suggest that this mandible once belonged to a Middle Pleistocene hominin sharing anatomical features with Neandertals and specimens from the Denisova Cave. Attached to the mandible was a heavy carbonate crust, and by applying U-series dating to the crust the researchers found that the Xiahe mandible is at least 160,000 years old. Chuan-Chou Shen from the Department of Geosciences at National Taiwan University, who conducted the dating, says: “This minimum age equals that of the oldest specimens from the Denisova Cave“.

“The Xiahe mandible likely represents the earliest hominin fossil on the Tibetan Plateau,” says Fahu Chen, director of the Institute of Tibetan Research, CAS. These people had already adapted to living in this high-altitude low-oxygen environment long before Homo sapiens even arrived in the region. Previous genetic studies found present-day Himalayan populations to carry the EPAS1 allele in their genome, passed on to them by Denisovans, which helps them to adapt to their specific environment.

“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,” says Dongju Zhang. According to Hublin, similarities with other Chinese specimens confirm the presence of Denisovans among the current Asian fossil record. “Our analyses pave the way towards a better understanding of the evolutionary history of Middle Pleistocene hominins in East Asia.”

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

Expert Reaction

These comments have been collated by the Science Media Centre to provide a variety of expert perspectives on this issue. Feel free to use these quotes in your stories. Views expressed are the personal opinions of the experts named. They do not represent the views of the SMC or any other organisation unless specifically stated.

Dr Nic Rawlence, Director of the Otago Palaeogenetics Laboratory, and Senior Lecturer (beyond the bar) in Ancient DNA, Department of Zoology, University of Otago

Ever since the discovery of Denisovans, (the cousins of the extinct Neanderthals), from fragmentary remains excavated from Denisova Cave in Russia’s Altai Mountains, scientists have been in search of morphologically identifiable bones that would allow detailed comparisons with other archaic hominids, Neanderthals and modern humans. Morphologically identifiable remains, thought to be rare as hens teeth, would help answer important questions as such were Denisovans a distinct hominid species, or just another evolutionary branch of Neanderthals?

"Add to this is the fact that Denisovans left a genetic legacy within the genomes of east Asian, Aboriginal Australians and Melanesians, through interbreeding, hinting at a more widespread and larger population, (compared to Neanderthals), potentially hiding out in the existing fossil record.

"Now Chen et al. have found the holy grail. By extracting ancient protein sequences, (which work like ancient DNA but over longer time scales especially when ancient DNA is too degraded, as is the case here), from a 160,000-year-old partial jawbone (complete with teeth) found in a cave on the Tibetan Plateau, they have shown that this morphologically important fossil is from none other than a Denisovan. Shape analysis of the teeth in this jawbone show them to be comparable to isolated Denisovan teeth from the Altai.

"Not only did Chen et al. find the holy grail, but they have also potentially found other grails. This Tibetan fossil is comparable to similar aged archaic hominid fossils from central east Asia, which just goes to show that Denisovans may have been hiding out in the fossil record all this time. Further ancient protein and ancient DNA analysis of these, and other well preserved specimens, will help confirm these hypotheses.

"The genes that allow modern day Tibetans to survive at high altitudes can be traced back to interbreeding between Denisovans and the ancestors of Tibetans. Until now this has always intrigued scientists as there was no evidence of Denisovans in central east Asia, and modern humans only arrived on the scene around 30,000-40,000 years ago.

"The 160,000-year-old Tibetan Denisovan goes someway to potentially explaining where and when this interbreeding occurred, but in my view, the jury is still out regarding Chen et al.’s claim that Denisovans were adapted to living at high altitudes – it may be a case of pre-adaptation (i.e. genes were used initially for another purpose then repurposed for surviving at high altitudes). Further ancient genomic research is needed to test to confirm or refute this.

Last updated: 30 Apr 2019 2:58pm
Declared conflicts of interest:
No conflict of interest
Murray Cox is Professor of Computational Biology at Massey University

We always knew that Denisovans had to live somewhere other than Denisova cave, but it’s fantastic to finally have that confirmation. 

"We now know that Denisovans lived on the Tibetan plateau.  We used to think that only modern humans could do that, and only relatively recently, from around 30 thousand years ago.  There’s a strong bias in much of our thinking – we tend to believe that only modern humans are clever enough to go to certain places or live in certain ways. It’s now clear we’ve overestimated our uniqueness.  Archaic humans like Denisovans were much more resourceful and adaptable that we have given them credit for.

"Perhaps the most important finding is that human remains that were misclassified in the 1980s are now being recognized as Denisovan.  This suggests that other Denisovan bones and remains are hiding in plain sight – sitting in museums and university collections around the world  – and we just need to put the correct label on them to get a better idea of what Denisovans looked like. This study is the first, probably of many, that I expect will find them.

"The big direction we need to go in now is to look for Denisovan remains well beyond the Altai mountains of Siberia.  This means looking carefully again in existing collections, but also doing more archaeological research in parts of the world that have been severely understudied.  There are too many research resources flowing to well-studied places like Europe, and too little going to amazingly understudied places like Asia and Oceania.

"The way the remains were confirmed as Denisovan was also very clever.  Methods that look at protein rather than DNA are going to be especially important for studying remains from warmer regions, where DNA does not survive long. We are used to ancient DNA riding to the rescue, but DNA does not survive in warm locations. Human remains from some of the more interesting places are just not going to have DNA that survives.  We’ll need to rely on different approaches, such as looking at bone morphology, but also new methods like the protein analysis used in this study.

Last updated: 30 Apr 2019 9:08am
Declared conflicts of interest:
No conflicts of interest.

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  • Xiahe mandible
    Xiahe mandible

    Xiahe mandible, only represented by the right half, was found in 1980 in Baishiya Karst Cave

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    Attribution: Dongju Zhang, Lanzhou University

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  • The excavation
    The excavation

    A team led by Dongju Zhang (top right in the trench) were excavating in one of the two 2m2 trenches in Baishiya Karst Cave in 2018.

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    Attribution: Dongju Zhang, Lanzhou University

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  • Top-down view of virtual reconstruction of the Xiahe mandible
    Top-down view of virtual reconstruction of the Xiahe mandible

    Views 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.

    File size: 835.2 KB

    Attribution: Jean-Jacques Hublin, Max Planck Institute for Evolutionary Anthropology

    Permission category: © - Only use with this story

    Last modified: 02 May 2019 3:02am

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