Population Continuity and Replacement in the Pre-contact Valley of Mexico

Settlement patterns in the pre-contact period in the Valley of Mexico are often characterized by the collapse and regeneration of civilizations, creating a series of power vacuums over time. How did these abrupt political changes affect population structures throughout the region? Can population structure in the Valley of Mexico be best characterized as population replacement, population continuity, or both? In this chapter, biological distances are compared with distances representing population continuity and replacement models. Biological distances based on dental morphological observations represent samples from Valley of Mexico populations from the Preclassic (1200 BC to AD 200) to the Late Postclassic (AD 1200–1520) periods. The results in this chapter support a population replacement model in the Valley of Mexico, confirming archaeological and ethnohistoric accounts of migration patterns. Population replacement is most evident during the transition from the Classic to Postclassic periods and throughout the Postclassic period.