MITOCHONDRIAL-DNA HAPLOGROUPS IN 4 TRIBES FROM TIERRA-DEL-FUEGO PATAGONIA - INFERENCES ABOUT THE PEOPLING OF THE AMERICA

The four major founder haplogroups in native Americans were analyzed, including new data from four extinct tribes from Tierra del Fuego-Pata gonia, to look into the relationship between genes and geography. A mu ltiple regression analysis was performed using the haplogroups as inde pendent variables and latitude as the dependent variable. The results show that haplogroups A, C, and D are significantly distributed along a north-south geographic cline. The distribution of haplogroup B, whic h is absent in northern North America and in extreme southern South Am erica, could be related to other nongeographic variables, such as inde pendent mutations in region V or an intermediate migration, The absenc e of haplogroup B in Tierra del Fuego-Patagonia also supports the exis tence of at least two different migration waves in the Amerind group, the first lacking haplogroup B, The Central American Amerind and North American Amerind samples are the populations that least fit the theor etical model. This difference can be related to the geographic charact eristics of Central America and the existence of a sharp genetic bound ary between the northern Na-Dene and the northern Amerind, re spective ly, In addition, a neighbor-joining tree was generated from the haplog roup data using the F-ST distance. The genetic tree shows that the pop ulations are roughly distributed according to their geographic locatio n. Therefore the genetic pattern observed is compatible with different successive migrations along the continent. The north to south directi on of the migratory movements can be inferred from the mtDNA diversity data.