Why has nothing evolved to not need sleep?

[-RA-]

An animal that does not need to sleep would be at a huge advantage over all other animals as animals are more vulnerable when asleep, so why are there none that have done that?

(i think i am correct in saying that all animals sleep)

 

[jim mcnamara]

Probably not correct - either of your assumptions.

-- more vulnerable

One view of sleep is that it EVADES predators. Example: human night vision is very poor compared to a lion. If humans sleep in a group, maybe in a tree, they are much safer than bumping around in darkness and walking right into the midst of a pride of lions to beome lion chow.


-all animals sleep (my definition of sleep is an altered brain state that shuts off or reduces incoming stimuli, not just a period when an animal waits for a meal to hop by):

example -
Animals like pit vipers - snakes that are active in darkness or daytime. They slow down only when they are digesting food, or temperatures are out range for functioning.

Otherwise, they are on the alert 24X7 when hunting. I do not know of any research that shows an altered brain state for snakes. By this I mean the reptilian equivalent of sleeping 'delta' waves, or REM sleep. Or even if snakes even have sufficient "higher" brain function to show altered brain states.

Anybody else know about snake EEG patterns?

 

[-RA-]

One view of sleep is that it EVADES predators. Example: human night vision is very poor compared to a lion. If humans sleep in a group, maybe in a tree, they are much safer than bumping around in darkness and walking right into the midst of a pride of lions to beome lion chow.

but they would be a lot safer if they were awake up the tree at night tham if they were all asleep up a tree. Animals are more vulnerable when they sleep, that's the very reason why they have to dig a burrow, or climb a tree in the first place.

-all animals sleep (my definition of sleep is an altered brain state that shuts off or reduces incoming stimuli, not just a period when an animal waits for a meal to hop by):

thats similar as to how i would describe sleep, although i would tend to call it an altered state of conscious.

i should have been more specific, why do all mammals sleep even though they have all evolved separately.

 

[mgb_phys]

i should have been more specific, why do all mammals sleep even though they have all evolved separately.

They all evolved from a common ancestor - that was probably nocturnal and hid in a burrow all day. If you are hiding in hole during the day it makes sense to reduce your energy demands by slowing down that calorie hungry brain so that when you do go out looking for food you don't need to find so much.

I would expect to see a reduction in hours slept as go from small to large animals.

 

[jim mcnamara]

-RA-

Okay, lose the tree. That's a non-sequitur response, you know.

Try a personal experiment.

Go to a field where you cannot see any electric lights closer than 100 yards or so. Go out on a dark moonless night.

Try to walk about. You will personally experience why some researchers think being awake at night and moving around was a bad idea for early humans. While you are stumbling around, pretend there are predators nearby. They can silently run 40mph, too. And you are on the menu.

You will also learn why lots of "primitive" people use walking sticks.

 

[-RA-]

Go to a field where you cannot see any electric lights closer than 100 yards or so. Go out on a dark moonless night.

Try to walk about. You will personally experience why some researchers think being awake at night and moving around was a bad idea for early humans. While you are stumbling around, pretend there are predators nearby. They can silently run 40mph, too. And you are on the menu.

point taken, although i think i'll leave the experiment for someone else to try!. I suppose that is a good reason for mammals with bad night vision; but what about animals that hunt at night, as well as the day? they still sleep periodically.

If you are hiding in hole during the day it makes sense to reduce your energy demands by slowing down that calorie hungry brain so that when you do go out looking for food you don't need to find so much.

i can understand that aswell, but i also can't see why we have to sleep to replenish our brains in the first place. An animal with a brain that 'replenishes' as it is use, and so would never need to rest, would be at a much bigger advantage than animals that do rest. I would have thought that over time some animals would have developed to not need sleep as it would be so advantageous.

I guess in an indirect way i am asking why exactly do animals need sleep so badly in the first place.

 

[mgb_phys]

It depends wether you sleep to replenish your brain (ie. allow chemicals to be built up or waste products to be removed ) or it is purely a low power state to save energy.

Cats sleep most of the time - to save energy, you might as well ask why they haven't evolved to chase and eat prey 24hours a day.

