[pkoird]

I'm not sure if there are any research showcasing the effects humanity has had in general due to low sun exposure. From all the benefits of Vitamin D and the recent human behavorial shift leading to low sun exposure (car travel, air conditioning, sunscreens even), there are bound to be new biological or psychological changes humanity is experiencing for the first time.

[logicchains]

One study found a difference in mortality between the max-sun-exposure and min-sun-exposure cohorts: the second was twofold higher, which is comparable to the effect of cigarette smoking. https://pubmed.ncbi.nlm.nih.gov/24697969/ . I.e. avoiding sun exposure completely is as harmful as smoking cigarettes.

[api]

I've wondered for a while if the apparently higher cognitive performance and resulting societal wealth at higher latitudes might be some kind of second order side effect from long-term selection for lower sun exposure. We already know this vitamin D is almost certainly why Northern peoples evolved lighter skin.

(I realize this is a frought topic, so please hold the race science bullcrap replies or the over-reactions in the other direction. I am not a believer in hard biological determinism or "race science," but I also don't dismiss the existence of variations. As with everything else in population genetics and biology, any variations that do exist probably have more than one cause.)

If there's any truth to this, it might be further compounded as people with darker skin spend more time indoors in the modern world. If you have darker skin you need, as far as I know, more sun to make vitamin D, which normally is not a problem if you're outdoors near the equator. Maybe darker skinned people need to be taking more D supplements.

[georgeburdell]

Does not explain India where there is high genetic diversity and generally the South is more educated and wealthy

[bethekidyouwant]

The reason that southern India is generally richer is very complicated.

[HexPhantom]

The vitamin D angle seems much more plausible to me as a public-health issue than as an explanation for broad population-level cognitive differences

[api]

Doesn’t that make a feedback loop though? Poor health equals higher health care overhead, lower productivity, more family issues, and overall worse outcomes all over the place. That in turn is going to make educational outcomes worse and child rearing worse. Some diseases can even have lasting cognitive side effects.

[HexPhantom]

What I find more plausible is that low sun exposure is one small contributor among many

[maipen]

Yes, I think that too. Besides sports, most young people studying today are aiming for jobs that are mainly indoors. It's not a requirement, of course, but because a lot of modern careers consist of working in offices or other enclosed environments.

No movement, No sun, Stale Air (Unless you have good ventilation). Pretty harmful if we think about it.

[therein]

>car travel, air conditioning, sunscreens even

And even clothing.

[throwup238]

Tailored clothing is at least 80,000–170,000 years old based on genetic clock research in body lice [1] but archaic humans have probably been wearing hides for at least a million years (there’s currently a big debate about how they managed to migrate to colder climates like Spain 800k-1.2m years ago).

I don’t think clothing is that big a factor because all humans in hot environments adapt and very little survives in the archaeological record. Many populations lived in heavily forested jungles where they was little sun exposure and those in deserts used stuff like Otjize for sun protection. Given all the ethnographic reporting from the age of exploration, tons of that clothing was probably made of feathers, cordage, bark, and other materials we wouldn’t even think of using for clothing.

[1] https://academic.oup.com/mbe/article/28/1/29/984822

[ezekiel68]

Still, 170,000 - 1.2M years is a fairly short amount of time if we go back only to the common ancestor who begat progeny that would become Pan and Autralopithecus (around 12 million years ago). It could be that early hide wearers started a trend that, to this day, continues to interfere with natural vitamin D metabolism (while also providing many benefits).

[throwup238]

Our ancestors started losing their hair about 2 million years ago and the MC1R gene giving us eumelanin pigmentation was fully fixed in the population around 1.2 million years ago by which point we were mostly hairless. In that range is when our vitamin D metabolism evolved, so clothing would have been present for large fractions of our existence.

Going back to a common ancestor with monkeys is pointless because their vitamin d pathways are significantly different like 7-dehydrocholesterol secretions that metabolize to vitamin D via external UV exposure and are ingested during grooming.

[ezekiel68]

Thank you for helping remove my ignorance!