Ancient millet growers brought barley to the Qinghai-Tibet Plateau

Recently, Kong Qingpeng, a researcher at the Kunming Institute of Zoology of the Chinese Academy of Sciences, teamed up with Dong Guanghui, a professor at Lanzhou University's School of Resources and Environment, to crack the migration history of barley agriculture to the Qinghai-Tibet Plateau by analyzing data on mitochondrial DNA genetic variation in a large number of modern Tibetans and their surrounding populations, and combining published archaeological evidence. The results were published in the National Science Review.
about 3,600 years ago, barley and livestock appeared at high altitudes in the Qinghai-Tibet Plateau. However, the introduction of barley by the spread of foreign people and carried to high-altitude areas, or through cultural exchanges, and then from the eastern edge of the plateau valley of the agricultural population spread to high-altitude areas, which is not clear to the academic community.
Li Yuchun, the first author of the paper and a doctor at the Kunming Institute of Zory of the Chinese Academy of Sciences, said that by in-depth analysis of mitochondrial DNA genetic variation data from 8,277 modern Tibetan populations and 58,514 samples from surrounding populations, combined with carbon XII annual data and human bone carbon isotope data from crops at different altitudes, the researchers finally identified two monogroups, whose origins corresponded well to the origin, reinforcement and western transmission of agriculture. At the same time, these two genetic groups have also been found in the DNA of human bones unearthed at neolithic sites in northern China, further suggesting that they may represent the remaining genetic groups in the Tibetan population from the agricultural population of the millet.
the study also showed that the two thymossions were widely distributed among different geographical groups of modern Tibetans, with an average frequency of 20.86 per cent, and reached their highest proportion (about 50 per cent) about 3,300 years ago. Together, these evidence suggest that some 5,200 years ago, a portion of the population living in North China, which grows millet crops for a living, migrated to low-altitude areas in the north-eastern Qinghai-Tibet Plateau and settled there. About 4,000 years ago, they absorbed foreign cultures and learned to grow barley. Some 3,600 years ago, some people living at low altitudes in the Qinghai-Tibet Plateau migrated to high-altitude areas and carried barley cultivation traditions there, opening up large-scale permanent settlement of humans at high altitudes on the Qinghai-Tibet Plateau.
study also found that the Tibetan population and other East Asian populations have obvious genetic differentiation, and the greatest contribution to this differentiation is precisely the genetic group of the agricultural population, indicating that the genetic input of the agricultural population of the smouldering population has made an important contribution to the gene pool of the modern Tibetan population.
The study not only confirmed the existence of a large number of genetic groups from the agricultural population in northern China, but also showed that after long-term settlement in the low-altitude areas of the Qinghai-Tibet Plateau, the agricultural population chose cold-resistant barley agriculture and further migration to high altitudes, and eventually settled permanently on a large scale in the Qinghai-Tibet Plateau. This study is of great significance for understanding the pattern of barley agriculture spreading to the plateau and the origin and evolution history of the Tibetan population in the plateau.