Update: After this post a researcher who is planning on publishing work on the genetic structure of Great Britain and Ireland and who has a very large N forwarded me a PCA which he gave me permission to repost. I’ve uploaded it here.
As you might infer from the post below I’ve started to get interested in African population structure. It’s not just me. Readers regularly query me about the relationship of various groups, such as the Nilotic peoples who reside amongst the Bantu in northeast Africa. Additionally, there is a consistent problem with 23andMe generating weird results for people of African ancestry, usually those with East African ancestry.
But to figure out the nature of African variation in more detail we also need to give some thought to outgroups. My initial assumption was that using Tuscans would be sufficient, but several people pointed out that many Mediterranean groups have trace African admixture. Probably not enough to matter, but why take the risk? So how about looking to Northern Europe? The Utah Whites and Orcadians jump out as plausible alternatives, but there was a third which I thought I’d try out: the Irish.
Last fall my friend Paul bought a bunch …