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In this work, we study diet composition of prehistoric human populations of Northwest Patagonia by exploring the combination of two different approaches frequently used in bioarchaeology, Bayesian isotope mixing models, and zooarchaeological analysis. For this purpose, we compiled a large dataset of previously published δ13C and δ15N human and resource values, as well as zooarchaeological data, corresponding to the Middle–Late Holocene and distributed throughout Northwest Patagonia. We first propose a replicable approach to divide the region into different areas comprising human individuals that shared the same available resources and perform isotope mixing models at individual level using default (i.e., uninformative) prior distributions in the Bayesian mixing models. Then, we explore a potential complementation of isotopic and zooarchaeological evidence by introducing the frequency of zooarchaeological assemblages with the different resources, as well as NISP, as priors in the Bayesian mixing models to guide diet estimations. Additionally, we use these frequencies to analyze the possible absence of some important resources in previous analyses. Based on the species distribution and geographical location of bioarchaeological sites, we divided the region into five areas (Northwest and Northeast Neuquén, South Neuquén/Rio Negro, and Southwest and Central‐east Mendoza) that differ in the resources available for potential human consumption. The results obtained show high diet variability among these areas, with individuals from Northwest and Northeast Neuquén consuming mainly large animals (i.e., guanaco and rhea, respectively) and South Neuquén/Rio Negro and Center‐east and Southwest Mendoza consuming a larger diversity of resources. Our results show that considering zooarchaeological priors in the analyses results in diet composition estimations more in line with the ecological diversity present in the region than previous estimations. We propose that approaches like this, which are common in ecological studies, should be considered in bioarchaeology to make more robust estimates of diet composition. [ABSTRACT FROM AUTHOR]

Objectives: Ancient hunter‐gatherer diets were heterogeneous, varying substantially across time and space, and frequently showing considerable intrapopulation variation. The diet composition of these human groups depended primarily on resource availability, but also on the active selection of certain prey due to different bio‐cultural factors. In this context, we explore resource availability, diet composition, and prey choice in the human populations of the Middle‐Late Holocene from Northwest Patagonia. Material and Methods: We employ species distribution models using current and zooarchaeological data to estimate species availability throughout Northwest Patagonia, and we use Bayesian stable isotope mixing models on a large number of samples to analyze human diet composition at the individual level during the Middle‐Late Holocene. Finally, we calculate a prey selectivity index to address the different dietary choices of human individuals in the region. Results: Our results show large differences in species available for consumption throughout the region, as well as a high dietary variation between human individuals, which is mainly related to their spatial location. Some species, such as guanaco, were widely distributed and consumed in the region. Notably, species of small mammals were actively selected in several areas, indicating greater importance in human diets than previously appreciated. Discussion: Species availability does not appear as the only factor driving human diets in the region, since prey choice seems to have been a recurring phenomenon among these populations. The novel approach used in this study overcomes several limitations of previous studies employing isotopic analysis in prehistoric human diets, allowing new insights into the bioarchaeology of the region. [ABSTRACT FROM AUTHOR]

The great importance of the guanaco (Lama guanicoe) for the subsistence of the human populations of Patagonia during the Holocene has been demonstrated in numerous studies. This species is considered as the main prey of the hunter-gatherer groups of the Patagonian interior, indicating the existence of a strong ecological relationship of predator-prey type. Despite the importance of this ungulate for prehistoric human populations, its spatial distribution throughout the Holocene has not been systematically explored, assuming that it was ubiquitously distributed in almost all of Patagonia. In this work, the spatial distribution of the guanaco in Patagonia during different periods of the final Pleistocene and Holocene is explored using zooarchaeological and paleontological evidence together with species distribution models and paleoclimatic reconstructions. Likewise, the spatial variation in the importance of this species for the diet of human populations is assessed. The results show that there were large differences in the distribution of guanaco in Patagonia over time. In general terms, this camelid suffered a constant contraction in range since the Late Pleistocene period to the present. There is an Andean range and peri-cordilleran core of population distribution that remains observable during all this time. Human subsistence was strongly influenced by this pattern of distribution. The differences in the guanaco distribution described in this work are important not only for archaeological and paleontological problems, but also for the current conservation of guanacos. [ABSTRACT FROM AUTHOR]

The interaction between human populations and their prey is of great interest in ecological, anthropological and archaeological studies. In Patagonia, several works have revealed the importance of one particular species in the diet of prehistoric human populations, the guanaco (Lama guanicoe). Especially after the megafaunal extinctions and, specifically, after 8000 years ago, the great predominance of guanaco in the diet of the hunter-gatherer groups from Patagonia has been pointed out. Here, we use zooarchaeological and molecular data to study the relationship between the changes in human diet in Patagonia during the Late Pleistocene-Holocene and the evolutionary and demographic history of guanaco populations. The joint use of these evidences allows us to quantitatively explore and discuss the changes in the human diet in an ecological context. The obtained results suggest an increase in the consumption of guanaco by the humans associated with a geographic and demographic expansion of this camelid in Patagonia after 10,000 years ago. These changes in the guanaco populations and human diet are also correlated with the previously described demographic changes of hunter-gatherer groups from Patagonia, suggesting a strong relationship among these phenomena. • Zooarchaeological data show an increase in guanaco consumption through the Holocene. • Molecular analyses suggest a demographic and geographic expansion of modern guanaco. • Guanaco population growth correlates with recently described human demographic growth. • The existence of a strong ecological link of predator-prey type is sustained. [ABSTRACT FROM AUTHOR]