This is something weird to me. I think skin color is pretty diverse no matter where you go, or at least, I don't know enough to say otherwise. But take hair color. Europe has more diversity in hair color than almost anywhere else. Same with eye color. Why is this? Is it just because I interact with more people of European heritage on day to day business, or has Europe actually had more mutations which affect hair color, eye color, etc? Or is it that Europe, being a crossroads has had more people immigrate through it.

If this is racist, it's unintentional, this is just an observation, which I've been unable to find an answer to.

If you have an answer, a link to a paper would be great.

Edit: A point against what I just wrote that I thought of: Asia has both mono and double eyelids, which is something Europe doesn't have. Native americans don't count either for or against, since they immigrated fairly late in a small group, which also explains why almost all native americans are type O