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| Sleep. Why have we not evolved out of the need for it?
Posted: 1/19/2008 8:20:50 PM | | for some of youpeople to be so smart...i can't believe this has contiued.
and actually the statement..."that's like asking why you need to recharge your camera batteries"...is entirely accurate.
your cells don't have "brains" that operate on the level our "brain" does. through ou the course of a day you drain your brain of chemicals "energy" used for thought which is well, used for EVERYTHING you do...even when it seems like it took "no thought" to do something. it is the way we are built. and cells and bacteria are "simple" organisms. we on the other hand are "complex" so they may seem to share similarities but they are drastically different. cells don't need to think. they are imprinted with what to do. sleeping gives those cells time to repenish our brains with the chemicals it needs to operate. nw as far as the advantage of not sleeping giving aid to "survival of the fittest" not sleeping and having an endless amount of energy makes you no more fit for survival than the prey that can simply out wit you... | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 1/19/2008 8:21:14 PM |
That is why I have a problem with sleep. Why do we need sleep, if our bodily functions are replicated in cells, and yet we need sleep but our cells don't seem to need sleep? The more simple the structure, the more difficult it is to identify a difference in level of activity that could be called sleep. From wikipedia:
Cattle, horses, and sheep can sleep while standing or while lying down; however, they cannot experience REM sleep while standing. If deprived of REM sleep for a long time, the animal may involuntarily collapse in order to reach REM sleep, a condition not to be confused with narcolepsy. Whales and dolphins are also different from humans: they always have to be conscious, as they are conscious breathers, so only one half of their brain sleeps at a time, so called unihemispheric slow-wave sleep. Sleep becomes difficult to define in lower order animals, such as the bullfrog. Its resting state is too similar to its active state to be considered by many to satisfy the criteria for sleep, but brain activity in the resting state is similar to other amphibians that do meet the criteria when they sleep. I thought it was interesting about whales and dolphins too -- they need to remain conscious, but there is still clearly a need for sleep. I wonder if it feels different to them, like split personality or something, depending on which half of the brain is in control. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 1/19/2008 8:29:30 PM | | msg 52... yeah, i can't remember what it's called but the last case i heard of was a guy who lived in england. he worked 3 jobs back to back for basically 10 months out of the yr. the other 2 he spends on vacatin travelling the world. i'm also pretty sure he has periods where he has to sleep for almost a week straight only waking to eat stretch and use the bathroom. their ar always a few exceptions to rules...even in nature. being born without the need to sleep "normally" is kind of like being norn a "two headed sheep" (yes, that can be from inbreeding and blah blah blah) there's exceptions to ALMOST everything. it's still a rule that we can't drink lava...so no need for some of the but...but...but...replies. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 1/20/2008 1:07:30 PM | | People assume that a person does nothing in their sleep. I suspect that sleep has played (and continues to) a positive role in our evolution... perhaps guiding consciousness, providing emotional support during difficult times, and divertisement during dreary periods. Just ask anyone in solitary confinement how important their dreams become to them. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 1/26/2008 2:40:41 PM | Actually ive read a study which shows that we sleep to repair our cerebal cortex as sleep is the ONLY time that this area can recover (its always active at other times). Without sleep, it gradually falls in to disrepair over a number of months.
I have heard of people who never sleep there are really two groups:
1. Those who can live without sleep. somehow this repair process occurs when they are awake they have adapted to NOT sleeping and live fairly normal lives.
2. Those who suffer from a genetic disorder fatal familial insomnia which comes on during adulthood and makes sleep impossible (even drugs are useless!). They hallucinate all the time and their brain starts malfunctioning and after about 6-9 moths, they die miserably........... | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 1/26/2008 3:20:33 PM | Maybe the reason we sleep is because we need faults to protect other species from us.
