This is a common, but poor framing of evolution. Remember: the only real rule with evolution is "did this evolutionary change mean they survived / reproduced more"? Evolution is not a local or global maxima solving function. I find this kind of attempt at interpreting selection common with engineers, programmers, etc.
So in that sense, a global maxima (minima?) solving function will probably not arrive at what we have, it has to take into account our evolutionary path, in its entirety (as in the whole tree.), because it is all encoded in 1 (or several) long molecules, and a radical changes would take a rewrite of many parts at the same time, which just does not happen. Maybe at some point we can do it ourselves... though I imagine there being a lot of unintended consequences in other places in the body :).
Another example is that sometimes complexity in a cell signalling cascade is simply there to get some timing right (ie delay some response), and the complexity is just there, and won't simplify by itself -> But then later the complexity may start to serve some purpose. Just like proteins that are "copypasta-ed" in the genome, leaving one copy free to mutate and attain a function, or not... etc etc.
https://futurism.com/evolutianary-proof-the-recurrent-laryng...
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 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.
As for "discontinuous evolution"... Again, what is discontinuous? I'm sure there are events to be found of which the probability of them occurring is so small and the effects so large that they'd fall into someone's definition of "discontinuous". But I think there is by definition no such thing as discontinuous evolution. If it occurred, it had a non-0 probability of occurring, then again, maybe the universe is infinite and everything has a non-zero probability of occurring. This is getting philosophical haha. Maybe listen to some Mindscape podcasts (Sean Caroll).
Actually rabbits eat their excrement again. That's also probably not how an engineer would make it (or an intelligent designer would design it, since we seems to be going in that direction ;) ).
So, it's a bit context dependent, and definitely dependent on other mutations that have occurred in other parts of your DNA. Most complex diseases are "polygenic", meaning it's a culmination of quite a few factors that would contribute to a specific good or bad outcome.
So, yes, it could be modeled as a sort very context dependent with a lot of highly correlated non-independent covariates. We do use quite a lot of statistical and ML methods to understand the genome (I work in statistical genetics), but the complexity of biology has so far proved a tough nut to crack.
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.
This feels like the key point to me. These societies follow their body and go to sleep when they are tried, while us in the west have to sleep at a specific time to fit our schedules.
Does that have stronger historical backing?
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 prefer.
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.
And why wouldn't they? This is (presumably) the only kind of sleep they know.
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...
Like, it seems obvious to me that sleep has a higher opportunity cost in humans than most other animals. So naturally there's more evolutionary pressure in humans to sleep more efficiently.
Is this actually true? Dunno! But it was really weird that it doesn't get brought up.
Really? My instinctive reaction to this statement is that it's quackery. Would be very interested to see headlines appear about this if it's true.
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.
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.
What about the metal frame of a bed?
https://www.pbs.org/newshour/science/dogs-poop-in-alignment-...
but then again maybe not
https://www.sciencedirect.com/science/article/abs/pii/S15587...