 

[-RA-]

It depends wether you sleep to replenish your brain (ie. allow chemicals to be built up or waste products to be removed ) or it is purely a low power state to save energy.

what does sleep do out of those two options then?

i'm not sure if I'm saying this right, but i still can't see the real reason for sleep. If it was to replenish your brain why do you need to sleep for your brain to do that?, your brain builds up chemicals and removes waste products when you are awake aswell. If sleep is a low power state to save energy that implies that every animal has evolved to be inefficient at storing energy, and so has to sleep to save this energy. So if an animal evolved to become twice as efficient at using energy than its predecessors it should sleep for half the time. surely that's not correct?

 

[Count Iblis]

A long time ago on some science program I heard about a theory of how sleep is thought to have evolved. You have to go back way back to the pre-Cambrium. Just imagine that you have different primitive sea creatures that do not sleep. They eat and they use the energy from what they eat to find food move around etc. There is competition between different species. This drives the organisms toward the limit of their capabilities.

If you are a predator, then the prey will make sure you need to go beyond your maximum sustainable limit to catch them. This will then cause you to need a resting period of low activity to compensate for high activity periods.

Since sleep has evolved so long ago, it is basically hard wired into our system. When we are awake we function at a level that is simply not sustainable on the long run. You can think of undoing the necessity of sleep, but then the same dynamics of our early ancestors that led to the evolution of sleep will still apply: If you could somehow change your biology and go witout sleep and do theoretical physics 24 hours a day, then you could tweak your biological system a bit and obtain a system that can do physics much better for 10 hours but will need rest and sleep to recover.

 

[TVP45]

An animal that does not need to sleep would be at a huge advantage over all other animals as animals are more vulnerable when asleep, so why are there none that have done that? (i think i am correct in saying that all animals sleep)

I think it is correct to say many scientists are unsure whether insects really sleep or not.

How do you know that not sleeping would be an advantage? At this point, we are still not clear on why we need sleep (except that almost all people who do not sleep will fairly quickly die) and so cannot assess what, if any, advantage sleep provides.

 

[Proggle]

Here's my personal take on it:

I think sleep evolved because it was, at a given point in evolutionary history, more energetically efficient than being awake all day. That means, it was better to go into a low-energy consumption state at night than trying to find food or mating in poor lighting conditions (keep in mind that this happened long before eyes evolved to their current level).

After this happened, a further advantage could be gained by those species that performed certain vital functions while sleeping, say tissue repair, allowing all energy to be focused to productive activities during the day. As the number of these "sleep activities" grew in number, it became increasingly difficult for future species to be able to "evolve" out of sleep. So the evolutionary adaptation for taking advantage of the fact that other species were sleeping was to become nocturnal, not to abandon it altogether.

 

[TVP45]

I see your point. Rather like trying to evolve flying once we had dense bones.

 

[arildno]

jim:
Why should a creature stumble about in the dark rather than just sit quietly up in a tree?
The crucial distinction is between
1. the resting, but awake (i.e, alert) creature and the

2. the resting creature fallen asleep (i.e, inattentive).

1. would be the best choice, from the perspective of natural selection.


However, as to the original question:

It is not enough for natural selection that some other state would be a better adaptation to the environment; it must also be an ATTAINABLE state.
(The gradient in evolution can't be too large).

 

[scott_alexsk]

Who says they would be stumbling about in the darkness, couldn't they simply evolve to see in the dark.

 

[Proggle]

Who says they would be stumbling about in the darkness, couldn't they simply evolve to see in the dark.

To see in the dark you need:

- A lens, otherwise you simply won't gather enough light.
- A diaphragm (pupil), otherwise you'll go blind in daylight.
- A large number of sensitive photoreceptive cells.

If something like that had evolved instead of a mechanism for sleep, creationists would actually have a point.

 

[Moonbear]

Okay, I'm going to back up a few steps here. While everyone is speculating on the benefits/risks of not sleeping, there's a fundamental misunderstanding of evolution and natural selection in the opening post that needs to be addressed.

An organism cannot choose to evolve in a certain direction, or to acquire a particular trait. It doesn't matter how wonderful it might be, if a mutation that would permit it has never occurred, it can't happen.

However, as has been speculated above, it's possible that such a mutation HAS occurred, and turned out to NOT be adaptive, in which case it quickly disappeared from the gene pool again.

 

[Proggle]

Okay, I'm going to back up a few steps here. While everyone is speculating on the benefits/risks of not sleeping, there's a fundamental misunderstanding of evolution and natural selection in the opening post that needs to be addressed.

An organism cannot choose to evolve in a certain direction, or to acquire a particular trait. It doesn't matter how wonderful it might be, if a mutation that would permit it has never occurred, it can't happen.

