ISF Logo   IS Forum
Forum Index Register Members List Events Mark Forums Read Help

Go Back   International Skeptics Forum » General Topics » Science, Mathematics, Medicine, and Technology
 


Welcome to the International Skeptics Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.
Reply
Old 19th February 2018, 01:49 AM   #1
Cheetah
Graduate Poster
 
Cheetah's Avatar
 
Join Date: Feb 2010
Posts: 1,408
Why do animals need Sleep.

Dunno if this is the final answer but it looks like your brain needs a rest to recover.

Article here.

Quote:
Striking electron-microscope pictures from inside the brains of mice suggest what happens in our own brain every day: Our synapses - the junctions between nerve cells - grow strong and large during the stimulation of daytime, then shrink by nearly 20 percent while we sleep, creating room for more growth and learning the next day.
Quote:
The team deliberately did not know whether they were analyzing the brain cells of a well-rested mouse or one that had been awake. When they finally "broke the code" and correlated the measurements with the amount of sleep the mice had during the six to eight hours before the image was taken, they found that a few hours of sleep led on average to an 18 percent decrease in the size of the synapses. These changes occurred in both areas of the cerebral cortex and were proportional to the size of the synapses.
__________________
"... when you dig my grave, could you make it shallow so that I can feel the rain" - DMB
Cheetah is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 02:41 AM   #2
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Fascinating study, very simple, of course this may just be a correlation. Given the prevalence of sleep throughout the animal kingdom it is unlikely it doesn't serve a necessary purpose.
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 03:18 AM   #3
angrysoba
Philosophile
 
angrysoba's Avatar
 
Join Date: Dec 2009
Location: Osaka, Japan
Posts: 24,953
I once heard someone pointing out that we may have got this question back to front and asked ďwhy do animals need to be awake?Ē Given that some animals can probably get by without being conscious or with only a rudimentary consciousness, isnít wakefulness an adaptive survival strategy for such things as catching prey or building nests etc... given that sleep is far more economical, animals can stay alive longer by sleeping much of the time.
__________________
"The thief and the murderer follow nature just as much as the philanthropist. Cosmic evolution may teach us how the good and the evil tendencies of man may have come about; but, in itself, it is incompetent to furnish any better reason why what we call good is preferable to what we call evil than we had before."

"Evolution and Ethics" T.H. Huxley (1893)
angrysoba is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 03:22 AM   #4
Cheetah
Graduate Poster
 
Cheetah's Avatar
 
Join Date: Feb 2010
Posts: 1,408
Yes Darat, it really must serve a necessary purpose, it's such a weird thing to have to do, sleep.
__________________
"... when you dig my grave, could you make it shallow so that I can feel the rain" - DMB

Last edited by Cheetah; 19th February 2018 at 03:23 AM.
Cheetah is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 03:37 AM   #5
Cheetah
Graduate Poster
 
Cheetah's Avatar
 
Join Date: Feb 2010
Posts: 1,408
Originally Posted by angrysoba
I once heard someone pointing out that we may have got this question back to front and asked "why do animals need to be awake?" Given that some animals can probably get by without being conscious or with only a rudimentary consciousness, isnít wakefulness an adaptive survival strategy for such things as catching prey or building nests etc... given that sleep is far more economical, animals can stay alive longer by sleeping much of the time.
That does not make sense to me. Animals need to be awake to do everything they do.

Whether an animal has no consciousness, only instincts, or just a rudimentary consciousness, they still use their whole brains to function.

It has been proposed that sleep allows animals to use less resources by being inactive but this theory also does not hold water.
__________________
"... when you dig my grave, could you make it shallow so that I can feel the rain" - DMB
Cheetah is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 04:39 AM   #6
GlennB
Loggerheaded, earth-vexing fustilarian
 
GlennB's Avatar
 
Join Date: Sep 2006
Location: Arcadia, Greece
Posts: 24,556
Originally Posted by Cheetah View Post
That does not make sense to me. Animals need to be awake to do everything they do.

Whether an animal has no consciousness, only instincts, or just a rudimentary consciousness, they still use their whole brains to function.

