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Why birds do not fall while sleeping

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Re: Why birds do not fall while sleeping

#131

Post by johnisgood »

Agentus wrote: post #122
johnisgood wrote: post #115

Earlier quoted context omitted.

Yes, adjusting our sleeping position has to do with the sensation of pain, a stimuli (pain, discomfort, pressure points) that cause most individuals to reposition during sleep, i.e. it is the sensation of pain from pressure buildup that triggers the need to move during sleep. You are right, it is to prevent prolonged compression of tissues, to avoid bedsores, nerve damage, etc. That said, this is not the whole story,…

I can do more than that. I used to wake up sweaty half the time from sleeping as child. Now that never happens as an adult, i instead wake up with my sweater mysteriously taken off. I wish sleep self would learn to put a sweater on if it turns cold though.

Yup, putting on a sweater is a more complex task which requires deliberate planning and coordination, it requires more cognitive control as opposed to tossing your shirt which is a simple reflexive behavior. Sleepwalkers can perform highly coordinated and complex behaviors as it does not happen during REM sleep where your body is paralyzed, but sleepwalking is a distinct phenomenon, plus when you are not sleepwalking, the brain's control over motor functions is very limited.

Not everything is lost though, you can potentially learn it through repetition, you just have to do this in a half-awake state or in a state close to sleep. Do it often enough, and theoretically you may be able to perform the task during non-REM sleep.

Re: Why birds do not fall while sleeping

#132

Post by jahnu »

avar wrote: post #77

This article doesn't even try to address what I feel is the deeper and more interesting question (but probably one that can't be answered): Why is it that horses, cows, giraffes and birds have all had to come up with a purely passive solution of "locking" themselves in place, either via their joints (for the four-legged), or via the tendon mechanism described here for birds? I.e. why wasn't in simpler in evolutionary…

Does locking require any energy to maintain? I suspect very little if any.

Re: Why birds do not fall while sleeping

#134

Post by harry_ord »

e40 wrote: post #124
LoveMortuus wrote: post #80

Earlier quoted context omitted.

I thought that dolphins could avoid having to sleep while travelling long distances by having part of the brain asleep and then switching when tired. I could just be misremembering things, so I’m not certain.

Each half sleeps alternately. Perhaps sleeping in water as a mammal requires mich more processing power.

Breathing is also a conscious action for them if I remember right

Re: Why birds do not fall while sleeping

#135

Post by VoodooJuJu »

avar wrote: post #77

This article doesn't even try to address what I feel is the deeper and more interesting question (but probably one that can't be answered): Why is it that horses, cows, giraffes and birds have all had to come up with a purely passive solution of "locking" themselves in place, either via their joints (for the four-legged), or via the tendon mechanism described here for birds? I.e. why wasn't in simpler in evolutionary…

Because evolution isn't a nerd optimizing a design. Design implies intent. Evolution is more random and serendipitous than a nerd with any sort of intent. It's not engineering. There's no specs & recs or post mortems or blueprints. Evolution is too beautiful, random, and mysterious for the enginerd to appreciate and understand.

Re: Why birds do not fall while sleeping

#136

Post by tsimionescu »

Ma8ee wrote: post #57
tsimionescu wrote: post #53

Earlier quoted context omitted.

> A single training session will iterate more than the number of generations of all birds. But that's not the right analogy. Evolution happens at the individual level, and even to some extent at the individual gamete level. So it's actually every single fecundated bird egg that ever existed, and even every single spermatozoon and egg cell every time two birds mated. Not to mention every division of every bacterial ce…

> since the DNA and gene expression of an individual actually changes during its lifetime, and those changes can be passed down to offspring through various mechanisms. That statements need a whole lot of backing. It contradicts the Central dogma of molecular biology [0]. The idea that an organism can pass on to its offspring physical characteristics that the parent organism acquired through use or disuse during its…

There are several processes, many of them documented on that very page, that allow an organism to pass on certain characteristics that happened during its lifetime to at least the next generation. One other example of such a process is horizontal gene transfer, typically through viruses, but also sometimes in plants through grafting.

