Phoodoo’s Origin of Life thread

For phoodoo. To discuss the Origin of Life.

Edit:

Just to offer my own thoughts on the matter, as a red rag for phoodoo’s contempt, I think that all theories that require some kind of ‘takeover’ of one genetic system by another are dead in the water. That includes the Cairns-Smith ‘dust’ notion, but also ‘proteins-first’ theories.

The fundamental characteristic of life is replication. For evolution to occur, it further needs to have the capacity for exponential replication. The ‘Darwinian’ arena, which we should extend to include the zone of neutrality, involves competitive replication in a finite container. If the exponent is less than 1, replication will fizzle out. If greater than 1, it will fill the container, at which point the net exponent becomes, approximately, 1 – a steady state. Novel variants may arise with an exponent greater than 1, which means that, relatively speaking, the resident now has an exponent of less than 1. The new one will tend to supplant the old, until back at a net 1 again.

Now, there is a fundamental characteristic of the nucleic acids that renders them exponential replicators: complementarity. One double strand can generate 2 identical molecules. This is the basis of PCR, whereby a few rounds of replication can generate millions of copies of a single molecule. And of course, this gives the fundamental motor to organic increase, be it bacteria in a chemostat, the cells of a body, or clouds of midges.

Nucleic acids are dual-function molecules – not only does one part specify its entire complement, it also specifies, in exactly the same way, any fragmentary complement. A single base has optimal affinity for its complementary base, permitting template polymerisation, but a sequence of bases also has physical affinity for the complementary sequence. This includes binding RNAs that control gene expression, hairpin folds in a single strand, and also tRNA anticodons. The latter permits repeat specification. One can copy a strand faithfully, generating millions of copies, and from each of those copies produce the exact same protein. This is not available to ‘proteins-first’, for example. By lucky accident one may produce a useful peptide, but only one. This cannot be a replicator, and so cannot evolve. And even if it could, it does not seem plausible that a completely different kind of molecule could subsequently ‘take over’ the genetic function.

For such reasons, I tend towards ‘RNA-first’ theories of origins. There has been a ‘takeover’ of sorts, DNA for RNA, but DNA is merely a minor variant of RNA. Its lack of a 2′ oxygen, and its use of methylated uridine (ie, thymine) serve to stabilise the double strand, making it more useful as an information store and less useful as a catalyst. There has also been a ‘takeover’ of catalytic function (largely) by protein. But the genetic function, I think, traces right back to the earliest beginnings.

One is left with major problems, of course. Where did the nucleotide bases come from? How did they polymerise? How did complementary bases become stabilised out of a more complex mess? How was the vital coupling with cyclic energy generation mediated? How did replication commence?

The RNA World has many critics, and difficulties. Nonetheless, its central evolutionary logic renders it my favoured bet. Life is replication, at its very core, and nucleic acid displays a potential continuity in that regard that is strongly suggestive that its role is fundamental.

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28 thoughts on “Phoodoo’s Origin of Life thread

  1. Allan THINKS I was discussing the origin of life, but actually I was discussing the believability for what causes life. I explained this, but apparently they still don’t get the issue. Its not what the first replicator was (evolutionists seem quite happy to assume it was so kind of meaningless dust) , it is the question of whether or not that can do all they claim.

    Are accidental, clumps of replicators enough to account for all the systems we see in life. Only if you believe cells, and epigentics, and the nervous system, or the respiratory system, or balance, or metabolism are easy things I suppose.

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  2. evolutionists seem quite happy to assume it was so kind of meaningless dust

    Where to start…

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  3. phoodoo: but actually I was discussing the believability for what causes life.

    OK, could you summarise what options there are to choose from?

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  4. phoodoo: Allan THINKS I was discussing the origin of life, but actually I was discussing the believability for what causes life.

    Maybe he thought it would be rude to use the title “A thread for phoodoo to blow smoke”.

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  5. Rudeness does have its place, unfortunately.

    It’s not even good smoke. Just fear mixed with nonsense.

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  6. walto:
    Rudeness does have its place, unfortunately.

    I agree but, per Lizzie’s rules, that place is not here.

    AtBC (see the Forum link from The Panda’s Thumb) is a good place to comment on the antics of the intelligent design creationists of Uncommon Descent. Here we’re supposed to assume good faith with the goal of understanding the roots of our disagreements.

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  7. FWIW, Patrick I do assume good faith on phoodoo’s part. Too good, actually. And the roots of our disagreement are eminently clear. There’s no mystery about that.

    So the question is whether one ought to “address the poster.” As you know, I think the prohibition about that in the rules here is unfortunate. I freely acknowledge that I often violate it, but I take comfort in the fact that perhaps 70% of ALL the posts here do so. So I don’t feel terrible about this weakness of mine.

