Xizang Prehistoric Sites: Unravel the Mystery of Ancestors

Today, we’ll talk about recent archaeological findings in Tibet, or Xizang - the so-called “rooftop of the world”. The new discoveries are helping to unravel the mystery of prehistoric Chinese ancestors’ migration patterns and how they were able to adapt to extreme environments.

Transcript

Xizang Prehistoric Sites: Unravel the Mystery of Ancestors

Today, we’ll talk about recent archaeological findings in Tibet, or Xizang - the so-called “rooftop of the world”. The new discoveries are helping to unravel the mystery of prehistoric Chinese ancestors’ migration patterns and how they were able to adapt to extreme environments.

Earlier this year, China’s National Cultural Heritage Administration unveiled the top 10 Chinese archaeological discoveries of 2024. On this list of outstanding representatives of work in the field of archaeology over the past year, the most noteworthy highlight goes arguably to the Mapu Tso Neolithic Site in Xizang Autonomous Region.

Standing at about 4,400 meters above sea level on the shore of Mapu Tso Lake, the site is likely the most challenging among the shortlisted archaeological projects. Recent archaeological findings suggest that humans lived there around 4,800 to 2,000 years ago and relied on resources from nearby lakes to survive.

These new discoveries are the result of a five-year excavation project and represent the most significant breakthrough in Neolithic archaeology in recent years in Xizang. According to Shargan Wangdue, deputy head of the Xizang Autonomous Region Institute for Cultural Heritage Conservation and leader of the Mapu Tso Site archaeological team, the site provides practical examples for researchers to better understand how ancient humans utilized lake resources and adopted various cultural and economic strategies, which enabled them to adapt to different development stages through cultural integration.

Located in the south-central part of the Eurasian continent, the Qinghai-Xizang Plateau stands as one of the world’s least-populated areas. However, as the main part of the Qinghai-Xizang Plateau, Xizang has never been an isolated “island”. Historically, it has been a “crossroads” where the civilizations of East Asia, South Asia, and Central Asia converged.

With more and more prehistoric relics discovered across Xizang, artifacts originating from outside the plateau, such as millet, bronzewares, talc beads, carnelian, and faience ornaments, have demonstrated the existence of an extensive network of trade on the plateau during prehistoric times, significantly expanding the temporal and spatial dimensions of prehistoric “globalization”.

Questions such as when humans first set foot on the Qinghai-Xizang Plateau, when they began to settle permanently on the plateau, and when they developed prehistoric economies are gradually answered through multidisciplinary research led by archaeology.

Since the 1950s, the Chinese Academy of Sciences have organized scientific expeditions to the Qinghai-Xizang Plateau and began to search for paleolithic sites in Xizang. Over the past decades, nearly 100 sites have been discovered. Unfortunately, they only found chipped stone tools on the ground; artifacts buried beneath the ground, whose age could be determined through sediment analysis, remain undiscovered.

But a breakthrough came in 2013, when thousands of stone artifacts were discovered from a paleolithic site on the southern bank of Xizang’s largest Serling Tso Lake, indicating that humans might have inhabited the planet’s harshest environments at least 30,000 years ago.

Researchers from the Chinese Academy of Sciences have collected more than 3,600 stone artifacts, including blades, flakes, and chunks, at Nwya Devu Site, located 4,600 meters above sea level about 300 kilometers northwest of Xizang’s capital Lhasa.

The Nwya Devu Site has exceptionally preserved its original stratigraphy, which allowed archaeologists to extract quartz sand grains from the same layer as the stone artifacts and conduct optically stimulated luminescence dating. Researchers also discovered two fragmented snail shells, on which they performed radiocarbon dating. The data from these two dating methods corroborated each other, confirming the age of the site to be between 40,000 and 30,000 years old. To date, the Nwya Devu Site remains to be the only paleolithic site discovered on the Qinghai-Xizang Plateau with a reliably established age.

To archaeologists, the most striking feature of the unearthed stone artifacts lies in the discovery of stone blades, a type of elongated stone tool with a more regular shape compared to other chipped stone tools. Stone blades are considered a distinctive tool from the upper paleolithic period, representing a marked advancement in humans’ tool-making techniques. Remains of such stone blades were usually found in Africa and Europe, but rarely found in China. This new finding shows that Xizang and Siberia might have had interactions as early as that time and thus offers a new clue to the extensive migration pattern of the time, as well as the origins of indigenous inhabitants in Tibet.

