I was reading a blog that I recently discovered and the author had an entry about the old Y-DNA data that is out there for Siwa Berbers. I already knew that they were peculiar for their high frequency of R1b, but I never really questioned the rest of the data.
According to
this study, the Siwi sample (n=93) was 28% B2a1a and 26.9% R-V88. We all know the only other place in Africa where R-V88 has been found at such high frequencies is around the Chadic-speaking zone, that is Chad, Cameroon, Niger, Nigeria, etc. I'm not too keen on downstream mutations so please correct me if I'm off, but B2a1a also appears to have a significant presence around the same region, around northern and southern Cameroon. The sample from Siwa carried E-V38 at 6.5%.
So my question is, does this say anything about the movement of the male ancestors of the people of Siwa and some of the people of the Sahel/West Africa(mostly Chadic speakers)? I haven't seen much autosomal work here. The paper confused me because it says Siwa Berbers have negligible SSA ancestry on one hand, and then as high as 51% on another. Then there is no telling how much is East African versus West African-related. Also, is it possible that the West African-related ancestry in Northwest Africans (and maybe all Berbers) is as old as their language shift?