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  8. walto:
    . . .
    So the question is whether one ought to “address the poster.”As you know, I think the prohibition about that in the rules here is unfortunate.
    . . . .

    I invite you to take that topic up on the Moderation Issues thread if you wish to change Lizzie’s mind. Hopefully she’ll drop by soon.

    In the meantime, I see this as a “Lizzie’s house, Lizzie’s rules” situation. It is discourteous to not abide by the guidelines clearly articulated by the owner of the site.

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  9. walto: So the question is whether one ought to “address the poster.”

    Maybe you are taking that too literally.

    Don’t say: “You are stupid”. Instead, say “that argument is stupid”.

    But I don’t see any problem with “I think you misunderstood what I wrote there”.

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  10. Patrick,

    I have done so (taken it up on the moderation thread). There has been no resolution. And again, if I am discourteous, so is everybody else.

    In the meantime, I’m sure all will be well when Godot returns!

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  11. Neil, what is a stupid argument? Is it an invalid/bad argument–or is it actually something that only a stupid person would utter?

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  12. phoodoo: Generally speaking, yours.

    What does it say about your argument that you can’t bring yourself to even make it?

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  13. Richardthughes:
    Trolls are the price of open dialogue, I guess.

    Worth repeating Lizzie’s mission statement:

    My motivation for starting the site has been the experience of trying to discuss religion, politics, evolution, the Mind/Brain problem, creationism, ethics, exit polls, probability, intelligent design, and many other topics in venues where positions are strongly held and feelings run high. In most venues, one view dominates, and there is a kind of “resident prior” about the integrity, intelligence and motivation of those who differ from the majority view.

    That is why the strapline says: “Park your priors by the door”. They may be adjusted by the time you leave!

    Plus she rather had “peanut-gallery” laughing and pointing taken elsewhere.

    Open dialogue (at least the chance of occasionally achieving it) is worthwhile and it’s why I continue to support Lizzie’s concept of civilised exchange It’s disappointing that she has apparently abandoned us like rats in a maze (or maybe like the lost boys in Golding’s Lord of the Flies). I think she last posted something here around mid-March but I see she is posting at Talk Rational currently.

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  14. walto: Neil, what is a stupid argument?

    That’s hard to define. But I have probably made some stupid arguments, and maybe you have too. As far as I know, one can make a stupid argument without actually being stupid.

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  15. Alan Fox,

    Personally I find it a much better site without her posting. Posts that are 20 paragraphs long, full of schematics, and her own humpty dumpty language are hardly conducive to entertaining dialogue. If you asked her where the morality in atheism resides, she would give you some rambling post about emergence in chemistry, and then be frustrated if you pointed out that she hadn’t answered the question.

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  16. phoodoo: If you asked her where the morality in atheism resides, she would give you some rambling post about emergence in chemistry, and then be frustrated if you pointed out that she hadn’t answered the question.

    Yet look at the two of you. You, in your basement….

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  17. phoodoo,

    Allan THINKS I was discussing the origin of life, but actually I was discussing the believability for what causes life.

    A necessary part of that ‘believability’ issue must be to discuss the things one might be expected to ‘believe’, surely? ‘Causing’ life is something that happens at its origin.

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  18. I’d think that “believability” or intuitive reasonableness would vary from person to person based on their background, experience, education, psychological predilections, etc.

    That means that someone who has not only studied science but also does not make it a paramount interest that he not be snuffed out at life’s end is likely to have a significantly different set of criteria for “believability” than one whose main motor is fear and who also has substituted church time for lab time over the years. In any event, for those reasons and others, assessments of intrinsic believability make a poor standard for truth.

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  19. Phoodoo, I know you’re busy throwing rocks but you might want to attend to this glass house.

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  20. And Allan, I think you might like this.

    In the same interview with Dawkins, he was asked what discovery could happen in biology that would shake his worldview. He said that if the Lamarkian like changes being discovered in recent biology turned out to be able to affect extended generations of organisms, then his whole theory of evolution would be unraveled, and he would have to rethink all of his fundamental beliefs.

    One thing he did NOT say was, “Its not a problem for evolution.” What he said was he doesn’t believe they will discover this. I guess he better hope not.

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  21. phoodoo:
    In the same interview with Dawkins, he was asked what discovery could happen in biology that would shake his worldview.He said that if the Lamarkian [sic] like changes being discovered in recent biology turned out to be able to affect extended generations of organisms, then his whole theory of evolution would be unraveled, and he would have to rethink all of his fundamental beliefs.

    One thing he did NOT say was, “Its not a problem for evolution.”What he said was he doesn’t believe they will discover this.I guess he better hope not.

    Sorry, WHICH same interview?

    I don’t see that you linked it in any of your posts in this thread. Maybe I just missed your link. Wrong thread?

    Or are we supposed to have memorized all of Pope Dawkins’ speeches so that we instantly recognize what you’re referring to?

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