[seanmcdirmid]

I don’t get what you are trying to claim here. There are well known differences between races (e.g. lactose tolerance) that are minor but medically relevant.

[padobson]

I think OP is trying to say something like, "The variance between groups is less than the variance among them"

[klenwell]

And that the racial categories used politically and socially don't always map cleanly to genetic categories used by scientists (thus "75 percent of Pacific Islanders" rather than 100%).

But in some (carefully defined) cases they get close.