Gaia - What Is Life?
It's pretty much an essay (which I actually wrote more or less out of my own free will) and doesn't leave much room for discussion. But hopefully you'll read it anyway. My main sources of information in writing this are as follows: In the Beginning by John Gribbin, A Brief History of Time by Stephen Hawking, and Wikipedia.
What is life? What is an organic material? And what is an organism? How are they different and how are they the same? These are questions I intend to answer in this thread: Gaia - What Is Life?
First, I feel I must illustrate where life begins. I'm not talking about sexual reproduction here. What I'm talking about is where ALL life on earth starts. What we do know is that it starts somewhere before a standalone cell - bacteria. But I'm sure any of us who have taken biology know that there are smaller entities. Advanced chemical compounds that cannot exist in a freeform state, but instead need to use cells as a vessel for their own production. Bicteriaphage, or phage.... Phage are a mixture of living and non-living, we are taught. But truly, can a phage really be considered living? Much like a human would not be alive if isolated from other organisms, a phage would not be alive if isolated from baceteria. The phage cannot reproduce without the bacterium, and ironically, when the phage takes over the bacterium, it also kills the bacterium when it overproduces copies of itself. So then, is a phage alive or not? A phage is obviously not where life begins. But when put under the right conditions, it takes on life-like characteristics. So then, we know that life may start somewhere between a phage and a cell. In fact, life probably starts between a phage and an organelle (as we know some organelles to be self-reproducing, and contain DNA, such as mitochondria and cloroplasts). But what about the inverse? Where does life stop? This is a question I cannot answer, but intend to search for answers on in this thread.
But first I must answer those key questions in the first paragraph: what are life, organic material and an organism, and how are they related?
According to a simpler source (and my own personal favorite) - Wikipedia - says that life can be attributed to objects which grow, metabolize, move, reproduce, and respond to stimuli. Now. There are obviously living things that don't follow these constituents. Hybrids for example cannot reproduce, yet they are without a doubt alive. Life obviously doesn't need ALL of these aspects to be apparent, it just needs to relate to these aspects in a way that isn't metaphorical. While mules cannot reproduce, reproduction was used to produce a mule, so maybe in that manner it can still apply to the rule of reproduction?
As for organic material, this is a definition which has been subject to much change over the past century. Originally, people decided that something organic was something alive. Though, science decided that there are too many chemical similarities between chemicals that combine to form living things. And so the current day definition of organic is that most compounds with carbon are organic; carbides, carbonates, carbon oxides and gases containing carbon. Interestingly, the universe is teaming (relatively speaking) with organic materials - while obviously not teaming with life. This is something I'll elaborate on later.
Lastly, an organism is a group of organs (and organ systems) whose functions work together to create a stable whole. While bacterium, and other single celled organisms are just that - organisms. For the purpose of this thread, single celled organisms will be referred to as bacterium, while multi-celled organisms will be referred to as organisms.
To go back to where life begins - many of you are probably familliar with the following chart:
atom-molecule-organelle-cell-tissue-organ-organ system-organism-population-community-ecosystem
Hell, we may as well add biosphere after eco-system, and planet after biosphere.
So then I raise the question - if the downward limit of life is somewhere between a phage (molecule) and a cell, and maybe even between a phage and an organelle, then what is the upward limit? The easy answer would be an organism. After all, one of the constrictions of life is that life is reproducing. Communities, populations, ecosystems, biosphere and planets don't reproduce... right? Even if they do, they don't grow, metabolize, move, or respond to stimuli, do they? In fact, populations do grow as the number of organisms increase, they move to wherever their hearts content, they respond to the changes in weather, they consume energy and excrete waste much like any other metabolism. And by GOD they reproduce. Communities follow the same trends as populations - I'm sure we've all seen our communities metabolize. New York City for example gets thousands of truckloads of energy every day, and every day, New York City must throw their waste in the ocean, the streets... and New Jersey.
What about eco-systems? They're so incredibly vast. How can we ever see the reproduction of the boreal forests, or the growth of the Himalayas, or heck, the response of the sahara dessert to stimuli!
