Yes, it’s “very unlikely”, but still likely enough that it has happened many thousands of times over the history of life. IIRC it’s been estimated there’s something like 10^4 unique protein folds used by cellular life on Earth. If we sort of spread that out equally over the 4 billion year history of life on Earth, we arrive at a new protein fold emergence once every 400 million years. Now of course that’s largely an oversimplification since much of this evolution has occurred in parallel in different lineages, rather than sequentially one after another.
But regardless, that’s definitely a very long time for novel fold emergence, no doubt about it. But what is then wrong with inferring that new protein folds can and do evolve, just extremely slowly and infrequently compared to human lifespans?
Yes, they’re “very unlikely”, but not too unlikely to evolve. They have, many thousands of times. But it’s taken tens to hundreds of millions of years on average for it to happen. Why can we not make this inference? If we can study the rock layers in geology and make statistical inferences about the frequency with which something occurs in geology, why can’t we do the same in biological evolution? If we can infer that cataclysmic volcanic eruptions take on every some X number of million years to occur, why can’t we do the same with biology? Why must there be this strange gulf of nothingness following things that occur on decade-like timescales?
How is this any different from innumerable other extremely slow processes that occur on our planet? Continental drift, emergence and erosion of mountain ranges, changes in the paths taken by rivers, the sizes and shapes of lakes and oceans, the coming and going of continent-spanning forests and deserts. And so on and so forth.
Some things are quite likely to happen, so they occur correspondingly quite frequently. Some things are less likely, so they’re a bit more infrequent. Some things are even more unlikely still, so they occur even less frequently, and so on and so forth - until we get to things so unlikely to only occur on average once every 100 million years, or once in a billion, und so weiter.
IDcreationists seem to have this strange picture of the world where there is only likely things occurring all the time, and then there are completely hypothetical things that are so unlikely that they never occur at all. And there’s just no space for something in between. Historical inference that new proteins might take millions of years to evolve, while that is certainly slow and unlikely, seem to be instantly rejected as impossible.
But we’re never told why it has to be impossible, or so unlikely so as to never occur in the history of life on Earth. It seems to just be an assumption you have. A faith. A sort of axiom you refuse to consider might not be true. Either you want it demonstrated to occur to you in real time in the span of a decade at most, and if we can’t do that, you reject the possibility of it occurring in any other amount of time. A sort of “were you there” rejection of historical inference.
There are only things so likely we can show them to you right now, or impossibly unlikely things that can’t occur. Nothing in between. There are no things that take thousands of years, no things that take hundreds of thousands of years, no things that take millions of years, in your strange perception of reality.
It’s like there’s no such thing as a spectrum of likelihoods and frequencies of occurrence. The prospect that some things are so unlikely they only occur once every 200 mya is just not part of your conception of reality, and that just doesn’t make any logical sense.
So somewhere in between simple double substitutions or triple mutations that you allow can occur in the span of a few decades to maybe, MAYBE a century, and then from that on there’s nothing other that can possibly happen in evolution. There are no complex mutations that happen once every 5000 years, once every 150 000 years, once every 25 million years.
Your view of these matters just don’t make any logical sense. And you all(IDcreationists) seem to be laboring under this extremely strange view of probabilities and frequency of occurrence. “It’s now or never”.
A process of intelligently guided information generation.