[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. ___________________________________________________________________ (page generated 2021-05-18 23:00 UTC)