What are the Odds of life coming into existence by chance alone?

Discussion in 'Biology & Genetics' started by Alan McDougall, Jul 26, 2012.

  1. Alan McDougall Alan McDougall Registered Senior Member

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    Hi, what are the Odds of life coming into existence by chance alone?

    There are claims by some disbelievers in evolution that the odds of life evolving by chance are so high that the probability is zero

    What do you think; I will add my take on the matter after the first few replies
     
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  3. spidergoat pubic diorama Valued Senior Member

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    Impossible to calculate. We could even add other data points, like other planets where conditions seem right but have no life, and other planets that have good conditions and life. We could develop a ratio. But how do we know those other places where life appears also appeared without external interference? How do we know those planets where conditions are right but don't have life won't develop life at some point in the future?
     
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  5. Alan McDougall Alan McDougall Registered Senior Member

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    Maybe we earthlings are just lucky maybe in the whole universe life only formed here?
     
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  7. Edward M. Grant Registered Member

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    There are billions of galaxies, each with billions of stars. That number of places where life could arise, combined with billions of years for it to do so, allows for an awful lot of improbabilities to still produce one of us.

    Even more so when you consider there could be many universes where life never arose and no-one was ever able to ask how something so improbable came about.
     
  8. spidergoat pubic diorama Valued Senior Member

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    That's a good point, we don't know if Earth conditions were unique. Or even if life developed here initially at all!
     
  9. AlexG Like nailing Jello to a tree Valued Senior Member

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    100%.

    After all, it happened.
     
  10. spidergoat pubic diorama Valued Senior Member

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    That presumes we know it happened by chance and not by seeding from an alien source.
     
  11. James R Just this guy, you know? Staff Member

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    We only have one known example of life coming into existence, so it's very difficult to estimate a probability.
     
  12. Alan McDougall Alan McDougall Registered Senior Member

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    The theory of evolution is based upon random mutations and survival of the fittest – i.e. a genetic mutation occurs, and if it is beneficial the organism prospers, but if it is detrimental the organism struggles, and the mutation dies out along with the organism. It sounds like a reasonable theory for explaining how small changes occur, e.g. to gradually adapt to changing environmental conditions. But it completely fails to address how complex bodily systems and structures form or how life began in the first place. Mutations are generally associated with detrimental effects like cancer and radiation sickness, not with intelligent design or positive evolution. They add chaos to a system; not order. Random mutations quite clearly did not give rise to human beings.
     
  13. spidergoat pubic diorama Valued Senior Member

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    It does explain complex systems, it just doesn't explain the first life form, which was simple. Mutation is only one mechanism that can produce variety, in fact, it's just a fancy way of saying genes get shuffled around, and that can happen in many ways. Most mutations are not detrimental, most are neutral, a few are detrimental and a few are beneficial, and it's natural selection that chooses which survives. Chaos is necessary for evolution to work. But natural selection is not random.
     
  14. SciWriter Valued Senior Member

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    Death is the 'chooser' of the 'wise' from the 'silly', the pointed from the pointless, as Robert Ardley noted, sifting the rest from the best (I say).

    The 'cause' is that of the environment and how things operate in it. 'Random' can't even exist. Creatures are fine-tuned to the Earth by evolution, this fine-tuning limited to what is handy to pull of of the shelf at the time.

    'Chance' is not the scientific alternative to Intelligent Design; natural selection is.
     
  15. Jeeves Valued Senior Member

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    And "alien source" needs its own source, so you're back to "How did that life arise?".
    We could say: "Life was an inevitable product of the given conditions." and somebody would answer "Who gave the conditions?" whereupon we could say "That who had to come from someplace" etcetera, ad nauseum.
    It happened at least once. That's all we know for sure.
     
  16. origin Heading towards oblivion Valued Senior Member

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    I agree with AlexG - looks like 100% to me.
     
  17. Grumpy Curmudgeon of Lucidity Valued Senior Member

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    Alan McDougall

    [QUOTEThe theory of evolution is based upon random mutations and survival of the fittest – i.e. a genetic mutation occurs, and if it is beneficial the organism prospers, but if it is detrimental the organism struggles, and the mutation dies out along with the organism][/QUOTE]

    And this has nothing to do with how chemistry became life in the first place, which is what you asked. Evolution is a fact, it is obvious in the history of life. The theory of evolution is our attempt to explain that fact.

