[HN Gopher] Hydras suggest that sleep evolved before brains
___________________________________________________________________
Hydras suggest that sleep evolved before brains
Author : theafh
Score : 224 points
Date : 2021-05-18 15:19 UTC (7 hours ago)
(HTM) web link (www.quantamagazine.org)
(TXT) w3m dump (www.quantamagazine.org)
| sva_ wrote:
| I feel like this article touches a lot more on the definition of
| what sleep is, rather than what people commonly refer to as
| sleep. I mean, what really defines sleep? I would've thought it
| is the temporary absence of consciousness in an otherwise
| conscious being. Or something along those lines. Of course that
| wouldn't make a lot of sense with medical comas and such.
|
| So maybe sleep is just a, perhaps regular, phase in which an
| organism is 'inactive', that is, doesn't perform a lot of actions
| or waste energy. Energy is limited after all. From an
| evolutionary perspective, it might make sense to have an organism
| not be dependent on a permanently available power source. It'd be
| better to alternate between using a lot of energy and using less
| energy, because permanent sources of energy are rare or even non-
| existing. Depending on such a permanent source would starve the
| organism to death and hence it wouldn't evolve. So you get those
| intervals and they'll naturally evolve to synchronize to the
| phases of their energy source. And that's supposedly the sleep
| cycle?
| forgotmypw17 wrote:
| Sleep is a whole-body process of repair and optimization. Many
| cultures chastise sleepers as lazy, but every time you sleep,
| it's like a big reconstruction process in your body.
|
| I think that sleep and allowing adequate time for it is the
| lowest hanging fruit for most people's health. Us site readers
| usually get enough to eat, and sometimes more, yet when was the
| last time you allowed yourself to sleep as much as you want to,
| without limit?
| slver wrote:
| Sleep is basic resource management: it takes too much resources
| to both run all macro systems, and also all microsystems (on
| cellular level). So they take turns and interleave through the
| sleep/wake cycle. As you say, microsystems take over during
| sleep.
|
| From a cell's perspective, they sleep while "we" are awake.
|
| This means sleep is advantageous to all multicellular
| organisms, unless there's great pressure for them to evolve
| hybrid alternatives (such as sleeping dolphins or migrating
| birds).
|
| It's a bit discouraging that in the mainstream we keep asking
| "but why sleep tho" or even worse, we keep propagating the
| wrong answers, when the principles lay before our eyes.
| est31 wrote:
| It's not just resource management. In humans, during sleep
| there is a cleanup program that gets rid of waste in your
| brain. My pet theory is that this is because running cleanup
| during the day would impair the function of the tissue too
| much, so it's ran during the sleep phase.
| slver wrote:
| Yes. Basically we're 2-in-1, we have two modes (macro and
| micro, or from macro perspective: operation and
| maintenance), and they're largely incompatible together for
| many reasons, but both are needed in order for the organism
| to exist within parameters.
|
| This pattern emerges in complex artificial systems as well.
| "Stop the world" garbage collection in some programming
| languages.
|
| Or the fact most stores prefer to not be open 24/7 not
| simply to save on salaries and power bills, but also to
| restock, reorganize shelves etc.
|
| The workweek/weeekend cycle is another trivial example. And
| so on.
|
| It's a bit like an OS that distributes time-slices of a
| single CPU core between a set of "background services" and
| "the main application".
| [deleted]
| wfn wrote:
| Your reduction is, I think, too simplistic. Some bacteria
| appear to also have some basic passive/active cycle, for
| example. It's really fascinating and there's tons of
| functions interleaved.
|
| _edit_ it 's not just multi/unicellular modes - REM is very
| close to awake state, cell activity wise (looking from PoV of
| brain waves emerging), with source of sensory input being
| switched to internal; and in deep sleep NREM, large parts of
| the brain (depends on the animal, hemispheres take turns in
| some) are in a sort of slow-mo sine wave "sync" (kinda
| amazing!) Etc. etc.
| slver wrote:
| My reduction strives to drive home the core of an idea that
| extends both at higher levels (i.e. we have passive/active
| cycles as a society as well, the most simple example being
| workweek/weekend), and lower levels, like your bacteria
| example.
|
| And yes, it's not about "one cell" vs. "all the cells",
| more generally it's about "higher-level systems" vs.
| "lower-level systems" where also some functionality
| serendipitously adapts/fits/evolves into one of those modes
| without specific regard about where it semantically sits in
| this hierarchy of complexity.
|
| Regarding REM sleep, I think our methodology and
| terminology is a bit too crude, electrical "activity" means
| very little about the state of the brain. For ex. you have
| no access to most of your memories while in REM sleep, you
| can't even determine you're sleeping most of the time, and
| when you do, you usually forget in a minute or two, your
| cognitive function is that low.
