What is life?

[ApeTheDog]

Take any living organism, and take, out of that, any single cell. It is alive, is it not?

If it is not alive, then how can a million of those same cells, be called alive? It then be the structure, the cooperation of those cells, that is alive?

But that formed, through chance. Is life as simple as chance?

Take a rock. Say that rock, through extraordinary vulcanic activities, became hollow, and a special type of gas was present inside of it. This gas causes the rock to always have a deviant point of gravity. It sometimes rolls to the left, it sometimes rolls to the right - it always moves somewhere. These are rolling stones. (I realise the physics here are a bit off - but frankly, I don't care. Just imagine that somehow, these dead rocks manage to end up rolling)

These rocks are only found near a special site, and that site is surrounded by lava. On three sides of the place where these rocks are slung out of the ground (by the volcano that created them) there is a lake of lava. This means that, if a rock rolls in that direction, it will die.

What will effectively happen is that only the rocks that roll in the direction where there is no fire, will survive.

Evolution at work. These rocks have learned to always move to the right.

Are these rocks intelligent? Are they alive?

Yet. What exactly is it that makes their type of intelligence different from the intelligence a living cell posesses? What makes the cell alive, and the rock dead?

Okay, cells have the ability to recreate. Surely that is what makes them alive. But can't a similar example be found in which, simply through chance, a cell learns to split itself up into two cells? I don't know enough about DNA to be able to go into how cells split up, but is that life?

[eyebyte_atWork]

I think this has been open for debate for a long time and will continue... but my take on it is...

I used to think that a good definition of life was determined by whether a organic entity could reproduce (in living cells - by splitting - while in dead cells - no splitting)

But now I have taken a step backwards and see it more like this... At the chemical level - some molecules get caught in a chain reaction that seems to exude the behavior described above - they seem to reproduce - not by splitting but by causing a reaction that results in the same molecules being formed. This would include organic things as well as potentially others.

Consciousness only muddys the water. After all fish don;t think and don;t have feelings.

[floid]

When you get down to it life, and similar words like love and freedom, are defined by those people who use them and wonder about them.
Beyond that they have no absolute meaning at all.

At one end of spectrum is the narrow minded rascist who sees only members of his own "race" as "alive" in any worthwhile sense.
At the other end is the buddhist to whom even presumably inanimate objects like rocks are seen as full of "life".


As trivial as it sounds, in both definition and action, life is whatever you make of it.

And no matter what you make of it, it will still be a moving target.

The great mysteries serve us better as problems than they ever could as solutions.

They keep us on the journey that is it's own destination.

[eyebyte_atWork]

When you get down to it life, and similar words like love and freedom, are defined by those people who use them and wonder about them.
Beyond that they have no absolute meaning at all.

At one end of spectrum is the narrow minded rascist who sees only members of his own "race" as "alive" in any worthwhile sense.
At the other end is the buddhist to whom even presumably inanimate objects like rocks are seen as full of "life".


As trivial as it sounds, in both definition and action, life is whatever you make of it.

And no matter what you make of it, it will still be a moving target.

The great mysteries serve us better as problems than they ever could as solutions.

They keep us on the journey that is it's own destination.

And that is why the waters are muddy- there's mud in it.

well put Floid.

[kuranes]

Which way did Jagger roll? "I'm so hot for her and she's so cold! I'm the bleedin' volCANO!"

[PiccoloNamek]

In addition to the traditional definition of life, to me, Consciousnes + Self-Awareness, even in the absences of traditional living processes, also = Life. I have always believed this. For example, if an android like, say, Commander Data, or Chii, or anything like them, actually existed, I would consider them to be just as alive as I am. Really, how could a being that thinks and feels and has a mind of its own not be alive?

Because after all, when you take away consciousness, what is "life?" Nothing more than self-replicating proteins and molocules.

[trendal]

I would loosely defive "life" as anything which has the ability to self-replicate when given the right conditions.

Of course, by that definition, crystals and stars are also "living" ;)


Oh and your example of rocks undergoing "evolution" isn't a good example of evolution - because the rocks themselves do not change over time nor do they breed new rocks.

