Not by Maize Alone: Assessing the Effects of Temporal, Geographic, and Cultural Variability on a Stable Isotope Mixing Model of Ancient Maya Diets

Abstract

Bayesian stable isotope mixing models (SIMMs) and stable sulfur isotope analysis have seen increasing utilization in the study of ancient diets and foodways in recent years. However, the latter has only recently seen usage in understanding diets of the Ancient Maya of Central America, and the former not at all. This is despite the long history of stable isotope investigation of human remains in the region. Uptake of these techniques in the field has largely been limited on two fronts - a lack of a suitable sulfur isotope baseline (which has only recently seen publication) and the inherent difficulties of using SIMMs in circumstances where both C3 and C4 cultigens formed substantial elements of human diet. While the requisite information to use both techniques to their full potential remains a work in progress, several unknowns can currently be rectified using existing data. These include the degree to which culturally specific preparation practices affect the nutritional (and potentially isotopic) composition of key foods (particularly maize), the degree to which modern cultigens can appropriately serve as proxies for foods consumed, and the degree of regional specificity required when using sulfur isotopes for dietary reconstruction. This dissertation will explore all three of these problems by comparing diet compositions of a sample of Ancient Maya individuals derived from a Bayesian mixing model (Food Reconstruction Using Isotope Transfer Signals) incorporating nixtamalized and raw maize, regionally derived and modern/industrialized plant food proxies, and local vs. pan-Mesoamerican sulfur isotope baselines.