|
| Honestly the way you described REM sleep, it started
| sounding a bit like unit testing (inputs/outputs come from
| the repository, not from the user, and this process goes
| through the entire brain in order). :-) Which... actually
| might not be far from truth (in some aspects of it).
| wfn wrote:
| > where also some functionality serendipitously
| adapts/fits/evolves into one of those modes without
| specific regard about where it semantically sits in this
| hierarchy of complexity.
|
| That did make sense, I oversimplified your reduction on
| first pass :D yea, I agree, nice generalization. And I
| like this idea re: it not caring where it sits. _edit_
| how to even place it on a linear complexity scale
| anyway...
|
| > it started sounding a bit like unit testing
|
| In the book I mentioned elsewhere in the thread (Why we
| sleep), there are some interesting theories related to
| this... sifting through memories, colliding them
| together, decisions being made on what to keep, and so
| on. I sometimes wonder if REM sleep as we experience it
| is, in part, the phenomenological perception of a kind of
| encoding and compression process, looking from the
| inside, as it were. Well, in a way I didn't say much I
| guess, because you can model so many things as a type of
| compression :D but anyway. Yea, cool stuff...
| rorykoehler wrote:
| I slept for 10 hours last night and felt great today. It really
| is a great way to stay healthy (or regain health). I burned the
| candle a bit much last year building a side project and now I
| decided not to launch it because it really messed me up health
| wise and I can't commit to day job, family AND side project
| without it making me ill.
| kevmo314 wrote:
| > when was the last time you allowed yourself to sleep as much
| as you want to, without limit?
|
| I was told premature optimization was the root of all evil.
| the_local_host wrote:
| > Many cultures chastise sleepers as lazy, but every time you
| sleep, it's like a big reconstruction process in your body.
|
| The morning alarm is society telling you "stop reconstructing
| yourself, start working on our problems."
| have_faith wrote:
| Not using an alarm clock 90% of the time is one of the
| greatest privileges I experience in life. One which I wish
| more people were fortunate to share.
| falcor84 wrote:
| As a parent of a young child, I'd welcome the routine
| tyranny of an alarm clock
| fullstop wrote:
| Eventually the human alarm clocks do grow up.
|
| Part of the problem is that children occupy a lot of your
| time. After you get them in bed, it's tempting to stay up
| later than one usually would in order to have some
| personal time. This doesn't change the time that the
| human alarm clocks go off, though, and it can quickly
| spiral out of control.
|
| It gets better. When they are older you can include them
| into your passion projects, or whatever sort of hobbies
| you have. This part is great because you are both
| teaching them and having fun at the same time.
|
| I say this all the time because it showcases how little
| time you have with them, but you only have about 1,000
| weekends with them until they are adults. It all happens
| so fast. I enjoy the time that I spent with them,
| especially over the last year when we were all together
| as a family for so many months. I, myself, am nearing the
| end of those 1,000 weekends with my oldest and I miss
| some of those human alarm clock days when they were up
| early and just wanted to play together.
| bumby wrote:
| On a similar note:
|
| "It turns out that when I graduated from high school, I
| had already used up 93% of my in-person parent time."
|
| https://waitbutwhy.com/2015/12/the-tail-end.html
| astrange wrote:
| Even if you just have a pet, many of them are very
| excited for you to get up in the morning and feed them.
| And worse, they don't even understand DST!
| alostpuppy wrote:
| Oh man. You aren't kidding.
| nefitty wrote:
| A lot of us get a taste of this on weekends or days off,
| but what have you personally noticed the difference to be?
| Maybe in terms of productivity, fatigue, mood, health, etc.
| causasui wrote:
| I went from waking up at 6AM every day for 6 years (US
| mil) to not setting an alarm in the last 6 (remote
| employee). The main thing I notice in the rare event
| where I have to set an alarm these days is this 15-30
| minutes of heavy brain fog after waking up. In my
| experience it feels very similar to the sensation in your
| head shortly after you've taken a dose of melatonin,
| which I guess makes sense. It's hard to put into words
| but obviously we've all experienced it. I don't ever
| experience this sensation waking up naturally.
|
| The end result is early morning grumpiness, in my case.
| I'm just in a foul mood for the first hour or two after
| being ripped from sleep via an alarm. I otherwise don't
| feel more productive or healthy.
|
| I'm curious why this is; I assume it has to do with the
| natural sleep cycle. Do those chemicals metabolize in
| some way shortly before you wake up naturally vs waking
| up by an alarm where they're still present?
| have_faith wrote:
| I find it to be almost universally positive. I'm a
| freelancer and I work practically "full time" but I don't
| start work until I naturally wake up unless I happen to
| have a meeting scheduled.
