Calculating the Odds of life

Hello Ganapati:

The point is that we don’t have a sufficient domain of knowledge on life to even know if our probability estimates of life, whether as we know it or as we don’t know it. Calculating the probability of whether a quarter will land heads or tails starts with the knowledge of the set of alternatives for the facing of the coin, the domain of possibilities. Life as we know it on Earth may be not exist anywhere else, but any planet that sustains life has a different form. The principle of life may be a generation of self-motive bodies using the chemicals available on the planet provided certain solar characteristics exist. In such a definition, life made of silicon that floats through a gas giant and which drinks liquid methane instead of water would not be life as we know it, and the standard or definition of life would be so out of touch with our probability characterizations that they would be useless. Heck, life may originate from persistent sound waves on a planet - how would our probability calculations or your definition account for that? These are speculations on other types of life to be sure, but our very narrow frame of reference in a universe with quadrillions of planets makes any calcuations on our part equally speculative or purely in the realm of metaphysics, not natural science.

As to your argument that our knowledge of life’s current forms will “have to do”, I would ask “have to do for what?” What good will they serve as a scientific foundation when we do not have sufficient observations and data to draw a conclusion under the Scientific Method?

The answer is to forget grounding such discussions in science and instead put it where it belongs - as a metaphysical inquiry. That’s not such a bad thing.

There is one form of life we know exists and infinite forms that we don’t know if they exist. We can define life as we know it to be the only possibility in the domain of possibilities and then proceed to calculate the probability of it. It may still be very difficult to compute it, but it will not be meaningless. If we have evidence about other forms that we are forced to concede are life, we will have to recalculate our probabilities, the domain of possibilities having changed.

When I said “it will have to do”, I meant for a scientific enquiry. Science proceeds precisely based on available evidence that can be extrapolated. If we do not find a phenomena in our observations and by inference on earth or anywhere else, we don’t go under the assumption it exists i.e, we proceed as if it did not exist.

Nothing is barred from speculation, but in order to make scientific sense, it needs to be more than speculation, it needs some supporting evidence. That is why if there exists evidence for life distinct from what we know it to be, it has to be considered. If not, it is pure speculation.

By that token anything can be taken out of the discipline of science, not just life. How do we know the laws of physics were the same before we discovered them? Perhaps they were all different with the consequences being exactly the same as we observed?

This can be discussed at a scientific level as well as a metaphysical level. Since the thread is in the natural sciences forum and used scientific terms, I chose a scientific approach to my responses rather than a metaphysical one.

Ganapati:

I admit I don’t see the complete uselessness of approaching it scientifically, and your arguments for doing so are sound enough. We’re looking at it just from two different angles in the end. The key is to recognize the limts of scientific understanding in this area, and from reading your post I think we are aligned on that premise.

What I think you mean to say here is that until that time abiogenesis will remain hypothetical. I don’t think anyone (and certainly not myself) is claiming that abiogenesis is more than a hypothesis, though as a hypothesis it does have a fair deal of evidence supporting it as well as a great degree of explanatory power.

I’m not sure what you are trying to establish with this point, though.

Sure, I never claimed that. However, when we look at the evidence supporting abiogenesis I will say that the support in favor of abiogenesis is greater than the support in favor of any of the other hypotheses being thrown around at present (at least insofar as I’m aware). However, there still does remain a great deal of mystery left to be solved.

I’ve noticed a series of moving goalposts within this discussion, this being the latest of them. It went from, “We have nothing” to, “Well, show me this very specific experiment”. This lends your entire argument a “god-of-the-gaps” feel to it, which is very weak ground to stand on both rhetorically and philosophically. Simply because unknowns do exist does not mean that the entire structure is unknown, unknowable, or that we are unable to understand it. But if you want a demonstration of possibility, these self-replicating RNA contains nucleotides that could be created under the abiotic conditions described and the shortest of them, 165 nucleotides, is significantly shorter than other nucleotides which have been created under simulated pre-biotic environments (some of which have reached around 400 nucleotides in length). While not a rigorous proof by any means, that does serve as a proof of concept.

Yes.

Beg to differ. I find the evidence supporting it to be quite slim and its explanatory power being extremely limited.

I was trying to establish the point, not something else with it. Frankly I find it very uncomfortable when an unproven scientific hypothesis, like abiogenesis, and a valid scientific theory, like evolution, are mentioned in the same context with the same degree of conviction. When discussing abiogenesis, we can leave evolution completely out, since evolution comes into play only after the first self-replicating forms appear.

