This has absolutely nothing to do with anything, except my interest in genetics, and that I’m a redhead and I’ve always wondered why (no one else in my family is besides my sister).
…Oh, and I think the sexual selection thing is a bunch of bull.
This discovery provoked interest in determining why there is an unusual prevalence of red hair and pale skin in some northern European populations, specifically Britain and Ireland. The Out-of-Africa model proposes that modern humans originated in Africa and migrated north to populate Europe and Asia. It is most likely that these migrants had an active Mc1r variant and, accordingly, darker hair and skin (as displayed by indigenous Africans today). Concordant with the migration north, the selective pressure maintaining dark skin decreased as radiation from the sun became less intense. Thus variations in Mc1r began to appear in the human population, resulting in the paler skin and red hair of some Europeans.
Studies find no evidence for positive selection driving these changes. Instead, the absence of high levels of solar radiation in northern Europe relaxed the selective pressure on active Mc1r, allowing the gene to mutate into dysfunctional variants without reproductive penalty, then propagate by genetic drift.