1Anthropology, University of Utah, Salt Lake City UT, 2Anthropology, University of Utah, Salt Lake City UT, 3Antropologia Biologica, Universidad de la Republica, Monevideo, Uruguay
Friday 4:30-4:45, Grand Ballroom II
Studies of genetic variation in prehistoric populations (ancient DNA) are the natural linkage between archaeology and modern population genetics. Scores of recent aDNA studies have confirmed the antiquity of strong geographic structure in mtDNA variation in North American populations, but such patterning is less clear in South America.
There are significant mtDNA haplogroup frequency differences between coastal and highland populations in both prehistoric and modern South America. Additionally, mtDNA haplogroups A and B are rare to absent in the Southern cone of South America, but common in the north of the continent. Haplogroup A appears to have been introduced to Southern South America only after 3000 BP, while the status of haplogroup B in the south remains enigmatic. These coastal and interior continental contrasts are consistent with both archaeological and modern genetic data in North America that suggest a coastal entry into the Americas, and a different interior colonization process.
Paleoclimatic and paleoecological data suggest that Pleistocene South America was sufficiently ecologically distinct from North America as to imply a different set of processes for interior human dispersal and adaptation on the continent, resulting in unique population histories and patterns of genetic variation. As coastal routes of entry become more important to continental colonization models additional aDNA studies focusing on earlier prehistoric samples from the South American coast (North Pacific, Caribbean, South Atlantic) will yield more direct evidence on the timing and routes of entry into South America, and permit direct testing of alternative colonization models.