The maternal genetic make-up of the Iberian Peninsula between the Neolithic and the Early Bronze Age

Abstract

Agriculture first reached the Iberian Peninsula around 5700 BCE. However, little is known about the genetic structure and changes of prehistoric populations in different geographic areas of Iberia. In our study, we focused on the maternal genetic makeup of the Neolithic (~ 5500-3000 BCE), Chalcolithic (~ 3000-2200 BCE) and Early Bronze Age (~ 2200-1500 BCE). We report ancient mitochondrial DNA results of 213 individuals (151 HVS-I sequences) from the northeast, middle Ebro Valley, central, southeast and southwest regions and thus on the largest archaeogenetic dataset from the Peninsula to date. Similar to other parts of Europe, we observe a discontinuity between hunter-gatherers and the first farmers of the Neolithic, however the genetic contribution of hunter-gatherers is generally higher and varies regionally, being most pronounced in the inland middle Ebro Valley and in southwest Iberia. During the subsequent periods, we detect regional continuity of Early Neolithic lineages across Iberia, parallel to an increase of hunter-gatherer genetic ancestry. In contrast to ancient DNA findings from Central Europe, we do not observe a major turnover in the mtDNA record of the Iberian Late Chalcolithic and Early Bronze Age, suggesting that the population history of the Iberian Peninsula is distinct in character.