If humans never slept we'd also consume a lot more and soon expend not only our resources, but those of others as well and do even more damage to the environment than we already do. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 1/27/2008 2:45:35 PM | | Actually, if you spend your day meditating you will lose the need to sleep. I've only done short 10 day retreats at 11 hours/day of meditation but already I had reduced my need to just a few hours. Mind you... that's still alot of time being quiet and still. My meditation instruction's opinion is that 1 hour of meditation roughly is equivalent to 30 minutes of sleep. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 1/31/2008 3:20:23 AM |
Maybe the reason we sleep is because we need faults to protect other species from us.
ding ding ding! An out of the box thinker!  (and not unlike my more poetic explanation a few weeks back in this thread.) | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 1/31/2008 9:58:37 AM | | I agree with LBP.... I always tell people who think I'm lazy for sleeping in a lot: "The more I sleep, the less damage I am doing to the environment". As as environmentalist, I think it's important to minimize the damage that i do...I have the same reason for not breeding. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 1/31/2008 4:52:06 PM | | It is because of our advanced state that we NEED sleep. Lower organisms do not take in or acquire as much information (sensory, abstract thought, complex reasoning,...) as we do and so they need (less/different types/no) sleep. Sleep is the period during which our mind organizes and arranges the information we remember during the day. Think of our mind as a computer and sleep as a decompiling session, where information is more efficiently stored so it can be accessed more easily and allows more 'space' for the next session of information gathering. As such sleep is very important for us and why people who are sleep deprived end up having memory problems and psychoses- since it becomes exponentially harder to store information and process abstract thoughts and emotions. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 1/31/2008 9:00:46 PM | Random I went back and read your post.
Why we haven't evolved out of it? We are not as sophisticated as we like to think.
You nailed it. There is something far more evolved than humans at work here, mother nature. Mother Nature has to take in the "big picture" of impacts and humans not sleeping would have a MAJOR and detrimental impact that would not only lead to the destruction of the environment, other species, but to our own destruction as well.
We sleep...because we have to. Mother Nature being the efficient creature she is, I'm sure has efficiently set aside tasks better accomplished while in this state....but those tasks aren’t the reason we sleep.
Creatures that don't fit into Mother Nature's system go extinct. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 2/2/2008 2:51:56 PM | | If you anthropomorphize "mother nature" to the point that he is making special plans in regards to humans not evolving out of sleep. You may as well just ignore the scientific discussion of evolution all together. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 2/13/2008 3:19:12 AM | Sleep helps you to restore and rejuvenate many body functions:
Memory and learning – Sleep seems to organize memories, as well as help you to recover memories. After you learn something new, sleep may solidify the learning in your brain.
Mood enhancement and social behaviors - The parts of the brain that control emotions, decision-making, and social interactions slow down dramatically during sleep, allowing optimal performance when awake. REM sleep seems especially important for a good mood during the day. Tired people are often cranky and easily frustrated.
Nervous system – Some sleep experts suggest that neurons used during the day repair themselves during sleep. When we experience sleep deprivation, neurons are unable to perform effectively, and the nervous system is impaired.
Immune system – Without adequate sleep, the immune system becomes weak, and the body becomes more vulnerable to infection and disease.
Growth and development – Growth hormones are released during sleep, and sleep is vital to proper physical and mental development.
http://www.helpguide.org/life/sleeping.htm
Sounds good to me. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 2/13/2008 6:35:15 AM | | In primitive times we needed to sleep so we wouldn't be moving around and get eaten. Modern history is just a flash in the pan in evolutionary times; that's too little time to evolve so that we don't need sleep. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 2/15/2008 11:10:37 PM | Because we like having some time when we aren't constantly aware of our surroundings, like people who get drunk or stoned. Sleep helps us deal with stress, and that makes people more cooperative, thus able to avoid dying from stress, tiring out and getting eaten, killing other members of one's own species, or other undesirable outcomes. That gives any creature that sleeps an evolutionary advantage. Not surprisingly, sleep is pretty universal. Even my goldfish like to sleep at night. Switch on the light suddenly and they appear to be paralyzed in their tanks. It takes them a while to adjust, then they get moving again. Just like us humans.
