Investigating wheat consumption based on multiple evidences: Stable isotope analysis on human bone and starch grain analysis on dental calculus of humans from the Laodaojing cemetery, Central Plains, China

Abstract

AbstractThe introduction and spread of wheat contributed to the transformation of the tradition millets agriculture in North China. However, when and how wheat came to be a staple crop in China is still unclear. Stable isotope data from some archaeological sites suggested that the dietary change from C4 based diet to C3/C4 mixed diet occurred during the Eastern Zhou Dynasty (770–221 BC) on the Central Plains of China. However, the role of each C3 crop (wheat, rice and soybean) in human diet is not well understood in this key period. Some scholars have argued that wheat made the biggest contribution to human diet among the C3 crops. To further investigate the dietary role of wheat and agricultural economy in the Eastern Zhou on the Central Plains of China, combined methods of stable isotope analysis on human bones and starch grain analysis on human dental calculus were conducted at Laodaojing cemetery during the Warring States period.The mean δ13C values (−14.7 ± 2‰, n = 24) and mean δ15N values (9.1 ± 0.9‰, n = 24) of individuals from Laodaojing cemetery suggest that Laodaojing humans had a reliance on the mixture of C3/C4 foods and a certain proportion of animal protein was consumed. Given that the small elevation of δ15N values (<3‰) of Laodaojing humans, the contribution of domesticated animals to the mixed C3/C4 diet of Laodaojing population is relatively limited. Combined with starch grains extracted from human dental calculus, we argue that C3 and C4 foods at Laodaojing were mainly derived from wheat and millets respectively.Temporal investigations of stable isotope data and archaeobotanical evidences from the late Longshan period to Eastern Zhou Dynasty show the importance of wheat increased in agricultural economy slowly since its introduction into the Central Plains of China. Until the Eastern Zhou Dynasty, wheat as a C3 crop played an important dietary role in human diet of the Central Plains. A transformation from millet‐based to millets/wheat‐based agricultural economy occurred along with the shift of dietary pattern during this period.