Multi-isotopic and morphometric evidence for the migration of farmers leading up to the Inka conquest of the southern Andes

Ramiro Barberena,Cecilia Frigolé,Luis Cornejo,Gabriela Da Peña,César Méndez,Sol Zárate,Andrés Troncoso,Francisca Santana Sagredo,Petrus Le Roux ,Carina Llano,Fernanda Falabella,Paula Novellino,Erik J Marsh,Diego Winocur,Marcelo Cardillo,Judith Sealy,Anahí Benitez ,Víctor Durán ,A Delaunay ,Augusto Tessone,Lorena Sanhueza,Julie Luyt,Daniela Guevara,Lumila Paula Menéndez ,Gustavo A Ferreyra ,Alejandra Gasco,Valeria Cortegoso

doi:10.1038/s41598-020-78013-x

Abstract

We present isotopic and morphometric evidence suggesting the migration of farmers in the southern Andes in the period AD 1270–1420, leading up to the Inka conquest occurring ~ AD 1400. This is based on the interdisciplinary study of human remains from archaeological cemeteries in the Andean Uspallata Valley (Argentina), located in the southern frontier of the Inka Empire. The studied samples span AD 800–1500, encompassing the highly dynamic Late Intermediate Period and culminating with the imperial expansion. Our research combines a macro-regional study of human paleomobility and migration based on a new strontium isoscape across the Andes that allows identifying locals and migrants, a geometric morphometric analysis of cranio-facial morphology suggesting separate ancestral lineages, and a paleodietary reconstruction based on stable isotopes showing that the migrants had diets exceptionally high in C4 plants and largely based on maize agriculture. Significantly, this migration influx occurred during a period of regional demographic increase and would have been part of a widespread period of change in settlement patterns and population movements that preceded the Inka expansion. These processes increased local social diversity and may have been subsequently utilized by the Inka to channel interaction with the local societies.

Highlights

Migrations are an intrinsic aspect of human societies in the present as in the past[1,2,3]
Our research focusses on the analysis of human life histories by studying place of residence and migration by means of strontium isotopes (87Sr/86Sr), dietary changes and the importance of maize agriculture based on stable isotopes of carbon and nitrogen, and phenotypic variation by means of cranio-facial 3D geometric morphometrics in human remains
The geology of the southern Andes is especially suited for tracking local residence and immigration to the Uspallata Valley due to the high diversity of bedrock age and composition in a restricted area (Fig. 2a; see33,34)

Summary

Introduction

Migrations are an intrinsic aspect of human societies in the present as in the past[1,2,3]. Since the Uspallata Valley has a remarkable mortuary record spanning the last 1200 years[27,28,29,30], it offers a unique window for studying the transition to productive economies, migration, and social interaction between diversely organized societies ranging from incipient farmers to expansive empires during a highly dynamic period along the Andes. Building from this regional case, we zoom-out to a macroregional level to assess the broader historical context underlying these local processes. Total for understanding economic shifts, demographic fluctuations, and multi-ethnic dynamics of interaction before and during the Inka expansion

Methods

Results

Conclusion