Quite frankly, the boreal forests of North America have been popping up all over the continent, and I can't see any other way to describe this, than by saying that these forests reproduce themselves. But that's a pretty obvious way to answer the question - I mean, they are using organisms to reproduce after all? What about the Himalayas? Do they grow? Well, of course they grow. Anyone and their mother (sarcasm?) knows that the continental drift of the Indian subcontinent causes the Himalayas to grow larger every year! But... they certainly don't reproduce. Then again, if this continental drift is the cause of the Himalayan eco system in the first place, is it not a part of the Himilayan eco system? As new mountains pop up (not overnight, mind you) how can it not be considered reproduction? Then there's the Sahara desert... what sort of stimuli could it possibly respond to? Well, we do know for a fact that deforestation causes deserts to move, and expand and this is no exception with the sahara desert. The sahara desert also grows in this expansion, and reproduces as the wind causes its arid dusts to carry it - and the inhabbitants of this eco system - into places the sahara shouldn't even be! Mini-deserts, begin to form their own populations within other eco-systems, some of these grow, and some of these die - depending on the principles of natural selection and survival of the fittest!
Some of you may be saying (if you even read this far) "That's all fine and dandy, but I thought you said this wasn't a metaphorical analysis, Void?"
Indeed I did. But let me ask you this. If the act of human reproduction (sexual intercourse) isn't a metaphor for true cellular reproduction, then why not the reproducion of an ecoystem? Afterall, when a male inserts a penis into a female's vaginal cavity, the resultant isn't that the two sexual organs combine and grow, and the result certainly isn't that the sexual organs themselves reproduce. Hell, sexual intercourse isn't reproduction at all - else reproduction would occur during all acts of sexual intercourse - yet several of us on the forums know this is not the case (if by first hand count, or second hand :P). The sexual organs are in fact tools. Tools that allow reproduction to happen. Reproduction does not occur during sexual intercourse, but rather, it occurs when the two reproductive cells join to create one whole cell. One cell that can from that moment on split into two cells, which in turn split into two more, and so on and so forth. So then, we've established that organisms themselves do not reproduce (except for the individual cells IN said organism), but rather they are tools of reproduction. Similarly, eco-systems make suitable habbitats for organisms, organisms whose cells reproduce. This is the case, and we know it's the case, So if this is the case, then why can't an eco-system be a living thing outside of the metaphorical sense, just like an organism? Why can't organisms be to eco-systems as cells are to organisms?
The answer is they can, and they are.
But surely this doesn't go further BEYOND ecosystems. Planets - outside of gravity - are purely stationary, some don't even contain life, so how then could planets be considered alive? Let's consider that planet MAY be a living entity. The fact is that planets have a finite period in which they exist before being disembled; for whatever reasons. In this light, one would be hard pressed to think of a planet as being anything more than a host for life, as when the planet itself comes to an end, life from that planet will not spread - in effect reproducing. Reproduction seems to be the key aspect of life, and with this sort of existence, one would think that a planet can never be capable of reproducing life.
Do you remember when I mentioned the universe, teaming with organic material and said "I'll elaborate on this later"? Well, it's pretty late now, and so I'll elaborate now. Organic material is in fact abundant throughout the universe, while non-organic material makes up the vast majority of material in this universe (About 99% of the matter in the universe is dark matter. Out of the remaining 1%, 99% is hydrogen and helium - the rest being heavy elements creation by nuclear fusion. Out of that 1% of elements that aren't hydrogen or helium, 99% of the material is non-organic. The remaining 1% is organic material, so 1% of 1% of 1% of all the matter in the universe is organic material, while everything else is non-organic.) By measuring the length of atomic lines coming from microwaves in gas cloud (which used to be stars), astronomers discovered that these clouds, which are by and large composed of hydrogen and helium, are also composed of carbon, oxygen, and nitrogen which along with hydrogen are the building blocks of life. Interestingly, in the high temperatures of a star (6000 K) there is enough heat energy and radiation for nuclear fusion to take place. This means elements break down into smaller atoms and recombine into new elements. In this way, simple hydrogen protons and even helium with two protons and a neutron, can break down and recombine to make much heavier matter (and this is how that 1% of matter that isn't hydrogen or helium came into existence in the first place). This is in fact, where the building blocks of life originated (a little of topic, in giant stars there are cycles of fusion that end with iron and a huge explosion which = a black hole). Every proton of every atom in your body once came from the nuclear fusion of hydrogen - baked at extremely high temperatures.
