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Only problem is that the Miller Urey experiment never told us anything about the origin of life. Inorganic to organic compounds, sure. But nobody has ever been

Only problem is that the Miller Urey experiment never told us anything about the origin of life. Inorganic to organic compounds, sure. But nobody has ever been able to get from there to cells and DNA.

pfdietz 5y ago
Indeed. There is just enormous amounts of shoddy thinking out there from people on the subject of Origin of Life. I'm particularly annoyed by the non sequitur "the universe is large, so there must (with high probability) be life elsewhere." (If anyone reading this thinks that's a valid argument, go look in a mirror and slap yourself.)
- whaaswijk 5y ago
  Would you like to say a bit more about why that's not a valid argument. To be clear, I'm not saying it is (I don't know enough about the subject to do so) but it doesn't seem that far-fetched to me. Isn't similar probabilistic reasoning used to explain why evolution by natural selection gives rise to various complex life forms? If so, do you also think that that reasoning is shoddy?
  - pfdietz 5y ago
    Let N be the number of places life could arise, and p the probability that life arises in one of those places. That argument is basically "there is a value of N such that for any p > 0, N p is much greater than 1." But that's obviously wrong. For any N, there are values of p > 0 that make the product N p arbitrarily close to 0. The dim intution behind the argument was that p can't be "too small". But given our current understanding of OoL, that's not a justified assumption. p could be exponentially small, if OoL requires some extremely unlikely step. Natural selection is great once the system's reproductive fidelity is good enough to support it. The problem is bridging the gap from small molecules to that system. The smallest system we know of that can independently support Darwinian evolution has billions of atoms.
    - csee 5y ago
      What about the argument that our existence is some evidence that a Bayesian estimates of p can't be so small that N p is less than one? You're focusing on (lack of) evidence for a mechanistic explanation but that's not exhaustive.
      - pfdietz 5y ago
        The problem there is we don't know the "world" of possibilities from which our existence was drawn. It might be the universe (which I read "observable universe"), or it might be out of a large number of causally disconnected universes, or even other branches of a universal wave function (in a Many Worlds interpretation). The "N" there is not the same as the "N" of "our universe".
        csee 5y ago
        We know approximately the lower bound of N, which is the approximate number of stars in the observable universe multiplied by an informed estimate of the expected number of planets within the goldilocks zone. That's usually what people mean when they discuss N. N could be that, or it could be much much larger, but I think it's fine to limit the discussion to the lower bound, we still have a huge N to work with. Also I think you missed my point which is about Bayesian estimation of p, not of N.
        pfdietz 5y ago
        I ignored the comment about Bayesian estimation because I couldn't turn that comment into something that made any sense. Perhaps you could explain in detail what you meant?
        csee 5y ago
        Your statements in this thread have assumed we have no info to work with (as far as estimating p goes) because we have no understanding of the mechanisms behind how life came to be. But this ignores the evidence that we are here, which is info that can be used in a Bayesian framework to estimate p. The fact we exist, as well as information about how many billions of years it took for us to evolve, contains significant information about p.
FabHK 5y ago
> never told us anything about the origin of life There are several steps to go from no life to life as we know it. This experiment illuminates one of those steps. How is that "nothing"?
- dekhn 5y ago
  this experiment only reduces the uncertaintly that the building blocks are widely available. The big problem wiht this experiment is that it misestimated the nature of the early atmosphere and os they basically simulated another planet. We don't know if any other planets have life, so simulating another planet isn't useful to illuminate anything about life on earth.
  - ls612 5y ago
    Huh? We know whatever the early conditions of earth were they were clearly amenable to the formation of these organic compounds since life arose here. It's absolutely also interesting to know that in certain known conditions this can also arise, even if those conditions are not the only conditions capable of creating the phenomenon.
    - Socketier 5y ago
      That's circular reasoning. We're here so it must have happened in this specific way therefore it happened. Sure, an expertly guided experiment in a glass tube can make some basic amino acids but they had to be removed from the experiment immediately before the the product was ruined by further reactions. It was a guided process which we've got no further in accounting for in the wild. We've made no progress since these experiments to answering the questions posted by the theory of abiogenesis. We've got no concrete answers, only suppositions. This is not a popular thing to talk about but the fact remains that we are absolutely nowhere close to solving this in the manner in which we are proceeding in OoL studies. The track record for uncondendable conjecture is abysmal.
- ballenf 5y ago
  It's kind of like saying learning to jump really high is the first step to getting to the moon.
phonypc 5y ago
It doesn't tell us nothing, it's just not the whole story. And why should one expect a single experiment to tell the whole story?
- TheRealDunkirk 5y ago
  It would seem that the next logical experiment is to take Miller-Urey as a given, throw a perfect blend of polymer chains into the "soup," and see if they can start forming RNA chains. I thought I had read about such an experiment, but I can't find a reference to it now. Anything coming up in Google for me is being obfuscated by this recent study, and mRNA COVID vaccine stuff.
  - JumpCrisscross 5y ago
    The term you’re looking for is the RNA world hypothesis.
mannykannot 5y ago
I think what the naysayers are missing is that if this experiment had failed to generate any of the sort of organic molecules strongly associated with life, that would have shaken things up - or would you have been just as eager to dismiss this experiment in that case?
- SavantIdiot 5y ago
  I think this is the fallacy of arguing the middle usually deployed against science. There's a great example of Futurama, where the evolutionary naysayer demands an intermediate form, and Farnsworth shows him one... then he demands another, and Farnsworth shows THAT form... and this cycle repeats hundreds of times until Farnsworth has no intermediate form and the naysayer declares victory.

