A diagrammatic map of the Wayan reservoir site in Dulan county, Qinghai Province Photo: Courtesy of Wang Chuanchao

Located in Northwest China's Dulan county, Qinghai Province, the Wayan reservoir site is a representative archaeological spot containing historical evidence from the ancient Tubo Empire, the first regime to have a clear historical record in Southwest China's Xizang Autonomous Region. 

According to a 2014 excavation report from the Shaanxi Academy of Archaeology (SAA) and Qinghai Antique Archaeology Institute (QAAI), the site, known for its 25 tombs, has produced eye-catching treasures such as "dragonfly eye beads." However, it wasn't until recently that DNA research has revealed information about the tomb owners' origins. 

Story hiding among genes 

A team led by Fudan and Xiamen university researchers Wen Shaoqing and Wang Chuanchao found genome data of 10 individuals dating from 1202 to 1380 years ago. 

Nine individuals were discovered to be closely linked to ancient highlanders from the southwestern Himalayas and carry features of the modern core-Tibetan population. Wang explained that the 10th individual showed similar genetic signs as the ancient nomadic people of the Eurasian steppes. 

"This hints at possible interactions between the Dulan region and Central Asia," said Wang.  

Du Panxin, a researcher in the team, told the Global Times that besides a similarity to the modern core-Tibetan population, they also found that the generic composition of the Dulan population is close to ancient farmers in the upper reaches of the Yellow River. 

The study proves that the Tubo group was related to modern Han and Tibetan people from a biological perspective, the researcher added. 

The Tubo Empire has a history that traces back to the 7th century. It was an ancient regime rooted in the Tibetan Plateau. The Wayan reservoir site is located at the Plateau's northeastern edge. Du told the Global Times that their study sheds light on the demic immigration and expansion patterns of the Tubo Empire as it headed northeast. 

Called an "empire," the territory on the Tibetan Plateau helmed by the Tubo reveals the unified sphere of ancient Xizang society. Under laws and policies inspired by its leader Songtsen Gampo, various small states and tribes were integrated to form this realm.

The northeastern migration was not the only destination that ancient Tubo people aimed at. 

Prior to the new research, another genetic analysis had been completed in Nepal. It sampled ancient individuals' DNA from more than 3,300 years ago and also discovered a connection. Many scholars see this as proof that the Tubo Empire also expanded to the southwest of the Tibetan Plateau. 

As they set foot in different places, the ancient Tubo also brought about cultural exchanges. 

The Wayan reservoir site is a classic example showing how China embraced cultures from the West during the Tang Dynasty (618-907).

Wang told the Global Times that the site's cultural landscape was influenced by the Han culture of China's Central Plains and also the cultures of the ancient West region. 

Nearly 900 relics, including pottery and bronze wares, leather goods and intricately designed amber pendants and gold earrings, have been found at the site's tombs. 

Kai Yuan Tong Bao coins, a type of copper coin minted during the Tang Dynasty to regulate the currency market, have been unearthed at the site, showing that the social customs of the Central Plain's were acknowledged by the ancient Tubo people. 

Along with a large number of silk products, the "dragonfly eye beads," a type of glass art ware glossed by green, blue and yellow colors, was found to carry exotic Western aesthetics that make it look deceptively modern. 

Wang told the Global Times that the study is not only an exploration of demographic migration, but also a look into the "cultural co-diffusion" of the Tubo Empire and the Tang Dynasty.

The Tubo made significant impact on promoting "ethnic integration," the scholar made remark.  

"In fact, the Tubo people and the Han and Tibetan people have shared the same roots since ancient times," Wang noted.  

"Tang Princess Wencheng's journey to Xizang was an example of opening up good Han-Tibetan friendship." 

Bigger picture 

The Wayan reservoir site is only the tip of the iceberg when it comes to Dulan county's ancient Tubo history. 

In 1996, the 2018 Xuewei Tomb No.1 was also found in the county. The tomb was later nominated as one of top 10 archaeological discoveries in China for that year. Known for its mysterious configuration, the tomb consists of an aboveground area meant to conceal structures underground and the tomb chamber, which was decorated with murals and two color painted coffins. 

Tons of gold, silk and leather relics have been unearthed, among which a silver seal bearing the inscription "seal of the King Achai, the nephew" reveals the "Tubo" identity of the tomb owner. 

Both the Wayan reservoir site and the 2018 Xuewei tomb No.1 revealed the Qinghai Dulan region was an important area for cultural interchange between China and the West along the ancient Silk Road. 

Revealing the cultural history of the ancient Silk Road is the goal of many Chinese scholars today. 

Wang told the Global Times that their project was done from the angle of DNA to study the blending of ethnic groups along the Silk Road powered by biological archaeology and DNA anthropology. This was inventive as most Silk Road studies mainly focus on the history of material and cultural exchanges. 

Combining interdisciplinary subjects like archaeology, linguistics and genetics in one, the team's next project will focus on prehistoric human migration and the language transmission of the Dongtai, Miao, Yao and South Asian languages in South China and Southeast Asia.