Genomic insights into Inca expansions and the spread of Quechua languages
Quechua is the largest surviving language family of the native Americas, by number of speakers. This was long seen as a legacy of the Inca empire spreading one form of Quechua as its official language. Linguistic analysis sets the first phases of Quechua dispersal far earlier, however, among predecessor cultures a millennium or so before the Incas; and Quechua continued spreading even after the Spanish conquest.
This project has two main objectives. Firstly, to help tease apart which parts of the Quechua family, in which regions of the Andes, were or were not spread by the Incas. Secondly, to work out whether those Inca-era expansions were primarily demographic or cultural. Did Quechua spread by mass movements of people resettled under Inca imperial policies, or by local populations remaining, but learning Quechua once incorporated into the Inca empire?
To test this, we collect and analyse genetic data from modern populations, which are then compared with ancient DNA from skeletal remains, to reveal the magnitude of any migrations and the level of admixture with local populations. Our genetic sampling and analysis is explicitly informed, targeted and interpreted in the light of the corresponding linguistic, archaeological, historical and social contexts.
We focus initially on the genetically understudied regions of northern Peru and Ecuador, home to a diverse range of isolated regional forms of Quechua. These have always been difficult to place in the traditional family tree structure of Quechua, so we hope also to contribute to this linguistic (re)classification.