15 replies to this topic

[Baniboy]

So, me, anwiii and Nameless_ had a small discussion the other day. There was a short moment we were discussing about definitions, and defining life and organism came up.

Basically the biological definition for an organism is a living system which means that it responses to stimuli, has self-sustaining biological processes and is capable of reproduction and growth.
What do you think? Is there anything else? If you had a definition of your own, what was it?

If someone builds a robot that fills all these conditions, are you ready to call it life?

Edited by Baniboy, 17 November 2009 - 03:21 PM.

[anwiii]

define robot.

now how about this....

http://www.genpets.com/index.php

from now on, leave me out of your threads! haha. how nameless and i can be talking about philosophy/religion/spirituality and the unknown, to definitions and organisms when you decided to enter the conversation, i will never know! haha

Baniboy, on Nov 16 2009, 03:38 PM, said:

So, me, anwiii and Nameless_ had a small discussion the other day. There was a short moment we were discussing about definitions, and defining life and organism came up.

Basically the biological definition for an organism is a living system which means that it responses to stimuli, is self-sustaining and is capable of self-replication and growth.
What do you think? Is there anything else? If you had a definition of your own, what was it?

If someone builds a robot that fills all these conditions, are you ready to call it life?

[truefusion]

Baniboy, on Nov 16 2009, 03:38 PM, said:

What do you think? Is there anything else? If you had a definition of your own, what was it?

I don't really like the scientific definition for an organism (and many definitions for scientific terms), as it kind of goes against casual intuition. However, i also realize that when you try to make a definition that tries to exclude everything you don't want to be included, it can become difficult to define a word. The part that goes against casual intuition is the part after responding to stimuli—i would have stopped at "responding to stimuli;" although, i would not have used "stimuli" but "pain." For example, consider the following problem: viruses are considered (from what i hear) non-living organisms since they require a host to replicate. However, consider humans or any other creature: they require the opposite sex. Creatures can't split in half like bacteria and other living organisms—this is what i call self-replication, as it is an exact copy of the original. And as far as i'm concerned, no physical thing is self-sustaining (i.e. does not require external resources for survival). In other words, terms like "self-duplication" and "self-sustaining" are ambiguous.

Baniboy, on Nov 16 2009, 03:38 PM, said:

If someone builds a robot that fills all these conditions, are you ready to call it life?

I can make a program that fulfills the definition of an organism that you have provided, but i would not call it a (living) organism.

[Baniboy]

@anwiii:
Do genpets fulfill the biological definitions? Do they have self-sustaining biological processes, are they capable of reproduction, growth and development? And how the term "robot" means that it is NOT an organism? The link you provided is just an example of bioengineering.

@truefusion:

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The part that goes against casual intuition is the part after responding to stimuli—i would have stopped at "responding to stimuli;" although, i would not have used "stimuli" but "pain."

I don't really get what you're trying to prove here?
Pain is a response to stimuli. Are you saying that an organism feels pain for no reason? I'm guessing you response was a little hurried into. Sure organisms respond to pain, but that's after the organism has responded to a stimuli with "pain". Besides, many single-cellular organisms don't have a central nerve center. So they chemically respond to the stimuli directly, like some bacteria release anti-antibiotics(don't know what they are called in English) when they encounter antibiotics of a certain type. This of course doesn't apply if they aren't capable of responding to that particular stimuli.

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For example, consider the following problem: viruses are considered (from what i hear) non-living organisms since they require a host to replicate.

Viruses are considered the "edge of life".
For example, Chlamydia bacteria also can't reproduce without a host cell. Yet it is considered life. Viruses respond to stimuli, they require a host cell to replicate but it's the same as I need proteins to grow. They use the contents of the cells for their advantage and replicate. They are also affected by natural selection and mutation like most if not every other life forms on this planet. They aren't dead, but not exactly living either, they're a RNA/DNA chain(and sometimes the combination of both) inside a protein coat.

