I’m not terribly clear what you mean by “effectively random . . . with respect to their effect upon organisms,” but if you simply mean that “mutation” is random,” I’m inclined to disagree. As I’ve said, Carey, I just find randomness to be a rather ineffective explanation, a masquerade for ignorance, like not knowing which Monty Hall door has the prize, or not knowing how/why entropy at the beginning, 14 billion years ago, was so low; and that it’s my view that “randomness” is an illusion . . . although ignorance certainly seems to be real, and probabilities are nothing more than our attempts to quantify our ignorance . . . whether we’re talking physics, cosmology, or biology.

As far as I know Carey, we can’t prove randomness, and randomness is not falsifiable.