The Caribbean and Mesoamerica Biogeochemical Isotope Overview (CAMBIO).

The Caribbean & Mesoamerica Biogeochemical Isotope Overview (CAMBIO) is an archaeological data community designed to integrate published biogeochemical data from the Caribbean, Mesoamerica, and southern Central America to address questions about dynamic interactions among humans, animals, and the environment in the region over the past 10,000 years. Here we present the CAMBIO human dataset, which consists of more than 16,000 isotopic measurements from human skeletal tissue samples (δ13C, δ15N, δ34S, δ18O, 87Sr/86Sr, 206/204Pb, 207/204Pb, 208/204Pb, 207/206Pb) from 290 archaeological sites dating between 7000 BC to modern times. The open-access dataset also includes detailed chronological, contextual, and laboratory/sample preparation information for each measurement. The collated data are deposited on the open-access CAMBIO data community via the Pandora Initiative data platform ( https://pandoradata.earth/organization/cambio ).

Migration and biological continuity in central Mexico during the Classic-Epiclassic transition.

OBJECTIVES: The role of migration in the cultural development of central Mexico has long been debated. Archaeological models suggest that central Mexico likely experienced increased migration during the Epiclassic period (600-900 CE) and that migrants may have originated in northwestern Mexico. While previous biodistance analyses of Classic and Postclassic populations have come to similar conclusions, none have incorporated Epiclassic skeletal populations. This study uses multi-scalar biodistance analyses to directly evaluate archaeological Epiclassic migration models within central Mexico. MATERIALS AND METHODS: This study uses finite mixture and relationship (R) matrix analyses of cervicometric tooth dimensions to reconstruct patterns of biological affinity among Classic and Epiclassic Mesoamerican populations (n = 333), including at the central Mexican Epiclassic shrine site of Non-Grid 4 where the remains of at least 180 individuals were interred. RESULTS: Estimated inter-site phenotypic distances demonstrate support for some degree of both biological continuity and extra-local gene flow within central Mexican populations during the Classic-Epiclassic transition. Furthermore, estimated phenotypic distances and finite mixture posterior probabilities indicate central Mexican Epiclassic populations were biologically diverse, originating from various source populations throughout Mesoamerica, including the Bajío region, the Malpaso Valley, and the Oaxaca Valley. DISCUSSION: Results suggest that emphasizing both local and extra-local gene flow rather than population replacement may be more appropriate to understand central Mexican population structure during the Classic-Epiclassic transition. Moreover, analyses support previous archaeological migration models positing that Epiclassic migrants into central Mexico originated in northwestern Mexico, but also find evidence of Epiclassic migrants originating from previously unanticipated locales like southern Mexico.

Twenty-first century bioarchaeology: Taking stock and moving forward.

This article presents outcomes from a Workshop entitled "Bioarchaeology: Taking Stock and Moving Forward," which was held at Arizona State University (ASU) on March 6-8, 2020. Funded by the National Science Foundation (NSF), the School of Human Evolution and Social Change (ASU), and the Center for Bioarchaeological Research (CBR, ASU), the Workshop's overall goal was to explore reasons why research proposals submitted by bioarchaeologists, both graduate students and established scholars, fared disproportionately poorly within recent NSF Anthropology Program competitions and to offer advice for increasing success. Therefore, this Workshop comprised 43 international scholars and four advanced graduate students with a history of successful grant acquisition, primarily from the United States. Ultimately, we focused on two related aims: (1) best practices for improving research designs and training and (2) evaluating topics of contemporary significance that reverberate through history and beyond as promising trajectories for bioarchaeological research. Among the former were contextual grounding, research question/hypothesis generation, statistical procedures appropriate for small samples and mixed qualitative/quantitative data, the salience of Bayesian methods, and training program content. Topical foci included ethics, social inequality, identity (including intersectionality), climate change, migration, violence, epidemic disease, adaptability/plasticity, the osteological paradox, and the developmental origins of health and disease. Given the profound changes required globally to address decolonization in the 21st century, this concern also entered many formal and informal discussions.

Expanding radiogenic strontium isotope baseline data for central Mexican paleomobility studies.

Radiogenic strontium isotopes (87Sr/86Sr) have long been used in analyses of paleomobility within Mesoamerica. While considerable effort has been expended developing 87Sr/86Sr baseline values across the Maya region, work in central Mexico is primarily focused on the Classic period urban center of Teotihuacan. This study adds to this important dataset by presenting bioavailable 87Sr/86Sr values across central Mexico focusing on the Basin of Mexico. This study therefore serves to expand the utility of strontium isotopes across a wider geographic region. A total of 63 plant and water samples were collected from 13 central Mexican sites and analyzed for 87Sr/86Sr on a Thermo-Finnigan Neptune multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). These data were analyzed alongside 16 published 87Sr/86Sr values from two additional sites within the region of interest. A five-cluster k-means model was then generated to determine which regions of the Basin of Mexico and greater central Mexico can and cannot be distinguished isotopically using 87Sr/86Sr values. Although the two clusters falling within the Basin of Mexico overlap in their local 87Sr/86Sr ranges, many locations within the Basin are distinguishable using 87Sr/86Sr values at the site-level. This study contributes to paleomobility studies within central Mexico by expanding knowledge of strontium isotope variability within the region, ultimately allowing researchers to detect intra-regional residential mobility and gain a greater understanding of the sociopolitical interactions between the Basin of Mexico and supporting outlying regions of central Mexico.