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Creatures can't split in half like bacteria and other living organisms—this is what i call self-replication, as it is an exact copy of the original.

Creatures? I don't know if that is a term for multi-cellular organisms in English, but I'm going to assume you mean multi-cellular organisms here, correct me if I'm wrong.

Bacterias and "other living things" can't make "exact copy of the original", this is because of mutation. Bacterias have as much mutation and natural selection happening in their populations as we "creatures" have in our populations. I'm sorry that I put "self-replication" in place of reproduction. My bad, I corrected it now. But anyway, let's move on.

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And as far as i'm concerned, no physical thing is self-sustaining (i.e. does not require external resources for survival). In other words, terms like "self-duplication" and "self-sustaining" are ambiguous.

By self-sustaining I think biologists mean the capability to get the external resources to sustain its biological processes. Of course everything has to die sometime, exclude that.

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I can make a program that fulfills the definition of an organism that you have provided, but i would not call it a (living) organism.

This is the exactly kind of discussion I wanted to take place here. So what defines life in your opinion?
Is that program capable of reproduction, growth and development? Excluding python scripts that don't need compiling. You could compare compiling to viruses needing a host cell, but can you make your program to use a compiler and compile a copy of itself?

In addition, I'm going to say that biologists missed one thing in the things that defines life.
My suggestion is the ability to variate and by variation more practically I mean mutation of genetic code, but there might be life forms that do not posess genetic code. Think about it, life can not exist without variation. Without variation, the resources burn out and the possibility to have a stable ecosystem formed by many organisms is destroyed.

Remembering tho, definitions are man-made and the point of them is to group things. So we can make difference between things, living things and non-living things, gas and liquid, HP and AMD ().

[truefusion]

Baniboy, on Nov 17 2009, 10:45 AM, said:

I don't really get what you're trying to prove here?
Pain is a response to stimuli. Are you saying that an organism feels pain for no reason? I'm guessing you response was a little hurried into. Sure organisms respond to pain, but that's after the organism has responded to a stimuli with "pain". Besides, many single-cellular organisms don't have a central nerve center. So they chemically respond to the stimuli directly, like some bacteria release anti-antibiotics(don't know what they are called in English) when they encounter antibiotics of a certain type. This of course doesn't apply if they aren't capable of responding to that particular stimuli.

Pain is a stimuli, but to say "stimuli" you basically allow for "stimuli" to mean "input"—in other words, any form of input, which can be either pain or typing symbols into a computer, et cetera. Using "pain" instead of "stimuli" is more restrictive, therefore avoiding robots.

Baniboy, on Nov 17 2009, 10:45 AM, said:

Viruses are considered the "edge of life".
For example, Chlamydia bacteria also can't reproduce without a host cell. Yet it is considered life. Viruses respond to stimuli, they require a host cell to replicate but it's the same as I need proteins to grow. They use the contents of the cells for their advantage and replicate. They are also affected by natural selection and mutation like most if not every other life forms on this planet. They aren't dead, but not exactly living either, they're a RNA/DNA chain(and sometimes the combination of both) inside a protein coat.

I wouldn't say that "life" and "living organism" have the same definition in science.

Baniboy, on Nov 17 2009, 10:45 AM, said:

Creatures? I don't know if that is a term for multi-cellular organisms in English, but I'm going to assume you mean multi-cellular organisms here, correct me if I'm wrong.

Creatures as in things of creation. I did not want to group humans as animals (through implication) by saying "humans and other animals," so i said "creatures"—which works perfectly fine for me.

Baniboy, on Nov 17 2009, 10:45 AM, said:

Bacterias and "other living things" can't make "exact copy of the original", this is because of mutation. Bacterias have as much mutation and natural selection happening in their populations as we "creatures" have in our populations. I'm sorry that I put "self-replication" in place of reproduction. My bad, I corrected it now. But anyway, let's move on.

