Early interaction of agropastoralism in Eurasia: new evidence from millet-based food consumption of Afanasyevo humans in the southern Altai Mountains, Xinjiang, China

Different agricultural and metallurgical systems had developed at the eastern and western ends of Eurasia continent before 3000 BC. As one of the earliest Bronze Age cultures in the Eurasian steppe, the Afanasyevo Culture originating from Southern Siberia, Russia, had played an extremely significant role in facilitating cultural interactions and the spread of domestic species in Eurasia. Hence, investigating the diets of Afanasyevo populations during their movements across the Eurasian steppe possibly provides important clues to explore when, where, and how the earlier cultural interactions happened. Here, we present the isotopic analysis of Afanasyevo humans found in Ayituohan Iota Cemetery (ca. 2836-2490 cal BC) in the southern Altai Mountains, Xinjiang of China, and compare with those of Afanasyevo humans from the different regions in Southern Siberia of Russia. All of the high delta N-15 values indicate that the subsistence strategies of Afanasyevo populations were dominated by the animal husbandry during their movements; meanwhile, the obviously high delta C-13 values in this study suggest that a certain amount of millet-based foods (millet crops and/or domesticated animals fed on millets) appeared in their diets as they settled in the southern Altai Mountains in Xinjiang of China. It provides new evidence for the millet transmission along Inner Asian Mountain Corridor and especially for the early interaction of multiregional agropastoralism between Eurasian steppe and northwest China.