Source: Ancient Ethiopian genome reveals extensive Eurasian admixture in Eastern Africa (Science) 2015 A.D.
From the source, “Tracing the migrations of anatomically modern humans has been complicated by human movements both out of and into Africa, especially in relatively recent history. Gallego Llorente et al. sequenced an Ethiopian individual, “Mota,” who lived approximately 4500 years ago, predating one such wave of individuals into Africa from Eurasia. The genetic information from Mota suggests that present-day Sardinians were the likely source of the Eurasian backflow. Furthermore, 4 to 7% of most African genomes, including Yoruba and Mbuti Pygmies, originated from this Eurasian gene flow…Using Mota as an unadmixed African reference and the early farmer LBK as the source of the West Eurasian component, it is possible to reassess the magnitude and geographic extent of historical migrations, avoiding the complications of using admixed contemporary populations (6). We estimated a substantially higher Eurasian backflow admixture than previously detected (3), with an additional 4 to 7% of the genome of most African populations tracing back to a Eurasian source. Moreover, we detected a much broader geographical impact of the backflow, going all the way to West and Southern Africa (Fig. 2B). Even though the West Eurasian component in these regions is smaller than in Eastern Africa, it is still sizable, with Yoruba and Mbuti, who are often used as African reference populations (15, 16), showing 7% and 6%, respectively, of their genomes to be of Eurasian origin (table S5).”