Did their genes survive more, you mean. Hyper-vigilance could be maladaptive for the individual and still survive if it benefits others that carry the gene for it.

> "did this evolutionary change mean they survived / reproduced more"

You're just renaming the terms. More/less is a fitness gradient, and the thing that lives there is called an optimizer.

Evolution is a tunable-scale optimizer. It's not perfectly local, because it shotguns to avoid local optima on a (bumpy/noisy) fitness landscape. If you tune the 'shot pattern' really wide (infinite copies with infinite variation), you'd genuinely get a one-shot global optimizer at the limit. But that's not efficient nor realistic, so typically it's somewhere in between.

Uh, compare maze solvers: you've got your greedy direct route (gets stuck in the first corner) , Dijkstra (finds all the answers but takes ages), and then stuff like A*, which is a happy medium. Evolutionary algos can be used to solve mazes just the same. I think it's a bit heavier on resources than A*, but well suited to embarrassingly parallel optimization.

edit: Heh, I actually had claude build a comparative simulation. Turns out evolution is actually very slow on a single optimization axis, and gets stumped in mazes where the detour length is greater than the "temperature"/"spread"/"noise". The actual performance metrics are fascinating. But once tuned, it is able to solve mazes. Thus an optimizer. QED :-P

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

To be precise inclusive genetic fitness not idealized bayesian optimality.

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...

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.

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Do you really need to know other kinds of sleep in order to know if you feel like shit after waking up or if you feel fine?

They're probably also less confronted with articles/videos/social media posts telling them they're doing it wrong and how they should sleep instead. Sometimes ignorance (or rather, not overthinking things) is bliss...

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.

Well probably us modern human only know the "8h sleep at night" kind of sleep, yet a lot of people would tell you whether they're satisfied or not with their sleep

Also, they may not want to complain to strangers.

Also, we humans can get used to a lot of things and just be okay with it. For an extreme example, look at domestic abuse victims...

It's definitely quackery. There's way more "natural" magnetic variation between two different cities than between a ground floor apartment and a 30th floor apartment (see magnetic declination maps), and that's even before you get into the way-more-powerful magnetic fields generated or present in a home.

You can write pretty much anything you want after “Some emerging research suggests”

This is called "grounding" or "earthing" and Wikipedia doesn't pull punches in dismissing it [0]. You can buy grounding wires for your mattress or copper rivets for your shoes.

From my tissue engineering class in undergrad my 2 cents is this is maybe 95% supplements quackery and 5% genuine mystery. You can find papers that claim EM fields have cellular interactions [1]. I don't think serious scientists will touch conventional earthing, though.

[0]: https://en.wikipedia.org/wiki/Energy_medicine#Earthing

[1]: https://pubmed.ncbi.nlm.nih.gov/38068954/

I would not jump to such conclusions, I would assume is not fully known and needs to be further understood.

on the other side, do you know we have polarized and non-polarized cells? do you know they can be affected by electromagnetism?

this two things already establish the existence of a relationship and effects between them. If we then consider that cells mechanism work based on differential of electrical or chemical potentials, and that they continuously use that for their functions, reactions or environmental compensations well...

I just think they are related and we need to understand better.

More evidence this may have been written by a pigeon...

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.

So colour me skeptical of this claim as well.

And while I like going barefoot for other reasons, I don't think it makes much of a difference to the magnetic fields.

And Earth's magnetic field is extremely weak

There might be precedent for being able to detect changes in magnetic field

https://www.pbs.org/newshour/science/dogs-poop-in-alignment-...

but then again maybe not

https://www.sciencedirect.com/science/article/abs/pii/S15587...

It's a creative innovation!

I could only wish for low unnatural rumbles of cars. In 3rd world countries it's non stop horns and noisy motorbikes

737s are fine its dog barking that gets me.

I actually find it easier to sleep with the sound of people talking around me, it's very comforting.

I tried to imitate japanese people in the public transport when i was there, meaning I managed to kinda sleep/nap with eyes closed for 10-15minutes between rides and it was astonishing.

while I understand might be a more known thing, it was surprising to try it and feel very rested after that. I'm still surprised and I wonder why not the whole world does it.

of course without the music at the stops would not be possible :P

  > It's still very odd that no species has ended up evolving a continuous maintenance system that can run while conscious

- will gains of 24/7 hunting/foraging offset the extra energy costs? Lions sleep 16-20 hours a day, according to the internet.

- do continuous maintenance systems imply duplicate systems? If so, I have a hunch that even a mere 40% increase in energy expenditure would quickly undo the gains in waking hours.

> It's still very odd that no species has ended up evolving a continuous maintenance system that can run while conscious, the benefits when hunting other animals that need sleep would be enormous, so there has to be significant evolutionary push for it.

I disagree. Endurance hunters walk an animal down throughout a single day. Sleep isn't the bottleneck. Efficient bipedalism and sweat are enough.

There's a similar mechanism called USWS https://en.wikipedia.org/wiki/Unihemispheric_slow-wave_sleep (Half of the brain remains awake while the other sleeps, not an expert so please correct if wrong)

The fact they electrically signal via chemical analogs fuelled by immersion in nutrient bearing fluid that also accretes waste products, yet is kept separate from the primary loop of the cardiovascular system by the blood-brain barrier?

How do you think sleep scientists got their data in the first place? Some of them went to Tanzania.