And so, everything that makes up our planet earth, was baked in an ancient star, that predates our own sun. At the end of this stars life time, it exploded, leaving behind a gas cloud much like the ones we are analyzing today. A cloud carrying all the building blocks of life. Over billions of years, gravity created a new star from this cloud, and nine (maybe more!) planets, with hundreds of moons and planetoids. After the formation of earth, it wasn't but 500 million years that life began on earth. That's quite a feat, you know. For a planet with an atmosphere that absorbs energy from the stars, energy that should fuel the chemical reactions which create organic material, organic material which in turn creates long carbon chains which lead to proteins, fats, sugars, and ultimately DNA. It seems as though life just popped up on Earth as soon as earth had enough time to cool down from it's birthing process. Earth itself is 5 billion years old, and the first organism popped up at MOST 1.2 billion years ago, while the first bacterium popped up a staggering 4.5 BILLION years ago. If life then, is such a complicated thing to create, how come the Earth created it when it was just barely cooling from a magmated state? The answer is that it probably had a helping hand.
As I mentioned in the previous paragraph, the atmosphere of earth absorbs a lot of energy from the sun. However, in a gas cloud energy is constantly being bathed apon clouds by stars in every direcction (yes, these far away stars have lots of energy too!) As we know, radiation energy from stars fuels chemical reactions. It wasn't long after discovering that gas clouds contained complex elements, that humanity discovered gas cloud also contain complex compounds - organic compounds. Fermeldehyde, glycene and even cellulose were found by measuring the atomic lines coming from the microwaves of these gas clouds. These does indeed mean that organic material forms in space, much like it would form on earth if given the right conditions. With this knowledge in hand, one can imagine the early sol system (our solar system), and the gravity of the ever growing earth constantly pulling organic material towards its surface. Protected from the harsh elements of precambian earth - in water, these organic materials can undergo even more chemical reactions, and must have eventually formed long carbon chains, these chains being DNA in its simplest form. By skipping the process of creating organic material, earth could easily have had enough time mix the organic material up enough to make the first strand of DNA. Of course one might raise the question that without the proteins needed to create a cell membrane, this DNA would constantly be consumed. Of course, even with the harsh elements of pre-cambian earth I'd ask "what is there to consume this DNA in a world where life does not yet exist to consume anything?" And so, DNA could be left to its own divices, until it finally comes in contact with proteins that can jump start the whole process of reproduction. And this is the long story of how life on earth was seeded in a process that began before the earth itself even came into existence.
And so to go ALL the way back to the point of earth and the question of "can earth be considered anything more than a host of life?" Well, quite frankly, yes. The organic material on our planet had to originate from somewhere. Even IF it did originate on earth, consider first that the elements which formed this organic material had to come from a gas cloud. A gas cloud that was formed by the destruction of a star, and planets before our own solar system. Planets and stars which also must have contained carbon, oxygen, nitrogen and hydrogen - the building blocks of life. And when our planet comes to an end, what is to become of the organic material that makes us? It will be added to the cycle once again, to be drawn in by the gravity of the resulting gas cloud, where chemical reactions will continue to take place, and gravity will continue to form new planets and new stars that are seeded with organic material... until one planet is formed in the right conditions, not too hot so that there is too much energy, and not too cold so that there is too little energy. A planet where there is water for these organic materials to be added to the mixing pot. Then again, this raises yet another question "If planets aren't a host for life, but living things themselves, then how come not all planets have life?" It's evolution at it's finest - natural selecction. Survival of the fittest; the one who most fits their environment is the one who survives. Through all it's chance mutations in birth - the gathering of water, organic material and energy all in one place - earth has evolved into a planet that can support life, while other planets did not make these chance mutations, and as such have no life.
Our planet is alive. It breaths and exhales, it grows, it moves, it reacts to stimuli. It even seeds life for planets yet to come in a process known as reproduction. The planet earth is alive in no less of a metaphoric sense as our own bodies are are alive. In no less of a sense are we made up of many living things as is the planet earth. I said earlier that we are the cells to the ecosystem. In fact, the ecoystem is more like an organ is to an organism - with us being the cell - the planet being the organism.
