Oxygen isotope analysis of ancient bone collagen and its application in the study of human migration

Abstract

Oxygen isotope analysis of archaeological bone can provide information on the drinking water of animals and human ancestors and determine the possible conditions in their living environment. This provides important reference information for exploring the origin and migration of ancient humans. This study used bones from 17 ancient animal and human individuals unearthed from the Xiaoshuangqiao archaeological site (XSQS) for oxygen, carbon, and nitrogen isotope analysis. Together with the palaeodiet conditions reconstructed from carbon and nitrogen stable isotope analysis, we used the oxygen stable isotope measurements to determine the differences between the d δ 18O values of different species and explore the relationships of these values with drinking water, metabolism, and diet. In addition, the reasons for the different d δ 18O values among human ancestors and their identity were discussed. There was a large difference in collagen d δ 18O values between different species; we assumed this phenomenon was mainly caused by different sources of drinking water and methods of metabolism (ruminants and non-ruminants), and had little to do with the dietary proportions of C3 and C4 food. The d δ 18O values of ruminant animals were significantly higher than those of non-ruminant animals. In addition, the d δ 18O values of human collagen were highly variable, suggesting that these individuals had lived in at least two regions. Specifically, the individuals buried in H66 of V District may have lived in an area closer to the ocean than did those buried in deposits in IX District. Combining our findings with historical literature and archaeological data, we speculate that the humans buried in the H66 gravel pit could be Dongyi people.