Pleistocene-Holocene boundary in southern Arabia from the perspective of human mtDNA variation (original) (raw)

It is now known that several population movements have taken place at different times through- out southern Arabian prehistory. One of the principal questions under debate is if the Early Holocene peopling of southern Arabia was mainly due to input from the Le- vant during the Pre-Pottery Neolithic B, to the expansion of an autochthonous population, or some combination of these demographic processes. Since previous genetic stud- ies have not been able to include all parts of southern Arabia, we have helped fill this lacuna by collecting new population datasets from Oman (Dhofar) and Yemen (Al- Mahra and Bab el-Mandab). We identified several new haplotypes belonging to haplogroup R2 and generated its whole genome mtDNA tree with age estimates under- taken by different methods. R2, together with other considerably frequent southern Arabian mtDNA haplogroups (R0a, HV1, summing up more than 20% of the South Ara- bian gene pool) were used to infer the past effective popu- lation size through Bayesian skyline plots. These data indicate that the southern Arabian population underwent a large expansion already some 12 ka. A founder analysis of these haplogroups shows that this expansion is largely attributed to demographic input from the Near East. These results support thus the spread of a population coming from the north, but at a significantly earlier date than presently considered by archaeologists. Our data suggest that some of the mtDNA lineages found in south- ern Arabia have persisted in the region since the end of the Last Ice Age.