It has been proposed that sleep allows animals to use less resources by being inactive but this theory also does not hold water.
Being awake when activity is useless could be wasteful, so it's better to sleep? If you feed by gathering fruit and nuts in high branches you might need daylight. If you hunt nocturnal animals then being awake during the day is pointless.
__________________
"Even a broken clock is right twice a day. 9/11 truth is a clock with no hands." - Beachnut
GlennB is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 08:34 AM   #7
Cheetah
Graduate Poster
 
Cheetah's Avatar
 
Join Date: Feb 2010
Posts: 1,408
Originally Posted by GlennB View Post
Being awake when activity is useless could be wasteful, so it's better to sleep? If you feed by gathering fruit and nuts in high branches you might need daylight. If you hunt nocturnal animals then being awake during the day is pointless.
Yes, sleep saves a lot of energy in comparison to being active, but not that much in comparison to being awake and inactive.
Animals that are active 24h a day, like dolphins, albatrosses, walruses etc. are still forced to sleep, but half a brain at a time for short periods.
I addition animals are very vulnerable when sleeping, it is quite a risk.

If sleep was purely a energy saving mechanism you would also expect at least some animals to, during times of plenty, not sleep, as they would be able to gather more resources during "sleep time" and end up ahead of animals that do sleep. This would be especially advantageous to grazers/herbivores during seasons of plenty. I know of no animals that do not need any sleep.
__________________
"... when you dig my grave, could you make it shallow so that I can feel the rain" - DMB
Cheetah is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 08:41 AM   #8
Belz...
Fiend God
 
Belz...'s Avatar
 
Join Date: Oct 2005
Location: In the details
Posts: 81,554
Originally Posted by Cheetah View Post
Yes Darat, it really must serve a necessary purpose, it's such a weird thing to have to do, sleep.
Why? It seems reasonable to assume that a biological machine needs some off time.
__________________
Master of the Shining Darkness

"My views are nonsense. So what?" - BobTheCoward


Belz... is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 08:47 AM   #9
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Originally Posted by Belz... View Post
Why? It seems reasonable to assume that a biological machine needs some off time.
Why does it seem a reasonable thing?
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 08:49 AM   #10
Belz...
Fiend God
 
Belz...'s Avatar
 
Join Date: Oct 2005
Location: In the details
Posts: 81,554
Originally Posted by Darat View Post
Why does it seem a reasonable thing?
Because things that operate, break. Resting allows you to not only save energy but repair damage and perform maintenance, for lack of better terms.
__________________
Master of the Shining Darkness

"My views are nonsense. So what?" - BobTheCoward


Belz... is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 08:57 AM   #11
fuelair
Cythraul Enfys
 
fuelair's Avatar
 
Join Date: May 2006
Posts: 58,235
Originally Posted by Belz... View Post
Because things that operate, break. Resting allows you to not only save energy but repair damage and perform maintenance, for lack of better terms.
Pretty much this according to medical /biological studies - especially the brain but not only the brain. There is a lot of research and a lot of sources on the internet about these things. And in the offices of the doctors I occasionally need to sit in - I am the one who reads their journals, not the general audience
stuff. My deceased wife even moreso.
__________________
There is no problem so great that it cannot be fixed by small explosives carefully placed.

Wash this space!

We fight for the Lady Babylon!!!
fuelair is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 08:57 AM   #12
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Originally Posted by Belz... View Post
Because things that operate, break. Resting allows you to not only save energy but repair damage and perform maintenance, for lack of better terms.
I think your analogy is flawed, biological machines are designed to work 24 hours a day, your liver continues to function, your heart beats, cells continue to metabolize even the brain is in fact still doing something when you are sleeping.

That's why sleep is such a puzzle, it seems to be rather different to other biological machines.
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 09:02 AM   #13
Cheetah
Graduate Poster
 
Cheetah's Avatar
 
Join Date: Feb 2010
Posts: 1,408
I wonder if it has more to do with learning than off-time specifically.
I wonder if parts of the brain that do not learn throughout life, ie parts of the brain involved in routine housekeeping, doing the exact same thing day after day, also need off-time. Do these areas also suffer from swollen synapses?