|
| One of first things I noticed is hunger. When I wake up
| to an alarm I generally feel sluggish and immediately
| hungry. If I wake up to my alarm at 8 then I need to eat
| almost immediately. If I naturally wake up at 9 I might
| potter about and eat breakfast at 10 without thinking
| much about it. Alarms seem to induce stress and stress
| induces hunger.
|
| I generally find that only having weekends alarm free
| provides just enough respite and replenishment for taking
| on the work week but not enough to reduce mental stress
| across the board. Being able to have a lay in on any
| given day that requires it makes a world of difference to
| mid week slumps.
| SketchySeaBeast wrote:
| Do you find your sleep skews? Any longer (2-3 week)
| vacations I've taken I've found that my waking up time
| keeps skewing even if I'm not going to bed later. Maybe
| I've never seen the end where it stabilizes.
| have_faith wrote:
| My wake up time is a 2 hour window between 7:30 and 9:30
| but usually around the middle of that. It varies day to
| day. Whether it's earlier or later mostly depends on how
| much exercise I do the day before. My training has large
| spikes where I go out rock climbing all day and then have
| multiple "rest" days so I let my body get whatever sleep
| it needs.
| jedberg wrote:
| At the beginning of the pandemic, no one in our family
| had any fixed time obligations other than my afternoon
| meetings, so we basically stopped enforcing any bedtimes
| or wake up times for the kids (and ourselves).
|
| Pre-pandemic we were all waking around 8am to get my
| daughter to pre-school. Within a week of foregoing
| bedtimes, we were all going to bed between 2am and 4am
| and waking up around 11am. So the kids still got their 9
| hours and the adults got their 7, but it did stabilize.
| gibspaulding wrote:
| My waking times definitely skew, but for me I think it
| happens because my bed time pushes it later and later
| until my night owl habits and my guilt over sleeping late
| reach an equilibrium.
|
| When I was in college I'd pretty quickly drift to a
| 4:00AM to noon sleep schedule on holidays. Even today (in
| my mid 20's) I find I'm happiest sleeping from roughly
| 2:00AM to 10:00AM.
| hypertele-Xii wrote:
| (Not the parent)
|
| My sleep cycle naturally drifts infinitely by some 30
| minutes a day on average.
|
| It makes life strange at times, especially on this
| latitude. Imagine waking up at night through a whole
| winter, not seeing the Sun for months.
|
| I've tried to hold steady cycle but I just grow more and
| more tired every day until finally the alarm fails to
| wake me. School was hell. Was absent a lot simply for
| sleeping.
| kenjackson wrote:
| Isn't it the case that physical height growth occurs during
| sleep? That's more evidence that sleep is a whole body process.
| slver wrote:
| That part in particular is as simple as... you get higher
| because you're laying down, so there's no vertical pressure
| on your back.
| kenjackson wrote:
| Not the nightly half-inch, but like your growth from 18" to
| 6' over the course of your life happens while you sleep.
| wombatmobile wrote:
| How would you measure 8 hours of that?
| forgotmypw17 wrote:
| I think the basic answer to that is: by measuring height
| before and after, controlling for laying down still but
| not sleeping, perhaps also with some intermediate
| measurements.
| wombatmobile wrote:
| If most of human height growth occurs in the first 20
| years of life, that's about 200 microns per 24 hours. Can
| you measure that accurately? What sort of fluctuating
| errors would be introduced by for example, temperature
| and hydration?
| slver wrote:
| Ah yeah, growth occurs mostly during sleep. Vast majority
| of it. Growth hormone is actually released mostly during
| sleep.
|
| When a cell has to function as part of a higher-level
| system, "dividing" is kind of disruptive. So this happens
| while we sleep.
| yamrzou wrote:
| > Sleep is a whole-body process of repair and optimization.
|
| This is what I felt when I watched the Netflix documentary "My
| Octopus Teacher".
|
| At some point, the octopus was vigorously attacked by a shark,
| which cost her a tentacle. She was bleeding and retreated to
| her den.
|
| The attack made her very weak. She could no more change colors,
| nor get out of the den, even to get food.
|
| After a week or so in the den, presumably sleeping, she started
| recovering and her arm started to regenerate.
| manquer wrote:
| This is not surprising, for consciousness to awaken, it has to be
| asleep first !
| ajdude wrote:
| I wouldn't be surprised if sleep is an aspect of a nervous system
| in general. Last year an article came out about how even
| artificial neural networks benefited from sleep. Perhaps it's the
| nature of the beast.
|
| https://news.ycombinator.com/item?id=24018131
| wombatmobile wrote:
| Hydras, like c. elegans, cockroaches, fruit flies, humans,
| sponges and all the other animals named in TFA are eukaryotes.
|
| What about prokaryotes? Do they sleep?
| _Microft wrote:
| Here is something on cyanobacteria showing sleep-like behaviour
| during which they do not divide.
