eli5: If more melanin is advantageous in warm climates, why is less of it advantageous in colder climates? Wouldn’t darker skin still be most advantageous in cold climates where it might occasionally be hot?
In: 1641
OP, you might be confusing heat with radiation from the Sun? What I’ve read as hypotheses about how European peoples “became pale” (if the theory on all early human migration originating from the prehistoric river valley civilizations and/or Africa is the one we’re going by for how physical differentiation/adaptation of human traits developed) is that it was something that occurred through a long process of evolutionary advantage having to do with vitamin D production/storage. Anyway, with the fact that many humans coexist with or live in the context of modern engineering and agriculture, concepts like “biological advantage” are basically moot.
OP, you might be confusing heat with radiation from the Sun? What I’ve read as hypotheses about how European peoples “became pale” (if the theory on all early human migration originating from the prehistoric river valley civilizations and/or Africa is the one we’re going by for how physical differentiation/adaptation of human traits developed) is that it was something that occurred through a long process of evolutionary advantage having to do with vitamin D production/storage. Anyway, with the fact that many humans coexist with or live in the context of modern engineering and agriculture, concepts like “biological advantage” are basically moot.
I hate winter time cause I’m always in the office when the sun is out and it’s dark by the time I get off work. I tried vitamin D supplements but maybe I need to increase my dosage.
I always feel livelier in the summer when I’m out doing yard work or hanging out at the pool.
OP, you might be confusing heat with radiation from the Sun? What I’ve read as hypotheses about how European peoples “became pale” (if the theory on all early human migration originating from the prehistoric river valley civilizations and/or Africa is the one we’re going by for how physical differentiation/adaptation of human traits developed) is that it was something that occurred through a long process of evolutionary advantage having to do with vitamin D production/storage. Anyway, with the fact that many humans coexist with or live in the context of modern engineering and agriculture, concepts like “biological advantage” are basically moot.
I hate winter time cause I’m always in the office when the sun is out and it’s dark by the time I get off work. I tried vitamin D supplements but maybe I need to increase my dosage.
I always feel livelier in the summer when I’m out doing yard work or hanging out at the pool.
I hate winter time cause I’m always in the office when the sun is out and it’s dark by the time I get off work. I tried vitamin D supplements but maybe I need to increase my dosage.
I always feel livelier in the summer when I’m out doing yard work or hanging out at the pool.
Melanin is useful for blocking against large amounts of UV radiation. It lowers chances of skin cancer from running around in the sun constantly.
But you need to take in *some* UV light to get vitamin D. If you live in someplace cold, you don’t go out much if you like having all of your limbs. That means you don’t get much sunlight, so you need to take in as much UV as you can so you can get your vitamin D.
TLDR:
Light Skin = All the Vitamin D. Good for minimal sunlight
Dark Skin = None of the Skin Cancer. Good for lots of sunlight
No.
It’s an adaptive advantage, and the lack of it is also an adaptive advantage. Skin with less melanin is more efficient at gleaning vitamin D from smaller amounts of sunlight, but is also more easily burned by prolonged exposure. This is why people who live closer to the poles tend to have less melanin. People with more melanin are more suited to sunnier climates and longer exposure to the sun, because their skin takes vitamin D in more gradually, and is less prone to burning.
Beyond that, and this is just anecdotal, but people with more melanin also seem to be more sensitive and uncomfortable with the cold. And people with less melanin seem to be more easily exhausted by heat.
Of course we’re all conscious beings and can take measures to adapt to wherever we find ourselves in, so it’s not that big of a deal in most cases, however people with darker skin ARE more prone to vitamin D deficiency in northern climates, which is actually a pretty big health issue. Not one that can’t be dealt with, but one that a lot of people just seem to be unaware of.
No.
It’s an adaptive advantage, and the lack of it is also an adaptive advantage. Skin with less melanin is more efficient at gleaning vitamin D from smaller amounts of sunlight, but is also more easily burned by prolonged exposure. This is why people who live closer to the poles tend to have less melanin. People with more melanin are more suited to sunnier climates and longer exposure to the sun, because their skin takes vitamin D in more gradually, and is less prone to burning.
Beyond that, and this is just anecdotal, but people with more melanin also seem to be more sensitive and uncomfortable with the cold. And people with less melanin seem to be more easily exhausted by heat.
Of course we’re all conscious beings and can take measures to adapt to wherever we find ourselves in, so it’s not that big of a deal in most cases, however people with darker skin ARE more prone to vitamin D deficiency in northern climates, which is actually a pretty big health issue. Not one that can’t be dealt with, but one that a lot of people just seem to be unaware of.
As a Scandinavian i can tell you that often even we need to take vitamin D. But culturally we are alot outdoor. Especially during summer. I wouldn’t be supprised if this is partly because of how much we can feel the vitamin D produced by the sunlight.
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