Subsistence transition preceded population turnover in the eastern Colombian Andes

Northwest South America was a pivotal region for human dispersals and cultural exchange during the Holocene. The Altiplano Cundiboyacense, a high-altitude plateau in the Eastern Cordillera of the Northern Andes of Colombia, preserves one of the most continuous archaeological sequences in the Americas, spanning from late Pleistocene hunter-gatherer groups to final late Holocene Muisca chiefdoms. Increasing the regional ancient DNA sample size 11-fold, we report genome-wide data from 209 individuals who lived over a period of more than 7,000 years. This includes hunter-gatherers from the early-middle (10,000-7000 BP) and middle (7000-4000 BP) Holocene, initial late Holocene people (4000-2500 BP) who have the first isotopic evidence of C4-enriched diets (attributed to maize), and populations associated with increasing sedentism and food production in the Herrera (2200-1300 BP) and Muisca (1200-500 BP) Periods. Previous work identified a major population turnover distinguishing earlier groups from Herrera-Muisca Period populations, but the absence of individuals dating 6000-2000 BP in that study left unresolved whether this ancestry shift was gradual or abrupt and whether it accompanied the earliest isotopic evidence of dietary input from maize or coincided with the later emergence of Herrera culture. We show that individuals predating the Herrera Period form a lineage that persisted for over five millennia, with population structure driven by drift in small groups and no detectable external gene flow. Two individuals who lived ~2800 years ago – one directly dated to 983-835 calBCE – exhibit genetic profiles entirely consistent with hunter-gatherer ancestry yet have isotopic values consistent with the incorporation of maize into their diets, indicating subsistence change without population replacement. The emergence of Herrera culture ∼2200 BP coincided with a sharp genetic break, reflecting the migration of people carrying ancestry diverged by up to ten millennia into the Sabana de Bogotá and displacing previously established peoples. By co-analyzing ancient data with modern Native Americans, we show these later populations derived from a mixture ∼4000 years ago of groups related to Chibchan language speakers of lower Central America and ones related to present-day people at the Amazonian-Andean interface who may have lived along the Chibchan expansion route. In the Herrera and Muisca Periods, genetic substructure distinguishes people from the southern and northern Altiplano, consistent with the cultural differentiation of these regions in the archaeological record. IN BRIEF Ancient DNA data from the eastern Colombian Andes reveal five millennia of population continuity during which C4 plants were incorporated into subsistence systems without population replacement, followed later by a major ancestry turnover involving a population with ancestry admixed between that found in Chibchan-related groups and at the Amazonian-Andean interface. Competing Interest Statement The authors have declared no competing interest. National Institutes of Health, https://ror.org/01cwqze88, HG012287 John Templeton Foundation, 61220 Howard Hughes Medical Institute, https://ror.org/006w34k90 National Geographic Society Paul G. Allen Family Foundation, https://ror.org/01degd278