The emergence, development, and impact of prehistoric agriculture on the Tibetan plateau

Abstract

The Tibetan Plateau, the highest region in the world, presents significant challenges for human survival due to its extreme environment characterized by hypoxia, low temperatures, intense radiation, and limited food resources. The formation and development of agriculture (including crop cultivation and livestock husbandry) on the Tibetan Plateau reflect human adaptation to high-altitude environments. In the past decade, in addition to traditional archaeobotany and zooarchaeology based on morphological studies, analyses of stable carbon and nitrogen isotope, lipid, ancient DNA, and ancient sedimentary DNA have been employed to investigate the history of agricultural development on the Tibetan Plateau, resulting in a series of new findings. Based on comprehensive analyses of flora and fauna remains, along with a database of archaeological radiocarbon dates, we summarize the evolution and impacts of prehistoric agriculture on the Tibetan Plateau as follows. (1) The development of agriculture can be divided into three phases: millet agriculture, mixed millet-barley-wheat agriculture, and barley-wheat agriculture. (2) Crops from the East and the West spread via the “Plateau Road.” (3) The sequential emergence of millet and barley-wheat agriculture triggered two significant waves of human exploitation of the high-elevation regions. This is evidenced by the onset of sedentism in the lower-elevation river valleys (1500–3000 masl) initiated by intensive millet agriculture, followed by the expansion of settlements into higher altitudes (>3000 masl) facilitated by barley-wheat agriculture. Future research directions may focus on several key areas: the adaptation processes of introduced domesticates (including crops and livestock such as cattle, sheep, goats, and horses) to high-altitude environments, the local domestication of yak and Chenopodium, and the impacts of introduced crops and domestic animals on both human societies and alpine ecosystems. These investigations could be advanced through increased archaeological work and the application of cutting-edge methods, particularly ancient DNA and ancient sedimentary DNA analyses.