Instead, that's an example of a physical process which leans towards a specific result. After 10,000 years, the rocks being produced will still have the SAME likelyhood of rolling into the lava as the FIRST rock that was produced. The large pile of rocks collecting which didn't fall into the laval have no effect on the new rocks being produced. There would still be rocks falling in the lava all the time - that's not evolution.

[nomir_dva]

I cannot come up with a satisfactory defenition for life, though I do think that the distinction between living and non-living things is overemphasized. Viri, for example, are somewhere in between.

[meshou]

Cells, DNA, bacteria etc are alive by themselves.

So far (believe), RNA, Viruses, and prions are not. They lack complexity, and are little more than machines. We seem to only believe things qualify as alive to have been once complex enough to surprise us.

As for the rock, if they were continually pared down (and were able to "reproduce"), they might eventually get to the point where they "think" they're alive.

[illusivemind]

ApeTheDog,

I think your take on evolution might be a little off.
Natural selection only occurs when certain mutations favour genetic replication. Thus if the second generation of rocks were ‘given birth to’ by the first, then that generation would be entirely descendant from the ‘right rolling rocks’ as none of the other rocks ‘lived’ long enough to reproduce. As the generations were created only those rocks that rolled to the right would pass their genes on, increasing the chances that, that mutation would be passed on.

If all new rocks are made by the same volcano, with much the same consistency you will find the same numbers of rocks rolling in all directions over any length of time.

As to the question of the definition of life, it depends on what context you are talking about. The view of human life is centred on consciousness so we cad regard someone as being dead even if they’re heart is beating and their lungs are ‘breathing’.

Anencephalic babies are babies born without a brain only a brain-stem, their ‘life-spans’ are very short. They’re not really alive, but they’re still a kind of life form. We are constantly trying to divide up the world into categories that can be easily cogitated, this is human, this is not. This is organic, this is inorganic. This is alive, this is dead, this is life, this is rock. If you want to subscribe to it, then take your pick of whatever lines in the sand suit you, they are very useful. I’ve used such delineations in my explanation of natural selection. This is evolution and this is not.

If you want to be more holistic then consider it as floid said, “a moving target”.

[ApeTheDog]

Illusivemind, I know this. My example served mostly as a think exercise about what intelligence is. I think life and intelligence are practically synonyms. What is reproduction, other than an intelligent way to avoid dying?

Learning to do the smart thing does occur in the same way as my rock example went. There is no intelligence, no deliberateness, involved in it.

My point is that if this reproduction were, somehow, the end-result of a random biological process, just like what happened to these rocks, then life is simply a matter of chance as well.

Life exists because nothing has been able to kill it.

If I had been able to think of a way to make the rocks reproduce, and pass on characteristics to a next generation, i would have fit that in somewhere, but... I fear that would have been stretching reality a bit too far :)

[Hexchild]

My personal take on this definition is that any process that has the ability to self-repair and/or self-improve, is alive. Reproduction, whether it's in the form of sex, cell division or something else, is a specialized combination of both of these criteria. Seen from this point of view, life has nothing to do with chemicals (such as organic substances, DNA replication etc.) or even reality for that matter; those are only examples of systems where this kind of process is possible.

[PsiKik]

Life is something that you know when you see it.

I believe that an advanced computer program or machine could be alive as they can satisfy all of the so called criteria for life e.g.
reproduction, growth, evolution etc.

[jimore]

Life is what you are aware of having. When you stop having it, you are no longer aware of having it.

[illusivemind]

ApeTheDog,

Then intelligence is anything that is alive. I wouldn't go that far.

[meshou]

Life is what you are aware of having. When you stop having it, you are no longer aware of having it.I think you're confusing "aware" with "alive."

Germs aren't aware. They most certainly are alive and can be killed.

[meshou]

Illusivemind, I know this. My example served mostly as a think exercise about what intelligence is. I think life and intelligence are practically synonyms. What is reproduction, other than an intelligent way to avoid dying?I think you are putting intention where it does not belong. A germ does not "want" to live. It simply does. Protens do not have to think about being complex, they just are. Complexity may be something a mind made up, but that does not assume there is a mind contemplating this anywhere but after the fact.

Tangent: This is one of my pet peeves with intilligent design. "How can a germ want to be something else? How can protein want to reproduce? It can't! Therefore, something else must have wanted it for it! Thus, design!"