Previously, archaeologists estimated that humans first set foot on the margins of the plateau about 12,000 years ago as hunter-gatherers, who only began to settle down about 3,600 years ago, after they had mastered herding yak and sheep, as well as cultivating barley. The discovery of the site has significantly added to the historical timeline of early human activity and provided an essential link for tracing the evolution of human culture on “the roof of the world”.

Researchers speculated that our prehistoric ancestors might have used the Nwya Devu Site as a seasonal camping site, when they followed herds of animals onto the plateau and camped for weeks at a time. But according to Gao Xing, a research fellow with the Chinese Academy of Sciences, they still needed to find remains of animals, plants or humans and collect DNA samples in order to answer important questions such as who these prehistoric humans were and how they managed to survive in this extremely challenging environment.

Another breakthrough came five years later in 2018, when the highest-altitude prehistoric cave site in the world was discovered. Located in Ngari Prefecture, Xizang, the Melong Tagphug Cave Site is perched at an elevation of about 4,700 meters.

The site consists of three separate caves in a linear arrangement. Carbon-14 dating indicates that human activity at the upper strata of Cave No. 1 dates back to nearly 4,000 years ago, while its lower strata dates back to no later than 53,000 years ago, and may even date back to as early as 80,000 years ago.

Between 2018 and 2023, archaeologists unearthed more than 10,000 artifacts spanning the Paleolithic to Neolithic periods. These included stone tools, pottery fragments, animal bones, bronzeware, iron tools, and plant remains. Besides these abundant artifacts, ochre rock paintings composed of geometric patterns, human figures, palms and the sun were also found.

According to archaeologists, the cave had been deserted due to climatic factors or cave collapses, before it was inhabited again in the later period. Therefore, multi-period cultural remains were discovered in the cave, shedding light on human activities, environment change, origins of agriculture and animal husbandry, as well as prehistoric art in an extreme high-altitude environment.

During almost the same period, a mandible fossil was found in a karst cave located 3,280 meters above sea level in the northeastern part of the Qinghai-Xizang Plateau. Researchers from Lanzhou University excavated over 1,400 stone artifacts and about 600 pieces of bone fossils from the Baishiya Cave in Xiahe County in northwest China’s Gansu Province.

The mandible fossil is believed to belong to an extinct branch of human ancestors called Denisovans, who are known to have lived in Siberia around 160,000 years ago. The Denisovans carried a unique gene known as EPAS1. Genetic studies suggest that this genetic segment might help reduce hypoxia and tolerate frigidity. Researchers suggest that ancient humans on the Qinghai-Tibet Plateau acquired this gene from the Denisovans, which prepared them with the physical traits necessary to survive and thrive in the high-altitude environment.

Previously, the Denisovans were known only from fossil fragments found at the Denisova Cave in Russia. The fossil from the Baishiya Cave is thus not only the earliest known human fossil identified on the Qinghai-Xizang Plateau, but also provides direct evidence of the Denisovans outside the Altai Mountains, and considerably prolongs human history on the plateau.

According to Zhang Dongju, a professor at Lanzhou University and leader of the excavation team, the Baishiya Cave is of great significance not only for reconstructing the history of ancient human activity on the Qinghai-Xizang Plateau, but also for shedding more light on the evolutionary history of ancient humans in East Asia.

But how the ancient humans adapted to the high-altitude and oxygen-deficient environment, as well as how they made fire, crafted stone tools, and hunted for sustenance, are still awaiting research and investigation. The team’s follow-up studies will provide further evidence and information to reveal more about early human history on the plateau, particularly in terms of their physical morphology, genetic characteristics, and cultural traits.

Research on ancient human activities in the highest and most extreme environments not only offer insights into reconstructing the history of human evolution, but also holds profound practical relevance for understanding contemporary human strategies to cope with environmental changes.

Our prehistoric ancestors managed to migrate to and settle on the plateau despite the cold temperature, low oxygen level, and scarce resources. This process encapsulates critical information about human biological and cultural adaptability.

The adaptive strategies of our prehistoric ancestors, for example, how they overcame the natural constraints through genetic evolution, technological innovation, and adjustments in social organization, provide valuable references for reflecting on human resilience in extreme environments.

As archaeologist Gao Xing commented, leveraging the past to inform the present is not merely about tracing the footsteps of our ancestors but also about tapping into human wisdom over the millennia to explore more resilient adaptation pathways in the face of increasingly frequent and severe environmental challenges in the future.

Well, that’s the end of our podcast. Our theme music is by the famous film score composer Roc Chen. We want to thank our writer Ni Wei, translator Yang Guang, and copy editor Pu Ren. And thank you for listening. We hope you enjoyed it, and if you did, please tell a friend so they, too, can understand The Context.