However, as has been speculated above, it's possible that such a mutation HAS occurred, and turned out to NOT be adaptive, in which case it quickly disappeared from the gene pool again.

The point I'm trying to make is that we may be so far down the path of depending on sleep that a mutation that disables it may not be feasible.

If an organism that doesn't sleep is born, it is very likely it will die, as systems that are supposed to function during that time are unlikely to have mutated to compensate for the change. This makes a one-step leap from sleep to no sleep extremely unlikely.

You may say "An animal could start sleeping less, and eventually abandon it." but if those intermediary states provide a disadvantage in survivability, even if the final state is better, the evolutionary path that leads that way will not be followed.

 

[Moonbear]

The point I'm trying to make is that we may be so far down the path of depending on sleep that a mutation that disables it may not be feasible.

If an organism that doesn't sleep is born, it is very likely it will die, as systems that are supposed to function during that time are unlikely to have mutated to compensate for the change. This makes a one-step leap from sleep to no sleep extremely unlikely.

You may say "An animal could start sleeping less, and eventually abandon it." but if those intermediary states provide a disadvantage in survivability, even if the final state is better, the evolutionary path that leads that way will not be followed.

I have no problem with any of those concepts presented. I just wanted to make sure that the OP clearly understands how natural selection works, since their statement sounded like there was a more fundamental misconception that needed clarifying.

 

[-RA-]

I have read that the part of sleep that is the important part is REM sleep, the part where you dream. Is this the only part of sleep that is really needed? or are the other less active phases just as important? i would imagine tests have been done on REM's comparitive importance to other phases, i just can't find any.

 

[arildno]

I have read that the part of sleep that is the important part is REM sleep, the part where you dream.

Correction:
It is that phase of sleep from which an awoken person is able to remember that he dreamt something.

Is this the only part of sleep that is really needed? or are the other less active phases just as important? i would imagine tests have been done on REM's comparitive importance to other phases, i just can't find any.

I know of no specific REM-deprivatory sleep experiments that could be used to provide evidence for that hypothesis.
While it certainly is a scientific hypothesis, I do not think we have the ability to carry out the necessary experiments to give us the answers to it, at the present.

 

[-RA-]

Is it true that the pineal gland produces the drug DMT at night, which is the chemical that gives us our dreams. Apparently (according to doctor Rick Strassman, and others) when a person is approaching death, the pineal gland releases DMT, thus accounting for much of the imagery reported by survivors of near-death experiences.

It is a very strong hallucinogen, the type that shamans have used to visit, what they call, the 'spiritworld' for centuries. Is it that dreams are a milder version of this experience as less DMT is released by the brain?

 

[Cincinnatus]

Interesting, I've heard of endogenous DMT before, but I don't think I'd heard it varied in concentration during sleep. Do you have a reference for that by any chance?

 

[-RA-]

I am no expert on this but I think that the fact that there is DMT produced in the brain is well known, but as it is used up very quickly by the brain compared to most other drugs it is very hard to test where it originates without being unethical to living people. Whether it originates from the pineal gland is just a hypothesis at the moment until it is proved/disproved in the future.

"Since these same Psychoactive tryptamines occur in humans, it is possible that their activity may be promoted by the actions of endogenous beta-carbolines for normal psychological processes; e.g. the production of visual / emotive imagery in sleep. The periodic altering of consciousness in sleep may even be necessary for the maintenance of normal mental health, since only a few days of sleep deprivation will result in a seepage of hallucinatory phenomena into the waking state."

From Tryptamines, Beta-carbolines and You. Dr J.C. Callaway, Dept. of Pharmaceutical Chemistry, University of Kuopio, Finlandstrassmans book of the original research into the drug; http://www.rickstrassman.com/pages/dmt/ (i reccomend the book he wrote about peoples experiences, 'DMT: the spirit molecule')

some similar topic journal articles that he often sites; http://www.rickstrassman.com/pages/writings/

 

[TVP45]

I have read that the part of sleep that is the important part is REM sleep, the part where you dream. Is this the only part of sleep that is really needed? or are the other less active phases just as important? i would imagine tests have been done on REM's comparitive importance to other phases, i just can't find any.

The link below gives an excellent starting point for learning about sleep. The brief answer to your question is that there is a normal range for each phase of sleep and deprivation of any of them can be life-threatening.
http://www.ninds.nih.gov/disorders/brain_basics/understanding_sleep.htm

 

[-RA-]

Interesting, I've heard of endogenous DMT before, but I don't think I'd heard it varied in concentration during sleep. Do you have a reference for that by any chance?

