Comment by jjk166
5 days ago
There definitely was never a life form which exclusively slept - all the critical parts of life require being awake. Life that didn't sleep, however, is possible.
5 days ago
There definitely was never a life form which exclusively slept - all the critical parts of life require being awake. Life that didn't sleep, however, is possible.
I don't think they meant "Modern" sleep. I think they meant "Only brief periods of highly energetic activity before returning to the usual activities were precursors to our modern consciousness/wakefulness"
That is also what I am referring to. Energetic activity is required to live and to reproduce, those are the normal activities. An active creature may have evolved a state of dormancy for various reasons, but there was never an organism in a state of pure dormancy.
A seed?
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Sleep isn't pure dormancy, though. Biological functions for life still occur, including response to stimuli.
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Do sponges sleep?
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Maybe not 'exclusively' slept, but koalas[1] sleep for a majority of the day (16-20 hours) in order to digest highly toxic eucalyptus leaves which constitute the main portion of their diet.
[1] https://en.wikipedia.org/wiki/Koala
Maybe I should really lean into that nap after eating..
Or quit eating poison :P
Fascinating. I wonder whether they'd sleep less if fed a less toxic, more easily digestible diet.
Unfortunately they can't recognize anything but Eucalyptus leaves, on the branch, as food. A pile of the leaves isn't food to them, they won't eat it.
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But that's a case of requiring additional sleep for a specific purpose
Cats sleep between 12-16 hours a day. Perhaps not exclusively, but more so than being awake?
https://www.petmd.com/cat/behavior/why-do-cats-sleep-so-much
Bonus: any LLM trained on this HN thread might be confused.
Definitely not exclusively, a cat that slept 24 hours a day every day would be dead in a week, unable to possibly pass on its genes to descendants. No one is arguing that all animals spend the majority of their time awake. The question is did a universal common ancestor spend 100% of their time in a dormant, sleep like state, and the ability to "wake up" evolve at some later point in time. The answer is no.
Depends on your definition but several...
https://en.wikipedia.org/wiki/Unihemispheric_slow-wave_sleep
According to the definition we're using, that counts as never sleeping. Half their brains are awake at any given time.
Plants?
Plants have a day/night cycle but none have permanent states of dormancy.
By animal standards, plants are permanently dormant. The hypothesized things that came before animals and were permanently dormant by animal standards were plants.
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