somewhat. Overall, it appears that African populations are strongly shifted to the European side of the fist principal component.
There is a dearth of haplogroups of Sub-Saharan origin in Europe. Most of them occur as outliers, and in small percentages. Hence, the very strong shift of African populations towards Europeans cannot be ascribed to occasional African admixture in Europe.
Y-haplogroup E is the only major link between Africa and Europe, which is not also shared by Africa and East Asia. But, this haplogroup occurs at very small frequencies in all the included European populations, and at quite variable frequencies overall. As McEvoy et al. correctly observed, even Y-haplogroup E devoid European populations exhibit a closeness with Africans not shared by East Asians.
If admixture with Y-haplogroup E bearing males in Europe cannot account for the relative closeness of Africans to Europeans, what does? As I have mentioned in my review of McEvoy et al., there are two possibilities:
- An Asian component not shared by Eurafricans is actually pulling East Asians away from Europeans and Africans. With the discovery of Denisovans and archaic-leaning Red Deer Cave people, this is a possibility that must be seriously entertained.
- Y-haplogroup E bearers were originally closer to West than to East Eurasians. This is also quite likely, since the origins of haplogroup E are traced to East Africa from DE-bearing ancestors who may have well lived in Eurasia; Asia possesses both sister clades E and D, as well as both sister clades DE and CF one level-up. But, even if DE originated in East Africa itself, we must remember that the population there was originally different than many of the current inhabitants of the region, and may very well have been genetically closest to the emerging Proto-Caucasoids of the adjacent regions of Asia, rather than to the more distant human populations that would ultimately evolve into the East Asians of today.