After refreshing my memory on cellular mitosis, according to the images (computer animations) (though i would have preferred actual microscopic recordings—since anyone can make a computer animation, and we have to accept things as is, therefore making things not necessarily true), when a cell splits, "information" is "lost," and both halves look the same. Therefore forget what i said about exact copies.

Baniboy, on Nov 17 2009, 10:45 AM, said:

By self-sustaining I think biologists mean the capability to get the external resources to sustain its biological processes. Of course everything has to die sometime, exclude that.

However, i can't necessarily work on what you think they mean.

Baniboy, on Nov 17 2009, 10:45 AM, said:

This is the exactly kind of discussion I wanted to take place here. So what defines life in your opinion?
Is that program capable of reproduction, growth and development? Excluding python scripts that don't need compiling. You could compare compiling to viruses needing a host cell, but can you make your program to use a compiler and compile a copy of itself?

Just like cells may have DNA within themselves that supposedly hold their structural information within, so do objects (as in object-oriented programming). Normally, if you don't provide your own copy constructor, the compiler will do it for you. The copy constructor takes (i believe) one parameter: the object you want to make an exact copy of. I don't think you need to ask if the program is capable of development. But you don't need a compiler for a program to make a copy of itself; albeit, you do need a compiler to turn the source code into machine code. But concerning a compiler compiling a compiler: GCC is normally used to compile GCC.

But how does GCC compiling GCC fit into the definition you provided? Executing GCC to compile GCC is GCC responding to input (stimuli). Once the compiling is done (assuming you compiled the same version), you have made an exact copy of the GCC you have installed. If i assume what you think biologists mean about "self-sustaining," you could look up "statically-linked" and "dynamically-linked."

Baniboy, on Nov 17 2009, 10:45 AM, said:

In addition, I'm going to say that biologists missed one thing in the things that defines life.
My suggestion is the ability to variate and by variation more practically I mean mutation of genetic code, but there might be life forms that do not posess genetic code. Think about it, life can not exist without variation. Without variation, the resources burn out and the possibility to have a stable ecosystem formed by many organisms is destroyed.

If life cannot exist without variation, then you have to explain how the first living organism came into existence and how it managed to survive and mutate into all that we see today without other forms of variation (the resources you speak of). The way you mention it implies an abundance (at least enough to survive) of resources for that first living organism.

[anwiii]

first of all, i used genpets as an example in general. not an example to what you say the definition is.

have you forgot what i said in the shoutbox, i like true fusion don't believe in the scientific definitions in general.

this point was not worth arguing in the shoutbox as it's not worth arguing here.

i'm glad you changed part of the definition from self replicating to reproduction because that would have been one of my main arguements against the definition....or my opinion at least. but i do feel that an organism can be considered an organism without the ability to reproduce....but that's my opinion only and differs from your scientific definition.

and while we are on this topic, i would actually like to know the history of that definition you state and how(if it was) it was molded in to what we know today about organisms.

Baniboy, on Nov 17 2009, 09:45 AM, said:

@anwiii:
Do genpets fulfill the biological definitions? Do they have self-sustaining biological processes, are they capable of reproduction, growth and development? And how the term "robot" means that it is NOT an organism? The link you provided is just an example of bioengineering.

@truefusion:

I don't really get what you're trying to prove here?
Pain is a response to stimuli. Are you saying that an organism feels pain for no reason? I'm guessing you response was a little hurried into. Sure organisms respond to pain, but that's after the organism has responded to a stimuli with "pain". Besides, many single-cellular organisms don't have a central nerve center. So they chemically respond to the stimuli directly, like some bacteria release anti-antibiotics(don't know what they are called in English) when they encounter antibiotics of a certain type. This of course doesn't apply if they aren't capable of responding to that particular stimuli.


