Intergroup Craniometrical Variation From the Argentina Populations in the Context of Ancient and Modern World Populations

ABSTRACT Cranial morphological variation provides an important source of information for reconstructing population history in South America, particularly in contexts where genetic data remain limited. In this study, we examine intergroup craniometric variation among ancient Indigenous populations of Argentina within a broad comparative framework that includes ancient and recent populations from the Americas, northern Asia, and the Arctic. Craniological series from five Argentine regions were analyzed. Published data on ancient and modern populations of North America, as well as North and East Asia, were used as comparative material. Thirteen cranial measurements and 11 indexes were recorded. Statistical analyses included canonical discriminant analysis (CDA), multidimensional scaling (MDS), and k ‐means clustering, all conducted in R. The analyses reveal a high degree of morphological heterogeneity among Argentine populations. In CDA, most Argentine groups align with Arctic populations (Chukchi, Inuit), while MDS further specifies that samples from Chubut, Rio Negro, and Buenos Aires cluster with near‐modern Arctic and North American groups. This pattern, involving neurocranial traits considered to be predominantly neutral, is interpreted as a signal of shared ancestral structure rather than climatic convergence, which at this stage of research is a hypothesis. The Araucanian series and the southern most Fuegian and Lago Colhue Huapi samples show similarities with ancient northern Asian populations (e.g., Neolithic Baikal). We interpret this as a potential retention of an ancient morphological substrate, possibly facilitated by geographic isolation in the far south. The provisional placement of peripheral groups like the Araucanians highlights the need for further testing. Overall, these findings are consistent with a model of South American settlement involving recurrent gene flow and deep population structure, where southern Patagonia may represent a region with a distinct evolutionary trajectory.