And so an intending intelligent being is assumed at the beginning ("want"), and so is the only answer to the question.

Things do not need to intend to be alive to live. When it comes down to it, there's a very weak line in the sand between viruses and bacteria because the line between of "living" and "merely following a chemical code in a simple mechanical way" is very very thin.

[jimore]

I think you're confusing "aware" with "alive."

Germs aren't aware. They most certainly are alive and can be killed.
1. How did you determine that germs are not aware?
2. When I responded, I was aware that my tongue was in my cheek. Nonetheless the statement is defensible.

[PiccoloNamek]

1. How did you determine that germs are not aware?

I think it has something to do with them not having brains.

[ApeTheDog]

I think you are putting intention where it does not belong. A germ does not "want" to live. It simply does. Protens do not have to think about being complex, they just are. Complexity may be something a mind made up, but that does not assume there is a mind contemplating this anywhere but after the fact.

Tangent: This is one of my pet peeves with intilligent design. "How can a germ want to be something else? How can protein want to reproduce? It can't! Therefore, something else must have wanted it for it! Thus, design!"

And so an intending intelligent being is assumed at the beginning ("want"), and so is the only answer to the question.

Things do not need to intend to be alive to live. When it comes down to it, there's a very weak line in the sand between viruses and bacteria because the line between of "living" and "merely following a chemical code in a simple mechanical way" is very very thin.

No, I do not think I put intention where it does not belongs, because I do not believe there is such a thing as life. I think we appear alive, and appear intelligent, but that really ALL intelligence is of the rock rolling in the right direction, and surviving kind.

I believe when germs learned to reproduce, they were doing something mechanical and coincidential that just happened to merit results.

Life exists because it finds a niche in the world that allows for it to exist, and then occupies that empty space.

Intelligence is nothing but, in my opinion, the occupation of that niche, and the 'learning' to carry on doing that. In a way, intelligence equals stupidity and rigidness.

What we call intelligence - and I comprise a whole lot of things under that (because when a being learns to survive rather than die, it is intelligence - not intelligent, but intelligence - in action) is simple luck and evolution.

I do not believe we are intelligent. I don't come up with ideas, i understand them. I'm not smart, i'm perceptive. And when I think something, i'm certain that I choose what ideas to follow up on because they make sense - because the world pushes them on me, rather than because I have free will.

Is it not the same thing when a one-celled organism learns, through intensive dying, how to do something (ie the world pretty much forces a way of being upon it, by leaving it no other options) - and when we learn through intensive mistake-making how to do things in an intelligent way?

Intelligence, in itself, IS life - is survival, to me. Life is simply an intelligent way to evade perpetual death.

[jimore]

I think it has something to do with them not having brains.
Same basic question. How did you (we) determine that awareness is exclusively a function of the brain? For homework, you might check out the excellent NOVA program on line entitled The Elegant Universe, in particular the segment called The Quantum Cafe.

[PiccoloNamek]

What kind of awareness are you talking about? Awareness of ones environment, or awareness of ones own awareness? Are you trying to imply that germs have minds?

I think it is fairly safe to conclude the the kind of awareness I'm talking about (that is, self-awareness) is a functioning of the brain. Sensory information processing, storage and recall of memories, advanced thought and emotion, and what have you. A bacteria cannot think to itself "I exist". Its body is, to an exent, aware of its environment and capable of responding to chemical changes in it, but this is nothing more than a fully automatic function carried out in a manner not unlike a machine following its programming.

I could probably build and program a simple walker machine that could function in such a manner. I could program it to know, say, that fire is bad and to avoid excess heat, but no matter how detailed the program was, the machine itself wouldn't ever have a conscious understanding of why fire is bad and why it's good to avoid it. It would only be following the program I wrote, just like the germs are following the program nature wrote for them.

[jimore]

What kind of awareness are you talking about? Awareness of ones environment, or awareness of ones own awareness? Are you trying to imply that germs have minds?.

Since you came to class without doing your homework, I will just put my tongue back in my cheek and back out the door. :)

[PiccoloNamek]

I finished my homework a long time ago.

[ApeTheDog]

What kind of awareness are you talking about? Awareness of ones environment, or awareness of ones own awareness? Are you trying to imply that germs have minds?

