1000 years of population, warfare, and climate change in pre-Columbian societies of the Central Andes

PLoS One. 2023 Nov 30;18(11):e0278730. doi: 10.1371/journal.pone.0278730. eCollection 2023.

Abstract

Different Andean societies underwent processes of expansion and collapse during propitious or adverse climate conditions, resource boost or depletion along with population variations. Previous studies have emphasized that demographic collapses of polities in the Central Andes Area were triggered by warfare and the negative impacts of fluctuating climate (droughts) on crop productivity. Nevertheless, the interactions between climatic variability, demography and warfare have been less thoroughly evaluated. We develop population dynamic models to test feedback relationships between population growth, climate change and warfare in the Central Andes, where considerable regional hydroclimate variations have occurred over a millennium. Through population models, we found out that the rise and demise of social polities in the northern coast of the Central Andes appear to be a consequence of climate change. In contrast, for the highlands of Peru and the Titicaca basin, population models suggest that warfare intensity has a negative effect on population growth rates.

MeSH terms

  • Climate Change*
  • Peru
  • Population Growth
  • Warfare*

Grants and funding

This research was supported by FONDECYT Project #1180121, ANID PIA/BASAL FB0002, ANID FONDAP 15110009, ANID FB210006 and ANID–Millennium Science Initiative Program–NCN19_153. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.