Compositional data supports decentralized model of production and circulation of artifacts in the pre-Columbian south-central Andes

ArticleThis is the author accepted manuscript. The final version is available from National Academy of Sciences via the DOI in this record.The circulation and exchange of goods and resources at various scales have long been considered central to the understanding of complex societies, and the Andes have provided a fertile ground for investigating this process. However, long-standing archaeological emphasis on typological analysis, although helpful to hypothesize the direction of contacts, has left important aspects of ancient exchange open to speculation. To improve understanding of ancient exchange practices and their potential role in structuring alliances, we examine material exchanges in northwest Argentina (part of the south-central Andes) during 400 BC to AD 1000 (part of the regional Formative Period), with a multianalytical approach (petrography, instrumental neutron activation analysis, laser ablation inductively coupled plasma mass spectrometry) to artifacts previously studied separately. We assess the standard centralized model of interaction vs. a decentralized model through the largest provenance database available to date in the region. The results show: (i) intervalley heterogeneity of clays and fabrics for ordinary wares; (ii) intervalley homogeneity of clays and fabrics for a wide range of decorated wares (e.g., painted Ciénaga); (iii) selective circulation of two distinct polychrome wares (Vaquerías and Condorhuasi); (iv) generalized access to obsidian from one major source and various minor sources; and (v) selective circulation of volcanic rock tools from a single source. These trends reflect the multiple and conflicting demands experienced by people in small-scale societies, which may be difficult to capitalize by aspiring elites. The study undermines centralized narratives of exchange for this period, offering a new platform for understanding ancient exchange based on actual material transfers, both in the Andes and beyond.We thank the former directors of Museo Etnográfico (University of Buenos Aires), M. N. Tarragó (2005–2015) and the late J. A. Pérez Gollán (1987–2005), who provided access to key samples and enthusiastic support for this project since its earliest stages. We also thank M. Berón (current Director of Museo Etnográfico, University of Buenos Aires), R. Cattáneo (Director of Museo de Antropología, University of Córdoba, 2011–2013), J. P. Carbonelli, M. E. De Feo, V. Puente, G. Míguez, and R. Spano for providing access to additional samples; A. Brechbuhler and E. Gillispie for assisting with lithic sample preparation and measurements; and C. Roush for preparing the samples for irradiation and for general laboratory management responsibilities. This research was primarily funded by Arts and Humanities Research Council Early Career Grant SX–5317 (2011–2013) and preliminary research was funded by British Academy Small Grant 51798 (2009) (both to M.L.). Fieldwork and petrography analyses have been supported by successive grants from Argentinean National Agency for Science and Technology (ANCyT) Raíces Program PICT 2007-00116 (to M.C.S.) and ANCyT PICT 2010-1048 (to M.A.K.). Funding was also provided by the National Council for Science and Technical Research PIP 112-2008 01-00256 (to M.C.S.) and PIP 11/042 (to M.A.K.). The Archaeometry Laboratory at the University of Missouri Research Reactor is supported in part by the National Science Foundation (BCS-1415403 and BCS-0922374)

Latin Americans show wide-spread Converso ancestry and imprint of local Native ancestry on physical appearance

Historical records and genetic analyses indicate that Latin Americans trace their ancestry mainly to the intermixing (admixture) of Native Americans, Europeans and Sub-Saharan Africans. Using novel haplotype-based methods, here we infer sub-continental ancestry in over 6,500 Latin Americans and evaluate the impact of regional ancestry variation on physical appearance. We find that Native American ancestry components in Latin Americans correspond geographically to the present-day genetic structure of Native groups, and that sources of non-Native ancestry, and admixture timings, match documented migratory flows. We also detect South/East Mediterranean ancestry across Latin America, probably stemming mostly from the clandestine colonial migration of Christian converts of non-European origin (Conversos). Furthermore, we find that ancestry related to highland (Central Andean) versus lowland (Mapuche) Natives is associated with variation in facial features, particularly nose morphology, and detect significant differences in allele frequencies between these groups at loci previously associated with nose morphology in this sample

The scale, governance, and sustainability of central places in pre-Hispanic Mesoamerica

Examinations of the variation and relative successes or failures of past large-scale societies have long involved attempts to reconcile efforts at generalization and the identification of specific factors with explanatory value for regional trajectories. Although historical particulars are critical to understanding individual cases, there are both scholarly and policy rationales for drawing broader implications regarding the growing corpus of cross-cultural data germane to understanding variability in the constitution of human societies, past and present. Archaeologists have recently highlighted how successes and failures in communal-resource management can be studied over the long term through the material record to both engage and enhance transdisciplinary research on cooperation and collective action. In this article we consider frameworks that have been traditionally employed in studies of the rise, diversity, and fall of preindustrial urban aggregations. We suggest that a comparative theoretical perspective that foregrounds collective-action problems, unaligned individual and group interests, and the social mechanisms that promote or hamper cooperation advances our understanding of variability in these early cooperative arrangements. We apply such a perspective to an examination of pre-Hispanic Mesoamerican urban centers to demonstrate tendencies for more collective systems to be larger and longer lasting than less collective ones, likely reflecting greater sustainability in the face of the ecological and cultural perturbations specific to the region and era.Accepted manuscrip