Using mixing models to study human paleodiets in central-western Santa Cruz (Argentina) during Late Holocene

During the final Late Holocene, there was a socio-economic reorganization among the people in the central-western of Santa Cruz, Argentina. Analysis of bone collagen revealed that hunter–gatherer groups maintained a consistent diet rich in steppe animal protein for the past 3000 years. However, there was a change in bioapatite δ¹³C values in the last 1000 years, indicating a shift in the whole diet that was not reflected in the protein component. This article seeks to evaluate the differential consumption of resources over time and between sexes among hunter–gatherer populations in the region. A total of 39 adult individuals of both sexes, recovered from stone burial structures with different chronologies, were analyzed. Quantitative diet reconstruction was achieved through the use of the Bayesian mixing model known as Food Reconstruction Using Isotopic Transferred Signals (FRUITS). The results show that the guanaco (Lama guanicoe) was the most consumed animal throughout the studied period, considering both temporal and sex differences. Additionally, there is an increased importance of plant consumption in the last millennium, particularly among females. However, this can be the result of overrepresentation of this resource in our food web samples, due to the impossibility of resolving the origin of the carbon for the formation of bioapatite values.