Adjusting the relative strengths of synaptic connections are the basis of learning and might be the cause of the swelling and the need for sleep.
__________________
"... when you dig my grave, could you make it shallow so that I can feel the rain" - DMB

Last edited by Cheetah; 19th February 2018 at 09:07 AM.
Cheetah is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 09:06 AM   #14
Belz...
Fiend God
 
Belz...'s Avatar
 
Join Date: Oct 2005
Location: In the details
Posts: 81,554
Originally Posted by Darat View Post
I think your analogy is flawed, biological machines are designed to work 24 hours a day, your liver continues to function, your heart beats, cells continue to metabolize even the brain is in fact still doing something when you are sleeping.
None of this works against what I said, nor was it an analogy. In fact, performing maintenance requires that the damned thing work.

Quote:
That's why sleep is such a puzzle
To you, maybe. Most people seem to have figured out a while ago that your brain needs rest, too.
__________________
Master of the Shining Darkness

"My views are nonsense. So what?" - BobTheCoward


Belz... is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 09:45 AM   #15
Cheetah
Graduate Poster
 
Cheetah's Avatar
 
Join Date: Feb 2010
Posts: 1,408
Originally Posted by Belz... View Post
Most people seem to have figured out a while ago that your brain needs rest, too.
Sure, people knew they needed sleep since they were people, but up to now why has been the problem.
Do a google on "why do we need sleep", lots of stuff, different theories but nothing conclusive.
This is really the first solid reason.
__________________
"... when you dig my grave, could you make it shallow so that I can feel the rain" - DMB
Cheetah is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 09:47 AM   #16
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Originally Posted by Belz... View Post
None of this works against what I said, nor was it an analogy. In fact, performing maintenance requires that the damned thing work.
You were comparing biological systems to machines weren't you?

Originally Posted by Belz... View Post
To you, maybe. Most people seem to have figured out a while ago that your brain needs rest, too.
Which isn't what the thread is about, the thread is about why.
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 10:00 AM   #17
Belz...
Fiend God
 
Belz...'s Avatar
 
Join Date: Oct 2005
Location: In the details
Posts: 81,554
Originally Posted by Darat View Post
You were comparing biological systems to machines weren't you?
No.

Quote:
Which isn't what the thread is about, the thread is about why.
Precisely why. We've had a good idea for a while now, which is why I find your puzzling puzzling.
__________________
Master of the Shining Darkness

"My views are nonsense. So what?" - BobTheCoward


Belz... is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 10:16 AM   #18
Cheetah
Graduate Poster
 
Cheetah's Avatar
 
Join Date: Feb 2010
Posts: 1,408
This ties in nicely with the "memory consolidation" thing and the effects of sleep deprivation on memory and mental function.
This has been known for long, but also not exactly how or why.
__________________
"... when you dig my grave, could you make it shallow so that I can feel the rain" - DMB
Cheetah is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 01:37 PM   #19
fuelair
Cythraul Enfys
 
fuelair's Avatar
 
Join Date: May 2006
Posts: 58,235
OK, article covering : https://www.ninds.nih.gov/Disorders/...standing-Sleep
__________________
There is no problem so great that it cannot be fixed by small explosives carefully placed.

Wash this space!

We fight for the Lady Babylon!!!
fuelair is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th February 2018, 01:45 PM   #20
William Parcher
Show me the monkey!
 
William Parcher's Avatar
 
Join Date: Jul 2005
Posts: 22,470
I think I remember reading a hypothesis that mammals evolved full sleep when they were living with dinosaurs and it gave some advantages to avoiding being eaten for a percentage of a day and of a lifetime. You are mostly immune to predation when you are inside a hidden nest and are essentially lying there paralyzed.
__________________
Bigfoot believers and Bigfoot skeptics are both plumb crazy. Each spends more than one minute per year thinking about Bigfoot.
William Parcher is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 03:45 AM   #21
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Originally Posted by Belz... View Post
No.
Then your comment is patently wrong, your heart doesn't stop for repairs every 12 hours or so, your liver doesn't stop processing chemicals, yet your brain stops doing something obviously significant. (Obviously in terms of evolutionary theory).

