Dental evidence for wild tuber processing among Titicaca Basin foragers 7000 ybp

Stable isotope chemistry reveals plant-dominant diet among early foragers on the Andean Altiplano, 9.0-6.5 cal. ka

Current models of early human subsistence economies suggest a focus on large mammal hunting. To evaluate this hypothesis, we examine human bone stable isotope chemistry of 24 individuals from the early Holocene sites of Wilamaya Patjxa (9.0-8.7 cal. ka) and Soro Mik'aya Patjxa (8.0-6.5 cal. ka) located at 3800 meters above sea level on the Andean Altiplano, Peru. Contrary to expectation, Bayesian mixing models based on the isotope chemistry reveal that plants dominated the diet, comprising 70-95% of the average diet. Paleoethnobotanical data further show that tubers may have been the most prominent subsistence resource. These findings update our understanding of earliest forager economies and the pathway to agricultural economies in the Andean highlands. The findings furthermore suggest that the initial subsistence economies of early human populations adapting to new landscapes may have been more plant oriented than current models suggest.

Testing the reliability of CT scan-based dental wear magnitude scoring

OBJECTIVES

Digital models are now frequently used in biological anthropology (bioanthropology) research. Despite several studies validating this type of research, none has examined if the assessment of dental wear magnitude based on Computerized Tomography (CT) scans is reliable. Thus, this study aims to fill this gap and assess if dental wear magnitude scoring based on CT scans provides results consistent with scoring based on direct observation of the physical specimens.

MATERIALS AND METHODS

Dental wear magnitude from 412 teeth of 35 mandibles originating from the Portuguese Muge and Sado Mesolithic shell-middens was scored. The mandibles were also CT scanned and visualized using 3D Slicer. CT scan-based scoring of dental wear magnitude was then undertaken. Two scoring rounds were undertaken for each observation method (totaling four scoring rounds) and an intra-observer error test was performed. The averaged results of the two observation methods were compared via boxplots with paired cases.

RESULTS

Intra-observer error was negligible and non-significant. Scoring results are comparable between the two observation methods. Notwithstanding, some differences were found, in which CT scan assessment generally overestimates dental wear when compared to direct observation.

DISCUSSION

Our results generally validate the use of CT scans in studies of dental wear magnitude. Notwithstanding several caveats relating to CT scanning and visualization limitations should be considered to avoid over or under-estimation of dental wear.

Female hunters of the early Americas

Sexual division of labor with females as gatherers and males as hunters is a major empirical regularity of hunter-gatherer ethnography, suggesting an ancestral behavioral pattern. We present an archeological discovery and meta-analysis that challenge the man-the-hunter hypothesis. Excavations at the Andean highland site of Wilamaya Patjxa reveal a 9000-year-old human burial (WMP6) associated with a hunting toolkit of stone projectile points and animal processing tools. Osteological, proteomic, and isotopic analyses indicate that this early hunter was a young adult female who subsisted on terrestrial plants and animals. Analysis of Late Pleistocene and Early Holocene burial practices throughout the Americas situate WMP6 as the earliest and most secure hunter burial in a sample that includes 10 other females in statistical parity with early male hunter burials. The findings are consistent with nongendered labor practices in which early hunter-gatherer females were big-game hunters.

An introduction to advances in Andean South American paleopathology

In the 20 years since the publication of John Verano's foundational paper "Advances in Paleopathology of Andean South America," paleopathological and bioarchaeological investigations of human skeletal remains in the region have increased dramatically. Today, primary foci have grown to span the identification of disease, detailed reconstructions of biocultural interactions, embodied social experiences, and ancient living worlds. In this special issue, more than a dozen scholars reflect on the state of developments in the scientific analyses of ancient disease, life, and society across the region. For this introductory article, we frame the current state of Andean paleopathology by reviewing key historical contributions beginning in the last century. More recent trends since 1997 are defined via a meta-analysis of the literature. We then highlight current innovations and consider future directions of study. We then close with an overview of the papers comprising this special issue. Each article explores major theoretical, topical, and methodological advances that have transpired since 1997 and charts the course for the next two decades of work - with implications and insights that transcend the Andes and speak to key paleopathological issues around the world.

Exploring oral paleopathology in the Central Andes: A review

This targeted review of oral paleopathology in the Central Andes explores research that focuses on a set of interrelated, multifactorial processes: dental caries, macrowear, alveolar abscess, antemortem tooth loss (AMTL), periodontal disease, and the presence of dental calculus. These conditions help characterize oral health because they result from the culturally mediated interaction of individuals' oral cavity with their external environment. To better understand how osteologists working in the Central Andes have interpreted the frequencies of these conditions, I review the etiology of each, as well as discuss the important issues in their analyses. I then highlight studies that integrate of a number of oral paleopathological conditions, that examine associations between oral conditions and other skeletal indicators of health, or that use multivariate statistical techniques to analyze conditions. In the Central Andes, these proxies for oral health have generally focused on several key research themes including the introduction of domesticated foods may have occurred earlier than expected, but that populations may have maintained mixed subsistence strategies for a significant period. Researchers have also identified that changes accompanying Inca imperialism were likely not as detrimental to local populations as was Spanish colonialism. Finally, the long-practiced, culturally important, activity of chewing coca has been shown to create an identifiable pattern of oral paleopathological conditions.

The genetic prehistory of the Andean highlands 7000 years BP though European contact

The peopling of the Andean highlands above 2500 m in elevation was a complex process that included cultural, biological, and genetic adaptations. Here, we present a time series of ancient whole genomes from the Andes of Peru, dating back to 7000 calendar years before the present (BP), and compare them to 42 new genome-wide genetic variation datasets from both highland and lowland populations. We infer three significant features: a split between low- and high-elevation populations that occurred between 9200 and 8200 BP; a population collapse after European contact that is significantly more severe in South American lowlanders than in highland populations; and evidence for positive selection at genetic loci related to starch digestion and plausibly pathogen resistance after European contact. We do not find selective sweep signals related to known components of the human hypoxia response, which may suggest more complex modes of genetic adaptation to high altitude.