Archaeogenetic analysis of Neolithic sheep from Anatolia suggests a complex demographic history since domestication.

Sheep were among the first domesticated animals, but their demographic history is little understood. Here we analyzed nuclear polymorphism and mitochondrial data (mtDNA) from ancient central and west Anatolian sheep dating from Epipaleolithic to late Neolithic, comparatively with modern-day breeds and central Asian Neolithic/Bronze Age sheep (OBI). Analyzing ancient nuclear data, we found that Anatolian Neolithic sheep (ANS) are genetically closest to present-day European breeds relative to Asian breeds, a conclusion supported by mtDNA haplogroup frequencies. In contrast, OBI showed higher genetic affinity to present-day Asian breeds. These results suggest that the east-west genetic structure observed in present-day breeds had already emerged by 6000 BCE, hinting at multiple sheep domestication episodes or early wild introgression in southwest Asia. Furthermore, we found that ANS are genetically distinct from all modern breeds. Our results suggest that European and Anatolian domestic sheep gene pools have been strongly remolded since the Neolithic.

Mitochondrial DNA diversity of modern, ancient and wild sheep(Ovis gmelinii anatolica) from Turkey: new insights on the evolutionary history of sheep.

In the present study, to contribute to the understanding of the evolutionary history of sheep, the mitochondrial (mt) DNA polymorphisms occurring in modern Turkish native domestic (n = 628), modern wild (Ovis gmelinii anatolica) (n = 30) and ancient domestic sheep from Oylum Höyük in Kilis (n = 33) were examined comparatively with the accumulated data in the literature. The lengths (75 bp/76 bp) of the second and subsequent repeat units of the mtDNA control region (CR) sequences differentiated the five haplogroups (HPGs) observed in the domestic sheep into two genetic clusters as was already implied by other mtDNA markers: the first cluster being composed of HPGs A, B, D and the second cluster harboring HPGs C, E. To manifest genetic relatedness between wild Ovis gmelinii and domestic sheep haplogroups, their partial cytochrome B sequences were examined together on a median-joining network. The two parallel but wider aforementioned clusters were observed also on the network of Ovis gmelenii individuals, within which domestic haplogroups were embedded. The Ovis gmelinii wilds of the present day appeared to be distributed on two partially overlapping geographic areas parallel to the genetic clusters that they belong to (the first cluster being in the western part of the overall distribution). Thus, the analyses suggested that the domestic sheep may be the products of two maternally distinct ancestral Ovis gmelinii populations. Furthermore, Ovis gmelinii anatolica individuals exhibited a haplotype of HPG A (n = 22) and another haplotype (n = 8) from the second cluster which was not observed among the modern domestic sheep. HPG E, with the newly observed members (n = 11), showed signs of expansion. Studies of ancient and modern mtDNA suggest that HPG C frequency increased in the Southeast Anatolia from 6% to 22% some time after the beginning of the Hellenistic period, 500 years Before Common Era (BCE).