Viruses are considered the "edge of life".
For example, Chlamydia bacteria also can't reproduce without a host cell. Yet it is considered life. Viruses respond to stimuli, they require a host cell to replicate but it's the same as I need proteins to grow. They use the contents of the cells for their advantage and replicate. They are also affected by natural selection and mutation like most if not every other life forms on this planet. They aren't dead, but not exactly living either, they're a RNA/DNA chain(and sometimes the combination of both) inside a protein coat.


Creatures? I don't know if that is a term for multi-cellular organisms in English, but I'm going to assume you mean multi-cellular organisms here, correct me if I'm wrong.

Bacterias and "other living things" can't make "exact copy of the original", this is because of mutation. Bacterias have as much mutation and natural selection happening in their populations as we "creatures" have in our populations. I'm sorry that I put "self-replication" in place of reproduction. My bad, I corrected it now. But anyway, let's move on.

By self-sustaining I think biologists mean the capability to get the external resources to sustain its biological processes. Of course everything has to die sometime, exclude that.

This is the exactly kind of discussion I wanted to take place here. So what defines life in your opinion?
Is that program capable of reproduction, growth and development? Excluding python scripts that don't need compiling. You could compare compiling to viruses needing a host cell, but can you make your program to use a compiler and compile a copy of itself?

In addition, I'm going to say that biologists missed one thing in the things that defines life.
My suggestion is the ability to variate and by variation more practically I mean mutation of genetic code, but there might be life forms that do not posess genetic code. Think about it, life can not exist without variation. Without variation, the resources burn out and the possibility to have a stable ecosystem formed by many organisms is destroyed.

Remembering tho, definitions are man-made and the point of them is to group things. So we can make difference between things, living things and non-living things, gas and liquid, HP and AMD ().

[Baniboy]

Let me update the biological definition, I ripped this one off Wikipedia:

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• Homeostasis: Regulation of the internal environment to maintain a constant state; for example, electrolyte concentration or sweating to reduce temperature.
  
• Organization: Being structurally composed of one or more cells, which are the basic units of life.
  
• Metabolism: Transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.
  
• Growth: Maintenance of a higher rate of anabolism than catabolism. A growing organism increases in size in all of its parts, rather than simply accumulating matter.
  
• Adaptation: The ability to change over a period of time in response to the environment. This ability is fundamental to the process of evolution and is determined by the organism's heredity as well as the composition of metabolized substances, and external factors present.
  
• Response to stimuli: A response can take many forms, from the contraction of a unicellular organism to external chemicals, to complex reactions involving all the senses of multicellular organisms. A response is often expressed by motion, for example, the leaves of a plant turning toward the sun (phototropism) and by chemotaxis.
  
• Reproduction: The ability to produce new individual organisms, either asexually from a single parent organism, or sexually from two parent organisms.

http://en.wikipedia....ki/Life#Biology

AWW... variation was already there, (adaptation) I suppose it means genetic adaptation.

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Pain is a stimuli, but to say "stimuli" you basically allow for "stimuli" to mean "input"—in other words, any form of input, which can be either pain or typing symbols into a computer, et cetera. Using "pain" instead of "stimuli" is more restrictive, therefore avoiding robots.

Yes, a very clever way to avoid robots... + plants, most single-celled organisms, viruses etc. Pain is just a message that nerve cells send to the brain to report damage, then the central nerve system reacts to it to avoid more damage.

Self-sustaining is up there 1st in the list above.

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I wouldn't say that "life" and "living organism" have the same definition in science.

I'm going to assume you meant my sentence of "Yet it is considered life". Okay, messed up the words a bit. Replace it with "Yet it is considered a living organism". Besides, aren't living organisms considered "life"?

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Creatures as in things of creation. I did not want to group humans as animals (through implication) by saying "humans and other animals," so i said "creatures"—which works perfectly fine for me.

There are no major differences in the anatomy of human and "animals". And no I'm not going to even start with the "creation"-part, as I don't know if you mean "godly creation" here. I assume you're not a young earth creationist tho.