|
| https://phys.org/news/2010-03-cell-division-cyanobacteria-ki...
| Sniffnoy wrote:
| I mean, they're all _animals_. Prokaryotes are far less related
| to animals than e.g. fungi or plants would be.
| wombatmobile wrote:
| You would know that eukaryotes evolved from prokaryotes.
|
| So, the interesting point of the question is whether sleep is
| something that occurs at the cellular level or the organism
| level.
|
| See the article linked to in the comment above, about
| cyanobacteria.
|
| > Cyanobacteria maintain their circadian rhythms even when
| isolated from the naturally occurring daily light-dark cycles
| of the sun, just as humans do. The researchers found that
| under conditions of moderate constant light, the
| cyanobacteria undergo cell division about once per day, and
| the divisions take place mostly at the midpoint of the
| 24-hour cycle.
| periheli0n wrote:
| Strictly speaking insects are not animals AFAIK
| Balgair wrote:
| Insects are animals:
|
| https://en.wikipedia.org/wiki/Grasshopper
|
| Infobox on the right-> Kingdom: Animalia, Phylum:
| Arthropoda, Class: Insecta.
| [deleted]
| kens wrote:
| The article describes how sleep has been found in simpler and
| simpler animals. But I wonder if you could go further: do plants
| sleep? It seems like an absurd idea, but on the other hand there
| was an article a few months ago, "Anesthesia works on plants too,
| and we don't know why".
|
| https://news.ycombinator.com/item?id=25591443
| Voyiatzis wrote:
| Anesthesia works on humans too, and we still don't know why.
| coderintherye wrote:
| Plants also have nyctinasty which isn't sleep but is
| interesting: https://www.livescience.com/34569-why-flowers-
| close-at-night...
| perl4ever wrote:
| There was a paper, I think it was also linked on HN via quanta
| magazine, where some researchers seemed to have pinpointed the
| reason why sleep is necessary to live, at least for animals and
| insects.
|
| However, it seemed too good to be true (I can only wait to see
| if there is a Nobel prize) and it's not clear to me what to
| make of it.
|
| The gist of it was that the fundamental damage from lack of
| sleep actually originates in the gut, not the brain, across
| rather different species, (mice and fruit flies) where
| "reactive oxygen species" (iirc) cause cumulative damage that
| is eventually fatal.
|
| The researchers claimed they had confirmed causality by
| reversing the shortened lifespan in fruit flies deprived of
| sleep by feeding them antioxidants.
|
| I have never seen a paper that seemed to so thoroughly
| eliminate the possibility of a misleading correlation, but the
| sticking point for me is, if it is so simple to avoid the need
| for sleep, why hasn't it been eliminated by evolution in the
| first place?
|
| (Sleep Loss Can Cause Death through Accumulation of Reactive
| Oxygen Species in the Gut Vaccaro, Alexandra et al. Cell,
| Volume 181, Issue 6, 1307)
| Buttons840 wrote:
| The book Why We Sleep mentioned an experiment. Some plants
| obviously change during day or night, extending leaves during
| the day and letting them droop at night, something like that
| from what I remember. People thought the plant was just
| reacting to the sunlight, until they put the plant in total
| darkness for several days and observed it going through the
| same cycles. The plant was not only responding to light, but
| also to an internal timer. Depending on how you define sleep,
| this is sleep. Granted plants don't use sleep for all the same
| purposes as animals.
| xxpor wrote:
| I don't know if you could call it "sleep" per se, but there are
| certainly plenty of plants that need a daily period of darkness
| to grow properly. This comes up when growing indoor plants when
| people say you shouldn't run a grow light 24/7.
| grawprog wrote:
| Plants increase their respiration at night and stop
| photosynthesizing.
|
| https://www.bbc.co.uk/bitesize/guides/zxtcwmn/revision/1
|
| It seems kind of like sleeping to me.
| Florin_Andrei wrote:
| I mean, that's like 99.9999....% expected, since they all
| evolved with a big light signal in the sky that operates on
| a 24 hr cycle. Plants, even more than animals, should be
| optimized to function that way (do mostly resource
| production at day, do mostly maintenance at night).
| dan-robertson wrote:
| One difference at night is that it is cooler, so less water
| may be lost when the stomata are opened for gas exchange.
| Many plants (separately) evolved a photosynthesis cycle
| where gases need only be exchanged at night and the stomata
| may be closed during the day.[1] While the actual
| photosynthesis reaction happens during the day, the
| nighttime preparation is needed, and should perhaps be
| counted towards the effort.
|
| https://en.m.wikipedia.org/wiki/Crassulacean_acid_metabolis
| m
| ASalazarMX wrote:
| Although without sunlight, they have no choice but to stop
| photosynthesizing.
