Synthesis of human isotopic data (8000–5000 BP) reveals subsistence strategies and social complexity at the southeast edge of the Loess Plateau, China

The southeast edge of the Loess Plateau (SELP) is a crucial area for studying subsistence strategies and social complexity in prehistoric China. Currently, no systematic isotopic study has been conducted to reveal shifts in subsistence strategies and their link to the trajectory of social complexity. This paper compiles previously published isotopic data from human and fauna bones at 24 sites dating from 8000 to 5000 BP, aiming to uncover diachronic changes in subsistence strategies and their relationship with social complexity. The results indicate a gradual increase in millet consumption by humans and an increasing utilization of millet-based byproducts as feed for domestic animals (pigs and dogs) over time. The isotopic data of humans and animals demonstrate the establishment of millet agriculture during the Early Yangshao period (7000–6000 BP). Millet agriculture creates a crucial material foundation for population growth and cultural prosperity. Two modes of millet cultivation, intensive and extensive, are proposed to explain the continuous development of millet agriculture since the Early Yangshao period. Finally, significant dietary heterogeneity among the human population during the Late Yangshao period strongly suggests the emergence of social differentiation and complexity, supported by other archaeological evidence such as settlement hierarchies and the presence of exquisite objects in burials.