I might be wrong, but I think the word "predominan
Post# of 148169
"Geneticists say that the CCR5 delta 32 mutation existed as many as 2,500 years ago, but back then it likely occurred in only 1 in 20,000 Europeans, as compared to 1 in 10 today. They believe that some viral disease provided the selection pressure needed to increase the frequency of the mutation."
I think that Iceland has actually mapped the DNA of a third of its population, so it should be possible to get a fairly accurate count there.