Would you find it racist to say that people living closer to the equator have darker skins? While there's no evidence for any complex adaptive differences between groups of people there are certainly adaptive responses to specific environmental hazards that we can see. People's levels of melonin in their skin balance skin cancer against vitamin D deficiency against folate deficiency, at least for their ancestral environment. Some groups of hunters living in the far north are harmed less by a nearly all meat diet than most people would be. Many groups living at high altitudes have higher quantities of red blood cells or similar adaptations. And since Guns, Germs, and Steel came out we've located genes influencing the immune system that trade off resistance to parasites versus resistance to contagious disease and found that Native Americans tend to have genomes that make the former trade while settled peoples in Eurasia tend to have genes pushing more in the later direction. So Jared Diamond's assertions about disease resistance have been entirely born out.