For an extremely simple example, if a female organism is exposed to significant doses of radiation, the DNA inside the egg cells it was born with will have a high chance of suffering mutations. If one of those eggs remains viable and later gets fertilized, the DNA of the offspring produced from it will be significantly different from the DNA that of offspring born before the radiation exposure.

There are other more subtle and more common processes, though. The most surprising one is that DNA methylation, a process in which environmental stimuli encountered in a living sexually mature individual affect gene expression, has been proven to be transmissible to offspring across several generations in certain species. This includes stimuli such as prolonged exposure to heat or cold, long-term starvation, and others. This is indeed a form of Lamarckism that has actually been proven to happen, though of course it involves much subtler changes than some of what Lamarck envisioned.

Re: Why birds do not fall while sleeping

#137

Post by nonameiguess »

meindnoch wrote: post #78
avar wrote: post #77

This article doesn't even try to address what I feel is the deeper and more interesting question (but probably one that can't be answered): Why is it that horses, cows, giraffes and birds have all had to come up with a purely passive solution of "locking" themselves in place, either via their joints (for the four-legged), or via the tendon mechanism described here for birds? I.e. why wasn't in simpler in evolutionary…

Also, why didn't any animal evolve a way to avoid sleep completely?

Cnidarians and flatworms don't have a CNS and sponges don't have nerve tissue at all. I would think that means they don't do anything on a daily cycle that would match what we commonly call sleep.

I'd also wonder about creatures inhabiting extremely sparse environments like deep caves and undersea trenches, that spend most of their lives dormant and only seem to do anything at all when food happens to come around, which might only happen every few weeks or even every few years. They're probably not studied extensively enough to answer, but do they have anything like a sleep/wake cycle?

Re: Why birds do not fall while sleeping

#138

Post by onemoresoop »

harry_ord wrote: post #134
e40 wrote: post #124

Earlier quoted context omitted.

Each half sleeps alternately. Perhaps sleeping in water as a mammal requires mich more processing power.

Breathing is also a conscious action for them if I remember right

Dolphins need to come to surface to take air so you may be right. I also remember reading about how dolphins sleep and I remember there were 3 parts of the brain that were alternating sleep to make breathing possible.

Re: Why birds do not fall while sleeping

#139

Post by wruza »

cassepipe wrote: post #128
wruza wrote: post #107

Earlier quoted context omitted.

They must work just well enough. Nature doesn’t strive for an ideal, cause it has no ideas. It’s a semi-working minimum based on another semi-working minimum. A duplicated bone is just infinitely more likely than a completely new organ. And you don’t have to be free from cancer or arthritis or heart diseases if your population leaves just enough offspring in time. Iow, it’s not only robust enough, but just robust eno…

So evolution is a big pile of hacks ? :)

A concurrent optimization of stable reproduction (and nothing more) modulated by natural+emergent logistic maps.

Personally, and in hindsight ofc, I find abiogenesis much more miraculous than the life/evolution following it, cause the latter was sort of obvious and almost indestructible by its nature after it all started. It sort of just happens unamazingly in the complexity space it is lazily exploring (which itself is amazing that it exists).

Only intelligent agents can explore it with a goal different from (but still including) stable reproduction.

Re: Why birds do not fall while sleeping

#140

Post by palata »

Crazyontap wrote: post #12

When I was younger, I was fascinated by evolution, especially the intricacies of how things just work. This fascination also explains why many people believe in the intelligent design theory. However, witnessing the rapid evolution of AI with just a few hundred GPUs, enough data, and power, I no longer wonder what a billion years of feedback loops and randomness can achieve.

> However, witnessing the rapid evolution of AI with just a few hundred GPUs, enough data, and power, I no longer wonder what a billion years of feedback loops and randomness can achieve.

The thing with evolution is that it is robust. Even after the human species collapses (with everything it manages to bring down with it), evolution will still work.

Modern humans have been very quick at many things, but at the cost of breaking the conditions of their survival. One may say "that's wrong, with enough GPU a solution will appear", but on the other hand maybe we have already passed the tipping point where we actually cannot solve it anymore.

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