|
| Then we have plants like the dracaena fragans, whose
| flowers remain closed at day, but open and release their
| delicious fragrance all night. I'm not sure how sleep would
| work for her.
|
| https://en.wikipedia.org/wiki/Dracaena_fragrans
| periheli0n wrote:
| Daytime sleeping is not unheard of.
| einpoklum wrote:
| Nitpicking: "stop photosynthesizing" is just a direct
| consequence of the lack of ambient light. People stop
| getting sunburn at night, that's not part of "sleeping".
|
| Other than that: +1.
| ivanhoe wrote:
| Plants physiology changes significantly during the night,
| so it's not just "no more photosyntheses without Sun"...
| respiration rates at night are strongly correlated with
| the amount of stored carbon and sucrose in the leaf
| tissue, which is probably related to the fact that plants
| also grow faster at night.
| DoreenMichele wrote:
| Maybe not.
|
| Plants have two sources of nutrition: uptake via their
| roots and photosynthesis. My general understanding is
| that photosynthesis is what provides them energy whereas
| uptake via roots provides water and some essential
| nutrients they can't synthesize.
|
| The details will vary and some plants, for example, grow
| in total darkness or feed parasitically on other plants.
| But I think photosynthesis is roughly the equivalent of
| humans eating carbs for energy.
|
| So it's a little like saying "One defining characteristic
| of sleep is that animals stop eating." And, in fact,
| hibernation through the winter when food is in very
| limited supply is a known mechanism of survival for some
| species in harsh climates: They sleep instead of eating.
|
| In fact, my understanding is that to some degree eating
| and sleeping are substitutable. If you can't sleep, you
| can eat to help keep yourself functional while awake on a
| long shift.
|
| I think they do this on episodes of _Deadliest Catch_ :
| feed people more when they are pulling a long shift and
| going to be awake for 24 hours straight.
| wombatmobile wrote:
| Well, you raise a non-trivial point that is more than
| just a semantic issue, viz what do we mean by "sleep"?
| [deleted]
| dandare wrote:
| Shout out to the beautiful design of this web. The loop video of
| the hydra at the beginning is meaningful and super informative!
| lethologica wrote:
| I came here to say this as well. The video is so crisp and
| detailed that it is mesmerising. And being able to view it from
| the comfort of my iPad screen? Wow. Technology really is
| amazing. It's funny (and maybe sad) that it took something as
| small as a quality video loop for me to really appreciate all
| of the things involved in the process of me being able to view
| that video.
| stevenalowe wrote:
| Every complex mechanism requires some form of downtime for
| maintenance
| Phenomenit wrote:
| I would rather say all forms of combustion produces pollutant
| that needs to be dealt with.
| papito wrote:
| I mean, do you want to live in a world where no one ever
| sleeps?
| amelius wrote:
| proof -> evidence
|
| Evolution has reinvented many things in different ways.
| mark_l_watson wrote:
| Interesting that sleep has functionality for resting the body as
| well as then brain. Off topic, sorry, but: hydras and rotifers
| were my favorite pond creatures to look at under my microscope
| when I was a little kid. Hydras were much more difficult to find.
| DoreenMichele wrote:
| _Sleep might have helped to maintain the first sleeper's
| rudimentary nervous system, but it could just as easily have been
| for the benefits of its metabolism or digestion. "Before we had a
| brain, we had a gut," he said._
|
| I will note that the nervous system of the human gut is so
| complex that some people speak of it as "a second brain" and
| there is growing evidence that the gut biome and what we eat
| significantly impact brain chemistry.
|
| _If jellyfish sleep, that suggests sleep may have evolved more
| than 1 billion years ago_
|
| This is sort of off topic.
|
| When me and my adult sons were first homeless, we spent a month
| in Port Aransas. While we were there, there was a big storm and
| this storm left a lot of jellyfish stranded on the beach.
|
| My oldest son set out to rescue some of them. He would take a
| plastic container and plastic utensils and flip them into the
| container so they couldn't sting him. He would get five or six of
| them into the container and in his first attempt, he just walked
| out into the water and dropped them in the water and then he had
| to get the hell out of the way so they wouldn't wash into his
| legs and sting his legs.
|
| So he began walking out onto the jetty so he could drop them into
| the water while standing on a rock. That way he was in no danger
| of being stung because he wasn't standing in the water he was
| dropping them into. The other reason he began going out onto the
| jetty is because they were getting washed back up onto the beach.
| He felt it wasn't working at all.
|
| And he told me that the jellyfish stranded on the beach all
| closed themselves up as best they could, as if trying to conserve
| water while on dry land in hopes of surviving long enough to wash
| back out to sea.
|
| He reads really fast and has always been interested in science.
| He knows more about science than I ever will and he told me he
| had never read anything like that about jellyfish behavior.
