Level of Proof for Evolution

Discussion in 'Biology & Genetics' started by BenTheMan, Mar 23, 2007.

  1. Ophiolite Valued Senior Member

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    Please talk to Stuart Kaufmann.

    And to assure me that's it is worthwhile even talking to you, rather than Wolf, would you tell me how many order's of magnitude difference we are looking at in the question I posed you.
     
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  3. Idle Mind What the hell, man? Valued Senior Member

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    We aren't have this conversation with Dr. Wolf, though. We are speaking with you, Reiku. Why are you trying to hide behind his apparent expertise?
     
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  5. Reiku Banned Banned

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    Why do you deny the fact someone can back my claims?
     
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  7. Idle Mind What the hell, man? Valued Senior Member

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    One person is not enough. That's not how science works.
     
  8. Reiku Banned Banned

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    Obviously Wolf does not talk out out of personal experience. He will know mathematicians that have calculated such odds. If he hasn't, he should not speculate.
     
  9. Reiku Banned Banned

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    If you want a bone, he refers to high calculations made by Fred Hoyle.
     
  10. Hercules Rockefeller Beatings will continue until morale improves. Moderator

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    Getting away from Reiku’s idiotic pseudoscience moronic rubbish for a minute….

    (Seriously people, let’s just ignore the idiot…)


    With respect to these sorts of statements….


    I thought that Darwin’s idea of the “primordial soup” had fallen out of favour long ago. In other words, first life could not have formed in puddles on land or even in the oceans. Earth was regularly (on a geological timescale) bombarded by large rocks left over from the formation of the Solar System whose impacts were energetic enough to vaporise whole oceans. It’s hard to imagine life forming under those conditions, even on the sea floor at hydrothermal vents. I was under the impression that the consensus had moved towards sub-stratum formation of first life, ie. in pockets of water in the Earth’s crust where extemophiles could evolve protected from the asteroid impacts and where pockets in the rock with mineral shells could act as pseudo membranes, and so on and so forth.

    Yes? No?
     
  11. Reiku Banned Banned

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    Of course, he is impervious. Let's all listen to him. Put down the joints and dildo's.
     
  12. Ophiolite Valued Senior Member

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    It is an area of active debate. There has been somewhat of a bandwagon effect that followed on from the discovery of organisms living in such environments. The field is, however, wide open and no single concept has been wholly discarded. Even Cairns-Smith retains an active following for his hypothesis of the first genetic code being clay based, even though there is not a shred of evidence to support it.

    The bolide impact issue is not much of an issue if life can arise quite promptly from a prebiotic mix, say something of the order of 100 million years. Nor should we rule out the possibility that facets of life may have arisen in differnet environments before coming together to form what we would consider to be life.

    The balance of opinion is probably along the lines you have stated, but it is certainly not a firmly held position.
     
  13. Idle Mind What the hell, man? Valued Senior Member

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    To be honest, I haven't read too much on the topic in recent years. Were the asteroid impacts really that common? How long did it take the solar system to "settle", at least to a point where the impacts were infrequent enough to allow for early life whether it first arose in pockets below the crust or in the oceans? I have some reading to do, it appears.
     
  14. Ophiolite Valued Senior Member

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    The end of the Late Heavy Bombardment Period (Which was quite probably more than one period) is dated to around 3,800 million years ago. If you wish to get an idea how sever it was take a look at the moon. Life seems to have been established by 3,600 million years ago, so there is a fairly narrow window for abiogenesis to occur.
     
  15. Hercules Rockefeller Beatings will continue until morale improves. Moderator

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    Righto, it (unsurprisingly) seems things aren't quite as cut and dried as I was thinking.

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  16. Idle Mind What the hell, man? Valued Senior Member

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    200,000,000 years. Hmm. Is that really a short window? I mean, given the proper conditions one would think that things could snowball rather quickly. How accurate do we think we are with the estimation at life being established at around 3.6 bya?
     
  17. Hercules Rockefeller Beatings will continue until morale improves. Moderator

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    I thought the date was more like 4.0 bya. There's an extra 400,000,000 years right there.

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  18. Idle Mind What the hell, man? Valued Senior Member

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    Well, the 200 million being the time frame between when the Late Heavy Bombardment period stopped and when life is thought to have been established. If the estimate for life is at 4 bya, then we are missing 200 million years somewhere. No biggie, right?
     
  19. Ophiolite Valued Senior Member

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    The earliest evidence for life is in the Isua supracrustals in Greenland, dated at 3.8 billion years. (Not 3.6. Apologies - its 5.00am for me, the brain's a little slow)

    I think there is some evidence a little earlier, but even the Isua claim is debated. Some researchers believe the isotope ratios that imply life could arise by inorganic processes.
     
  20. Walter L. Wagner Cosmic Truth Seeker Valued Senior Member

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    If we assume there are 1,000,000 craters on the moon, and the earth is about 10 times that number during bombardment era, that would be about one impact every century [1,000,000,000 years/10-million-craters]. Hard to see how that would prevent life from arising. Even at 100 times that rate [one impact every year], with evolving organisms drifting with the ocean currents, it would be a stretch to say that that bombardment would preclude life's evolution. Maybe if we got to 1,000 impacts per year, but it doesn't appear to have been like that.

    Good theory suggests the bombardment was caused by the debris from planets that collided, sending their debris everywhere in wild elliptical orbits. Only the debris that was in relatively stable circular orbits still remain there. The rest likely was swept relatively clean [by hitting the sun, inner planets and moon] during the time periods referenced, but it does not appear at all clear that that would have been a period of preclusion of life's evolution.
     
    Last edited: Aug 29, 2008
  21. Ophiolite Valued Senior Member

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    You are overlooking the size of some of these bolides. That, combined with their kinetic energy, means that some impacts were sufficient to entirely vaporise oceans and melt a considerable portion of the primitve crust. While there is dispute amongst specialists as to whether life originated in 'a warm pond', around a sub-sea vent, within a subterranean haven, or arrived fully formed from space, there is no disagreement I am aware of that the bombardment was sufficently intense to prevent life forming and surviving.
     
  22. Iasion Registered Senior Member

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    348
    Hi all,

    No it didn't.

    The Big Bang was the start of eveyrthing - it happened 14 billion years ago.

    The start of LIFE occured here on earth only about 3 billion years ago.

    They are compleley different things that happened about 10 billion years apart.


    Iasion
     
  23. Iasion Registered Senior Member

    Messages:
    348
    Hiya,

    Nonsense.

    No-one claims life started in a "singularity".
    Except ignorant creationists.


    Iasion
     

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