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The most obvious evidence to me has always been that Europeans are not black. A change like the loss of melanin requires selective pressure, which in this case

by api 6y ago

The most obvious evidence to me has always been that Europeans are not black. A change like the loss of melanin requires selective pressure, which in this case was likely furnished by less vitamin D as we migrated away from the equator. The pressure must have been significant since being white carries a big downside: higher vulnerability to sunburn and skin cancer. When I lived in Cali I always envied my darker skinned friends who did not have to smear goo on themselves at the beach. I gotta say though... the world would have far less race problems had that odd little quirk of photosynthesis of a key nutrient not existed.

ComputerGuru 6y ago
> I gotta say though... the world would have far less race problems had that odd little quirk of photosynthesis of a key nutrient not existed. Humans being humans, I’m sure nose shape, eye color (just ask Bran Sanderson), hair color/texture, or something else would readily suffice in the absence of a perceptible difference in skin tone.
DanTheManPR 6y ago
What's interesting is how strong the selection pressure seems to be to have melanin content adjusted to match the local conditions for sunlight. In the western hemisphere, where humans have only lived for ~20,000 years, there was already notable variations in pigmentation developing prior to 1500AD. That would make sense if vitamin D production is very important to health.
coldtea 6y ago
>I gotta say though... the world would have far less race problems had that odd little quirk of photosynthesis of a key nutrient not existed. It's not so much about the race, but about the exploitation. Blacks and whites co-lived without racism for millenia, back when anybody could become a slave. When around the 16th century the Europeans started to exploit latin americans, indians and blacks as slaves, they spread the various theories of racism to justify the practice (both the advance of christianity and englightenment meant that such a thing should now be justified, whereas in the ancient/pagan world just being more powerful was enough to justify making slaves of the less powerful, you didn't need an excuse). So, if Europens where also blacks, the exploitation would just have found some other justification than skin color (kind of how Hitler didn't have much issue to discriminate against the also-white Jews).
- tszymczyszyn 6y ago
  I agree with the general conclusion about exploitation, but racist theories and justifications existed in different cultures long before the 16th century.
kevin_thibedeau 6y ago
You can still get sunburn with darker skin. It just takes a lot more exposure.
basementcat 6y ago
"Race problems" would just be replaced by individuals subjugating each other based on other physical attributes, religion or choice of text editor.
- api 6y ago
  The great tabs vs. spaces war of the 28th century devastated our solar system of origin...
meiraleal 6y ago
> I gotta say though... the world would have far less race problems had that odd little quirk of photosynthesis of a key nutrient not existed. Not really, Europeans alone are capable of the same level of mess, before and after slavery.
tchaffee 6y ago
> A change like the loss of melanin requires selective pressure It does? What about genetic drift, random mutations, and artificial selection, where humans select based on qualities not necessarily conducive to survival? There is also some evidence that this change in skin color was only widespread as recently as 8,000 years ago [1]. > which in this case was likely furnished by less vitamin D How likely? > The pressure must have been significant since being white carries a big downside: : higher vulnerability to sunburn and skin cancer. Unless you are trying to hide from predators or your prey in snow? As far as skin cancer, as long as it doesn't kill you before you breed, it's not going to have a big impact on natural selection, right? [1] https://www.smithsonianmag.com/smart-news/heres-how-europeans-quickly-evolved-lighter-skin-180954874/ https://www.smithsonianmag.com/smart-news/heres-how-european...
- leftyted 6y ago
  > It does? What about genetic drift, random mutations, and artificial selection, where humans select based on qualities not necessarily conducive to survival? It seems unlikely to be due to these factors since there's a gradient from black to white as you move away from the equator.
  - tchaffee 6y ago
    > It seems unlikely That's fairly far from any scientific method I would have confidence in.
    - leftyted 6y ago
      You could have responded to my post but instead you did this. Why? There are more than two skin tone phenotypes. It's a gradient that gets lighter as you move away from areas of higher UV radiation to areas of lower UV radiation.
      - tchaffee 6y ago
        > You could have responded to my post but instead you did this. Why? I responded to the part of your post that was the most important to me: that discussions like this head towards more scientific rigor the longer they go on. > There are more than two skin tone phenotypes. It's a gradient that gets lighter as you move away from areas of higher UV radiation to areas of lower UV radiation. Sure. And I'm not much interested in what "seems likely" in terms of what caused that. Lots of things that seem likely turn out to be wrong when it comes to causation.

