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.
The global ban on CFCs (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-oz...
...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
Still, the Montreal Protocol is a good example of what can be achieved when we finally reach an imminent crisis.
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.
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).
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.
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.
Given that the risk of birth defects goes up significantly the older a woman is, menopause is probably evolutionarily advantageous.
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.
As the parent said, plenty of nuance to go around.
This is why tanning studios have been banned in Australia.
I figure I was getting much more sun exposure as a kid running around in t-shirt and shorts then the local shepherds did.