I pointed yesterday toward a piece by Bruce Gerencser that takes-up the Biblical explanation of differing skin colors, an explanation used even today to justify racism. What do you know? Discover published today a piece that tells you how scientists think it happened rather than a bunch of Bronze Age anonymities.
Human skin color reflects an evolutionary balancing act tens of thousands of years in the making. There’s a convincing explanation for why human skin tone varies as a global gradient, with the darkest populations around the equator and the lightest ones near the poles. Put simply, dark complexion is advantageous in sunnier places, whereas fair skin fairs better in regions with less sun.
BTW, did you notice the usage error in that paragraph? Fairs instead of fares? It may be finicky of me, but I once subscribed to Discover and cancelled because of the regularity of editing failures like this.