Chemical evolution:

Discussion in 'Biology & Genetics' started by paddoboy, Aug 7, 2020.

  1. Traverse Registered Member

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    What a shame. We could've had such potentially interesting discussions had the cantankerous troll been up to the task of putting into his own words (rather than bleatingly linking to, or blatantly plagiarising) the points being touted from the 'other (poltergeistic?) side.' But a 50p well spent to be deloused, methinks.
     
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  3. Q-reeus Banned Valued Senior Member

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    Some don't seem to understand or rather are very selective in acknowledging the huge labor saving advantage the internet provides. The ability to link to relevant carefully itemized and colated info (often with copious reference material itself having further links elsewhere) rather than tiresomely retyping a necessarily small fraction here 'in ones own words'. As though that would somehow add value and/or authenticity. Whatever. Some just feel the need to seemingly win every argument. And have three fingers pointing back when pointing the finger at 'the troll'.
    I'd rather not keep this up but always reserve the right to defend myself. It could all stop now.
     
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  5. Traverse Registered Member

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    At secondary school, teacher makes the kids write things out in their own words precisely so that they're made to process (think about, come to understand, and thus be able to intelligently converse & debate on) wtf they're talking about. Dunces are generally incapable of such.
     
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  7. Q-reeus Banned Valued Senior Member

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    Someone here has tried to bury a failure to make good on a boast. Using an inappropriate analogy as foil. I did invite a return to the OP topic, but vindictiveness I cannot remotely control.
     
  8. Yazata Valued Senior Member

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    5,599
    How would we ever know whether we had indeed solved the problem?

    It seems to me that the best we can do is concoct hypotheses that seem plausible given what we believe we know about conditions on the early Earth. (Or in space, or wherever we imagine prebiotic chemistry to have taken place.) So we are apt to end up with multiple hypothetical possibilities as to how it might have happened: different steps in different orders all of which might hypothetically have led to the same place. (LUCA, whatever that looked like.)

    But absent the invention of time machines, we probably won't ever be certain what the precise conditions were on the early Earth. (The early Earth may not have been a homogeneous ball and there may have been different conditions in different places. Complexity.) And perhaps more important, we probably will have no way of knowing which of our seemingly plausible hypothetical life origin scenarios is indeed the correct one.

    That looks like a non-sequitur to me. The fact that life on Earth is hugely diverse and seemingly extremely (but not infinitely) adaptable doesn't imply a whole lot about how easy it was to originally get it up and running or how common Earth life or things functionally similar to it might be throughout the universe.
     
    Last edited: Jan 19, 2021
  9. exchemist Valued Senior Member

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    And you would never be vindictive...........

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  10. Traverse Registered Member

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    I don't think that any of us is looking to find the accurately historical way in which Life definitely arose naturally on the early Earth; rather that we'd just like to have at least one or two scientifically rational & completely lab-reproducible routes by which it could have arisen on this planet, entirely according to the laws of Physics, Chemistry, Geology, Biochemistry, Molecular Biology, & Evolutionary Biology. So the problem isn't at all expected to be one of historical accuracy, but of rational scientific argument for hopefully several conceivable & demonstrable origins-of-life scenarios.

    And I'll bet right now that when Science does finally arrive at such rational routes, that with then-hindsight they'll seem obvious once they've been described, and that they'll be scientific universals.
     
    Last edited: Jan 19, 2021
  11. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

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    Ummm suppose we stumbled upon a way in which life did appear in the test tube or what ever vessel we were conducting the experiment

    What then? Do we continue to let it evolve into one of those generational experiments?

    Generations from now we have a cell but to coin a phase it is not life as we know it

    No sign of RNA or DNA

    What.......

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  12. Traverse Registered Member

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    With scientists generally being indefatigably curious & persistent types, then yes, I'd bet that they'd keep on going with any kind of stumbled-upon interesting result, haha. One never knows what else might turn up unexpectedly, and give one the excitement of a priceless "Eureka!" moment. My money's riding on the RNA World to be the first successful route.
     
  13. Yazata Valued Senior Member

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    5,599
    If the question of the emergence of homochirality is a subject deserving of ridicule, then I wonder why it's such an active area of scientific discussion.

    https://scholar.google.com/scholar?start=0&q=origin of life homochirality&hl=en&as_sdt=0,5&lookup=0

    I certainly don't think that it's a problem unexplainable by naturalistic means or that it necessarily implies any divine influences on the origin of life.

    But having said that, I don't think that our discussion board atheists should be dismissing the problem either, trying to sneer it into submission, or insisting that it's as good as solved, just because they fear that it might conceivably be used by those that they have chosen to be their ideological enemies.
     
    Last edited: Jan 19, 2021
    Q-reeus and dumbest man on earth like this.
  14. Xelasnave.1947 Valued Senior Member

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    That is somewhat the point.
    Alex
     
  15. Traverse Registered Member

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    Nobody's said that the homochirality of biomolecules is an unimportant aspect in origins-of-life research, nor that it's a piece of unmatchable 'heavy ordnance' for the godflies.

    In 1848, Louis Pasteur was the first scientist (chemist) to identify the existence of a chiral bias in organic molecules derived from living things. He sought in vain, right up until his death, for a physical/chemical/mineralogic/crystallographic/etc origin for this bias, which he then fully intended to invoke as the defining chemical demarcation line between Life and non-life, hopefully providing for an ultimate origin of life. But despite many succeeding generations of scientists having looked for some such mechanism, nothing has ever been found that's clinchingly convincing for an origin-of-life via chiral biases in populations/assemblages of prebiotic molecules.