I am sorry you find that goalposts are being moved. When you mention something specific in response to a claim of nothing exists, why would you find it uncomfortable to show that the specific you mentioned meets the criteria?

I haven’t read the artcile in the link, since the site requires registration. I will do so later.

But if all the components, nucleotides and the enzymes piecing them together to form the self-replicating RNA molecule are themselves known to be formed in pre-biotic environment and the only things controlled in the experiment were abiotic parameters, it would have demonstrated abiogenesis of some kind of life if not the one as we know it. If any of them is not known to have formed in a pre-biotic environment, it would have demonstrated little to someone who is not already assuming the validity of abiogenesis.

May I ask on what grounds you base that conclusion off of?

While they are occasionally mentioned together, I usually only see that occurring when the origin of life is mentioned as a critique of evolution. Within the confines of this thread, it was brought up because we need to first define what we mean by “life” before we can properly begin considering what conditions are necessary for it to arise and what their probabilities are.

I don’t have a problem providing the information – clearly, as I did provide the information. I merely wanted to point out the regression being employed in your argument before it gets out of hand.

You are displaying an ignorance of biochemistry here. Enzymes are protein catalysts. The RNA world hypothesis doesn’t involve enzymes, it involves ribozymes, which are nucleotide catalysts. In this case, the ribozyme in question is an RNA polymerase which can replicate itself. What the paper describes is a self-replicating RNA molecule that is built from nucleotides which could have been present in the pre-biotic world and is short enough that it could have been generated in the pre-biotic world. As I said before, that seems a rather strong proof of concept in terms of the RNA world hypothesis within abiogenesis.

May I ask on what grounds you believe abiogenesis has “a fair deal of evidence supporting it as well as a great degree of explanatory power”? In the end, until something is proven (and I don’t think you are claiming abiogenesis to have been proven), whether the evidence supporting it is “fair deal” or “slim” and the explanatory power “great” or “limited” is a judgment call. If I wanted to convert you to my judgment, I may make such an attempt. Since I am not interested in whether you, or anyone else, believe(s) abiogensis is true or not, I don’t see much point in discussing what are clearly subjective judgments on the same objective basis.

There isn’t any regression being employed. Abiogenesis will remain hypothetical until either a living cell is created in a simulated but exclusively pre-biotic environment or its probability of happening computed rigorously and shown to be close to 1 over geological time.

OK. So replace enzymes in what I said above with catalysts.

Are you referring to the higher probability of this self-replicating molecule being formed as one of the many possible random combinations of the nucleotides which were themselves capable of forming in a pre-biotic environment as opposed to a longer chain as “strong proof”?

The struggles between determinism and randomness always come to the same conclusion.
Determinism trend to have subjective selection of information received (Psychology).
Randomness favors the scientific minds (e.g. Darwinism – everyone was born to be).
Randomness prevails.

The manipulation of the God, which I strongly believed in and repeated endlessly, comes from the natural role. The interconnection between the God (the cell nucleus and the mother cell) and the humankind (a part of the biosphere – Life Cycles of this planet) must be solid. The physical connections allow us to have communications. The gifted power of the God comes from birth. Free Will (our minds generated by the thinking regions / central nerve systems) allows us to have random despite of the God’s will.

Discovery is a rebellion to the rests. I guess many people were making jokes on Galileo when he was still a little nobody confronting the authorities (the teachings of the churches). “All truths are easy to understand once they are discovered; the point is to discover them.” My scientific hypothesis “Lives in Different Levels” reveals the true nature of lives. The hierarchy of lives has given us the concrete idea on how the universe works (the natural rules). This discovery is a natural course in human history because of the bloom of knowledge and the technological breakthroughs. Religions are too weak to convince our new generations in the scientific era. The existence of the God is correspondent to the cell nucleus. There must be oppositions when someone comes up with a new cosmology (or I have to say, it is more likely to be a discovery). The relationship between the God (Conscious Earth) and the humankind become much clearer. Human is undoubtedly a part of the biosphere and we are the “LIFE CYCLES (including reproduction with regards to its biological meanings)” of this planet.

Teru Wong

I mentioned this earlier and you’ve been avoiding it ever since. Your rhetoric is really, really shoddy. Bringing up spurious points which have already been addressed isn’t just poor philosophy, it is weak rhetoric. Not hacking it philosophically and rhetorically is a sad thing indeed.

