title: Climate change underlies global demographic, genetic, and cultural transitions in pre-Columbian southern Peru.
abstract: Several archaeological studies in the Central Andes have pointed at the temporal coincidence of climatic fluctuations (both long- and short-term) and episodes of cultural transition and changes of socioeconomic structures throughout the pre-Columbian period. Although most scholars explain the connection between environmental and cultural changes by the impact of climatic alterations on the capacities of the ecosystems inhabited by pre-Columbian cultures, direct evidence for assumed demographic consequences is missing so far. In this study, we address directly the impact of climatic changes on the spatial population dynamics of the Central Andes. We use a large dataset of pre-Columbian mitochondrial DNA sequences from the northern Rio Grande de Nasca drainage (RGND) in southern Peru, dating from ∼840 BC to 1450 AD. Alternative demographic scenarios are tested using Bayesian serial coalescent simulations in an approximate Bayesian computational framework. Our results indicate migrations from the lower coastal valleys of southern Peru into the Andean highlands coincident with increasing climate variability at the end of the Nasca culture at ∼640 AD. We also find support for a back-migration from the highlands to the coast coincident with droughts in the southeastern Andean highlands and improvement of climatic conditions on the coast after the decline of the Wari and Tiwanaku empires (∼1200 AD), leading to a genetic homogenization in the RGND and probably southern Peru as a whole.
authors: Department of Anthropology, University of California, Santa Cruz, CA 95064;Historical Anthropology and Human Ecology, University of Göttingen, D-37073 Göttingen, Germany; lfehrens@ucsc.edu.
authors: Lars
authors: L
authors: Fehren-Schmitz
authors: Australian Centre for Ancient DNA, School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia;
authors: Wolfgang
authors: W
authors: Haak
authors: Geographisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany;
authors: Bertil
authors: B
authors: Mächtle
authors: Historical Anthropology and Human Ecology, University of Göttingen, D-37073 Göttingen, Germany;
authors: Florian
authors: F
authors: Masch
authors: Australian Centre for Ancient DNA, School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia;
authors: Bastien
authors: B
authors: Llamas
authors: Departmento de Humanidades, Pontificia Universidad Católica del Perú, Lima 32, Perú;
authors: Elsa Tomasto
authors: ET
authors: Cagigao
authors: German Archaeological Institute (DAI), Commission for Archaeology of Non-European Cultures (KAAK), D-53173 Bonn, Germany;
authors: Volker
authors: V
authors: Sossna
authors: Seminar of Geography and Geographical Education, University of Cologne, D-50931 Cologne, Germany; and.
authors: Karsten
authors: K
authors: Schittek
authors: Centro de Investigación para la Arqueología y el Desarrollo (ANDES), Lima 11, Perú
authors: Johny
authors: J
authors: Isla Cuadrado
authors: Geographisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany;
authors: Bernhard
authors: B
authors: Eitel
authors: German Archaeological Institute (DAI), Commission for Archaeology of Non-European Cultures (KAAK), D-53173 Bonn, Germany;
authors: Markus
authors: M
authors: Reindel
mesh_terms: D001106:Archaeology / Q000379:methods; D001483:Base Sequence; D001499:Bayes Theorem; D057231:Climate Change / Q000266:history*; D003198:Computer Simulation; D003468:Cultural Evolution / Q000266:history*; D004272:DNA, Mitochondrial / Q000302:isolation & purification; D055864:Droughts / Q000266:history*; D006239:Haplotypes / Q000235:genetics; D049668:History, 15th Century; D049690:History, Ancient; D049691:History, Medieval; D063426:Human Migration / Q000266:history*; D006801:Humans; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010568:Peru; D011157:Population Dynamics / Q000266:history*; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial
keywords: South America; ancient DNA; population history