Integration of ancient DNA with transdisciplinary dataset finds strong support for Inca resettlement in the south Peruvian coast

Abstract

Ancient DNA (aDNA) analysis provides a powerful means of investigating human migration, social organization, and a plethora of other crucial questions about humanity’s past. Recently, specialists have suggested that the ideal research design involving aDNA would include multiple independent lines of evidence. In this paper, we adopt a transdisciplinary approach integrating aDNA with archaeological, biogeochemical, and historical data to investigate six individuals found in two cemeteries that date to the Late Horizon (1400 to 1532 CE) and Colonial (1532 to 1825 CE) periods in the Chincha Valley of southern Peru. Genomic analyses indicate that these individuals are genetically most similar to ancient and present-day populations from the north Peruvian coast located several hundred kilometers away. These genomic data are consistent with 16th century written records as well as ceramic, textile, and isotopic data. These results provide some of the strongest evidence yet of state-sponsored resettlement in the pre-Colonial Andes. This study highlights the power of transdisciplinary research designs when using aDNA data and sets a methodological standard for investigating ancient mobility in complex societies.

A Multidisciplinary Review of the Inka Imperial Resettlement Policy and Implications for Future Investigations

“…This is strong evidence that the individuals or their ancestors had recently migrated to the Chincha valley. The genomic results were supported by archaeological findings of North and Central Coast style ceramics in the Chincha Valley and woven textiles of North Coast style [ 58 ]. This is particularly noteworthy given the imperial policy mandating mitmaqkuna individuals to maintain the production and wearing of their indigenous clothing style [ 14 ].…”

“…While archaeological studies of human activity in the Andes have been abundant [ 51 ], genetic studies are far scarcer but show that the region is characterised by high human mobility and genetic exchange [ 48 , 50 , 52 , 53 , 54 , 55 ]. High-resolution genome-wide aDNA data have only begun to be published in the last few years for pre-Columbian South America [ 46 , 56 , 57 ], with only two studies looking at the Inka period [ 55 , 58 ].…”

“…A recent paper integrated ancient DNA, archaeological, biochemical and historical evidence from 6 individuals from 2 cemeteries in the Chincha valley of southern Peru, which date to the Late Horizon (1400–1532 CE) and Colonial (1532–1825 CE) periods [ 58 ]. Whole-genome sequencing data revealed the Chincha individuals were genetically more related to ancient and present-day populations from the north Peru coast (several hundred kilometres away) than to populations from southern Peru [ 58 ]. This is strong evidence that the individuals or their ancestors had recently migrated to the Chincha valley.…”

“…This is particularly noteworthy given the imperial policy mandating mitmaqkuna individuals to maintain the production and wearing of their indigenous clothing style [ 14 ]. Strontium isotope abundance was also measured in bone tissues, but the results were inconclusive given the similar geology between all Peruvian coastal regions [ 58 ]. This study by Bongers and colleagues is the strongest yet combined set of empirical evidence for a case of the Inka state-enforced resettlement in pre-European contact Andes and it highlights the power of interdisciplinary research designs.…”

“…The genetic evidence collected so far gives preliminary support for impacts of the Inka empire on populations in the Andes [ 55 ], including some possible instances of relocated mitmaqkuna [ 58 , 59 ]. However, the low number of individuals for which high-resolution genetic data are available is a critical limitation.…”