But since you’ve asked, I’ve provided some of the evidence supporting abiogenesis in this thread. This is in contrast to other hypotheses regarding the origin of life where the evidence is scant if existent at all. As for the explanatory power, the origin of life remains a mystery. However, abiogenesis takes what we do know about pre-biotic conditions on Earth, what we know about life as it presently exists on Earth, and basic chemistry and manages to synthesize those elements into a coherent narrative.

If that doesn’t convince you, I’d be curious to know why.

Kicking the goal-post once again, with the addition of a strawman! Really?

See the information I’ve provided previously.

Since you seem unable to synthesize the evidence on your own:

Under pre-biotic conditions:

  1. RNA components are formed.
  2. Reducing conditions result in polymerization
  3. RNA molecules can reach a size of around 400nt.

Couple those with:

  1. Self-replicating ribozymes as short as 140nt have been observed.

Now, all I’ve claimed is a proof-of-concept. I’d say that those elements do represent a rather solid proof-of-concept.

Which is substantially more than other hypotheses going for them . . .

Coming in late on this, but… The ID game of numbers assumes one single instance of the right combination of molecules necessary to form self-replicating life. The numbers look overwhelmingly in favor of ID. But if you introduce just a tiny bit of reason, the pre-biotic “primordial soup” wouldn’t have just one each of the necessary molecules to begin life. The soup would have literally trillions of possible combinations when the correct conditions for life “arrived”. The only miracle of life is if it HADN’T happened.

The funny thing about science is no one need be convinced by a mere hypothesis nor explain why he remains unconvinced. However I will indulge you. For me, abiogenesis as a hypothesis for the currently known life is convincing only when life in some form is demonstrated to be capable of forming in an abiotic environment. Until then I will consider all the “evidence” offered to be slim.

The only thing that “coherent narrative” achieves is the absence of need for anything that is as yet unknown to science. None too convincing for me. If that is proven to be the case, so be it. If not, that in itself isn’t anything impressive for me. That we have discovered and understood all possible phenomena is a position that reminds me of Max Planck who discouraged students from going into research in physics because there was nothing left in physics to discover, only to account for the mass of the nucleus (neutron was discovered much later). But to his credit, he at least correctly identified those that defied any valid explanation in his day, failure of the Michaelson-Morley experiment (leading to Relativity) and problems in black-body radiation (leading to Quantum Mechanics).

Pretending omniscience is not science and offering a narrative that validates such pretentions isn’t a merit in itself.

You perhaps never saw the goal post. Where did you assume it was?

I am not concerned with what different hypotheses have to offer, I am not attempting to convince you with a hypothesis different from yours. Your hypothesis doesn’t meet the minimum conditions needed for me to consider it. If you are arguing the case for why your pet hypothesis needs more funding than another, go right ahead and argue with those funding such initiatives. I am not one.

I am concerned with whether something can considered a valid scientific theory or not.

Can you let me know how abiogenesis is falsifiable?

It is funny that those who believe in abiogenesis think the only reason it can be rejected is because someone is proposing an alternate hypothesis based on Intelligent Design. Any hypothesis can be rejected without proposing an alternate hypothesis either because the proposed hypothesis is not falsifiable and hence not scientific or because there isn’t enough evidence to support it.

But for some reason we cannot simulate the conditions and make even one such molecule happen in pre-biotic conditions.

The numbers game used in the OP… What would be the purpose if not to discredit abiogenesis as possible? Gee, I wonder what the agenda behind those numbers might be? :unamused: But if numbers used “scientifically” is useful, consider the potential opportunities given all the waters in all the oceans on the planet. The possible opportunities for abiogenesis to occur when conditions are right for self replicating life to appear is staggering. Why have all our efforts to replicate those conditions and create life failed? Experiments involving whole oceans and conducted over the period of a million years or so are a bit difficult to put together at this time. But you are right. Abiogenesis is just an unproven hypothesis and will likely remain such given the sheer magnitude of the necessary proofs. Still, failed experiments in a bathtub says nothing about an ocean. Yes, just a hypothesis, but it beats the hell out of anything else offered as explanation.

I am not so convinced about this “The possible opportunities for abiogenesis to occur when conditions are right for self replicating life to appear is staggering”. Until someone rigorously calculates the opportunities to claim one way or the other is meaningless. However the fact that none of the supporters of abiogenesis, including scientists, actually come out with any rigorous numbers is highly suspcicious in itself.