    But you asked "What are the Odds of life coming into existence by chance alone?". Though your question reveals a certain lack of knowledge of chemistry. Chemical reactions do not occur by chance, they follow the laws of physics. Hydrogen and oxygen(to greatly simplify)ALWAYS form water once the chemical reaction is started. We find amino acids(precursor to proteins)in gas clouds throughout the Universe. In fact we find many precursor chemicals in meteorites falling on Earth today. Given the right conditions these chemicals will combine to form more complex molecules. Complex molecules of a certain form ARE life, once a molecule exists which can make copies of itself evolution will choose those most fit to that environment simply by eliminating all those that do not fit as well and evolution is off to the races. In the case of Earth that first self-replicator had to appear between 4.5 billion years ago(bya)(when the Earth was a molten mess)and 3.7 bya(when the first fossil life we have evidence of existed), But before that life existed there was a period of chemical evolution among the complex chemicals delivered to Earth by the very material that makes up the Earth. And not one reaction in the uncountable googleplex of single reactions happened by chance. Statistically, the probability of life forming under the right conditions is near certainty. Where life can exist, it will exist.

    It is the probability that the right conditions exist that is very low, there is only a narrow band around our sun where liquid water can exist, where radiation is low enough, where bombardment is rare, etc. Lucky for us that our Earth orbits in that zone or we would not be here to wonder about it. But there are billions of other solar systems in our galaxy, and hundreds of billions of galaxies, so it is almost certain that there is nothing unique about Earth.

    Again, has nothing to do with your original question and only shows you incredulity. Every trait modern life has was developed by the same process repeated over and over throughout the 3.7 billion years we KNOW life has existed. That includes big ones and small ones. Rabbit fossils are not found in the Precambrian(~800mya)because the major features of a rabbit had not evolved yet. In 3 billion years life consisted only of simpler forms like single cells and clumps of cells. And since the Cambrian we have ample evidence of the evolution of every trait that collectively we call a rabbit, EVERY trait.

    Again, Abiogenesis is the study of chemistry developing into life, Evolution has nothing to say about how life started. As I said in another thread, it is similar to the two, separate processes of building a car and driving a car. Whether the car is assembled by a trained cadre of mechanics or by robots makes no difference to the fact the car exists and those driving the car can do so whether they know how the car was made or not. Abiogenesis is analogous to knowledge of how to build the car, driving the car is analogous to studying the evolution of life once it exists. While you are smoother than a certain other poster(WSRN), you are just as badly misinformed, it seems.

    Grumpy

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    Last edited: Jul 26, 2012
  18. Promo Registered Senior Member

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    chance
    A. The unknown and unpredictable element in happenings that seems to have no assignable cause.
    B. A force assumed to cause events that cannot be foreseen or controlled; luck: Chance will determine the outcome.

    Wouldn't Aliens "seeding" our planet still be chance?
     
  19. Alan McDougall Alan McDougall Registered Senior Member

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    For example, the simplest theorized self-replicating peptide is only 32 amino acids long. The probability of it forming randomly, in sequential trials, is approximately 1 in 1 to the power of 40, which is much more likely than the 1 in 1 to the power of 390 claim creationists often cite

    However, to be fair, 1 to the power of 40 is still a very large number. It would still take an incredibly large number of sequential trials before the peptide would form. But remember that in the prebiotic oceans of the early Earth, there would be billions of trials taking place simultaneously as the tidal forces of the moon and the harsh weather conditions of the Earth continuously churned the oceans, rich in amino acids.

    In fact, if we assume the volume of the oceans were 1 to the power of 24 litres, and the amino acid concentration was 10-6M (which is actually very dilute), then almost 1 to the power of 31 self-replicating peptides would form in a year or so, let alone millions of years. Therefore, even given the difficult chances of 1 in 1to the power of 40, the “first stages of Abiogenesis” could have started very quickly indeed.

    Yet the question simply of how? what? where, when? Rock- to- life Abiogenesis has not been answered?
     
  20. spidergoat pubic diorama Valued Senior Member

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  21. Crunchy Cat F-in' *meow* baby!!! Valued Senior Member

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    It's not possible at present to calculate; however, your question assumes by-chance probability and that assumption could be very well incorrect.

    I think those disbelievers don't understand what they are talking about. Where does the theory of evolution state that life evolves by chance?

    I suspect that life began simply due to the laws of physics doing what they do. I also suspect that life is not a phenomena unique to our solar system. As far as evolution is concerned, it doesn't matter what either of us thinks. It simply is.
     
  22. Dr Mabuse Percipient Thaumaturgist Registered Senior Member

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    Obviously the universe is set up/designed to try very hard to create life.

    Since we are here, we have undeniable evidence that it's quite likely to happen on some random planet in an unimportant outer ring of a an unremarkable galaxy trying to heal from its last galactic collision.

    It's damned likely, 100% in fact, there is a lot of life out there. Now distance is a problem as to finding out where they are, much less ever communicating.

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  23. spidergoat pubic diorama Valued Senior Member

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    Wow, how did we manage to broadcast in a square?
     

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