ADMIXTURE, African Ancestry Project, and confirmation bias

ADMIXTURE, African Ancestry Project, and confirmation bias

I’ve been running the African Ancestry Project for a while now on the side on Facebook. But it’s getting unwieldy, so I finally set up the website. The main reason I started it up is that there have been complaints for a while now of problems with the 23andMe “ancestry painting” and such for some African groups. For example, a Nubian might be 70% “European.” One might argue that this is due to Arab admixture, but this is clearly not so if you look at the PCA plot. What’s going on? Probably a problem with the reference populations (only Yoruba for Africa), ascertainment bias in the chip (they’re tuned to European variation), and the fact that African genetic variance can cause some issues. I don’t know. But the problem has been persistent, and since most of the other genome blogging projects exclude Africans because they’re so genetically diverse I decided to take it on.

Three groups of people have submitted:

– People of the African Diaspora in the New World

– People from Africa, disproportionately Northeast Africans (Horn of African + Nubia, etc.)

– People of some suspected or known minor component of African ancestry

I’m at ~70 participants now. As one reference …

Razib Khan