Ummm, reason alone suggests that the numbers game is bogus regardless the hypothesis. Any competent scientist isn’t about to proclaim “rigorous” numbers. At best, the number is “large”. the question isn’t the numbers, it is the plausibility of the hypothesis matching up with what little we know. If one examines carefully the processes of early evolution of self replicating life forms, it isn’t too difficult to suggest that that those processes had earlier precedents in the pre-biotic world. It seems more likely that abiogenesis is a bit more possible than a big guy in the sky.

We haven’t yet come to full undestanding of all the potential “ingredients” of our pre-biotic environment - both in the oceans and atmosphere. We know a little, but certainly not a lot. But the default position of ID simply because we don’t know is bogus. I would be highly suspicious of anyone declaring “rigorous numbers”. As we learn more, perhaps numbers will have more credibility, but at this point, it is simply choosing which hypothesis seems more likely.

If we don’t know anything about numbers how does anyone say it is “large” or “likely”?

So it is simply matter of what appeals to the individual in question, whether appearance of life can be expected from the currently known principles or not. There is nothing more to it. Intelligent Design is not falsifiable and hence not scientific. What makes abiogenesis falsifiable and hence scientific? Either of them can be proven, but neither can be disproved. Precisely the reason why I called abiogenesis a faith position. That it comes from “scientific-minded” people doesn’t make it less so.

See below. Goal-post moved!

I don’t know where you are going with this one. Coherent narratives provide vehicles for discovery, that is how they operate. When problems are identified within them, the narrative changes but knowledge progresses either way.

Ahhh, that is where you are going with it: straight into character-assassination. Ad-hom arguments are usually considered a tactic of desperation.

What I’ve provided meets those criteria, but now it is all about whether or not abiogenesis has been conclusively proven (which we all know it hasn’t). Seems to me like a rather drastic shift in goal-posts.

So what are you ever-changing minimum conditions at the moment? Oh, and there was some more character assassination in that part too. As I’ve been saying, you’ve got to be careful with these rhetorical devices. They harm your argument more than they help it.

From ad hom to strawman. Running the gamut of rhetorical devices here . . .

The RNA-world hypothesis I’ve described here is falsifiable in the following ways:

  1. If any of the components were unable to form in significant quantities under pre-biotic conditions.
  2. If any of the components were highly unstable under pre-biotic conditions.
  3. If ribozymes were unable to have autocatalytic nucleotide polymerase activity.
  4. If the size of self-replicating ribozymes were larger than can be (reasonably) expected to form under pre-biotic conditions.
  5. If viral taxonomy demonstrates that viruses came about after nucleotide encapsulation.

Probably some other ways, but those are off the top of my head.

Apparently only in your mind. What are the intermediate molecules that lead to your 165nt self-replicating molecule? Have the environments they are capable of forming been demonstrated? Has such progression of environments been demonstrated as what can be expected from laws of physics?

Or are you claiming that the nucleotides are themselves the intermediate molecules and the first self-replicating molecule appeared as one of a random combination of nucleotides? Has the environment it is capable of forming from a collection of single nucleotides been demonstrated? If that is your position, it shouldn’t be difficult for you to compute the probability of that happening and letting us know.

That some non-self-replicating molecules capable of forming in an pre-biotic environment are longer than the shortest self-replicating molecule (that has not been proven to form in a pre-biotic environment) means as much as the existence of a mountain taller than Mount Rushmore does to the hypothesis of erosion causing the faces on Mount Rushmore does, which is nothing.

ID is falsifiable by demonstraing that life formed in pre-biotic conditions and hence that becomes a scientific hypothesis too :unamused: Not sure if you understand what falsifiability means.

Yes.

See the papers I provided earlier.

Yes.

See the experiments I listed earlier.

Spurious comparison coupled with an argument from ignorance (an informal fallacy).

More ad homs? I’m beginning to think that represents the totality of your argument.

See, the way falsifiability works is that you set up experiments seeking to disprove the hypothesis. If any of those that I listed acted in a manner counter to the RNA world hypothesis, that would eliminate the RNA world hypothesis from the running.

You are really backing yourself into a corner here.

OK. I give up, since you haven’t provided what you claim to. If someone else thinks you are actually making sense, he can have a discussion with you, because I cannot have a discussion with someone where the only evidence exists in his mind.

PS: There is nothing in the papers to support your claim.