I found some good papers about endogenous DMT;

http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&list_uids=6792104&cmd=Retrieve&indexed=google
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=pubmed&dopt=AbstractPlus&list_uids=3412201
http://cat.inist.fr/?aModele=afficheN&cpsidt=3071296
http://leda.lycaeum.org/?ID=16837

there are plenty of reasons to expect that all animals produce DMT in their pineal gland, but i don't think any direct studies have been done to test for this. Certainly not on humans anyway.

 

[MagikRevolver]

Simple answer is evolution occurs on a need to basis. There is no direct or immediate need to evolve past sleep, thus we haven't evolved past sleep. Also, sleep is an evolution in itself. "Most animals, and probably most living organisms, exhibit a circadian rest-activity rhythm. It is possible that sleep may have evolved from rest to allow more flexibility within this rather rigid rhythm of rest and activity. Researchers think that sleep arose to allow organisms to conserve and restore their energy." (Irene Tobler, University of Zurich)

 

[Nexus555]

An animal that does not need to sleep would be at a huge advantage over all other animals as animals are more vulnerable when asleep, so why are there none that have done that?

(i think i am correct in saying that all animals sleep)

Sorry if I repeat anyone, for I didn't read all the responses.

Sleep isn't a survival skill with respects to dodging predators. We need sleep for replenishing energy and resting our muscles. Every animal needs this, in some way, shape or form. Insects do this, but they are only brief second pauses. Dolphins shut off half of their brain at a time to do this.

Another good reason is to conserve our energy. In nature, if all animals were awake at all times, they would constantly have to be hunting and eating. When animals go to sleep, this gives them time to rest (as I've said above,) slow down the organs and conserve their energy.

This has nothing to do with being eaten. Though some animals are nocturnal to take advantage of the night scene.

 

[-RA-]

I know of no specific REM-deprivatory sleep experiments that could be used to provide evidence for that hypothesis.
While it certainly is a scientific hypothesis, I do not think we have the ability to carry out the necessary experiments to give us the answers to it, at the present.

I have just found that exact experiment in a documentary. And it gives some very strong evidence for dreaming to be a form of pshchedelic trip due to endogenous DMT, as when the subjects were deprived of REM sleep they started to hallucinate and see patterns when they were awake. The brain certainly does seem to need this drug very frequently, and it seems very important to all animals.

you can see it in a short clip here; EDIT: clip does not work anymore.

The question arrises, why do all animals need this psychedelic so much? what purpose do you think it plays?

 

[Count Iblis]

I have just found that exact experiment in a documentary. And it gives some very strong evidence for dreaming to be a form of pshchedelic trip due to endogenous DMT, as when the subjects were deprived of REM sleep they started to hallucinate and see patterns when they were awake. The brain certainly does seem to need this drug very frequently, and it seems very important to all animals.

you can see it in a short clip here;

The question arrises, why do all animals need this psychedelic so much? what purpose do you think it plays?

I don't think the specific details are so important. Just think in terms of competition between (biological) machines. The machines have to repair themselves which limits the average performance. A machine that can run on turbocharge for a while and then needs extra repair will outperform a similar machine that doesn't have this option. Also, during the turbocharge phase the system will be optimized for doing the specific tasks it is designed for while during the rest phase the system can be optimized to do the self repair work more efficiently.

So, I think that sleep is more a game theoretical issue that leads to sleep being a universal phenomenon independent of the biological details. If we find complex living organisms on some other planet that work via totally different chemistry it will probably also have sleep cycles.

 

[moe darklight]

I don't think the specific details are so important. Just think in terms of competition between (biological) machines. The machines have to repair themselves which limits the average performance. A machine that can run on turbocharge for a while and then needs extra repair will outperform a similar machine that doesn't have this option. Also, during the turbocharge phase the system will be optimized for doing the specific tasks it is designed for while during the rest phase the system can be optimized to do the self repair work more efficiently.

