Burial practices and mtDNA variation in the Oaxacan Barrio of Teotihuacan, Mexico: On the genetic structure of the great Mesoamerican city and its external influences

Abstract

The Oaxacan Barrio (neighborhood) in Teotihuacan is relevant for understanding interaction between Mesoamerican cities during the Classic Period (CE 100–700). In this work, we analyzed the relationship between burial practices and mitochondrial (mt) DNA variation for the Oaxacan Barrio and the published data of other Teotihuacan neighborhoods and ethnic groups outside. We observed two Pre-Columbian burials in the Barrio, one in flexed lateral decubitus and another in extended dorsal decubitus, which was more common (79%). The extended dorsal burial persisted until the Colonial Period, when a burial with arms crossed over the chest, possibly Christian, appeared. The Pre-Columbian Oaxacan Barrio exhibited no mtDNA differentiation between sexes and was closer to northwestern Zapotecs of the Classic Period among the groups compared, suggesting that it was genetically and thus culturally isolated within the city. Teotihuacan neighborhoods exhibited different genetic affinities with Oaxacan groups and a spatial structure of mtDNA around the Street of the Dead, consisting of larger B-type contents in the city’s northeast, A types in the west and east, C types in the south, and D types in the midwest. Most mitochondrial lineages in the Barrio originated from Oaxaca, preceded by gene flow with the Maya region. A Barrio’s elite female, who exhibited Mayan ornaments and body modifications, showed a mitochondrial C1 type more closely related to Oaxaca than to the Maya region. Mitochondrial lineages also showed continuity between the Pre-Columbian and the Colonial Oaxacan Barrio, despite the arrival of new occupants—mainly Aztec—after the Classic Period.