I remember reading an article years ago about a village that put out an absurd amount of Olympic long distance runners. The article noted that the village was on a high plateau and far from other places. The extreme difference in height led to better lung capacity and the normalcy of having to travel by foot long distances just raised a bunch of people who conditioned their bodies from birth to be adept at long distance running. None of it resulted in any major changes in population physiology as it's just training your body to deal with environmental conditions after birth and doesn't cause the mutations in the genome that would mark evolutionary changes.

I mean, obviously there are some physical differences between races. They look different, some have more prevalence of certain diseases or conditions, but races are entirely a social construct. Scaled out, the differences in races aren't more severe than the differences in variability in smaller groups within a race, or even a family. It's like, yeah, uncle Steve's side of the family all have kinda pointy ears because he passed that on to his kids but his brother didn't pass that gene on but they're still family. Zoom out and view all humans not as different races but one giant group and uncle Steve's branch all just have darker skin or straighter hair, but they're still clearly part of the human family.