What is life? What is an organic material? And what is an organism? How are they different and how are they the same? These are questions I intend to answer in this thread: Gaia - What Is Life?
First, I feel I must illustrate where life begins. I'm not talking about sexual reproduction here. What I'm talking about is where ALL life on earth starts. What we do know is that it starts somewhere before a standalone cell - bacteria. But I'm sure any of us who have taken biology know that there are smaller entities. Advanced chemical compounds that cannot exist in a freeform state, but instead need to use cells as a vessel for their own production. Bicteriaphage, or phage.... Phage are a mixture of living and non-living, we are taught. But truly, can a phage really be considered living? Much like a human would not be alive if isolated from other organisms, a phage would not be alive if isolated from baceteria. The phage cannot reproduce without the bacterium, and ironically, when the phage takes over the bacterium, it also kills the bacterium when it overproduces copies of itself. So then, is a phage alive or not? A phage is obviously not where life begins. But when put under the right conditions, it takes on life-like characteristics. So then, we know that life may start somewhere between a phage and a cell. In fact, life probably starts between a phage and an organelle (as we know some organelles to be self-reproducing, and contain DNA, such as mitochondria and cloroplasts). But what about the inverse? Where does life stop? This is a question I cannot answer, but intend to search for answers on in this thread.
But first I must answer those key questions in the first paragraph: what are life, organic material and an organism, and how are they related?
According to a simpler source (and my own personal favorite) - Wikipedia - says that life can be attributed to objects which grow, metabolize, move, reproduce, and respond to stimuli. Now. There are obviously living things that don't follow these constituents. Hybrids for example cannot reproduce, yet they are without a doubt alive. Life obviously doesn't need ALL of these aspects to be apparent, it just needs to relate to these aspects in a way that isn't metaphorical. While mules cannot reproduce, reproduction was used to produce a mule, so maybe in that manner it can still apply to the rule of reproduction?
As for organic material, this is a definition which has been subject to much change over the past century. Originally, people decided that something organic was something alive. Though, science decided that there are too many chemical similarities between chemicals that combine to form living things. And so the current day definition of organic is that most compounds with carbon are organic; carbides, carbonates, carbon oxides and gases containing carbon. Interestingly, the universe is teaming (relatively speaking) with organic materials - while obviously not teaming with life. This is something I'll elaborate on later.
Lastly, an organism is a group of organs (and organ systems) whose functions work together to create a stable whole. While bacterium, and other single celled organisms are just that - organisms. For the purpose of this thread, single celled organisms will be referred to as bacterium, while multi-celled organisms will be referred to as organisms.
To go back to where life begins - many of you are probably familliar with the following chart:
atom-molecule-organelle-cell-tissue-organ-organ system-organism-population-community-ecosystem
Hell, we may as well add biosphere after eco-system, and planet after biosphere.
So then I raise the question - if the downward limit of life is somewhere between a phage (molecule) and a cell, and maybe even between a phage and an organelle, then what is the upward limit? The easy answer would be an organism. After all, one of the constrictions of life is that life is reproducing. Communities, populations, ecosystems, biosphere and planets don't reproduce... right? Even if they do, they don't grow, metabolize, move, or respond to stimuli, do they? In fact, populations do grow as the number of organisms increase, they move to wherever their hearts content, they respond to the changes in weather, they consume energy and excrete waste much like any other metabolism. And by GOD they reproduce. Communities follow the same trends as populations - I'm sure we've all seen our communities metabolize. New York City for example gets thousands of truckloads of energy every day, and every day, New York City must throw their waste in the ocean, the streets... and New Jersey.
What about eco-systems? They're so incredibly vast. How can we ever see the reproduction of the boreal forests, or the growth of the Himalayas, or heck, the response of the sahara dessert to stimuli!
