Why does the evolutionary process exist?

Discussion in 'Biology & Genetics' started by Theoryofrelativity, Aug 18, 2006.

  1. Theoryofrelativity Banned Banned

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    If it had organic molecules how can it be sterile?

    meanwhile:

    http://library.thinkquest.org/C003763/index.php?page=origin03

    "Chemical Evolution

    The Water Lily Nebula, a location where complex organic molecules are found. Courtesy Bruce Hrivnak and Kate Su

    Just as life has evolved into a plethora of different forms over an extended time period, the chemical elements which are the building blocks of matter have also, in a sense, evolved since the origin of the universe.

    Chemical evolution is essentially the process by which increasingly complex elements, molecules and compounds developed from the simpler chemical elements that were created in the Big Bang. Recent astronomical observations have discovered that chemical evolution has even led to the synthesis of complex organic molecules in space, a discovery that could have serious implications on current theories of how life developed."

    see bold

    What does this mean, what serious implications?
     
    Last edited: Aug 18, 2006
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  3. spuriousmonkey Banned Banned

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    sterile

    Free from living (micro) organisms.
     
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  5. Theoryofrelativity Banned Banned

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    explain to me the connection between sterile neutrinos and organic molecules please in relation to the big bang theory.
     
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  7. Ophiolite Valued Senior Member

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    TofR I wish you settle down. This is a vast subject that can't be dealt with in a single sitting. Here are some thoughts.

    You qouted yockey(?) earlier. I only scanned, but my thinking appears to be much the same as his. In short, we have damned all idea of the details of how life began, but we have a very good idea of the mechanisms that must be involved. Later, not today, I can post some material that addresses some aspects of this. Life is complex, we should not expect its origin to be simple.

    One early theory for the origin of life was that it came from space. Hoyle was a promoter of this. He believed in the Steady State Universe. A Universe that had always existed, and in which, perhaps, life had always existed. It then became simple to envisage life being seeded from space.
    He suggested that we would find an array of organic molecules in space. We did.
    He suggested we would find comets were rich in organic molecules. We did.
    He believed that life could arise in the giant gas/dust clouds from which stars and planetary systems eventually form.
    The significance of all those organic molecules is that they provide the raw materials for setting up those self catalytic metabolic pathways I spoke of. And, from my point of view, they do it in an environment that is orders of magnitude larger in size, and more extended in time, than the paltry half billion years or less we have to initiate the step on the Earth.
    Until and unless we are able to map out a plausible scheme, in detail, for the origin of life on Earth, I shall lean strongly to the suspicion that it arose in space. I shall not be surprised if proof were to emerge that it did originate on the Earth, but it is not where I would place my bets.
     
  8. Theoryofrelativity Banned Banned

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    5,595

    http://ase.tufts.edu/cosmos/view_chapter.asp?id=19&page=1

    you may find this interesting

    "Meteorites
    Meteorites
    Organic matter in meteorites

    Most meteors, or shooting stars, are produced by tiny fragments of comets, which burn up in the air and never reach the ground, but occasionally a stone will fall from the sky, producing a brilliant trail of light flashing across the night sky. A rumbling sound and what appears to be a great burst of sparks may accompany it. These are fireballs and they are produced by tougher chunks of matter from space, resembling rocks (Fig. 13.21).

    Extraterrestrial chunks of rock and metal that survive the fiery descent through the atmosphere and reach the ground have been given the name meteorite. And strictly speaking a meteoroid is the solid object in space that appears as a meteor when it lights up in the atmosphere and becomes a meteorite if it reaches the ground.

    For more than a century, organic molecules have been suspected inside meteorites, although their presence in newly arrived meteorites led to the suggestion that they were the result of terrestrial contamination. But their existence became a certainty when 20 kinds of amino acids were found in the carbonaceous chondrite meteorites from Antarctica. These meteorites had lain in a sterile environment and were collected using sterile procedures. The organic matter in these carbonaceous chondrites apparently formed with the meteorite parent bodies, probably when water was bound into the structure of its clay minerals.

    Many organic compounds, such as the amino acids, can come in two versions that are mirror images of each other. They are identified as left and right handed, based on their ability to rotate light in one direction or another. All living organisms on Earth use only left-handed amino acids. In contrast, the carbonaceous chondrites contain roughly equal amounts of both types, including the right-handed amino acids that are not found in living systems on Earth. This provides convincing evidence that the organic matter in meteorites did not originate on our planet, and that it is not directly related to life, as we know it.

    The discovery implies that the amino acids and other organic molecules probably existed in the solar system a billion years before the appearance of life on Earth. Does this imply the existence of early life before it came to Earth?

    Probably not. The molecules found in carbonaceous chondrites are generally thought to be of non-biological origin. Carbon monoxide and hydrogen can, for example, be converted into organic molecules in the presence of an iron catalyst, and when ammonia is present in a laboratory sample, amino acids can be produced by electrical sparks.

    So, the organic molecules found in meteorites are not in themselves vestiges of extraterrestrial life. But they are certainly primitive, and their cousins may have been the precursors to living matter
    "
     
  9. Fraggle Rocker Staff Member

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    24,690
    I don't see a necessity to postulate that life has not arisen again and again. Sure, the conditions have become less perfect so it would not arise as often, but it may still have done so. The problem is that it would have to be very small life, as small as the first of our line. And the world is now teeming with larger and better-developed lifeforms that eat things like that or at least compete with them for food. That one lonesome individual would be gobbled up or starve to death while trying to figure out how to reproduce.