pfdietz 5y ago

Indeed. There is just enormous amounts of shoddy thinking out there from people on the subject of Origin of Life. I'm particularly annoyed by the non sequitur "the universe is large, so there must (with high probability) be life elsewhere." (If anyone reading this thinks that's a valid argument, go look in a mirror and slap yourself.)

whaaswijk 5y ago
Would you like to say a bit more about why that's not a valid argument. To be clear, I'm not saying it is (I don't know enough about the subject to do so) but it doesn't seem that far-fetched to me. Isn't similar probabilistic reasoning used to explain why evolution by natural selection gives rise to various complex life forms? If so, do you also think that that reasoning is shoddy?
- pfdietz 5y ago
  Let N be the number of places life could arise, and p the probability that life arises in one of those places. That argument is basically "there is a value of N such that for any p > 0, N p is much greater than 1." But that's obviously wrong. For any N, there are values of p > 0 that make the product N p arbitrarily close to 0. The dim intution behind the argument was that p can't be "too small". But given our current understanding of OoL, that's not a justified assumption. p could be exponentially small, if OoL requires some extremely unlikely step. Natural selection is great once the system's reproductive fidelity is good enough to support it. The problem is bridging the gap from small molecules to that system. The smallest system we know of that can independently support Darwinian evolution has billions of atoms.
  - csee 5y ago
    What about the argument that our existence is some evidence that a Bayesian estimates of p can't be so small that N p is less than one? You're focusing on (lack of) evidence for a mechanistic explanation but that's not exhaustive.
    - pfdietz 5y ago
      The problem there is we don't know the "world" of possibilities from which our existence was drawn. It might be the universe (which I read "observable universe"), or it might be out of a large number of causally disconnected universes, or even other branches of a universal wave function (in a Many Worlds interpretation). The "N" there is not the same as the "N" of "our universe".
      - csee 5y ago
        We know approximately the lower bound of N, which is the approximate number of stars in the observable universe multiplied by an informed estimate of the expected number of planets within the goldilocks zone. That's usually what people mean when they discuss N. N could be that, or it could be much much larger, but I think it's fine to limit the discussion to the lower bound, we still have a huge N to work with. Also I think you missed my point which is about Bayesian estimation of p, not of N.
        pfdietz 5y ago
        I ignored the comment about Bayesian estimation because I couldn't turn that comment into something that made any sense. Perhaps you could explain in detail what you meant?
        csee 5y ago
        Your statements in this thread have assumed we have no info to work with (as far as estimating p goes) because we have no understanding of the mechanisms behind how life came to be. But this ignores the evidence that we are here, which is info that can be used in a Bayesian framework to estimate p. The fact we exist, as well as information about how many billions of years it took for us to evolve, contains significant information about p.

FabHK 5y ago

> never told us anything about the origin of life There are several steps to go from no life to life as we know it. This experiment illuminates one of those steps. How is that "nothing"?

dekhn 5y ago
this experiment only reduces the uncertaintly that the building blocks are widely available. The big problem wiht this experiment is that it misestimated the nature of the early atmosphere and os they basically simulated another planet. We don't know if any other planets have life, so simulating another planet isn't useful to illuminate anything about life on earth.
- ls612 5y ago
  Huh? We know whatever the early conditions of earth were they were clearly amenable to the formation of these organic compounds since life arose here. It's absolutely also interesting to know that in certain known conditions this can also arise, even if those conditions are not the only conditions capable of creating the phenomenon.
  - Socketier 5y ago
    That's circular reasoning. We're here so it must have happened in this specific way therefore it happened. Sure, an expertly guided experiment in a glass tube can make some basic amino acids but they had to be removed from the experiment immediately before the the product was ruined by further reactions. It was a guided process which we've got no further in accounting for in the wild. We've made no progress since these experiments to answering the questions posted by the theory of abiogenesis. We've got no concrete answers, only suppositions. This is not a popular thing to talk about but the fact remains that we are absolutely nowhere close to solving this in the manner in which we are proceeding in OoL studies. The track record for uncondendable conjecture is abysmal.
ballenf 5y ago
It's kind of like saying learning to jump really high is the first step to getting to the moon.

phonypc 5y ago

It doesn't tell us nothing, it's just not the whole story. And why should one expect a single experiment to tell the whole story?

TheRealDunkirk 5y ago
It would seem that the next logical experiment is to take Miller-Urey as a given, throw a perfect blend of polymer chains into the "soup," and see if they can start forming RNA chains. I thought I had read about such an experiment, but I can't find a reference to it now. Anything coming up in Google for me is being obfuscated by this recent study, and mRNA COVID vaccine stuff.
- JumpCrisscross 5y ago
  The term you’re looking for is the RNA world hypothesis.

mannykannot 5y ago

I think what the naysayers are missing is that if this experiment had failed to generate any of the sort of organic molecules strongly associated with life, that would have shaken things up - or would you have been just as eager to dismiss this experiment in that case?

SavantIdiot 5y ago
I think this is the fallacy of arguing the middle usually deployed against science. There's a great example of Futurama, where the evolutionary naysayer demands an intermediate form, and Farnsworth shows him one... then he demands another, and Farnsworth shows THAT form... and this cycle repeats hundreds of times until Farnsworth has no intermediate form and the naysayer declares victory.