Prehistoric Genetic and Culture Change: A Bioarchaeological Search for Pre-Inka Altiplano Colonies in the Coastal Valleys of Moquegua, Peru, and Azapa, Chile

Abstract

This investigation uses a bioarchaeological approach to test the existence of pre-Inka colonists within the Andean coastal valleys of Moquegua, Peru, and Azapa, Chile, as predicted by Murra's (1972) classic model of verticality. The archaeological evidence and biodistance results obtained using genetically controlled dental traits from 859 skeletal and mummified remains indicate that the Late Intermediate period (A.D. 1100-1476) coastal Chiribaya people of the Moquegua Valley, Peru, likely represent descendants of altiplano populations that migrated to the coastal region following the disintegration of the Middle Horizon (A.D. 750-1100) Tiwanaku colony located in the middle Moquegua Valley. In the neighboring Azapa Valley, Chile, genetic change among prehistoric populations was due to gradual in situ microevolution of local populations rather than colonization by altiplano people. Coastal populations of the Azapa Valley maintained biocultural continuity with the Archaic period Chinchorro coastal population. It is concluded that Murra's model of direct verticality should be evaluated using both biological and archaeological data on a case-by-case basis.