Why We Sleep - Matthew Walker

[vinod1]

Thanks Liberty!

 

On a related topic, what do you think of need for sunscreen? It seems to me that humans have evolved to be in the sun, so cannot see why it would be needed. Any thoughts or research you have done on this?

 

Vinod

 

I've seen both sides of the argument.. I ended up falling on the side of using sunscreen and getting more Vit D through supplementation.

 

I think humans throughout evolutionary time mostly didn't live long enough to worry too much about skin cancers and skin aging (the sun will make your skin visibly age much faster), a lot of the problems happened after reproduction age, which is an evolutionary blind spot, and throughout most of that time most humans probably had darker skin pigmentation than I do, which also provides some natural protection. There's also issues with the ozone layer being damaged in post-industrial times (some of that has been partially corrected by banning CFCs and such, but not entirely).

 

That's my vague understanding of the situation. I still get plenty of sun without sunscreen, but if I know I'm going to be out for a long time in the sun not being covered too much, I always try to wear good sunscreen now.

 

Excellent points! That makes a lot of sense.

 

I was recently talking about evolution with a biology professor and she made the point that evolution cared (in terms of increasing your chances of survival) only if it helped in reproduction. That is why women live longer than men, because older women help their daughters care for the children, which in turn led to women having more children. So evolutionary wise there is an advantage for mothers to have their grand mother live longer. Men, apparently no so much :)

 

Thank you!

 

Vinod

 

It's not quite as simple as that, but yes, things that tend to happen after reproduction don't get encoded (or at least, not directly, which also leads to the interesting stuff in epigenetic).. That's why aging and the diseases of aging aren't programmed, but rather, a blind spot that evolution hasn't had a time to solve against because for most of humanity's existence, there were few very old people, and they didn't reproduce. There can be secondary effects, like having longer-lived adults helping the germ-line indirectly (ie. grand-parents increasing the chance of survival of their grand-kids).. I'm no expert, but I remember that at the time (10-12 years ago), I learned a lot from this series of posts:

 

https://www.lesswrong.com/s/MH2b8NfWv22dBtrs8

 

Of course reading Darwin's Origins of Species is recommended as a good starting point, but this book is also a good place to learn:

 

https://www.amazon.com/Adaptation-Natural-Selection-Christopher-Williams/dp/0691026157

 

Thanks for the links! I did read Origin of the Species 20 years back. Need to read it again as I do not remember a thing.

 

Vinod

[Liberty]

Thanks for the links! I did read Origin of the Species 20 years back. Need to read it again as I do not remember a thing.

 

Vinod

 

With great books, it's worth re-reading once in a while. It's not just about forgetting; the books stays the same, but the reader can change quite a bit, so the "software" that is in the book will get interpreted quite differently by the new "hardware" of your brain.

 

My most recent re-read of Phil Fisher had a totally different impact on me than the first time I read him years ago, for example.

 

I'm about due to re-read 'Gödel, Escher, Bach', one of my faves...

[Liberty]

New interview with Walker:

 

https://peterattiamd.com/matthewwalker4/