Originally Posted by Belz... View Post
Precisely why. We've had a good idea for a while now, which is why I find your puzzling puzzling.
It would seem that the research team behind this paper do not share your view but do share my sense of puzzlement, so much so they've spent literally years of their careers studying this puzzling to them but not to you phenomenon.
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 03:47 AM   #22
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Originally Posted by fuelair View Post
Seems the authors of that article also share the puzzlement I have in regards to sleep - "Everyone needs sleep, but its biological purpose remains a mystery. "
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 04:00 AM   #23
Cheetah
Graduate Poster
 
Cheetah's Avatar
 
Join Date: Feb 2010
Posts: 1,408
Originally Posted by William Parcher View Post
I think I remember reading a hypothesis that mammals evolved full sleep when they were living with dinosaurs and it gave some advantages to avoiding being eaten for a percentage of a day and of a lifetime. You are mostly immune to predation when you are inside a hidden nest and are essentially lying there paralyzed.
Insects, fish, amphibians and reptiles also sleep, so sleep did not first evolve in mammals.
It seems to have happened with the evolution of brains.
__________________
"... when you dig my grave, could you make it shallow so that I can feel the rain" - DMB
Cheetah is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 04:37 AM   #24
GlennB
Loggerheaded, earth-vexing fustilarian
 
GlennB's Avatar
 
Join Date: Sep 2006
Location: Arcadia, Greece
Posts: 24,556
Originally Posted by William Parcher View Post
I think I remember reading a hypothesis that mammals evolved full sleep when they were living with dinosaurs and it gave some advantages to avoiding being eaten for a percentage of a day and of a lifetime. You are mostly immune to predation when you are inside a hidden nest and are essentially lying there paralyzed.
Sounds plausible. And if the animal had many hours of time to kill before the sun came up/went down and they could get usefully active again they might be prone to fidgeting and generally doing stuff just to pass the time. Sitting around for many hours overnight, awake, would drive most people totally nuts.
__________________
"Even a broken clock is right twice a day. 9/11 truth is a clock with no hands." - Beachnut
GlennB is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 04:42 AM   #25
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Originally Posted by GlennB View Post
Sounds plausible. And if the animal had many hours of time to kill before the sun came up/went down and they could get usefully active again they might be prone to fidgeting and generally doing stuff just to pass the time. Sitting around for many hours overnight, awake, would drive most people totally nuts.
But this is part of the same puzzlement - why wouldn't we literally be better of "killing" all the time? It's not as if hours of daylight and nighttime are fixed plus all the nocturnal critters show there is plenty of food and other activities to be doing during hours of darkness when some critters sleep and vice-a-versa for others.
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 04:55 AM   #26
Loss Leader
I would save the receptionist.
Moderator
 
Loss Leader's Avatar
 
Join Date: Jul 2006
Location: Florida
Posts: 26,382
What's the most "complex" or "animal-like" creature that doesn't need sleep?
__________________
I have the honor to be
Your Obdt. St

L. Leader
Loss Leader is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 04:56 AM   #27
angrysoba
Philosophile
 
angrysoba's Avatar
 
Join Date: Dec 2009
Location: Osaka, Japan
Posts: 24,953
Originally Posted by Darat View Post
But this is part of the same puzzlement - why wouldn't we literally be better of "killing" all the time? It's not as if hours of daylight and nighttime are fixed plus all the nocturnal critters show there is plenty of food and other activities to be doing during hours of darkness when some critters sleep and vice-a-versa for others.
But again, I have to wonder which side is the adaptive part. If we think of animal bodies as survival machines for genes then it makes sense that certain animals have adapted states of consciousness that are expensive in terms of resources in order to find food, mate, and do other things the survival machine needs to do to propagate itís genes. Thatís really all that animals have to do. But outside of those jobs animals themselves become prey wandering about trying to find things to do with themselves aside from the energy expenditure. This is why I wonder if instead of evolving sleep we have evolved wakefulness. Maybe this is empirically wrong; I donít know.
__________________
"The thief and the murderer follow nature just as much as the philanthropist. Cosmic evolution may teach us how the good and the evil tendencies of man may have come about; but, in itself, it is incompetent to furnish any better reason why what we call good is preferable to what we call evil than we had before."