Quite frankly, the boreal forests of North America have been popping up all over the continent, and I can't see any other way to describe this, than by saying that these forests reproduce themselves. But that's a pretty obvious way to answer the question - I mean, they are using organisms to reproduce after all? What about the Himalayas? Do they grow? Well, of course they grow. Anyone and their mother (sarcasm?) knows that the continental drift of the Indian subcontinent causes the Himalayas to grow larger every year! But... they certainly don't reproduce. Then again, if this continental drift is the cause of the Himalayan eco system in the first place, is it not a part of the Himilayan eco system? As new mountains pop up (not overnight, mind you) how can it not be considered reproduction? Then there's the Sahara desert... what sort of stimuli could it possibly respond to? Well, we do know for a fact that deforestation causes deserts to move, and expand and this is no exception with the sahara desert. The sahara desert also grows in this expansion, and reproduces as the wind causes its arid dusts to carry it - and the inhabbitants of this eco system - into places the sahara shouldn't even be! Mini-deserts, begin to form their own populations within other eco-systems, some of these grow, and some of these die - depending on the principles of natural selection and survival of the fittest!
Some of you may be saying (if you even read this far) "That's all fine and dandy, but I thought you said this wasn't a metaphorical analysis, Void?"
Indeed I did. But let me ask you this. If the act of human reproduction (sexual intercourse) isn't a metaphor for true cellular reproduction, then why not the reproducion of an ecoystem? Afterall, when a male inserts a penis into a female's vaginal cavity, the resultant isn't that the two sexual organs combine and grow, and the result certainly isn't that the sexual organs themselves reproduce. Hell, sexual intercourse isn't reproduction at all - else reproduction would occur during all acts of sexual intercourse - yet several of us on the forums know this is not the case (if by first hand count, or second hand :P). The sexual organs are in fact tools. Tools that allow reproduction to happen. Reproduction does not occur during sexual intercourse, but rather, it occurs when the two reproductive cells join to create one whole cell. One cell that can from that moment on split into two cells, which in turn split into two more, and so on and so forth. So then, we've established that organisms themselves do not reproduce (except for the individual cells IN said organism), but rather they are tools of reproduction. Similarly, eco-systems make suitable habbitats for organisms, organisms whose cells reproduce. This is the case, and we know it's the case, So if this is the case, then why can't an eco-system be a living thing outside of the metaphorical sense, just like an organism? Why can't organisms be to eco-systems as cells are to organisms?
The answer is they can, and they are.
But surely this doesn't go further BEYOND ecosystems. Planets - outside of gravity - are purely stationary, some don't even contain life, so how then could planets be considered alive? Let's consider that planet MAY be a living entity. The fact is that planets have a finite period in which they exist before being disembled; for whatever reasons. In this light, one would be hard pressed to think of a planet as being anything more than a host for life, as when the planet itself comes to an end, life from that planet will not spread - in effect reproducing. Reproduction seems to be the key aspect of life, and with this sort of existence, one would think that a planet can never be capable of reproducing life.
Do you remember when I mentioned the universe, teaming with organic material and said "I'll elaborate on this later"? Well, it's pretty late now, and so I'll elaborate now. Organic material is in fact abundant throughout the universe, while non-organic material makes up the vast majority of material in this universe (About 99% of the matter in the universe is dark matter. Out of the remaining 1%, 99% is hydrogen and helium - the rest being heavy elements creation by nuclear fusion. Out of that 1% of elements that aren't hydrogen or helium, 99% of the material is non-organic. The remaining 1% is organic material, so 1% of 1% of 1% of all the matter in the universe is organic material, while everything else is non-organic.) By measuring the length of atomic lines coming from microwaves in gas cloud (which used to be stars), astronomers discovered that these clouds, which are by and large composed of hydrogen and helium, are also composed of carbon, oxygen, and nitrogen which along with hydrogen are the building blocks of life. Interestingly, in the high temperatures of a star (6000 K) there is enough heat energy and radiation for nuclear fusion to take place. This means elements break down into smaller atoms and recombine into new elements. In this way, simple hydrogen protons and even helium with two protons and a neutron, can break down and recombine to make much heavier matter (and this is how that 1% of matter that isn't hydrogen or helium came into existence in the first place). This is in fact, where the building blocks of life originated (a little of topic, in giant stars there are cycles of fusion that end with iron and a huge explosion which = a black hole). Every proton of every atom in your body once came from the nuclear fusion of hydrogen - baked at extremely high temperatures.