|
| Once he dumped them in the water, they "uncurled" and began to
| pump immediately. So perhaps they were sort of "asleep" or
| hibernating while on land and once they were in water and safe
| from this harsh environment that was threatening to be the death
| of them, they would revive and resume pumping.
|
| He went on a bit about that. He thought it was really exciting
| and interesting stuff.
|
| I think he saved a few dozen jellyfish over the course of about
| three days.
|
| Edited for accuracy after fact checking with my son.
|
| In talking with him, he said that at first he thought it was
| coincidence that they were kind of closed up. But after seeing
| them all immediately open up and start pumping, he decided "No, I
| think this is deliberate."
|
| Additional update:
|
| He quit trying to rescue ones that were flat and a different
| color because he concluded they were dead. Those didn't pump when
| they went back in the water. The ones that were curled up were
| still alive.
|
| (Read by my son, edited in accordance with his wishes and signed
| off by him as an acceptable telling of the story. There should be
| no further edits after this.)
| it wrote:
| This is evidence in favor of the hypothesis that consciousness
| happens in microtubules.
| https://en.wikipedia.org/wiki/Orchestrated_objective_reducti...
| ncmncm wrote:
| My question is whether ctenophores sleep. These are the critters
| we used to call "comb jellies", and thought they were related to
| jellyfish. But it appears, according to some biologists, that
| they invented nerves independently of the other animals; they use
| different molecules for the job, controlled by different genes.
|
| For an eye-opening introduction to ctenophores, look up some
| youtube sequences of Beroe eating other ctenophores.
|
| https://www.youtube.com/watch?v=1xkNPp6mzzI , e.g., at 37s in, or
| https://www.youtube.com/watch?v=eDS_NMrPPKc at 2:50.
|
| I don't know if anybody has studied ctenophore sleep. You could
| be the first!
| papito wrote:
| Man, working from home has the advantage of a power nap, or a
| "coffee power nap", which basically makes you feel like it's the
| second morning of the day.
|
| https://www.vox.com/2014/8/28/6074177/coffee-naps-caffeine-s...
| nsxwolf wrote:
| Coffee, by itself, doesn't affect me much. Could this be the
| secret to making it work?
| astrange wrote:
| Most of the effect is because it's addictive. This does work,
| but of course it's better to get enough sleep at night.
| jimmytucson wrote:
| > She distilled a set of behavioral criteria to identify sleep
| without the EEG. A sleeping animal does not move around. It is
| harder to rouse than one that's simply resting. It may take on a
| different pose than when awake, or it may seek out a specific
| location for sleep. Once awakened it behaves normally rather than
| sluggishly. ... A sleeping animal that has been disturbed will
| later sleep longer or more deeply than usual, a phenomenon called
| sleep homeostasis.
|
| When you define "sleep" this way, without reference to the brain
| or consciousness, it's not all that surprising that animals
| without brains can "sleep".
|
| If you take out the criteria having to do with locomotion, so as
| not to exclude organisms that don't need it, plants probably
| sleep too...
| Sniffnoy wrote:
| Really? Certainly it's not surprising that animals without
| brains might go without movement for periods of time, but why
| would you expect them a priori to have a state that meets all
| these criteria?
| [deleted]
| Fellshard wrote:
| Alternatively: God Himself is one who rests, and He built a
| pattern of rest into His creation. (Genesis - 'on the seventh day
| He rested'; Deuteronomy 5:13 - 'Six days you shall labor and do
| all your work, but the seventh day is a sabbath of the Lord your
| God; in it you shall not do any work, you or your son or your
| daughter or your male servant or your female servant or your ox
| or your donkey or any of your cattle or your sojourner who stays
| with you, so that your male servant and your female servant may
| rest as well as you.')
|
| Why is that important? God cares for His creation and gave rest
| as a good gift to be enjoyed as He commands. But He also used it
| to point to Christ, and to eternal life! Hebrews 4 talks about a
| final 'Sabbath rest for the people of God', one that you may
| enter into, no longer having to strive and toil to accomplish
| things.
|
| Why the theology lesson on HN? There's always a dual to what
| evolutionary hypothesis tends to claim in its discoveries.
| Genetic links between different species that are better explained
| as common components from the same designer than mutual ancestry,
| for example.
| ceejayoz wrote:
| In your rush to inject religion, you've mixed up rest and
| sleep.
| chownie wrote:
| That, and if genome similarities were to be explained away by
| an intelligent designer using the same "toolbox" (so to
| speak) then why would he create crabs multiple times without
| using those same widgets?
|
| Leaps of faith seem to introduce more questions than they're
| able to answer.
| slver wrote:
| > That, and if genome similarities were to be explained
| away by an intelligent designer using the same "toolbox"
| (so to speak) then why would he create crabs multiple times
| without using those same widgets?