"Evolution and Ethics" T.H. Huxley (1893)
angrysoba is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 05:03 AM   #28
Cheetah
Graduate Poster
 
Cheetah's Avatar
 
Join Date: Feb 2010
Posts: 1,408
Originally Posted by Loss Leader View Post
What's the most "complex" or "animal-like" creature that doesn't need sleep?
The nematode Caenorhabditis elegans has only 302 neurons with 7000 connections and it needs sleep.
__________________
"... when you dig my grave, could you make it shallow so that I can feel the rain" - DMB

Last edited by Cheetah; 20th February 2018 at 05:06 AM.
Cheetah is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 05:06 AM   #29
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Originally Posted by angrysoba View Post
But again, I have to wonder which side is the adaptive part. If we think of animal bodies as survival machines for genes then it makes sense that certain animals have adapted states of consciousness that are expensive in terms of resources in order to find food, mate, and do other things the survival machine needs to do to propagate itís genes. Thatís really all that animals have to do. But outside of those jobs animals themselves become prey wandering about trying to find things to do with themselves aside from the energy expenditure. This is why I wonder if instead of evolving sleep we have evolved wakefulness. Maybe this is empirically wrong; I donít know.
Interesting thought. It would explain how we revert to coach potatoes given half a chance!
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 05:10 AM   #30
GlennB
Loggerheaded, earth-vexing fustilarian
 
GlennB's Avatar
 
Join Date: Sep 2006
Location: Arcadia, Greece
Posts: 24,556
Originally Posted by Darat View Post
But this is part of the same puzzlement - why wouldn't we literally be better of "killing" all the time? It's not as if hours of daylight and nighttime are fixed plus all the nocturnal critters show there is plenty of food and other activities to be doing during hours of darkness when some critters sleep and vice-a-versa for others.
Animals tend to specialise. Human eyes, for example, are unsuitable for doing anything very productive at night. Bugs tend to come out at night - for their own safety - so bug-eating animals might specialise by becoming nocturnal. For many/most animals being awake during their unproductive times would not only be a marginal waste of energy but would also be an added safety risk.

Anyway, it's a possibility. For the moment I find the 'brain recovery/reorganisation' a little hard to accept. How much of those does a mouse need?
__________________
"Even a broken clock is right twice a day. 9/11 truth is a clock with no hands." - Beachnut
GlennB is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 05:21 AM   #31
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Originally Posted by GlennB View Post
Animals tend to specialise. Human eyes, for example, are unsuitable for doing anything very productive at night. Bugs tend to come out at night - for their own safety - so bug-eating animals might specialise by becoming nocturnal. For many/most animals being awake during their unproductive times would not only be a marginal waste of energy but would also be an added safety risk.

Anyway, it's a possibility. For the moment I find the 'brain recovery/reorganisation' a little hard to accept. How much of those does a mouse need?

I doubt there is a single reason for it and I suspect it is a multifaceted behaviour but given how the simplest of animals seem to need "sleep" even those that live in an unchanging constant environment (so don't have to deal with adaptations that only work well either in the dark or light or warmth or cold) - for example critters living underground or deep in cave pools - I'd say there is strong evidence that resource conservation isn't at the heart of it.
__________________
I wish I knew how to quit you

Last edited by Darat; 20th February 2018 at 05:22 AM. Reason: got my rocks off so need to cave in
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 05:33 AM   #32
Belz...
Fiend God
 
Belz...'s Avatar
 
Join Date: Oct 2005
Location: In the details
Posts: 81,554
Originally Posted by Darat View Post
Then your comment is patently wrong, your heart doesn't stop for repairs every 12 hours or so, your liver doesn't stop processing chemicals, yet your brain stops doing something obviously significant. (Obviously in terms of evolutionary theory).
Ok, Darat. I see you're in "Woah! I don't understand the most basic things!" mode. Have you ever done any work? Physical or mental? It just so happens that you need rest after that. Why do you think that is, if all of your body is designed to work "24 hours a day"? And when you're asleep, most of your organs work at a reduced rate. You didn't include that in your response. Gee, I wonder why.

Quote:
It would seem that the research team behind this paper do not share your view but do share my sense of puzzlement
No, it wouldn't seem that at all. You're confusing not having a definitive answer with total puzzlement.
__________________
Master of the Shining Darkness

"My views are nonsense. So what?" - BobTheCoward


Belz... is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 06:12 AM   #33
Jono
Master Poster
 
