A synthetic view of morphological and genetic diversity in the Americas(As part of the symposium titled “New Developments in the Origins and Evolution of Native American Populations”).

ROLANDO GONZÁLEZ-JOSÉ; MARÍA CÁTIRA BORTOLINI; FRANCISCO RODRIGUES DOS SANTOS; SANDRO LUIS BONATTO

Congreso; 79th Annual Meeting of the American Association of Physical Anthropologists; 2010

A synthetic view of morphological and genetic diversity in the Americas.   Rolando González-José1, María. C. Bortolini2, Fabricio. R. Santos3, Sandro. L. Bonatto4. 1Centro Nacional Patagónico, CONICET, Argentina, 2Departamento de Genética, Universidade Federal do Rio Grande do Sul, Brazil, 3Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Brazil, 4Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul, Brazil. During the last decades, several studies based mainly on partial evidence such as skull morphology, archaeology, linguistics and molecular genetics have presented competing, apparently mutually exclusive, settlement hypotheses. In general terms, the main contradictory views are represented by the genetic-based “Single Wave” or “Out of Beringia” model and the cranial morphology-based “Two Components/Stocks” model.  Here, we present a geometric morphometric analysis of 576 ancient and modern skulls suggesting that the classical “Paleoamerican” and “Mongoloid” craniofacial patterns should be viewed as extremes of a continuous morphological variation. We discuss our results in the light of recent advances aimed to detect the stochastic or non-stochastic (e.g. selective) origin of the observed morphological patterns. Our results suggest that recent contact among Asian and American circumarctic populations took place during the Holocene. These results along with data from other fields are synthesized in a model for the settlement of the New World that considers, in an integrative and parsimonious way, evidence coming from genetics and physical anthropology.  This model takes into account a founder population occupying Beringia during the last glaciation characterized by high craniofacial diversity, founder mtDNA and Y-chromosome lineages, and some private autosomal alleles.  After a Beringian population expansion, which could have occurred concomitant with their entry into America, more recent circumarctic gene flow would have enabled the dispersion of northeast Asian-derived characters and some particular genetic lineages from East Asia to America and vice versa. This abstract is part of the symposium titled “New Developments in the Origins and Evolution of Native American Populations”, organized by Jeffrey C. Long and Maria C. Bortolini