|
| I also don't know why I keep writing StringUtils every few
| months, but I just... like it. Guess God likes crab-like
| things and it's too annoying to merge from old codebases.
| andrewprock wrote:
| Given that the default state of being is "not awake" it's
| reasonable to suppose that sleep evolved first, and then
| wakefulness.
| coliveira wrote:
| This gives additional evidence to my personal hypothesis that the
| normal state of living beings is sleeping. The awake state only
| appeared as a survival strategy, to better adapt to the natural
| environment.
| slver wrote:
| Depends what you focus on as your definition of "living
| beings". If you look at our cells, they behave more naturally
| while we sleep. While we sleep, they're "awake". So yes, that's
| their natural state.
|
| But the "multicellular organism" mode they switch while we're
| awake is necessary for them to be more than a pile of cells.
| Which indeed is very important for our survival, as complex
| behaviors that only multicellular organisms have, are crucial
| to our ability to adapt.
| jimmytucson wrote:
| "Normal" is arbitrary, but since most animals need to be awake
| to reproduce it's hard to envision enough of them always
| sleeping for it to be the default.
| coliveira wrote:
| By the time complex animals evolved, the awake state would
| already be the norm for survival. So, I guess everything we
| now assign to complex animals is already dependent on the
| appearance of an awake state.
| lisper wrote:
| > the normal state of living beings is sleeping
|
| This is reminiscent of the claim that zebras are black with
| white stripes (or is it the other way around?)
| outworlder wrote:
| > The awake state only appeared as a survival strategy, to
| better adapt to the natural environment.
|
| Well. Given that "awake" creatures react to stimuli, that might
| not be too far off the truth. If we could passively survive and
| not have to forage or hunt for food, what's the point of
| 'waking up'?
|
| Sleeping is advantageous (less energy use). Efficiency is
| usually selected for, unless there's some other kind of
| environmental pressure.
|
| Maybe that's why we haven't found other civilizations. They are
| all 'sleeping'. Maybe consciousness is also unnecessary (on
| that front, I love https://rifters.com/real/Blindsight.htm)
| ASalazarMX wrote:
| While Peter Watts' writing feels like he enjoys being
| intentionally abstruse, his books are very thought provoking.
| I still get reminded about the concepts in Blindsight from
| time to time, years after I read it.
| twhb wrote:
| A fascinating idea.
|
| For your hypothesis to work, and I think this is what you mean
| by the article supporting it, sleep would have had to evolve
| very early. Because being awake activates a great deal of a
| modern organism's complexity, and that complexity wouldn't have
| evolved in an always-sleeping organism that doesn't benefit
| from it. So either the predecessors were awake, or sleep came
| before all the complexity that is now activated only when
| awake.
|
| For the first wakers, then, being awake was little more than a
| period of increased activity. A boost mode. And indeed we've
| already seen the utility of boost modes across a variety of
| technology, from CPUs to cars to high output flashlights.
|
| But does that make the predecessors really asleep? To use a
| very HN analogy, were pre-boost CPUs always idling?
| gibspaulding wrote:
| It doesn't seem like too far of a stretch to guess that the
| earliest life forms would have been pretty passive, absorbing
| nutrients directly from their "primordial soup" and somehow
| replicating whenever they've stored up enough. I imagine
| "life" would have gone on for quite some time before "waking
| up" and evolving the ability respond to their environment by
| doing things like relocating to a more nutrient rich area or
| away from danger.
| coliveira wrote:
| > But does that make the predecessors really asleep?
|
| Well, not directly, but we can certainly talk about the
| appearance a distinct state, which would now be called awake
| state in comparison to previous organisms that had a single
| state. After this appearance it makes sense to talk about
| previous life forms as "sleeping".
| TylerLives wrote:
| What do you mean by "the normal state of living beings"?
| serverholic wrote:
| Surely you understand that most people consider being awake
| to be our default state and sleeping is just something that
| we need to do sometimes
| slver wrote:
| The way you phrased is reminded me how blindly we walk
| through life, doing things that our body forces us to do,
| because despite all our bravado about how smart we are...
| we really have no clue what we do and why we do it most of
| the time.
| vmception wrote:
| It means that being aware of surroundings with continual
| sensory input and influence is the aberration.
|
| This matches some other theories as well, where humans and a
| few other always awake organisms are the extreme, due to
| selective pressures. For example, humans "feel bored" because
| having nothing pressing to do for survival is usually the
| wrong option. Whereas that isn't true for many other
| organisms and they likely wouldn't have an opinion about
| staying still in the same place for prolonged periods of
| time.