    I also think you folks gave up too quickly on the "one minute life" issue. Remember that we're talking about a time period of hundreds of millions of years. It might take a thousand years for one living entity to arise spontaneously, and it might die within a minute. But that would still have happened a couple hundred thousand times. 199,999 of those could have been the one-minute variety, but it only takes one of the other kind to set the process in motion.

    I have noticed, even on this forum full of scientists, that people have trouble grasping the concept of such a long timeframe. They don't intuitively understand what can happen during that period by sheer chance. This is one of the reasons why so many laymen are skeptical of evolution, but there's no excuse for it here.

    Please Register or Log in to view the hidden image!

     
  10. Theoryofrelativity Banned Banned

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    I'm not skeptical of evolution I just want to go back to the beginning and find out how the first life form replicated being as it is such a complex process, how did that one thing spring from nothing with no genetic predecessor with the abilty to replicate. 999999999999999999million years of time is irrelevant if the thing had not undergone any evolutionary process, it may have popped up on day 1 as day 9999999999999999.

    I do get what you mean when you say the fact something random can occur in such lrage time frame etc etc, but replication is not a simple process it is complex is it not? Thus how much credit should be applied to it occurring randomly those first few times, when it does not appear to occur randomly any more? What is lacking in our knowledge of those first few 'randomly occurring organisms' that prohibits us knowing 'how'?

    Ophiolite considers that 'life' originated in space, I think this is more likely, but we are still no closer to knowing how replication occurred randomly, spontaneously. Unless wherever it originated the conditions were such that were we there we too would be able to replicate the process that 'creates' life where now we fail.

    What is the missing ingredient?

    What makes us more than the sum total of our parts?

    The only thing I conclude is that nothing is possible and 'puff' we all disappear.
     
  11. superluminal . Registered Senior Member

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    10,717
  12. superluminal . Registered Senior Member

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    So do we all.

    It is now. It probably wasn't always.

    Well, for one thing, life arose in a nitrogen/methane + other crap atmosphere. Not but a tiny trace of free oxygen, if that. Oxygen is a corrosive poisonous gas to anaerobic creatures, which still exist today. It may be simply that the oxygen rich environment of today is totally inhospitible to the new formation of basic replicating molecules. The active nature of oxygen may destroy any chance for that. Otherwise, we have no reason to think that life didn't arise robustly and early on in this other atmosphere.

    Exactly. And the space thing is an interesting idea, but until we know far more about the origin mechanism, well...

    Beer? A good dark ale?

    In a flash of probability...
     
  13. S.A.M. uniquely dreadful Valued Senior Member

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    So, about the regeneration of the base molecules?

    (is this the right thread?)
     
  14. superluminal . Registered Senior Member

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    Could you please expand on that? Do you mean the complementary molecules that make up the complete organism, post replication? If so, they come from the environment, just as they do today. There's tons of A,G,C, and T floating around in the fluid medium of an organism.
     
  15. S.A.M. uniquely dreadful Valued Senior Member

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    I mean that assuming that the biochemical reactions which promote replication are initiated, they would be limited by the immediate availablity of the base molecules. At some point, there would present a need for more base molecules (whatever they are, hypothetically speaking). In which case, one would need either for base moleculaes from a farther place to become available somehow or the synthesis of those molecules through recycling to prevent the process from being halted.
     
  16. superluminal . Registered Senior Member

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    10,717
    Right. The molecules are dissolved in the water. But as you point out, organisms that can move in a directed way to seek higher concentrations of useful molecules would have an advantage. Evolution by Natural Selection comes into play the instant there are replicators prone to mistakes.
     
  17. Zephyr Humans are ONE Registered Senior Member

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    Or organisms which dismantle other organisms in order to steal their molecules (predators)
     
  18. S.A.M. uniquely dreadful Valued Senior Member

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    The assumption Zephyr, is about the first molecules which were able to replicate and how they sustained the growth.
     
  19. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

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    Sorry to go back a bit...
    Common understanding and theory is that all life on Earth evolved from the same common first-life - as we all share the common element of DNA (albeit in different structures).

    Most people, when they talk of "evolution" are actually only referring to biological evolution.

    What Ophiolite is describing is biochemical evolution, which relates to abiogenesis.

    When the first-life moved from the biochemical to the biological, evolution moved from biochemical evolution to biological evolution.
    But it is still all "evolution".
     
  20. superluminal . Registered Senior Member

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    Right. The ocean-soup must have been a paradise for the first replicators. No predators (as zephyr said) and free lunch just floating by you. Makes you wonder who has the better deal. Us or...
     
  21. S.A.M. uniquely dreadful Valued Senior Member

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    Without predation, how could evolution continue? Unless you're happy as a single celled amoeba?
     
  22. superluminal . Registered Senior Member

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    As free lunches decline, some of you may develop a mutation that allows you to absorb the molecules of neighbors that you come in contact with, as zephyr pointed out.
     
  23. superluminal . Registered Senior Member

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    Amoebas are very complex. We're talking here about little balls of proto-cells that can do basic replication and still react mainly on a biochemical basis, as sarkus explained. Possibly small spheres of molecular membranes housing a rudimentary form of RNA/DNA that are attracted to specific types of other molecules. That's about it.
     

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