Project description:The extreme environments of the Tibetan Plateau offer significant challenges to human survival, demanding novel adaptations. While the role of biological and agricultural adaptations in enabling early human colonization of the plateau has been widely discussed, the contribution of pastoralism is less well understood, especially the dairy pastoralism that has historically been central to Tibetan diets. Here, we analyze preserved proteins from the dental calculus of 40 ancient individuals to report the earliest direct evidence of dairy consumption on the Tibetan Plateau. Our palaeoproteomic results demonstrate that dairy pastoralism began on the higher plateau by approximately 3,500 years ago, more than 2,000 years earlier than the recording of dairying in historical sources. With less than 1% of the Tibetan Plateau dedicated to farmland, pastoralism and the milking of ruminants were essential for large-scale human expansion into agriculturally-marginal regions that make up the majority of the plateau. Dairy pastoralism allowed conversion of abundant grasslands into nutritional human food, which facilitating adaptation in the face of extreme climatic and altitudinal pressures, and maximizing the land area available for long-term human occupation of the “roof of the world”.
