Reconstruction of diets based on the Δ15N values of individual amino acids at three sites in Sichuan, China

Abstract

AbstractThis study analyzes the nitrogen isotope composition of individual amino acids in collagen extracted from human bone samples from the Gaoshan, Yingpanshan, and Xinyicun sites in Sichuan, where the isotope baseline is unavailable or incomparable with the isotopic data derived from human remains. It aims to understand the food compositions of the inhabitants at these sites, spanning the period from the late Neolithic to the middle Bronze Age, during which time agriculture and domestication of animals were introduced to the region and became increasingly important. The δ15N values of two amino acids, phenylalanine (δ15NPhe) and glutamic acid (δ15NGlu), indicate that the peoples on the Chengdu Plain mainly consumed terrestrial foods. The contribution of aquatic resources to their diet was limited. A possible explanation for the low dependence on aquatic foods is that the developed agriculture and domestication of animals offered sufficient foods. Such subsistence economies and dietary patterns were shaped in the early Baodun period (ca. 2,500–2000 BCE) at the latest and did not seem to change when transiting to the Bronze Age. This study also assesses the significance of these subsistence practices in supporting the social development of the Chengdu Plain.