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After refreshing my memory on cellular mitosis, according to the images (computer animations) (though i would have preferred actual microscopic recordings—since anyone can make a computer animation, and we have to accept things as is, therefore making things not necessarily true), when a cell splits, "information" is "lost," and both halves look the same. Therefore forget what i said about exact copies.

*forget about whaa...?* hasta la vista, memories.

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However, i can't necessarily work on what you think they mean.

I didn't have the time to research and find exactly what they mean, so I put an "I think" there to indicate that I was not sure. You do not have to point out about something I did intentionally. And I was right.

As for program compiling thingy, I didn't really get it so I'll leave it alone for now
What I meant is that is the program capable of writing its source code and compile it by itself.
Moving on...

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If life cannot exist without variation, then you have to explain how the first living organism came into existence and how it managed to survive and mutate into all that we see today without other forms of variation (the resources you speak of). The way you mention it implies an abundance (at least enough to survive) of resources for that first living organism.

Life cannot survive without variation(didn't really mean the exist part, I was sleepy) as using the same resources would generate a new environment for the population to live in. Without variation, natural selection can't happen and the organism can't adapt to the new environment that is totally different. The first organisms on earth that are speculated to be capable of photosynthesis, they produced oxygen. They couldn't have lived forever, as they would've ran out of carbon dioxide since they produce more oxygen than CO2. So there came the first cells that could take advantage of the oxygen and an atmosphere that could reflect some of the harmful radiation back into space. Organisms have their own effect on their environment.

Sorry for saying life can't exist without variation, my bad.

EDIT: anwiii, there wasn't anything I could reply to you since all you say is that you don't care about science and its way of grouping things. I can't find the history of the definition you asked for, you could try searching more, I've to go to bed now

Edited by Baniboy, 18 November 2009 - 08:15 PM.

[anwiii]

damn straight....when i know science and it's theories have been wrong more than half the time. now we are talking about the definition of an organism. WHO CARES. people will have their own definition. i am no different than even scientist that argue about other scientists definitions....but at least i'm not wrong over 1/2 the time with what i know and my own beliefs and theories when i try to put the pieces of a puzzle together. just because i don't believe in science for answers doesn't mean i don't believe it's not needed. science has always opened up new ideas and possibilities.

personally, i think you're one cell short of being an organism. how's that for a definition.

in fact, the definition of organism stopped being a definition when there are so many arguments in what consititutes an organism. you may not know this, but you argued this point indirectly when you started this thread with a question. you might as well have asked for the definition of a human being

this thread will go nowhere as i have already predicted. this is why i asked for my name to be left out of this topic as i don't really like being associated with nonsense threads or discussions. as you recall, after you changed our subject in the shout box, i tried to get away from this topic as it holds no meaning to me. no man made defination does. science for the most part doesn't either.

after all is said and done though, i know that i am considered an organism under the definitions you state.....and if that can be the only thing that defines me for the rest of my life, i might as well kill myself now.

Baniboy, on Nov 18 2009, 02:13 PM, said:

EDIT: anwiii, there wasn't anything I could reply to you since all you say is that you don't care about science and its way of grouping things. I can't find the history of the definition you asked for, you could try searching more, I've to go to bed now

[truefusion]

Baniboy, on Nov 18 2009, 03:13 PM, said:

Yes, a very clever way to avoid robots... + plants, most single-celled organisms, viruses etc. Pain is just a message that nerve cells send to the brain to report damage, then the central nerve system reacts to it to avoid more damage.

Do i smell a hint of sarcasm or is that plus sign intended to mean something else? I can't say if a plant feels pain even though there have been studies that say that plants emit something that is only detectable by special machines when the plant is inflicted with what we call "damage," but we can nevertheless see the effects of the damage caused, to which a conscious being would declare as "pain." And concerning single-celled organisms and viruses, i wouldn't suspect them to enjoy becoming a meal for white-blood cells. In other words, while what i would consider "pain" may not be as scientifically sounding, i would define pain as some form of extreme discomfort.

