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I'm no way an expert on the matter but by pure logic it's still amazes me how we survived (and evolved!) as a species for thousand of years without almost no sh
by darkwater 6y ago
I'm no way an expert on the matter but by pure logic it's still amazes me how we survived (and evolved!) as a species for thousand of years without almost no shelter from direct sunlight and yet now (too much) sunlight exposure is seen as a cause of death. I know we lost almost all the body hair we used to have but still, we usually wear clothes when under the sun.
- saiya-jin 6y agoShepherds (like all folks) wear and wore clothes, long sleeves and often hats also in the summer. Also if skin is exposed to sun regularly, often, its much less sensitive compared to usual office worker seeing almost no sunlight and then having 2 weeks of mega exposure and sunburns on vacation.
- TheSpiceIsLife 6y agoThe last time I looked in to this, enough sun exposure to tan is also enough sun exposure for folk of northern European discent to badly increase skin cancer risks. This is why tanning studios have been banned in Australia.
- yakubin 6y agoAccording to my naive knowledge: 1. We have more ozone holes now. 2. We weren't constantly in direct contact with sunlight. If you move past very early stages, we had shelter in forests, caves, tents, igloos. 3. When we were in direct contact with sunlight, we had a darker skin, which is more resilient to that. Correct me if I'm wrong.
- onion2k 6y agoWe have more ozone holes now. The global ban on CFCs (https://en.wikipedia.org/wiki/Montreal_Protocol https://en.wikipedia.org/wiki/Montreal_Protocol) is working, and although there are still big holes that open and close every year we're on the way to getting back to pre-1980 levels of holes by 2060. https://public.wmo.int/en/media/news/record-breaking-2020-ozone-hole-closes https://public.wmo.int/en/media/news/record-breaking-2020-oz...
- TheSpiceIsLife 6y agoMaybe, if China would curtail their CFC usage perhaps. ...A recently reported slowdown in the decline of the atmospheric concentration of CFC-11 after 2012, however, suggests that global emissions have increased... We show that emissions from eastern mainland China are 7.0 ± 3.0 (±1 standard deviation) gigagrams per year higher in 2014–2017 than in 2008–2012, and that the increase in emissions arises primarily around the northeastern provinces of Shandong and Hebei. This increase accounts for a substantial fraction (at least 40 to 60 per cent) of the global rise in CFC-11 emissions. https://www.nature.com/articles/s41586-019-1193-4 https://www.nature.com/articles/s41586-019-1193-4 Still, the Montreal Protocol is a good example of what can be achieved when we finally reach an imminent crisis.
- Gravityloss 6y agoThat's from 2019, they have since reduced the leaks, this from 2021: https://www.nature.com/articles/s41586-021-03277-w https://www.nature.com/articles/s41586-021-03277-w
- TheSpiceIsLife 6y agoGreat news, thanks for the update.
- CalRobert 6y agoMoving to the country and being outside for 8+ hours of the day finally made it clear that cowboy hats, sombreros, etc. don't have wide brims just for fashion.
- gibspaulding 6y agoThis was my thought. Traditional clothing for people who live and work outdoors in sunny climates generally does not feature a lot of exposed skin. I'm pretty sure that the "shorts and a t-shirt" summer wear is a fairly modern phenomenon.
- notahacker 6y agoNobody counting skin cancer deaths and saying "this is completely avoidable and dying at that age is abnormal" back then either...
- Eric_WVGG 6y agoUnless that skin cancer thing is also actually overblown… https://elemental.medium.com/what-if-avoiding-the-sun-is-bad-for-you-4c21585180da https://elemental.medium.com/what-if-avoiding-the-sun-is-bad... As the parent said, plenty of nuance to go around.
- arisAlexis 6y agocomparing average lifespan of 30 to 80?
- darkwater 6y agoThat's actually a valid point, thanks. Although I don't know what's the age distribution for skin cancers.
- asaddhamani 6y agoWhy would sunlight cause us to lose hair but not other animals?
- blunte 6y agoI don't see how sunlight would cause us to lose any animals, unless perhaps it was too bright.
- rob74 6y agoIf the shepherd has kids before dying (of skin cancer or something else), it doesn't really make a difference for the survival of the species...
- steventharlow 6y agoEvolution (and survival) only cares about if you survive to reproduce. So human evolution (and survival) matters only until 14-40, and humans aren't dying of skin cancer at exceedingly large numbers at those ages. If we pushed back the reproductive age we'd eventually evolve to live longer (though would have more people dying without reproducing first). This experiment has been successfully shown in fruit flies.
- Denvercoder9 6y ago> So human evolution (and survival) matters only until 14-40 Not necessarily. I'd imagine it helps the survival chances of your grandchildren if you're around when they're growing up (though it probably mattered less back when children were raised by communities than in the nuclear families we have nowadays).
- notahacker 6y agoSure, it would have helped homo sapiens even more if more of their children had lived to childbearing ages (if, say, they'd discovered antibiotics a few millenia earlier or evolved more natural immunities). But the infant survival rates back then were enough to ensure the species survived, just like the smaller fraction of the population struck down by skin cancer every year wasn't enough to put evolutionary pressure on us to develop resistance to it or develop sunlight avoidance traits. Evolution doesn't guarantee that every possible beneficial adaptation takes place.
- throwaway0a5e 6y ago> I'd imagine it helps the survival chances of your grandchildren if you're around when they're growing up Keeping toddlers from walking off a cliff (and the other things unsupervised toddlers will do to kill themselves) is probably why he said 14-40 and not 14-30.
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- yarcob 6y ago> human evolution (and survival) matters only until 14-40 I just don't think that's true. I think grand parents being around was important for human survival. If it wasn't, if all that mattered was having the most kids, then why would women go through menopause? Wouldn't it be better if women continued having children until they die? I think it makes sense that young people have kids (the sooner the better, faster evolution and less chance of DNA degradation) Then they should live as long as possible to help raise their grandkids to ensure their genes survive.
- ehnto 6y agoI may be overly cautious given where I live has an 11+/Extreme UV rating all year round. Though I do want to point out that clothing doesn't protect against UV as much as you might think, and a sunburn or lack thereof doesn't tell you all that much about your UV exposure for the day. You could have exceeded your healthy exposure for the day without getting a sunburn.
- kosh2 6y agoSkin cancer probably plays no role for your ability to reproduce. By the time you die from skin cancer you already had children and probably even grandchildren.
- bluGill 6y agoThe longer you live as a male the more children you can have. Also grandparents helping raise grandkids is a factor in their survival in the village ..
- astura 6y agoWide brim hat and long sleeves.
- globular-toast 6y agoWe also used to be black. Humans now move to places for which they do not have a suitable skin colour, like Australia.