by api 6y ago

ComputerGuru 6y ago

> I gotta say though... the world would have far less race problems had that odd little quirk of photosynthesis of a key nutrient not existed. Humans being humans, I’m sure nose shape, eye color (just ask Bran Sanderson), hair color/texture, or something else would readily suffice in the absence of a perceptible difference in skin tone.

DanTheManPR 6y ago

What's interesting is how strong the selection pressure seems to be to have melanin content adjusted to match the local conditions for sunlight. In the western hemisphere, where humans have only lived for ~20,000 years, there was already notable variations in pigmentation developing prior to 1500AD. That would make sense if vitamin D production is very important to health.

coldtea 6y ago

>I gotta say though... the world would have far less race problems had that odd little quirk of photosynthesis of a key nutrient not existed. It's not so much about the race, but about the exploitation. Blacks and whites co-lived without racism for millenia, back when anybody could become a slave. When around the 16th century the Europeans started to exploit latin americans, indians and blacks as slaves, they spread the various theories of racism to justify the practice (both the advance of christianity and englightenment meant that such a thing should now be justified, whereas in the ancient/pagan world just being more powerful was enough to justify making slaves of the less powerful, you didn't need an excuse). So, if Europens where also blacks, the exploitation would just have found some other justification than skin color (kind of how Hitler didn't have much issue to discriminate against the also-white Jews).

tszymczyszyn 6y ago
I agree with the general conclusion about exploitation, but racist theories and justifications existed in different cultures long before the 16th century.

kevin_thibedeau 6y ago

You can still get sunburn with darker skin. It just takes a lot more exposure.

basementcat 6y ago

"Race problems" would just be replaced by individuals subjugating each other based on other physical attributes, religion or choice of text editor.

api 6y ago
The great tabs vs. spaces war of the 28th century devastated our solar system of origin...

meiraleal 6y ago

> I gotta say though... the world would have far less race problems had that odd little quirk of photosynthesis of a key nutrient not existed. Not really, Europeans alone are capable of the same level of mess, before and after slavery.

tchaffee 6y ago

> A change like the loss of melanin requires selective pressure It does? What about genetic drift, random mutations, and artificial selection, where humans select based on qualities not necessarily conducive to survival? There is also some evidence that this change in skin color was only widespread as recently as 8,000 years ago [1]. > which in this case was likely furnished by less vitamin D How likely? > The pressure must have been significant since being white carries a big downside: : higher vulnerability to sunburn and skin cancer. Unless you are trying to hide from predators or your prey in snow? As far as skin cancer, as long as it doesn't kill you before you breed, it's not going to have a big impact on natural selection, right? [1] https://www.smithsonianmag.com/smart-news/heres-how-europeans-quickly-evolved-lighter-skin-180954874/ https://www.smithsonianmag.com/smart-news/heres-how-european...

leftyted 6y ago
> It does? What about genetic drift, random mutations, and artificial selection, where humans select based on qualities not necessarily conducive to survival? It seems unlikely to be due to these factors since there's a gradient from black to white as you move away from the equator.
- tchaffee 6y ago
  > It seems unlikely That's fairly far from any scientific method I would have confidence in.
  - leftyted 6y ago
    You could have responded to my post but instead you did this. Why? There are more than two skin tone phenotypes. It's a gradient that gets lighter as you move away from areas of higher UV radiation to areas of lower UV radiation.
    - tchaffee 6y ago
      > You could have responded to my post but instead you did this. Why? I responded to the part of your post that was the most important to me: that discussions like this head towards more scientific rigor the longer they go on. > There are more than two skin tone phenotypes. It's a gradient that gets lighter as you move away from areas of higher UV radiation to areas of lower UV radiation. Sure. And I'm not much interested in what "seems likely" in terms of what caused that. Lots of things that seem likely turn out to be wrong when it comes to causation.