Mitochondrial and Metagenomic Analysis of Iberian Individuals from the Neolithic and Chalcolithic Periods

From the end of the Mesolithic to the onset of the Early Bronze Age (~5700-2000 BC), Iberia experienced a multitude of cultural changes reflected in the archaeological record. Genetic and genomic analyses of ancient populations have been able to provide insight into how these changes related to population shifts, as well as uncovering others not related to cultural changes.

This study presents mitochondrial genomic results from 3 individuals from the Middle Neolithic site of Algar do Barrão in the Tagus River valley of Portugal and 7 individuals from the Bell Beaker context of Convento do Carmo in the Estremadura region of
Portugal. Two more individuals from this site were also analysed, as well as individuals from the Late Neolithic sites of La Sagrera in Barcelona (N=10) and Casais da Mureta in the Tagus River valley (N=3), but reliable results could not be obtained.

Based on analysis from these individuals and previously published material, a migration event carrying HV, V, K, N, T2, and J mitochondrial lineages replacing the U5 hunter-gatherer associated lineages in the Early Neolithic period, followed by a ‘resurgence’ of hunter-gatherer associated genetic components that was especially visible in Portugal in the Middle and Late Neolithic periods, were observed. Subsequently, the Chalcolithic period saw the introduction of steppe-related ancestry in continental Europe, which this study shows was unrelated to the expansion of the Bell Beaker cultural complex.

Metagenomic screening revealed the first instance of Spirometra erinaceieuropaei, which also marked the oldest known tapeworm DNA discovered in an ancient sample, found in a tooth sample from Algar do Barrão dated to 3760-3650 cal BC.