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Where Human Sleep Went Wrong

nautil.us

61–70 of 139 posts

Re: Where Human Sleep Went Wrong

#61
post #38

Earlier quoted context omitted.

I'm a biologist so forgive me the poor wording, but there are "infinitely high" peaks/walls in the evolutionary landscape, as in: "the human urinary system has some evolutionary constraints and anatomical features that are not optimally designed from an engineering perspective, but they are generally functional and reflect our evolutionary history rather than deliberate design." So in that sense, a global maxima (min…

Interesting I did not know human urinary tract was suboptimal. Are there examples of "discontinuous" evolution where a chance mutation stumbled upon a much better way to do something that allowed a species to jump the gap? I imagine it would be very rare because chance mutations in a single individual that confer extraordinary survival / mating advantage to offset entire population would be rare like being a superman…

"I imagine it would be very rare because chance mutations in a single individual that confer extraordinary survival / mating advantage to offset entire population would be rare like being a superman among men."

-> This also depends on population size, if there is a bottleneck event (ie 99.99 percent of some species dying) then among the 100's of survivors perhaps there could be a superman. Either because this person got lucky, or the rest got unlucky. But in general the distribution of traits is quite continuous, given large populations.

It's also good to keep in mind that us biologists have messy definitions, ie we call specimen A and B the same species when they produce fertile offspring. Some species produce offspring but infertile (Horse-Donkey, Lion-Tiger). But what if A and B have fertile offspring and B and C do, but A and C do not? The whole definition of species falls apart (it leads to a paradox).

We have a lot of that in biology. You need to learn to deal with it (sunglasses dropping down), and assign uncertainties to terms you learn about, they are often just our attempts to name boxes on continuous, multidimensional scales.

Re: Where Human Sleep Went Wrong

#62

>18 degrees Celsius is considered optimal for sleep depth I'm instantly skeptical of anyone making universal statements like this, because they're certainly not true for everyone, and having looked into these and similar (f/x "ideal room/office temperature"), are based on many entangled assumptions. Most of the time I expect it's just people making after-the-fact justification for doing (or imposing) what they most p…

When statements like this are made usually it’s because studies would have been done comparing sleep depth at different temperatures and there would have been a statistically significant increase in sleep depth at 18 degrees Celsius in the tested group compared to groups sleeping at other temperatures.

I have no idea if that was actually done here but that’s usually how these statements are justified.

Of course we are all individuals so it may not apply to everyone but you can say that for everything in medicine. Only thing we can do is look for statistically significant differences between groups in double blind controlled studies after controlling for all other factors.

Re: Where Human Sleep Went Wrong

#63

>18 degrees Celsius is considered optimal for sleep depth I'm instantly skeptical of anyone making universal statements like this, because they're certainly not true for everyone, and having looked into these and similar (f/x "ideal room/office temperature"), are based on many entangled assumptions. Most of the time I expect it's just people making after-the-fact justification for doing (or imposing) what they most p…

[dead]

Re: Where Human Sleep Went Wrong

#64
post #7

Earlier quoted context omitted.

> People already live in different altitudes, ie with vastly different amounts of rock between themselves and the bits of the earth that produce her magnetic field. It's not really the same thing. Construction and especially the high content of charged metal (whether it's power conduits or plain old frame) may make a considerable difference.

Do many people sleep in such tall buildings? Obviously they exist, but I can't think of any over-20 story residential building I've ever been in. Office space, sure, but not residential.

See https://en.wikipedia.org/wiki/The_Pinnacle@Duxton

Re: Where Human Sleep Went Wrong

#65
post #38
post #30

Earlier quoted context omitted.

I can see why it isn't a local or global maxima solving function, but it surely can be modelled by one, right?

I'm a biologist so forgive me the poor wording, but there are "infinitely high" peaks/walls in the evolutionary landscape, as in: "the human urinary system has some evolutionary constraints and anatomical features that are not optimally designed from an engineering perspective, but they are generally functional and reflect our evolutionary history rather than deliberate design." So in that sense, a global maxima (min…

“recurrent laryngeal nerve” as well

https://futurism.com/evolutianary-proof-the-recurrent-laryng...

Re: Where Human Sleep Went Wrong

#66
> Most importantly, when we measured their circadian function directly, small-scale communities had much higher amplitude circadian rhythms than global north populations, which I think is why they report being happy with their sleep even though it’s more fragmented.

This could explain why I feel more rested when I wake up if I take glycine before going to bed, even though I don't sleep more.

Re: Where Human Sleep Went Wrong

#67
post #35

Earlier quoted context omitted.

This is a contentious theory with little actual historical backing. Most likely people have been sleeping in one block since forever.

> Most likely people have been sleeping in one block since forever. Does that have stronger historical backing?

It is more common in high-latitude countries. Very uncommon in lower latitude.

Re: Where Human Sleep Went Wrong

#68
post #35

Earlier quoted context omitted.

A single block of sleep is a relatively new behaviour, I suspect partially driven by the availability of cheap sources of light and heat. https://www.bbc.com/future/article/20220107-the-lost-medieva...

This is a contentious theory with little actual historical backing. Most likely people have been sleeping in one block since forever.

But the article discussed here also points in that direction when it mentions the importance of people on the lookout at night. The article also mentions primitive tribes partying all night, so that is yet another direction.

Re: Where Human Sleep Went Wrong

#69
post #30

Earlier quoted context omitted.

I can see why it isn't a local or global maxima solving function, but it surely can be modelled by one, right?

Great question! It maybe can be, but what is the maxima that is being solved for exactly? There are usually tradeoffs, the most common and prevalent is our body's immune response. If it's under-active, we might die from an infection. If it's over-active, we get diabetes, lupus, chron's, and (probably) lots of mental health disorders. So, it's a bit context dependent, and definitely dependent on other mutations that h…

> It maybe can be, but what is the maxima that is being solved for exactly?

Survival rate/reproduction rate/rate of genes being spread?

Re: Where Human Sleep Went Wrong

#70
post #12

>the Hadza uniformly reported high satisfaction with their sleep. And why wouldn't they? This is (presumably) the only kind of sleep they know.

True. But the article mentions that the amplitude of their circadian rhythm is higher (which tells you how much a relevant measure like the amount of melatonin or body temperature varies in a 24 hour cycle), so that is an indication of better sleep. A low amplitude means less difference between sleeping and being awake.
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