New evidence from the Qugong site in the central Tibetan Plateau for the prehistoric Highland Silk Road

Located in the central Eurasia, the Tibetan Plateau (TP) is a key area for the spread of culture, technology, and species. However, the Plateau’s role in the prehistoric food globalization has been underestimated due to the lack of archeological materials. The Qugong site was the only scientifically excavated site in the central TP up to now. It is the earliest and among the most important prehistoric settlements in the central TP, with charcoals dated to 3750–3500 cal. BP. Wild deer (Cervidae) and domesticated yak ( Bos grunniens) and sheep ( Ovis aries) remains were unearthed, but no archeobotanical studies had been conducted. Here we present new radiocarbon data from charred seeds as well as archeobotanical data of the Qugong site. Dating back to 3400 cal. BP, there were foxtail millet ( Setaria italica), broomcorn millet ( Panicum miliaceum), wheat ( Triticum aestivum), hulled barley ( Hordeum vulgare), naked barley ( Hordeum vulgare var. nudum), and bitter buckwheat ( Fagopyrum tataricum) identified at this site. We propose that millets in the central TP came from the eastern TP, while wheat and barley here probably came from northern South Asia. It indicates that the Eastern and Western cultures arrived in the central TP in prehistory via different routes in late fourth millennium BP. The intercultural communications not only flourished the prehistoric central TP but also laid the foundation for the later ‘Highland Silk Road’.