High-Altitude Hominins: How Denisovans Survived the Tibetan Plateau 48,000 Years Ago

Redacción HC
06/07/2024

For decades, the Denisovans have remained a shadowy branch of the human family tree. First discovered through a single finger bone in a Siberian cave, their story seemed limited to a few DNA samples and sparse fossil clues. But new research published in Nature is changing that. A multidisciplinary team has uncovered groundbreaking evidence of Denisovan presence and adaptation in the Tibetan Plateau at extreme altitudes between 48,000 and 32,000 years ago. Through a powerful blend of proteomics, zooarchaeology, and stratigraphy, the study reconstructs a vivid picture of these ancient high-altitude hunter-gatherers.

Reconstructing the Life of a Mysterious Hominin

Until recently, what we knew of Denisovans came almost entirely from genetics—traces left in modern Asian populations and sediment DNA. But in the Baishiya Karst Cave, located 3,280 meters above sea level in the Tibetan Plateau, researchers unearthed something more tangible: a human rib fragment identified as Denisovan through proteomic analysis.

This fragment, found in sediment layers dated to 48,000–32,000 years ago, is the most recent fossil evidence of Denisovan occupation in the area. Combined with prior discoveries like a partial mandible and genetic traces, it confirms a long-term, repeated presence of these hominins in one of the world’s harshest environments.

A Massive Bone Archive: What 2,500 Fossils Reveal

The study analyzed over 2,500 faunal bone fragments from the cave. Using ZooMS (zooarchaeology by mass spectrometry)—a technique that identifies animal species based on collagen fingerprinting—the researchers categorized nearly 1,900 of these remains.

Key Findings:

• The bones mostly belonged to Caprinae species like bharal (blue sheep), along with yaks, woolly rhinoceroses, spotted hyenas, and smaller mammals.
• Butchering marks—including cuts, fractures, and impact scars—indicate the animals were processed systematically for meat, marrow, hides, and tools.
• This suggests strategic hunting and resource use suited to cold, resource-scarce alpine environments.

Mastering the “Roof of the World”

The Denisovans’ ability to survive and thrive at high altitudes is one of the most astonishing takeaways of this study. The Tibetan Plateau is not only remote—it’s freezing, oxygen-depleted, and barren for much of the year. Yet evidence from Baishiya suggests that Denisovans:

• Lived there repeatedly over thousands of years
• Adapted their hunting strategies to climate shifts
• Exploited both small game and megafauna
• Processed bones into tools and possibly used animal fat for fuel

“These findings reveal that Denisovans weren’t just surviving—they were strategically adapting to one of the harshest climates on Earth,” says co-author Dongju Zhang.

This environmental resilience might explain the presence of Denisovan genes in modern Tibetan populations, including the EPAS1 gene variant that helps with high-altitude oxygen processing.

Proteomics: A Molecular Revolution in Archaeology

While ancient DNA often steals the spotlight, proteomics is emerging as a powerful tool, especially in sites where DNA doesn’t preserve well. In this study:

• ZooMS identified animal species from bone fragments otherwise too degraded for analysis.
• A human rib fragment was confirmed to be Denisovan based solely on its protein signature—no DNA required.

This reinforces the value of combining molecular biology with traditional archaeology, especially in fragmentary or remote contexts.

Why This Changes the Human Story

This research adds a crucial behavioral layer to our understanding of Denisovans:

• They were not passive wanderers but skilled hunters capable of planning, tool use, and large-animal processing.
• Their adaptability challenges assumptions that Homo sapiens were uniquely suited to varied climates and terrains.
• It broadens the debate on inter-species interaction during the Pleistocene, suggesting that Neanderthals, Denisovans, and early modern humans may have had overlapping behaviors—not just overlapping genomes.

Practical Implications:

• The Baishiya Cave study sets a new protocol for identifying hominin presence using multidisciplinary techniques.
• It calls for similar integrative approaches at other high-altitude and low-preservation sites across Asia and beyond.

Conclusion: A New Chapter in Human Evolution

The Baishiya Karst Cave continues to surprise. This latest discovery not only extends the known timeline of Denisovan activity by tens of thousands of years, but also reshapes our image of who they were: resilient, intelligent, and highly adapted hominins capable of thriving where few others could.

Future excavations may uncover more than just bones—tools, artwork, or even shelters. But for now, this study offers a powerful reminder: even the smallest bone fragment can rewrite history.

Topics of interest

History