Aminoisoscapes and palaeodiet reconstruction: New perspectives on millet-based diets in China using amino acid δ13C values. (January 2021)

• Record Type: Journal Article
• Authors: Ma, Ying; Grimes, Vaughan; Van Biesen, Geert; Shi, Lei; Chen, Kunlong; Mannino, Marcello A.; Fuller, Benjamin T.
• Is Part Of: Journal of archaeological science. Volume 125(2021)
• Publication Date: 2021-01
• Subjects: Proto-Shang -- Millet -- C4 -- Compound-specific isotope analysis -- Amino acids -- Principal component analysis; Archaeology -- Periodicals; Archéologie -- Périodiques; 930.1
• DOI: 10.1016/j.jas.2020.105289
• Languages: English
• ISSNs: 0305-4403

Abstract

Abstract: Foxtail millet ( Setaria italica ) and common millet ( Panicum miliaceum ) were important staple crops for the inhabitants of northern China since the Neolithic. The near exclusive consumption of these millets results in extremely elevated bulk collagen δ 13 C values (~−7‰ to −5‰), which serve as natural isotopic tracers in palaeodiet studies. Here we report individual amino acid δ 13 C results (δ 13 CAA ) for humans (n = 12) and animals (n = 9) that consumed varying amounts of millets at the Proto-Shang period (2000–1600 BC) site of Nancheng, China. Using established δ 13 CAA proxies (Δ 13 CGly-Phe, Δ 13 CVal-Phe, and plots of δ 13 CPhe vs. δ 13 CVal, δ 13 CLys vs. Δ 13 CGly-Phe, and δ 13 CLys vs. Δ 13 CVal-Phe ) and machine learning assisted principal component analysis (MLA-PCA), we compared the Nancheng data to published known archaeological C3, C4, marine and freshwater protein consumers. Exclusive millet-consuming humans and animals from Nancheng displayed highly 13 C-enriched amino acid results, which were distinct from C4 consumers of maize ( Zea mays ) in the Americas. Compared to δ 13 CAA dietary proxies, MLA-PCA provides improved separation for all of the different dietary categories reviewed. Further, this method was able to distinguish additional dietary details, such as identifying brackish species. Increased application of MLA-PCA in palaeodiet research utilizing δ 13 CAA measurements could create regional and global aminoisoscapes that can reveal unique dietary and environmental information that is otherwise hidden by bulk and existing δ 13 CAA proxy isotopic analyses. Highlights: First amino acid δ 13 C results for exclusive millet consumers from China. Exclusive millet consumers are different from maize consumers in the Americas. Machine learning assisted principal component analysis improves diet classification. Aminoisoscapes have potential to reveal additional palaeodiet information.