Something like 30-50% of all human genetic variants are shared across continents. It's hardly asinine to say that a significant proportion of genetic variation is shared with everyone. Depending where you are talking about, ~20% of variation is unique to a given continent.
I don't think PCA plots really tell us much beyond there being distinct genetic clusters? One could do a PCA only on people with european ancestry, or people living in a small town, and there would be plenty of interesting structure to look at.
I don't think PCA plots really tell us much beyond there being distinct genetic clusters? One could do a PCA only on people with european ancestry, or people living in a small town, and there would be plenty of interesting structure to look at.
https://www.nature.com/articles/nature15393