In Dr. Daniel MacArthur’s post on Roots into the Future Blaine Bettinger left an interesting comment:
It will be interesting to see how 23andMe deals with the pool of people that respond to the 10,000 free kits. Doesn’t seem like they can pre-screen applicants, since African American heritage is sometimes more sociological than genetic (based on previous genetic studies, anyway). In other words, who’s to say who is an African American and who isn’t?
And how will they deal with the unscrupulous people who apply with the full knowledge that they have no recent African ancestry? Certainly they won’t be screen those people out, even with surveys or other methods.
My concerns probably won’t apply to the genetic association studies, since they can look for test-takers that have, for example, a certain % of African American ancestry, or can look for African American ancestry in the region of the genome where the association is believed to reside (after it’s predicted to exist).
However, my concerns will certainly apply to any conclusions they might make about African American genetic ancestry. For example, a conclusion such as “XX% of African Americans have less than XX% of African American DNA,” or “XX% …