Baniboy, on Nov 18 2009, 03:13 PM, said:

Self-sustaining is up there 1st in the list above.

Other than homeostasis, i'ma assume you also mean to include metabolism (as homeostasis is implied in metabolism).

Baniboy, on Nov 18 2009, 03:13 PM, said:

I'm going to assume you meant my sentence of "Yet it is considered life". Okay, messed up the words a bit. Replace it with "Yet it is considered a living organism". Besides, aren't living organisms considered "life"?

They are, but i can't say whether a living organism continues being a living organism after it is dead (i.e. as we practically understand death). For even though it is dead, it still bears all that it had, that is, at least until decay occurs, albeit those parts would no longer be functional. Given the definition you provided from Wikipedia for the word "life," homeostasis implies functional parts, therefore assuring that it is also considered dead within biology. But because it is dead, does that in turn make it a "non-living organism" or will it remain a "living organism"? And does calling it now a "non-living organism" contradict the definition of a "non-living organism" as defined by the biological sciences?

Baniboy, on Nov 18 2009, 03:13 PM, said:

I assume you're not a young earth creationist tho.

You assumed correctly.

Baniboy, on Nov 18 2009, 03:13 PM, said:

As for program compiling thingy, I didn't really get it so I'll leave it alone for now
What I meant is that is the program capable of writing its source code and compile it by itself.

If you think about it, did a living organism write its own source code (i.e. DNA)? If it did, i would expect it to be a bit of a paradox, since DNA is said to hold the information needed to even construct the organism. I mean, i wouldn't suspect for such a simple organism to say, "Okay, i've got a good plan on how to construct myself. Now where to put it all? "

Baniboy, on Nov 18 2009, 03:13 PM, said:

Life cannot survive without variation(didn't really mean the exist part, I was sleepy) as using the same resources would generate a new environment for the population to live in. Without variation, natural selection can't happen and the organism can't adapt to the new environment that is totally different. The first organisms on earth that are speculated to be capable of photosynthesis, they produced oxygen. They couldn't have lived forever, as they would've ran out of carbon dioxide since they produce more oxygen than CO2. So there came the first cells that could take advantage of the oxygen and an atmosphere that could reflect some of the harmful radiation back into space. Organisms have their own effect on their environment.

Sorry for saying life can't exist without variation, my bad.

So the first microscopic lifeform lived off of carbon dioxide (though some might suggest that life started under water)? "Organisms" here seems a bit ambiguous. Even though you mention "first cells" a little bit into it, you say they came after the previously mentioned organisms. I am not sure if you are assuming a fully-formed organism (e.g. a plant), but if you are, it is not safe to do so, as there is no explanation on how these oxygen-causing organisms came into existence.

[Baniboy]

@anwiii:
Your post is useless(sorry dude). I wasn't inviting you to the conversation by mentioning your name. All I was simply telling was how I got the idea of making such a thread, just popped in my mind when talking to you and Nameless_. I was interested in knowing how other people recognize living things from non-living things and their definitions for them. I couldn't care less of you spamming here about how you don't care about science and definitions(and everyone uses definitions, even you). And FYI, this wasn't about science, just didn't find a sub-forum for philosophy and stuff.

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Do i smell a hint of sarcasm or is that plus sign intended to mean something else? I can't say if a plant feels pain even though there have been studies that say that plants emit something that is only detectable by special machines when the plant is inflicted with what we call "damage," but we can nevertheless see the effects of the damage caused, to which a conscious being would declare as "pain." And concerning single-celled organisms and viruses, i wouldn't suspect them to enjoy becoming a meal for white-blood cells. In other words, while what i would consider "pain" may not be as scientifically sounding, i would define pain as some form of extreme discomfort.

