Remember before when we agreed nothing has a probability? Bully. So if no thing has a probability, neither does abiogenesis, since abiogenesis is a thing.
Since abiogenesis is a thing and things have no probabilities, it makes no sense to speak of “the probability of abiogenesis.”
James Chastek hit upon this commonsense idea in lovely article at Just Thomism (a site to be bookmarked): Creationists vs. evolutionists on abiogenesis.
Given the level of passion on this topic from fire eaters on the sides named in the title—and there are more than two—Chastek wisely turned off comments to his post. I am reckless and leave them on. I hope the gentleman won’t mind my quoting him extensively. In any case, I am going to assume below that everybody (which includes you; yes, even you) have read his original.
To sum up, the sides are fighting over there is a 10390th [creationists] or 1040th [evolutionists] chance of some process terminating in life before either side specifies what the process would be. It’s hard to understand what this means. Compare the debate to a time when we can actually figure out the chances of something happening, like Bingo. A clever seventh-grader can tell you your odds of selecting B5, but only after he knows the process by which bingo balls get selected. Without this, what sense does the question have? What are your odds of choosing B5 right now? To be clear, I don’t mean (your odds of leading a bingo game)(your odds of picking B5). That sees like a question with a possible answer. I mean the much more incoherent question that asks without specifying any process by which a given number gets picked, what is your chance of picking it? The contradiction practically has a siren on top: you can’t know how likely you are to pick something without knowing how you could pick it at all.
I assume that both sides are assuming that all there is to forming life is having molecules bang around and form stuff, but the problem with this theory is not whether its parameters of probability are acceptable or not, but that it is not a theory at all. Saying “things just bang around and stuff happens” is not a process, since a process is a specified set of steps toward a definite terminus while “things just bang around” is not a specified set of steps and “stuff” is not a definite terminus. If we could actually specify the bingo-machine that led to the number of life, neither side would need to figure out the probability of the number popping up, any more than any winner at a game of chance cares what his odds were.
The problem is that we don’t have an acceptable mechanism for abiogenesis and so we have no idea how probable it is. Creationists and evolutionists are fighting over something that neither one of them has.
Putting it in my language, we don’t have a probability for abiogenesis because we haven’t specified the premises. Probability must needs have premises, for all probability is conditional.
We can say this more strongly. If we knew the process by which abiogenesis occurred, again it would not have a probability (except for 1), nor would anybody think to ask for one, since we would know the cause or causes of it. Since we do not know the cause, it’s appropriate to speak of probability, but because we cannot set up the premises, i.e. specify the process, we can’t even speak of probability.
In short, both sides are bluffing.
By a process Chastek (and I) mean something like this: molecule A hooks to molecule B, and the joint AB becomes more than A+B; and this hooking can happen in the following specified ways. These specifications do not need be true: if they were true, then again we would know the cause of abiogenesis. They can be guesses based on knowledge of chemistry, biology, and so forth. They can be wrong guesses. They can invoke fictional mechanisms known to be false, even. As long as we have the process, we can derive the probability.
This last fact emphasizes probability cannot be used to prove theories true or false.
About actual abiogenesis, I share Chastek’s opinion—which you will remember, because you read his article.