Denisovans on the Tibetan Plateau are now one of the clearest windows into this extinct human group. Fossils, DNA from cave sediments and living Tibetans all point to a high-altitude story, and a recent rib find suggests that Denisovans may have lived there alongside modern humans.
Source: Baishiya Karst Cave studies (2019 to 2024), including work reported by the University of Reading in July 2024.
The Baishiya Karst Cave evidence
The cave sits on the Plateau in Xiahe, Gansu, at roughly 3,200 metres above sea level. Researchers identified a jaw bone found there as Denisovan in 2019 and dated it to about 160,000 years ago. Before that, researchers knew Denisovans mainly from a few fragments in Denisova Cave in Siberia. The jaw showed that they also occupied a cold, thin-air environment.
| Evidence | Approximate age | What it shows |
|---|---|---|
| Xiahe mandible, Baishiya Karst Cave | About 160,000 years | Denisovans lived at about 3,200 m, far from Siberia |
| Denisovan DNA in cave sediments | About 100,000 to 60,000 years, and possibly later | Repeated or long occupation of the cave |
| Rib bone reported by Reading researchers | About 40,000 years | Possible overlap with modern humans on the Plateau |
DNA from the floor of the cave
In 2020, researchers recovered Denisovan mitochondrial DNA from cave sediments, with layers dated from about 100,000 to 60,000 years ago and possibly later. Sediment DNA matters because it can show who lived somewhere even when no bones remain. Taken together, the results suggest Denisovans used the cave over a very long period.
The Plateau setting adds weight to the finding. Cold, low-oxygen conditions are hard to live in, so evidence of long Denisovan presence suggests that this group had its own ways of coping with altitude, even if we do not yet know what they were.
The rib and the question of overlap
Researchers have linked a rib fragment, dated to about 40,000 years ago, to Denisovans. If that identification holds, Denisovans may have been present when modern humans were also living on the Plateau. That would give a chance for contact and interbreeding. At this stage, overlap is a reasonable inference and not a direct observation of people living together.
Genes and high-altitude life
Many Tibetans carry a version of the EPAS1 gene that helps the body cope with low oxygen. This variant seems to come from Denisovan-related ancestry. Researchers regard the link as likely but still treat the exact route of transfer as open. A fair summary: the gene variant associates with Denisovan ancestry, and it illustrates adaptive introgression.
The result is an example of biology and environment interacting, since gene flow supplied a variant that natural selection later favoured at altitude.
A second genetic finding: NOVA1
Denisovan and Neanderthal genomes also feature in a 2025 Nature Communications study by Yoko Tajima and colleagues on NOVA1, a gene whose protein regulates RNA in neurons. Modern humans carry a variant in which the amino acid isoleucine is replaced by valine. Neither Neanderthal nor Denisovan genomes carry that version, and it is almost universal in modern genomes (reports mention all but six of about 650,000 checked). Mice engineered with the human variant changed how they vocalise, so the authors suggest a link with spoken language. Treat this as an association supported by a mouse model, not as proof of what extinct humans could or could not say.
Evidence and inference
The jaw, the sediment DNA and the rib are observations, each with its own dating uncertainty. The idea of overlap and the transfer of EPAS1 are inferences drawn from them. Naming Denisovan geography beyond these sites would go beyond the evidence.
Using it in UPSC Mains
Use this under Paper I, Section 1.6 on human evolution, and in Section 9.7 on bio-cultural adaptation to high altitude. Denisovans are not named in the syllabus, so introduce them briefly as a recent discovery. A short answer can cover three points: the fossil, the sediment DNA and the EPAS1 link.
No verified PYQ on Denisovans is linked here, so connect the topic to broader human evolution questions in the Human Evolution and Primatology PYQs. For related reading, see Modern Humans and Neanderthals in the Zagros. The wider syllabus map is in the Anthropology Optional complete guide.
Sources
Baishiya Karst Cave studies on the Xiahe mandible (2019), sediment DNA (2020) and rib fragment (University of Reading, 2024).