Echoes of the Andean Civilizations

From wind-swept highland lakes to fog-draped Pacific terraces, the Andean cultural mosaic emerged over millennia. Archaeological data indicate human presence in high valleys such as Lauricocha (Highlands, samples spanning ~8600–3500 years ago) and coastal localities near Arica (Late Archaic Chinchorro contexts). Early Holocene foragers exploited diverse ecologies — puna wetlands, river canyons like Cotahuasi, and coastal fisheries — laying the foundations for later sedentary life.

Sedentism and horticulture gradually intensified during the mid-Holocene and into the second millennium BCE, visible in mound-building, irrigation traces, and early ceremonial architecture at sites like La Galgada and early Lima coast occupations. Limited evidence suggests regional differentiation by 1000 BCE, with emerging highland polities and coastal specialists. Over the first and second millennia CE, more visible political centers arose: Pukara and later Tiwanaku-linked sites (Akapana, Pumapunku in the Lake Titicaca basin) created stylistic and economic networks that would reshape Andean social landscapes.

Because preservation and sampling density vary widely across sites and periods, precise demographic reconstructions remain cautious. The 108 ancient genomes analyzed here offer a broad temporal sweep, supporting a narrative of long-term highland occupation punctuated by episodes of regional interaction and mobility.

Genetic analysis of 108 ancient individuals from Peru, Bolivia, and Chile reveals a coherent Andean signature through time, with nuanced regional variation. Male lineages are dominated by Y-haplogroup Q (53/56 Y-calls), consistent with longstanding paternal continuity in South America; rare CT and P calls (2 and 1 respectively) may reflect technical ambiguity or low-frequency inputs. Maternal diversity is richer: mtDNA haplogroups B2 (28), C1b (22), D1 (12), C1c (11), and B2b (9) together indicate multiple maternal lineages persisting across millennia.

Population structure inferred from genomes suggests strong highland continuity, particularly in central Andean valleys (Lauricocha, Laramate, Cotahuasi), punctuated by episodes of gene flow. Coastal samples (Arica, Huaca Pucllana) show affinities to highland groups but also signals compatible with coastal-forager ancestry found in Late Archaic Chinchorro contexts. Middle Horizon and Tiwanaku-period individuals (Akapana, Lukurmata, Pumapunku, Putuni) show genetic homogeneity across parts of the Titicaca basin, reflecting demographic expansion or increased connectivity during that era.

While 108 samples provide robust temporal coverage, uneven geographic sampling and preservation bias limit fine-scale inferences. Limited samples from some periods or sites mean conclusions about local migrations or elite-specific mobility should be treated as provisional pending broader sampling.