Earliest sustained settlement by farmers and symbiotic relationship with foragers at high altitude on the Tibetan Plateau

Abstract

Foragers had occupied high altitudes on the Tibetan Plateau (TP) since the Late Pleistocene. Millet farmers from the Middle Yellow River Valley migrated to TP during the Late Neolithic, but their settlements of over 2500 masl and interactions with indigenous foragers remain unclear. Multi-isotope (δ¹³C, δ¹⁵N, δ¹⁸O, and δ³⁴S) analyses of animal remains from the Liujiazhai site (2630 masl, 5300–4700 cal.BP) on southeastern TP reveal continuous presence of managed animals (Sus, Canis), fed by millets-based food. By using isotopic values of domestic animals (dogs and pigs) as proxies for human diets, our study provides the earliest sustained settlement by farmers at high altitudes. A complex subsistence strategy was established involving millet cultivation, animal husbandry, hunting, and gathering. Combining archaeobotanical, zooarchaeological, isotopic and archaeological data during the Late Neolithic, we reconstruct the dispersal of farmers into southeastern TP and highlight their symbiotic relationship with indigenous foragers when they entered eastern TP.