I think it is fairly safe to conclude the the kind of awareness I'm talking about (that is, self-awareness) is a functioning of the brain. Sensory information processing, storage and recall of memories, advanced thought and emotion, and what have you. A bacteria cannot think to itself "I exist". Its body is, to an exent, aware of its environment and capable of responding to chemical changes in it, but this is nothing more than a fully automatic function carried out in a manner not unlike a machine following its programming.

How do you know this? In specific, how do you know that when we think 'I exist' we are doing something different than the bacteria does? How do we know that the thoughts we think are in any way not as straightforward as the thoughts lower lifeforms have? Just because we think we're smart does not mean we are. The more I think about our thoughts, and our motivations, the less I think they're at all as elevated as we always asume they are.

Consciousness, freedom of thoughts - these are all things we ASSUME we have. But tell me what they are. Tell me what the difference is between when you think: "I am hungry. I'll just go and have a bite to eat" and when, say, a rat thinks the same thing.

Sure, we know we exist - it's a fact that is hard to miss. And it's a fact of which, knowing it - helps us survive. But a rat is aware of it's hunger. Is that not the same thing? It doesn't understand as much about itself as people do, but it's self-aware by nature - and being self-aware helps it take care of it's needs.


I could probably build and program a simple walker machine that could function in such a manner. I could program it to know, say, that fire is bad and to avoid excess heat, but no matter how detailed the program was, the machine itself wouldn't ever have a conscious understanding of why fire is bad and why it's good to avoid it. It would only be following the program I wrote, just like the germs are following the program nature wrote for them.

[ApeTheDog]

But the real question I'm asking myself with this thread is really:

How did dead matter turn into living matter?

[jimore]

But the real question I'm asking myself with this thread is really: How did dead matter turn into living matter?

Here's the closest I can come to what I think. String theory posits that everything in the universe is made out of little strings or loops of energy. They are so small that we can probably never detect them in the laboratory, and then it requires 11 dimensions to make them work mathematically. If that turns out to be correct, it may be that the distinctions we make between dead matter and live matter may not be as black and white as we have imagined. That is, were we able to truly measure everything in the universe, including strings, that what we perceive as a lifeless rock might have much more in common with a live bird (for example) than we now understand. That is that the differences may be a matter of dimensional perspective rather than a definitive state of being. ???

[meshou]

But the real question I'm asking myself with this thread is really:

How did dead matter turn into living matter?Protiens, baby.

A protien is just a self-reproducing molecule. That's it.

The chances of one being produced from primordial ooze were astronomical, but apparently it happened.

It needn't have made faithful copies, and was likely glitchy. But protiens can chain up to make new ones, and produce more. The more successful varients on the protiens made more faithful, durable copies. Faithful durable copies led to more complex ways of being faithful and durable.

DNA is just a self reproducing protien that got complicated enough to have a human attatched.

Alive is something we made up. Seriously. By the same criteria we call us alive (in terms of behavior-- we also now define by composition), fire is alive. The line is totally made up.

[Jacque]

Protiens, baby.

http://www.universetoday.com/am/publish/building_life_from_star-stuff.html?592005
"Dense molecular clouds in space eventually gravitationally collapse to form new stars. Some of the leftover dust later clumps together to form asteroids and comets, and some of these asteroids clump together to form planetary cores. On our planet, life then arose from whatever basic materials were at hand.

The large molecules necessary to build living cells are:

* Proteins
* Carbohydrates (sugars)
* Lipids (fats)
* Nucleic acids

Meteorites have been found to contain amino acids (the building blocks of proteins), sugars, fatty acids (the building blocks of lipids), and nucleic acid bases. The Murchison meteorite, for instance, contains chains of fatty acids, various types of sugars, all five nucleic acid bases, and more than 70 different amino acids (life uses 20 amino acids, only six of which are in the Murchison meteorite)."


http://www.space.com/scienceastronomy/solarsystem/comet_life_010405.html
"Peptide bonanza

In Blank's experiments, not only did a good fraction of the amino acids survive the simulated comet collision, but many evolved into chains of two, three and four amino acids, so-called peptides. Peptides with longer chains are called polypeptides, while even longer ones are called proteins.

