4 ms·
> vitamin D That is the driving force for lighter skin (unless your diet is mostly fish, such as the Inuit). Skin gets darker again when migration towards sunn
by zeotroph 9y ago
> vitamin D
That is the driving force for lighter skin (unless your diet is mostly fish, such as the Inuit). Skin gets darker again when migration towards sunnier climates happens: while UV light is essential for the synthesis of D3, it also destroys folic acid / vitamin B9 [1], which is essential when the neural tube of a fetus is being formed.
And since this mutation is so very visible, maybe here sexual selection plays a role, just like it is suspected with blond hair?
1: https://www.sciencedaily.com/releases/2014/03/140321095240.htm https://www.sciencedaily.com/releases/2014/03/140321095240.h...
- defen 9y agoI'm not saying vitamin D isn't involved; I'm just wondering whether it's the whole story. Is this single nucleotide change in SLC24A5 really the only way to decrease melanin production without having other harmful side effects? Naively I would expect lots of ways to have a loss-of-function mutation; why is this one so common? Sexual selection could be a factor, but that is not politically correct to say.
- lower 9y ago> Is this single nucleotide change in SLC24A5 really the only way to decrease melanin production without having other harmful side effects? Naively I would expect lots of ways to have a loss-of-function mutation In Asia, light skin evolved separately and is using different genes. https://en.wikipedia.org/wiki/Human_skin_color#East_Asia https://en.wikipedia.org/wiki/Human_skin_color#East_Asia