So, I think that sleep is more a game theoretical issue that leads to sleep being a universal phenomenon independent of the biological details. If we find complex living organisms on some other planet that work via totally different chemistry it will probably also have sleep cycles.

yea, this makes sense. If you look at the lifestyle of animals on earth, it is composed of only short spurts during which the animal's full potential or energy is required; during the rest (and majority) of its time, this energy is not needed. ... an animal that is always "on" and does not need periods of rest to repair itself would have to be going full blast all day long... in other words, it would have to be constantly on the hunt for nutrients. this seems rather impractical and inefficient... it's also not hard to see how such an animals would do quite poorly during even the shortest periods during which nutrients are not plentiful.

an animal that saves its energy and only goes full blast when in immediate danger or while hunting or doing whatever it needs to do to survive is much more efficient and likely to survive.RELATED QUESTION: do single-celled organisms and simpler multi-celled organisms rest? at what point along the complexity chain does the need for sleep and rest begin?

 

[-RA-]

Another interesting thing which indicates how important REM sleep is compared to other phases of sleep is that when you are in deep REM sleep you are paralyzed, often called 'sleep paralysis', you only move in your sleep when in other phases. Something seems very different about REM sleep when you are dreaming, compared to non REM sleep when you are not dreaming.

I suppose that the brain might do this so you do not start moving in accordance with your actual dream. But completely paralysing your whole body does seem quite a drastic measure, implying that something important is going on that takes a lot of brain power. I guess we just don't know exactly what yet.

 

[TVP45]

I have just found that exact experiment in a documentary. And it gives some very strong evidence for dreaming to be a form of pshchedelic trip due to endogenous DMT, as when the subjects were deprived of REM sleep they started to hallucinate and see patterns when they were awake. The brain certainly does seem to need this drug very frequently, and it seems very important to all animals.

you can see it in a short clip here; EDIT: clip does not work anymore.

The question arrises, why do all animals need this psychedelic so much? what purpose do you think it plays?

I think that may be a quite limited experiment with little control. As one who suffers from the opposite, i.e., over 90% of my sleep is REM (without medical intervention), I can assure you it isn't that simple. There are 5 basic sleep stages and we need them all.

 

[-RA-]

I think that may be a quite limited experiment with little control. As one who suffers from the opposite, i.e., over 90% of my sleep is REM (without medical intervention), I can assure you it isn't that simple. There are 5 basic sleep stages and we need them all.

The experiment was performed by leading sleep researcher prof Rosalind Cartwright, Rush of Presbyterian Hostpital, Chicago. I have uploaded the clip of the experiment myself now, as the other user removed it for some reason;
I have been reading some science papers on this as i find it a fascinating subject, and, just as I suspected, research into this area has been severely hampered due to the fact that DMT is one of the most illegal drugs in the world. A fine paper I dug up on this from the University of California, Berkeley, can be seen here; http://sulcus.berkeley.edu/mcb/165_001/papers/manuscripts/_794.html

They say;

Modern science has identified some of the active components of such sacraments, which has provided for limited research opportunities. Scientific research on these substances is currently very restricted by the U.S. Government's social agendas. Further research on entheogenic compounds coupled to dream state research will offer scientific advance in the study of dreams as well as cultural advances in understanding the value of entheogenic substances for therapeutic and religious use...
The striking similarity of entheogenic experiences to dream experiences tempts us to seek answers as to whether the benefits of dreaming are potentially linked to the benefits of entheogens. The molecular action of visions produced by dreaming is quite possibly very similar to visions produced by entheogenic drugs. Carefully designed research could lend great insight into the mystery of dreaming, the potential therapeutic value of entheogens, and the potential for neurochemical advances.

Serotonin has also been known for some time to play a role in sleep regulation. Numerous recent findings specifically implicate the 5-HT1 and 5-HT2 receptors in regulating sleep (Pastel et al. 1993; Sommerfelt et al. 1993, Tortella et al. 1989; Sharpley et al. 1994, 1990; Dijk et al. 1989; Kirov et al. 1995; Seifritz et al. 1996; Loas 1991). Sleep studies monitoring the effects of selective 5-HT1 and 5-HT2 agonists and antagonists administration in humans and laboratory animals have had impressive findings. It has been shown that the post-synaptic stimulation of 5HT1A receptors suppress REM sleep and increase slow wave (NREM) sleep in humans and laboratory animals (Seifritz et al. 1996; Loas 1991). Additionally, recent evidence establishes that antagonists at the 5HT2 receptors caused identical disruptions in sleeping pattern (Pastel et al. 1993; Sommerfelt et al. 1993, Tortella et al. 1989; Sharpley et al. 1994, 1990; Dijk et al. 1989; Kirov et al. 1995). In other words, when the relative activation of 5-HT2 to 5-HT1 was reduced, REM sleep (where the longest and most vivid dreams take place) was suppressed. Therefore, the relative activation of 5HT2 pathways compared to other 5HT pathways is implicated in REM sleep activation. The subjective experience of dreaming is likely a result of that activation, much like the pathway responsible for the effects of entheogenic drugs.

