I started to write a very long response and on reflection, stopped. This is a problem of computing the probability of getting from point A to point B using the pathway and rules of the road evolutionists claim should apply. Evolution claims it produced a man from a universe without life, so how was it done? Given that mutations are random and that they are either harmful, neutral or beneficial, what is the probability that what had to happen did happen on that path?
Not once has anyone claimed evolution cares about specific outcomes, so why is it raised as a defense of a perfectly legitimate inquiry into evolution? Just because people don’t like the numbers isn’t good enough. Man is but one of many endpoints, but so what? If an evolutionist wants to check out a clam, let them go to it. Checking one pathway does not preclude any other possible pathway and result.
The only reasoned argument I have seen against probability concerns how natural selection should be treated. It is not an argument against the use of probability for a specific endpoint. Nonetheless, unless a case can be made that natural selection greatly or totally negates randomness, it don’t see it faring to well.
By the way, Huxley used a horse for his endpoint. Curious that evolutionists, even today don’t jump up and down and throw tantrums over that, but he was one of theirs. Huxley didn’t like the result though and went about trying to undermine it.
But you're still hung up on the probability of a specified endpoint--maybe one of a number of possibilities, but you're still trying to estimate the probability of ending up with a human, or a clam, or some other specific organism. I'm surprised that someone so adamant about the need for math skills can't see the difference between the probability of a specific outcome--no matter what specific outcome you choose--and the probability of some outcome at all.
I'll try another analogy. You're standing at the mouth of a river and saying, "The chances of this river forming are astronomical." And you're right: it required that tree to fall over at that particular point, and that bank to wash away in the extra rainfall that summer, and and and. And now you're saying, "I don't care, pick a different river. The chances for that one are astronomical, too." And you're right again. The chances of any particular river forming are infinitesimal, requiring countless random acts, and there's no way you could predict the river's course by standing at its source.
And yet, given the snowpack in the mountains, it's practically a certainty that rivers will form.