"We saw variations in the ratios of peptides produced depending on the conditions of temperature, pressure and duration of the impact. This is the beginning of a new field of science," Blank said.

Freezing the target to mimic an icy comet increased the survival rate of amino acids, she added."


Combined with Infinite Monkey Theorem (http://user.tninet.se/~ecf599g/aardasnails/java/Monkey/webpages/index.html) produces genetics coherent to the evolution of William Shakespeare.

[PiccoloNamek]

How do you know this? In specific, how do you know that when we think 'I exist' we are doing something different than the bacteria does?

Because the bacteria doesn't have an advanced enough nervous system (or anything like it) to have such thoughts?


How do we know that the thoughts we think are in any way not as straightforward as the thoughts lower lifeforms have? Just because we think we're smart does not mean we are. The more I think about our thoughts, and our motivations, the less I think they're at all as elevated as we always asume they are.

I would say look at the world and everything we've achieved as proof of the awesomeness of our thoughts, but I suppose even that is a matter of opinion.


Consciousness, freedom of thoughts - these are all things we ASSUME we have. But tell me what they are. Tell me what the difference is between when you think: "I am hungry. I'll just go and have a bite to eat" and when, say, a rat thinks the same thing.

A rat doesn't think to itself "I am hungry, I'll just go and have a bite to eat." It simply feels that hunger and a need to get rid of it. But a human can not only think to themselves "Man, I'm hungry" but also things like "I don't feel like making food right now", or even choose to stop eating completely. The human also understands why it needs to eat and how the food it eats is used to maintain and repair its body, something a rat has no conception of.


But a rat is aware of it's hunger. Is that not the same thing? It doesn't understand as much about itself as people do, but it's self-aware by nature - and being self-aware helps it take care of it's needs.

I differentiate from self-awareness and mere bodily awareness. To me, they aren't the same thing.

[Conan]

But the real question I'm asking myself with this thread is really:

How did dead matter turn into living matter?

you should look up ribozymes (nucleic acid with enzymatic properties), since its a chicken and the egg problem (DNA or protein), this looks like a promising lead

[illusivemind]

And so an intending intelligent being is assumed at the beginning ("want"), and so is the only answer to the question.


Human beings have a wonderful habit of ascribing human characteristics to entirely non-human entities don't they? We can't imagine a living creature without a personality, intentions, thoughts and fears like our own.




Alive is something we made up. Seriously. By the same criteria we call us alive (in terms of behavior-- we also now define by composition), fire is alive. The line is totally made up.

I agree, one of the many lines in the sand we use to draw the world around us.

[tinribz]

Answer: organic -relating or belonging to the class of chemical compounds having a carbon basis.

Really though, if it wasn't for fire it would be easy to define as self replicating or is that just succesful life? As all life evolved from a single source and there is no proof of life anywhere else in the universe, then perhaps it is the potential to duplicate the current variety of life on earth given the the right resources and circumstances?

But where did the stuff on the comet come from?


Tangent: This is one of my pet peeves with intilligent design. "How can a germ want to be something else? How can protein want to reproduce? It can't! Therefore, something else must have wanted it for it! Thus, design!"

Are you being sarcastic? You do realise that it is a random design? Only the other billion random mutations fell by the wayside. Replication + Random mutation + resources + time (a long time) = any design you care to mention? - Its late I think I misunderstood u.

[headfonez]

life is a game! and you make the rules!

[meshou]

Are you being sarcastic? You do realise that it is a random design? Only the other billion random mutations fell by the wayside. Replication + Random mutation + resources + time (a long time) = any design you care to mention? - Its late I think I misunderstood u.Intilligent Design is something stupid they want taught in science classrooms. Basically, that it is not random and a God did it.

Yes, I undersand this is horseshit.

[NoahFence]

and there is no proof of life anywhere else in the universe,
There is no proof that there is no proof of life anywhere else in the universe. Our ability to go and find that proof is severely limited.

I guess what I'm saying is that "no proof of life elsewhere" does not equate to "proof of no life elsewhere." Given the context, it sounds as if you're assigning a very high probability to life being unique to our system. We have absolutely no idea how common or rare life may be. It is entirely possible that the development of life is a fundamental property of matter, and it will occur wherever conditions allow. This is a total unknown and we lack the technology to make it otherwise.