This data suggests a need for REM sleep but does not suggest what that need is. The most interesting findings are the symptoms of REM sleep deprivation (note that these subjects had full nights of sleep, but no REM sleep): Anxiety, irritability, difficulty concentrating, increased appetite, and even daytime hallucinations.

The data at this point is admittedly modest. It is provocative enough, however, to encourage further research on the subject. The relaxing of legal restrictions on entheogen research would contribute to the collection of quality data on the subject. Dreaming studies that administer entheogens and other powerful 5HT-2 agonists should prove useful in explaining dream/entheogen induced visions. Additionally, methods that allow for complete dream deprivation studies and scanning studies that monitor the activity of 5-HT pathways while the subject is dreaming could prove useful.

I noticed that DMT effects the brain in a similar way to the above described process.

and they conclude with;

Entheogenic drugs and dreams alike have a special place in the evolution of humankind and its value systems. Profound musical inspirations and scientific discoveries of the past century have even been inspired by them. Our ancestors religious views and values were influenced by their faith in visions communicated by entheogenic drugs and dreams. In an age of environmental destruction and moral erosion, the knowledge afforded by dream and entheogen induced visions could not be more valuable. Let us hope that our culture is fortunate enough to open our minds and build on the mysteries our ancestors have explored for ages.

Another paper I found which quite frankly states that dreaming is induced by tryptamine derivatives can be seen here; http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=pubmed&dopt=AbstractPlus&list_uids=3412201

The visions of dream sleep are suggested to occur through a dream mechanism which implicates tryptamine derivatives as endogenous paychedelics. The hallucinations that occur in some schizophrenic syndromes are also proposed to occur through a similar, though desynchronized, mechanism. These compounds occur in the human pineal gland and are regarded as neurotransmitters or neuroregulators. A protocol for experimental verification is suggested.

This is from Wikipedia, and looks at the speculative aspects of this idea, (also includes some references to journal entries) http://en.wikipedia.org/wiki/Dimethyltryptamine

Several speculative and as yet untested hypotheses suggest that endogenous DMT, produced in the human brain, is involved in certain psychological and neurological states. As DMT is naturally produced in small amounts in the brains and other tissues of humans, and other mammals,[11] some believe it plays a role in promoting the visual effects of natural dreaming, and also near-death experiences and other mystical states. A biochemical mechanism for this was proposed by the medical researcher JC Callaway, who suggested in 1988 that DMT might be connected with visual dream phenomena, where brain DMT levels are periodically elevated to induce visual dreaming and possibly other natural states of mind. [12]

Dr. Rick Strassman, while conducting DMT research in the 1990s at the University of New Mexico, advanced the theory that a massive release of DMT from the pineal gland prior to death or near death was the cause of the near death experience (NDE) phenomenon. Several of his test subjects reported NDE-like audio or visual hallucinations. His explanation for this was the possible lack of panic involved in the clinical setting and possible dosage differences between those administered and those encountered in actual NDE cases.
From a researcher's perspective, perhaps best known is Rick Strassman's DMT: The Spirit Molecule (ISBN 0-89281-927-8);[14] Strassman speculated that DMT is made in the pineal gland, largely because the necessary constituents(see methyltransferases) needed to make DMT are found in the pineal gland. However, no one has looked for DMT in the pineal yet. Strassman thought that because DMT falls in the large class of chemicals called Tryptamines, which includes Serotonin, LSD, Melatonin (a hormone the Pineal Gland does produce), and Psilocybin.

