Identification of Polynesian mtDNA haplogroups in remains of Botocudo Amerindians from Brazil

Abstract

America (sub-Arctic and Arctic regions), A2a, A2b, D2a, D3, and X2a (11–13), and others that have been exclusively found in populations located in the southernmost part of South America, including B2l, D1g, and C1b13 (14, 15). It has been proposed that most of these founding lineages were generated during a period of refuge of about 5,000 years in Beringia (13, 16). In contrast, genetic analyses of the nonrecombining portion of Y chromosome haplotypes have shown a significant founder effect (17). More than 80% of Amerindian Y chromosomes belong to the single haplogroup Q1a3a-M3, whose precursors could be traced back to central Siberia (18–20). Although this genetic evidence is suggestive of a single founding population for all Native South Americans, we have to realize that these studies have been largely limited to extant Amerindian groups or to relatively recent skeletal remains. Thus, molecular studies have not been capable of testing appropriately the Two Components model yet. Based on geometric morphometric studies, González-José et al. (21) have proposed that the Paleoamerican and Mongoloid cranial morphologies are not separate “types,” but simply extremes in a continuous gradient of variation. The authors postulate that the morphological pattern defining the Paleoamerican remains can be found in the range of extant Amerindian populations and that the previous separation of samples into discrete categories represented subjective assignments. González-José et al. presented a third model, called “Recurrent Gene Flow,” which is capable of integrating morphological and molecular data (21). Using 2D geometric morphometric data they propose that this model has better explanatory performance than either the Single Wave or the Two Components models. In the context of the genetic reconstruction of the Native American history, the study of the Botocudo Indians from Brazil might provide new information. Also known as Aimores, these Amerindians inhabited adjacent areas in the present-day states of Minas Gerais, Espírito Santo and Bahia, in Southeastern Brazil (22). They were a large community, divided into many separate groups, some of them in conflict with each other. In common, they were Macro-Je speakers, had a nomadic hunter-gatherer lifestyle, and used typical ornaments in the lips and ears, called “botoques”