Jono's Avatar
 
Join Date: Feb 2005
Location: Sweden
Posts: 2,015
Well, hmm, what about the cell-repairing function that happens during sleep? It does for humans, a specific process which only really starts to kick-in after you've been a sleep for a while (don't remember the exact count of hours, though I'd imagine it varies).
__________________
"I don't believe I ever saw an Oklahoman who wouldn't fight at the drop of a hat -- and frequently drop the hat himself." - Robert E. Howard
Jono is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 06:17 AM   #34
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Originally Posted by Jono View Post
Well, hmm, what about the cell-repairing function that happens during sleep? It does for humans, a specific process which only really starts to kick-in after you've been a sleep for a while (don't remember the exact count of hours, though I'd imagine it varies).
I'm sure I read something not so long ago that said the latest evidence had called into question the idea that more repairing occurs during sleep than during waking hours? I'll see if I can find it again.
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 06:25 AM   #35
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Originally Posted by Darat View Post
Interesting thought. It would explain how we revert to coach potatoes given half a chance!
Looking for the article I mentioned above came across this article which is a great starting point for folk like me who like many scientists still find the whole sleeping thing puzzling.

http://www.bbc.co.uk/earth/story/201...eason-we-sleep

That ends with this :

"...But you could turn this argument on its head, and say that sleep is so beneficial that the question is really why animals ever bother to wake up. Maybe it is actually the harmful state of wakefulness that is an evolutionary mystery, not sleep.

ďWhat about this hypothesis: sleep was the first state of life and it was from sleep that wakefulness emerged,Ē says Walker. ďI think itís probably a ridiculous hypothesis Ė but itís also not entirely unreasonable.Ē ..."
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 06:48 AM   #36
angrysoba
Philosophile
 
angrysoba's Avatar
 
Join Date: Dec 2009
Location: Osaka, Japan
Posts: 24,953
Originally Posted by Darat View Post
Looking for the article I mentioned above came across this article which is a great starting point for folk like me who like many scientists still find the whole sleeping thing puzzling.

http://www.bbc.co.uk/earth/story/201...eason-we-sleep

That ends with this :

"...But you could turn this argument on its head, and say that sleep is so beneficial that the question is really why animals ever bother to wake up. Maybe it is actually the harmful state of wakefulness that is an evolutionary mystery, not sleep.

ďWhat about this hypothesis: sleep was the first state of life and it was from sleep that wakefulness emerged,Ē says Walker. ďI think itís probably a ridiculous hypothesis Ė but itís also not entirely unreasonable.Ē ..."
Heh heh! I'll accept "ridiculous... but... not entirely unreasonable."
__________________
"The thief and the murderer follow nature just as much as the philanthropist. Cosmic evolution may teach us how the good and the evil tendencies of man may have come about; but, in itself, it is incompetent to furnish any better reason why what we call good is preferable to what we call evil than we had before."

"Evolution and Ethics" T.H. Huxley (1893)
angrysoba is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 07:08 AM   #37
GlennB
Loggerheaded, earth-vexing fustilarian
 
GlennB's Avatar
 
Join Date: Sep 2006
Location: Arcadia, Greece
Posts: 24,556
Originally Posted by Darat View Post
I doubt there is a single reason for it and I suspect it is a multifaceted behaviour but given how the simplest of animals seem to need "sleep" even those that live in an unchanging constant environment (so don't have to deal with adaptations that only work well either in the dark or light or warmth or cold) - for example critters living underground or deep in cave pools - I'd say there is strong evidence that resource conservation isn't at the heart of it.
Do they? Many fish are able to detect food by touch (for example, carp) or can detect food by vibration or other means (pike can be caught at night, despite being primarily sight-hunters) , and are active at all times. Night fishing for those species is a thing. Some prey fish (e.g. roach) have to see their food and become inactive in the dark. Whether that is actual sleep as opposed to plain inactivity I don't know, though I suspect the latter. If feeding is pointless or impossible then why move around?
__________________
"Even a broken clock is right twice a day. 9/11 truth is a clock with no hands." - Beachnut
GlennB is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 08:11 AM   #38
Myriad
Hyperthetical
 
Myriad's Avatar
 
Join Date: Nov 2006
Location: A pocket paradise between the sewage treatment plant and the railroad
Posts: 14,784
The evidence is very strong that sleep is a basic physiological need of nervous systems, and that other adaptive advantages it might have are secondary to that necessity. For example, an inherent need for sleep and the resulting rest periods would in turn permit the evolution of limb muscles that are adapted to a cycle of "hard work" and periodic rest. Muscles that don't require rest could have evolved instead, and did, in e.g. the case of cardiac muscle.