I smell BBQ yeah, sarcasm.
So as you would describe it, reacting to damage. Good enough, now I get what you mean(as I have not yet found any organisms that don't respond to damage. Single celled organisms have their own ways of detecting future "extreme discomfort"). Feeling extreme discomfort... wouldn't it mean the virus is already dead? Anyway, I don't know the reasons why you don't accept stimuli but extreme discomfort (although I could have a guess).

Quote

They are, but i can't say whether a living organism continues being a living organism after it is dead (i.e. as we practically understand death). For even though it is dead, it still bears all that it had, that is, at least until decay occurs, albeit those parts would no longer be functional. Given the definition you provided from Wikipedia for the word "life," homeostasis implies functional parts, therefore assuring that it is also considered dead within biology. But because it is dead, does that in turn make it a "non-living organism" or will it remain a "living organism"? And does calling it now a "non-living organism" contradict the definition of a "non-living organism" as defined by the biological sciences?

If I remember correctly, biological definition for death is when the organism cannot sustain its biological processes anymore (for multi-celled organisms for example cannot get the nutrients to the cells anymore). So you should try asking this from a biologist or something. I wouldn't scientifically define the remains of a dead organism a "non-living organism" - as it doesn't comply with the definitions of an organism anymore?(self-sustaining, responding to stimuli, etc.)

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If you think about it, did a living organism write its own source code (i.e. DNA)? If it did, i would expect it to be a bit of a paradox, since DNA is said to hold the information needed to even construct the organism. I mean, i wouldn't suspect for such a simple organism to say, "Okay, i've got a good plan on how to construct myself. Now where to put it all? "

No. The DNA is already within the cell, all it has to do is to reproduce more of it. And it would contain the information required to reproduce more. What I meant was, would the program be able to write a copy of its own source down to a for example c document and then compile it. And every time this happens, some damage would be inflicted on the source (kind of like adding random strings here and there, or deleting some). Through regeneration, it would create a better program (suiting to its environment). This would fill the adaptation one in the list.

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So the first microscopic lifeform lived off of carbon dioxide (though some might suggest that life started under water)? "Organisms" here seems a bit ambiguous. Even though you mention "first cells" a little bit into it, you say they came after the previously mentioned organisms. I am not sure if you are assuming a fully-formed organism (e.g. a plant), but if you are, it is not safe to do so, as there is no explanation on how these oxygen-causing organisms came into existence.

I totally crashed while reading the first sentence , you had me lolling for some time. I'm very disappointed. Water can have chemical compounds dissolved in it. Duh, plants under water for example? And considering many underwater volcanoes, carbon dioxide, sodium and sulfur components, small amounts of oxygen, etc were dissolved in the water. So it's safe to say that the first organisms on earth used these nutrients directly and then evolved into ones that could produce the oxygen by themselves through some kind of early chloroplast(I don't know if you know how photosynthesis works). It's again easy to speculate that the population of cells which could produce oxygen and support their own metabolism that way would rule the cells that had to live using the small amounts of oxygen available in the water. So these cells could've produced more and more oxygen and replacing carbon dioxide in the atmosphere. Oxygen-rich atmosphere would stop more UV radiation, which was the main reason why the lifespan was so short and it wasn't possible for other kinds of organisms to live there. And then it was possible for other organisms to feed on the ones that bind sun's energy into their cells. Doing this they would've released more carbon dioxide completing the ecosystem. The only part of the ecosystem that's not self-sustainable are the chemicals that aren't reboundable, like sulfur oxides and of course, the sun(because sun isn't a self-sustaining energy source, nothing is).

Well, instead of trying to debate these(actually you sound more like you're trying to discredit than debate), I would like to know your definitions. The whole thread was about telling about your own definitions, which you haven't yet done. So, could you please do that, too, and of course continue the conversation we have here if you have more to talk about.

EDIT: Why is it that when you, me and a few others maybe start talking in a thread, it becomes dead to everyone else? Nobody joins the conversation after it has started off, or is it just the "too long - didn't read"-thing?

Edited by Baniboy, 16 December 2009 - 07:56 PM.