    The conclusion drawn from this deficit of a plausibly-believable and sufficiently robust lab mechanism is that the advent of biomolecular homochirality is likely to be a slightly 'downstream' (in chemical evolutionary terms/time) phenomenon, possibly representing an early molecular biological evolutionary advantage for pre-RNAs, for example.

    So nobody's discounting or 'ridiculing' those whose attention is focused on biomolecular homochirality. Prof. S.F. Mason, who wrote "Chemical Evolution" (1991), was absorbed in its potentiality via the physically real parity-violating energy differences (PVEDs) between enatiomers (i.e., non-superimposable mirror-image molecules). He was a smart fellow, and his focus was, like Pasteur, intent on trying to define Life's origin on Earth via chirality.

    My money's riding on biomolecular homochirality having been: (1.) very early on in the origins story, but it not being the primary nexus between Life & non-living material in terms of incipient abiogenesis; & (2.) that the particular selection of D-sugars & L-amino acids (versus their enantiomers) will ultimately have been due to chance, but that there will be a good reason why it has to be either D-sugars & L-amino acids, or L-sugars & D-amino acids (i.e., rather than D & D, or L & L).
     
    Last edited: Jan 19, 2021
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  16. James R Just this guy, you know? Staff Member

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    Traverse:

    Welcome to sciforums.

    You might like to familiarise yourself with our site posting guidelines, which can be found in a sticky thread at the topic of the list in the "Site Feedback" subforum.

    Q-reeus is an acerbic character who has never really worked out how what good manners are. He would, I am sure, like nothing better than for you to break a few rules and attract moderator attention as a result. It's often best to ignore him or, failing that, to address the substance rather than the man.

    If he (or anybody else) breaches our rules, for example by insulting you, you are advised to hit the "report" button on the relevant post and let the moderators deal with it, rather than returning fire in kind.

    Some of our members are a bit overprotective of what they regard as "their" forum, and so don't welcome new posters in the way they should. Their actions and opinions should not be taken as reflecting any "official" position of this forum or its administrators (of whom, I am one).

    Best wishes.
     
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  17. Q-reeus Banned Valued Senior Member

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    Typical partisan (fellow atheist) piece from James R. Who ironically attempts here to provoke me to break the rules. Your reading of recent posts here is so skewed it's a joke. But the purpose is clear to me at least.
     
  18. James R Just this guy, you know? Staff Member

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    Q-reeus:

    What does atheism have to do with anything? And who's the "fellow"?

    Thanks for the feedback about your perception of my reading of recent posts. Not sure how you worked that out, exactly, but whatever.

    I'm glad my purpose in welcoming a new member to the forum is clear to you.
     
  19. Q-reeus Banned Valued Senior Member

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    Gee well there may be enough clues in say #837 to answer both your totally genuine I'm sure questions.
     
  20. James R Just this guy, you know? Staff Member

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    I can't see anything about atheism in #837. But at least I know who you're talking about, now.
     
  21. Q-reeus Banned Valued Senior Member

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    Clearly implied there.
    A basic premise of chemical evolution aka unguided abiogenesis is the absense of any supernatural thus any diety input. Allied to self-creation Cosmogenesis theories or hypotheses, one is left with a 'god' that has no creative presence at any stage thus becomes a ghost of the imagination. Atheism is the underlying dogma. Obviously. But cleverly deflected by spokespersons who piously declare there is no conflict between science (by definition free of anything supernatural) and 'true' religion (logically constrained to being just a system of morals with mythical and ceremonial garb).
     
  22. James R Just this guy, you know? Staff Member

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    Those two things are not necessarily the same. You can believe your favorite God guides chemical evolution, if you like. He has to do it in such a way that it leaves no detectable evidence that he's guiding it supernaturally, that's all.

    Self-creation sounds like pulling yourself up by your own bootstraps. I don't know what self-creation would look like, exactly. I assume you have something in mind.

    No. The underlying concept you want to try to grasp here is called "science".

    Science literally just refers to knowledge. Its methods assume naturalism, unless and until there is some convincing evidence of the existence of a supernatural.

    If, at some point, science hits a wall and can go no further in explaining the origin of life (or the universe, or whatever), then the answer won't default to God. We'd still need some positive evidence for God - or whatever else did the trick.

    I'll leave you religious types to fight out the question of what is "true" religion.
     
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  23. iceaura Valued Senior Member

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    And I agree. So?
    . I don't. I just point out its relevance is not as you describe - your mistake is in your attempt to discuss the sufficiency of Darwinian theory in the light of that issue. You don't understand Darwinian theory, is the problem (or statistics, but that can wait). That's my guess for your weird habit of linking to dumbass Evangelical Protestant Christian creationist sites instead of some site run by one of those "workers in the field" you are so familiar with - it makes more sense to you.
    ? Where? (Posted the exact opposite often, hate be contradicting myself via typo or whatever).

    Keyword for you: "4 billion years".
    I have posted nothing more clearly and plainly than the observation that almost nothing about abiogenesis is anywhere near "resolved", let alone something as vast and tricky and sophisticated as the evolution of large biological proteins. That's been one of my major objections to the creationist habit of inventing bogus scenes of supposedly irreducible complexity and using them to dismiss Darwinian theory entirely - their imagination is not nearly good enough. How could you possibly have missed that, if you read any of my posts here?
    Those issues do not "face" abiogenesis much at all, let alone confine their force to non-creationist theories of same.

    Abiogenesis begins before there is bio, remember. There's no bio until after it's "generated". If you assume bio - RNA, cells, living stuff, - you've jumped the gun by probably millions of years.

    And people complain about my repetition - - - -
     
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