The same goes for the behavioral advantages such as optimum timing of hunting behavior, or spending periods of relative safety in sheltered nests. These are clearly adaptive given the need to sleep in the first place, but if no such inherent need is assumed then the advantages are less clear. One interesting piece of evidence is that some hibernating animals have a cycle of periodic "arousals" to a higher body temperature during their hibernation period. As far as researchers have been able to determine, they do this in order to sleep. These arousals are metabolically costly during a critical period of resource conservation. So it seems these animals are surviving for months without food, water, or significant musculoskeletal activity, but can't manage to go without sleep.

For a long time it's been known that a rat kept awake long enough will die, but it wasn't clear whether it was the lack of sleep per se, or the effects of the means used to keep the rat awake, that was doing the damage. Some ingenious (and also, I have to say, fiendish) experiments in the 1990's resolved that question. Rats were caged in pairs but separated from contact with one another. Both rats in a pair were fitted with brain electrodes to detect the sleep state. One rat in each pair was prevented from sleeping by automatically triggering a stimulus whenever it began to sleep. The other "control" rat was equally exposed to those same stimuli, but the timing for that rat was random with respect to its behavior, so while the control rats slept less than normal due to the frequent stimuli, they were able to get some sleep. (The stimulus was the rotation of the cage floor, which was a disc-shaped platform over a larger area of shallow water; either the motion itself or being pushed into the water by the rotation would wake the rat up.) In all cases the sleepless rats deteriorated and died and the control rats remained healthy.

In humans, such complete prevention of sleep appears to be impossible (at least, under any ethically permissible test conditions), as "micro-sleeps" begin to occur as an individual becomes more sleep-deprived. There is, however, a disorder called fatal familial insomnia, which is just what it says on the tin: a genetic disorder that progressively causes insomnia and is fatal. It's possible, though far from certain, that it's the insomnia itself that causes the lethality. (It's equally possible that it's the underlying prion condition that's lethal and the insomnia is only a non-lethal symptom. The similarities of the progression of symptoms to the behaviors exhibited by the mortally sleep-deprived rats could be coincidence.)

The study in the OP is consistent with the hypothesis that sleep is inherently necessary rather than something that evolved due to the various benefits of its behavioral sequelae. It's the kind of neurological finding that would be expected in that case. By itself it's not definitive yet, of course.
__________________
A zÝmbie once bit my sister...

Last edited by Myriad; 20th February 2018 at 08:14 AM.
Myriad is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 08:12 AM   #39
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 85,702
Originally Posted by GlennB View Post
Do they? Many fish are able to detect food by touch (for example, carp) or can detect food by vibration or other means (pike can be caught at night, despite being primarily sight-hunters) , and are active at all times. Night fishing for those species is a thing. Some prey fish (e.g. roach) have to see their food and become inactive in the dark. Whether that is actual sleep as opposed to plain inactivity I don't know, though I suspect the latter. If feeding is pointless or impossible then why move around?
From memory fish do sleep, but don't have the equivalent of REM sleep.
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th February 2018, 10:36 AM   #40
Crawtator
Critical Thinker
 
Join Date: Apr 2016
Posts: 356
Jordan Peterson discusses an experiment done in which the brain and limbic system of a cat are removed, but the brain stem and spine left intact. Now, I couldn't pull up the text of the findings (if someone can, link would be appreciated), but the cat was able to walk just fine (videos available online easily) and was hyper-curious about it's surroundings (Mr. Peterson believes that this was because every experience was novel to the animal and it couldn't create memories which would avoid every experience from being overwhelming).

What I thought was interesting for this discussion was that Mr. Peterson states that the cat also slept. So, as a poster said above, this activity (sleeping) may not be associated only with brains but with the more general nervous system. I'm not sure if that does away with the argument in the main post, but I offer it as a curious example of how counter-intuitive the workings of the nervous system can be.
Crawtator is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Reply

International Skeptics Forum » General Topics » Science, Mathematics, Medicine, and Technology

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 08:30 PM.
Powered by vBulletin. Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.

This forum began as part of the James Randi Education Foundation (JREF). However, the forum now exists as
an independent entity with no affiliation with or endorsement by the JREF, including the section in reference to "JREF" topics.

Disclaimer: Messages posted in the Forum are solely the opinion of their authors.