| [deleted]
| [deleted]
| wfn wrote:
| This is basically what Matthew Walker
| (https://en.wikipedia.org/wiki/Matthew_Walker_(scientist)) sort
| of alludes to in his book, "Why we sleep". It's a good book. He
| specifically mentions hydras as well (iirc)... he's a
| neuroscientist who is a crazy maniac about sleep and he cites
| newest research and delivers a very clear message of urgency.
|
| Lots of fascinating stuff there, highly recommend if you're
| interested.
| slver wrote:
| What is his clear message of urgency?
| wfn wrote:
| In my view (of his view) - that in many cultures we see
| today, we've come to vastly underestimate the importance of
| sleep. For example, we've removed afternoon naps from
| workday routine (with field evidence showing effects on
| health such as heart disease (against comparative groups
| who haven't stopped taking naps - but not lab-controlled I
| think) etc.) We sleep less.[2]
|
| We shouldn't be asking what's the purpose of this pesky
| thing called sleep (which evolution turns to _always_
| incorporate into animal life, however inconvenient it
| is[1]; to route around the inconveniences as it were,
| rather than the other way around). We should rather be
| asking, is there a single function which isn 't improved by
| sleep (Walker thinks no). End of preach rant :)
|
| [1]: e.g.: some birds appear to sleep in patterns such as
| when there's a row of birds sleeping, the two birds at each
| end sleep with one hemisphere each - but opposite ones - so
| that the field of vision is maximised. At midpoint in time
| however they _swap places_. The rest of the birds sleep
| with both hemispheres. That sounds pretty cool.
|
| [2]: though apparently there's criticism directed at Walker
| re: this, and re: him not mentioning that mortality appears
| to increase beyond the 7 hour mark (but I'm just learning
| this, so basically, just a fair warning not to take all of
| this at face value, there's nuance).
| slver wrote:
| Ah, I align with him then.
|
| Regarding mortality and the 7 hour mark, this is such
| unfortunate bullshit, that keeps being propagated by
| people who should know better. Ill people sleep more
| (even if you catch a cold, once you get past the peak,
| you sleep more for a few days) because their body
| requires more recovery.
|
| In chronically ill people this continues for a long time
| and the body never is able to catch up to the problem
| it's trying to solve.
|
| But despite all the "correlation not causation" mantras
| repeated by everyone, we keep citing this as if we decide
| to sleep a bit more that'll make it more likely to die,
| which is nonsense.
| wfn wrote:
| Ah okay, so basically you're saying that the mortality vs
| > 7 hour sleep time correlation claim hasn't normalized /
| accounted for other parent causes (e.g. chronic illness
| and other things affecting / disturbing sleep quality)?
| I'm a noob here, but if that is the case, that is very
| unfortunate and frustrating.
| slver wrote:
| I've not seen a single study to demonstrate causative
| link, or conclusively eliminate other variables (which is
| frankly quite impossible anyway).
|
| Unfortunately a lie repeated a thousand times (by media)
| becomes truth. And it's just too juicy of a news to say
| "sleeping too much bad for health". Especially managers,
| they love that kind of news ;-)
|
| BTW my frustration is pointed at general media and
| society, not you in particular, I wasn't clear.
| tinyhouse wrote:
| Regarding naps. Pretty much every sleep expert I heard or
| talked to is against naps during the day. Mostly because
| it disturbs night sleep.
| pamplemoose wrote:
| Important to note there has been pushback on Matthew Walker's
| writing. Feel free to read more from Alexey Guzey [1] or
| Andrew Gelman [2].
|
| [1]https://guzey.com/books/why-we-sleep/
| [2]https://statmodeling.stat.columbia.edu/2020/03/24/why-we-
| sle...
| wfn wrote:
| P.S. are you familiar with Walker's response as well?
| https://sleepdiplomat.wordpress.com/2019/12/19/why-we-
| sleep-... I'll familiarize myself later, and thank you
| again
| wfn wrote:
| Hey, thanks, I'll check it out! Haven't gotten around to
| reading critique of Walker, but I should. Thank you
| agambrahma wrote:
| This is the most weird and interesting hypothesis I've heard in
| a LONG time !
| periheli0n wrote:
| The evolution of sleep may or may not predate the evolution of
| brains. It might have evolved twice, once in predecessors of
| hydras and once in predecessors of beings with brains.
| vmception wrote:
| agreed, divergent evolution is very common
| dragonwriter wrote:
| The upthread suggestion is actually of convergent, not
| divergent, evolution.
| vmception wrote:
| thats funny because I googled it before I wrote it and
| still wrote the wrong one
| jfengel wrote:
| It's amazing how bad our brains can be, even after a few
| million years of evolution. They're capable of flying a
| helicopter on Mars and cranking out a vaccine within
| months, as well as developing vast machines containing
| zettabytes of information -- and still can't retain a
| word for 15 seconds.
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