dmac2020
I'm sorry if this is mentioned in someone else's post, I don't have time to read them all, but I'd like to direct you to the work of Dr. Phil Gingerich. He's the world's foremost authority on the evolution of whales, and I saw him give a presentation titled, "How fast is evolution?"
While you certainly can't have a solid answer for such a question in all cases (because of infinite possibilities for environmental changes for a living organism, and the possibility of the organism dying accidentally or in a fluke), it apprears as though evolution occurs at a maximum of 0.1 of a standard deviation per generation.
I know that sounds a bit odd to put it that way, so I'll have to ask you to check out Gingerich's work yourself as I can't write a novels worth on the post to explain it here.