And so, everything that makes up our planet earth, was baked in an ancient star, that predates our own sun. At the end of this stars life time, it exploded, leaving behind a gas cloud much like the ones we are analyzing today. A cloud carrying all the building blocks of life. Over billions of years, gravity created a new star from this cloud, and nine (maybe more!) planets, with hundreds of moons and planetoids. After the formation of earth, it wasn't but 500 million years that life began on earth. That's quite a feat, you know. For a planet with an atmosphere that absorbs energy from the stars, energy that should fuel the chemical reactions which create organic material, organic material which in turn creates long carbon chains which lead to proteins, fats, sugars, and ultimately DNA. It seems as though life just popped up on Earth as soon as earth had enough time to cool down from it's birthing process. Earth itself is 5 billion years old, and the first organism popped up at MOST 1.2 billion years ago, while the first bacterium popped up a staggering 4.5 BILLION years ago. If life then, is such a complicated thing to create, how come the Earth created it when it was just barely cooling from a magmated state? The answer is that it probably had a helping hand.
As I mentioned in the previous paragraph, the atmosphere of earth absorbs a lot of energy from the sun. However, in a gas cloud energy is constantly being bathed apon clouds by stars in every direcction (yes, these far away stars have lots of energy too!) As we know, radiation energy from stars fuels chemical reactions. It wasn't long after discovering that gas clouds contained complex elements, that humanity discovered gas cloud also contain complex compounds - organic compounds. Fermeldehyde, glycene and even cellulose were found by measuring the atomic lines coming from the microwaves of these gas clouds. These does indeed mean that organic material forms in space, much like it would form on earth if given the right conditions. With this knowledge in hand, one can imagine the early sol system (our solar system), and the gravity of the ever growing earth constantly pulling organic material towards its surface. Protected from the harsh elements of precambian earth - in water, these organic materials can undergo even more chemical reactions, and must have eventually formed long carbon chains, these chains being DNA in its simplest form. By skipping the process of creating organic material, earth could easily have had enough time mix the organic material up enough to make the first strand of DNA. Of course one might raise the question that without the proteins needed to create a cell membrane, this DNA would constantly be consumed. Of course, even with the harsh elements of pre-cambian earth I'd ask "what is there to consume this DNA in a world where life does not yet exist to consume anything?" And so, DNA could be left to its own divices, until it finally comes in contact with proteins that can jump start the whole process of reproduction. And this is the long story of how life on earth was seeded in a process that began before the earth itself even came into existence.
And so to go ALL the way back to the point of earth and the question of "can earth be considered anything more than a host of life?" Well, quite frankly, yes. The organic material on our planet had to originate from somewhere. Even IF it did originate on earth, consider first that the elements which formed this organic material had to come from a gas cloud. A gas cloud that was formed by the destruction of a star, and planets before our own solar system. Planets and stars which also must have contained carbon, oxygen, nitrogen and hydrogen - the building blocks of life. And when our planet comes to an end, what is to become of the organic material that makes us? It will be added to the cycle once again, to be drawn in by the gravity of the resulting gas cloud, where chemical reactions will continue to take place, and gravity will continue to form new planets and new stars that are seeded with organic material... until one planet is formed in the right conditions, not too hot so that there is too much energy, and not too cold so that there is too little energy. A planet where there is water for these organic materials to be added to the mixing pot. Then again, this raises yet another question "If planets aren't a host for life, but living things themselves, then how come not all planets have life?" It's evolution at it's finest - natural selecction. Survival of the fittest; the one who most fits their environment is the one who survives. Through all it's chance mutations in birth - the gathering of water, organic material and energy all in one place - earth has evolved into a planet that can support life, while other planets did not make these chance mutations, and as such have no life.
Our planet is alive. It breaths and exhales, it grows, it moves, it reacts to stimuli. It even seeds life for planets yet to come in a process known as reproduction. The planet earth is alive in no less of a metaphoric sense as our own bodies are are alive. In no less of a sense are we made up of many living things as is the planet earth. I said earlier that we are the cells to the ecosystem. In fact, the ecoystem is more like an organ is to an organism - with us being the cell - the planet being the organism.