I also find it interesting that if you are deprived of REM sleep your brain will always make up what you have missed when you next fall asleep. This again indicates that the brain, for whatever reason, regards dreaming as a very important stage in sleep and does as much as it can to produce the drug that causes the visual imagery of dreams.

http://www.bbc.co.uk/dna/actionnetwork/A276257

Experiments carried out by Professor Patrick and Dr J A Gilbert of the University of Iowa on sleep deprivation showed interesting results. The subjects all showed an increase of weight during the experiment, reactions generally slowed, memory became defective and power of attention was largely lost. Strangely though acuteness of vision actually increased in all cases. One of their subjects even began to hallucinate on the third night of deprivation. When allowed to sleep after ninety hours, the subjects did so readily and slept very deeply, showing increased time in REM sleep. The subjects only found it necessary to make up from 16 to 35 percent of sleep. After sleeping they recovered fully with only slight physiological reminders of the experiment, such as increased phosphoric acid in the urine, and effectively felt as they had before the experiment. The need of a sleep deprived person is not just for sleep, but for the two types of sleep that compromise it. This is shown by studies on selective sleep deprivation (Cohen, 1972). If a subject is deprived of REM sleep, for example, by waking him/her every time he comes near to it, then the subject will spend more time in REM the next time they sleep. Although sleep deprivation is not as permanently injurious in humans as in young dogs, it still has serious effects.

some other interesting comments on hallucinations after sleep deprivation, from; http://www.macalester.edu/psychology/whathap/ubnrp/sleep_deprivation/tintro02.htm

Some of the subtle and most profound effects of sleep deprivation involve some aspect of cognition. One experimenter distinguished between three types of psychological changes during sleep deprivation. These include psychoneurotic-like, schizophrenic-like, and paranoid-like reactions. Each of these reactions includes a number of sub-symptoms. Psychoneurotic-like reactions include anxiety (e.g., not being able to sleep again, or fear of being harmed), psychomotor complaints (e.g., headaches, nausea, loss of appetite), and irritation.
Schizophrenic-like reactions include illusions, delusions, and hallucinations, disturbances in thinking, and unprovoked emotion, such as laughter. These types of reactions are some of the most commonly reported experience during extended periods of sleep loss. Visual hallucinations have been observed in other experiments as well. Examples of these include the perception of tile squares to be pulsating and growing darker and larger, mistaking a desk for a water fountain, and the floor of the lab “appearing to be covered by a layer of shimmering water”. The frequency of these hallucinations may increase with sleep deprivation. A number of stages of visual hallucinations have been identified. These include identifying a disturbed perception, labeling a hallucination with no doubt as to its reality (i.e., being sure the hallucination is not real) labeling a hallucination with doubt as to its reality, and labeling and believing in a misperception (which is the true definition of a hallucination).

I hope that research is allowed to continue into this subject. Though considering the political ramifications of discovering that the strongest illegal drug in the world is actually produced naturally every night as you sleep, I am not optimistic.

 

[Moonbear]

Simple answer is evolution occurs on a need to basis. There is no direct or immediate need to evolve past sleep, thus we haven't evolved past sleep. Also, sleep is an evolution in itself. "Most animals, and probably most living organisms, exhibit a circadian rest-activity rhythm. It is possible that sleep may have evolved from rest to allow more flexibility within this rather rigid rhythm of rest and activity. Researchers think that sleep arose to allow organisms to conserve and restore their energy." (Irene Tobler, University of Zurich)

Read my comments in post #16. Your post suggests you have the same common misconception about evolution that I attempted to clarify already.

 

[arildno]

I have just found that exact experiment in a documentary. And it gives some very strong evidence for dreaming to be a form of pshchedelic trip due to endogenous DMT, as when the subjects were deprived of REM sleep they started to hallucinate and see patterns when they were awake. The brain certainly does seem to need this drug very frequently, and it seems very important to all animals.

you can see it in a short clip here; EDIT: clip does not work anymore.

The question arrises, why do all animals need this psychedelic so much? what purpose do you think it plays?

Very fascinating, indeed!
Ponder for thought, anyway, although I would have liked that link to work properly.

I haven't read through the extracts posted yet.

 

[Count Iblis]

Why has nothing evolved to not need sleep?

In case of peole the answer is easy. It is because people who need less sleep do indeed sleep less, as a result have less sex and therefore have less children

 

[-RA-]

although I would have liked that link to work properly.

I haven't read through the extracts posted yet.

 

[MagikRevolver]

Read my comments in post #16. Your post suggests you have the same common misconception about evolution that I attempted to clarify already.

There is no misconception on my part. You provide in post #16 that evolution occurs through mutations I presume. That is true. A random mutation could save a species, for example the rudimentary moth near a factory and darkening bark example. However, if the bark didn't darken the mutated moth would die out and there would be no evolution taking place. However, since the moths NEEDED to be darker, those moths survived, spread their mutated genes and we consider them evolved. Thus evolution occurs on a need to basis. That was the only arguable point in my post, as the rest was simple quote from the University of Zurich on the subject.