Population structure of modern-day Italians reveals patterns of ancient and archaic ancestries in Southern Europe

Abstract

European populations display low genetic diversity as the result of long term blending of the small 64 number of ancient founding ancestries. However it is still unclear how the combination of ancient 65 ancestries related to early European foragers, Neolithic farmers and Bronze Age nomadic 66 pastoralists can fully explain genetic variation across Europe. Populations in natural crossroads like 67 the Italian peninsula are expected to recapitulate the overall continental diversity, but to date have 68 been systematically understudied. Here we characterised the ancestry profiles of modern-day Italian 69 populations using a genome-wide dataset representative of modern and ancient samples from across 70 Italy, Europe and the rest of the world. Italian genomes captured several ancient signatures, 71 including a non-steppe related substantial ancestry contribution ultimately from the Caucasus. 3 bioRxiv preprint doi: https://doi.org/10.1101/494898; this version posted December 13, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license. 72 Differences in ancestry composition as the result of migration and admixture generated in Italy the 73 largest degree of population structure detected so far in the continent and shaped the amount of 74 Neanderthal DNA present in modern-day populations. 75 76