Nature just provides it for us naturally ... get it? | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 2/28/2008 5:50:50 PM | Because we evolved to need sleep - our distant ancestors (very distant) that did not sleep didn't survive long enough to reproduce as much as those that did sleep...........
Not to mention, our eyes don't work so well at night, we don't have a reflective retina and we don't see as much detail so we cannot operate as effectively as we can in the day. We depend greatly on our visual ability - our smell and audio senses are less well developed. It is obvious that if humans in the hunter gatherer stage of history were stumbling around at night they would be much more prone to accidents or becoming dinner for any large animal that does hunt at night.
We are much more likely to survive (reproduce and raise offspring) if we huddle in groups in safe places and sleep at night. Small children tend to develop fears about the night and monsters around the ages when they become independently mobile. These fears occur almost universally in young children, so it is a trait selected by evolution as young children who wander at night are less likely to be safe, survive to adult hood and reproduce.
Those reasons are in addition to the fact that our body as an organism requires "down time" for rest and repair. An organism as complex as the human body cannot operate at "full power" 24 hours a day. There (as someone else mentioned) are costs for our abilities. Eyes for example - fantastic sense, really complex organs and they give us a huge survival advantage - however they are very delicate and really easily damaged and not easily repaired.
best,
E
I'd like to know which animal doesn't sleep but has a large frontal lobe...... | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 7/1/2008 10:02:06 PM | Perhaps when we sleep we are able to connect with the spirit realm in some way that cannot be measured whilst awake. Can anyone prove otherwise?
there was an experiment done with mice that demonstrated that while dreaming, the mice created scenarios in their minds that were combinations of the experiences that they had while awake. It could be that dreaming does have an evolutionary advantage. Perhaps it allows organisms to create new and better ways of surviving situations that they are likely to face while away. If sleep had no biological advantage I don't believe it would be so pervasive throughout the animal kingdom. Even jellyfish sleep! | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 7/2/2008 12:44:02 AM | I have a feeling that if I didn't sleep, my brain would be so full of random information by now, I would have believed my hands were marshmallows and tried to have eaten them long ago.
Also, I'd be even less coherent than I am now. | |
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| Sleep. Why have we not evolved out of the need for it?
Posted: 7/2/2008 1:11:57 AM | Energy Conservation
Because the body is in an exhaustive state of energy consumption. There must be a period of energy conservation. Shapiro & Flannigan, 1993.
Species Protection
Sleep is meant to keep animals out of harm’s way. While some animals are nocturnal and hunt at night, most animals are not. So the theory suggests that non-nocturnal animal sleep lowers the risk of being a nocturnal animal dinner. Greier, 1997.
Oleamide
Scripps Pharm researchers isolated Oleamide in spinal cord fluids of sleep-deprived cats. They extracted the Oleamide and injected it into rats. The rats fell asleep. Cravatt and Boger, 1995.
Oleamide is also found in human spinal fluid. Current studies seek to extract Oleamide from human CNS to decrease drowsiness and sleep and studies to determine of injecting Oleamide increases induction of sleep.
The mechanisms works like this:
1. You have no say in the buildup of Oleamide in your CNS. Just like you have no conscious control over production of blood cells.
2. During waking hours Oleamide is produced by the body and dumps in the CNS.
3. Like a glass being filled with water, the level of Oleamide increases in the CNS. When it hits a certain level, the reticular brain begins to send signals thru the body. The eyelids get heavy, muscle tone decreases, body temperature decreases, ....time for sleep.
4. During sleep the enzyme called fatty acid amide hydrolase (FAAH) breaks oleamide. As oleamide molecules breakdown the level decreases in the CNS. Decreasing sleep induction.
So, evolution has not taken away the need for sleep away for a variety of reasons including species protection, energy rejuvenation and bio-chemical activation. | |
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