The intelligent design post is #16 on Blogdex.

And one more follow up. Reader Michelle Dulak writes:

Just stumbled on the creationism/ID discussion via Cornett. You’re right, of course, that there are infinitely many theories of the universe that *might* be true but are unfalsifiable. But I’m not sure that ID is in that category, and I’m not sure that evolutionary theory isn’t.

To take the second first: *is* evolutionary theory falsifiable? Can you imagine any experiment that would be capable of disproving it to any scientist’s satisfaction?

I answered that question in a previous post. Not to speak for other scientists, but I can’t imagine one at this point. The key phrases being “I can’t imagine” indicating a possible failure of imagination on my part and “at this point,” that is, given the current overwhelming evidentiary record.

We’ve demonstrated short-term, small-scale natural selection in bacteria. (I don’t think anyone is really surprised by these results; natural selection in the sense of preserving favorable mutations and weeding out unfavorable ones is common sense — which doesn’t mean that Darwin’s insight wasn’t a tremendous breakthrough. Lots of things are obvious once someone has thought of them.) Suppose one experiment fails to produce natural selection & (micro)evolution — is anyone really going to throw out the theory of evolution on those grounds? There isn’t a Michelson-Morley Experiment for evolution, nothing that would settle the case either way.

That’s true, and I probably overstate the case when I say that evolutionary theory is as well founded as gravitational theory. But it’s sufficiently well founded to teach it as science, particularly considering the scientific alternatives (i.e., none).

The only experiments that might conceivably falsify evolutionary theory in the strong sense — i.e., that it not only preserves favorable mutations but can actually build vastly different organisms from its starting material — would have to run over tens of millions of years. And even then there’s no real falsifiability. The conditions of the original run aren’t replicable. We could run ten-million-year experiments on thousands of planets, find no large-scale evolution, and still not falsify Darwin, because it’s *not the same experiment.*

Yes, I made that point in a comment in an earlier post. Because it’s so chaotic and contingent, there no way to repeat the experience exactly (or perhaps even closely). All we can do is demonstrate the basic principles.

Whereas ID in the Behe sense is really very easily falsifiable. Find one irreducibly-complex system in your rapidly-mutating bacteria that wasn’t there when you started, and Behe is toast. Of course, your case is a lot better if you can explain how the irreducibly-complex system actually did evolve, but all you really need to refute ID is one such system that wasn’t there at the beginning of the experiment and was at the end.

That’s true. I should have been more careful in my wording. When claims get specific enough, “God did it” arguments are falsifiable in the limited sense that one can show an alternate means for it to occur, so the “God did it” argument becomes unnecessary. But it’s still not ultimately falsifiable–the claim can still be made, “Well sure, that’s what happened, but God made it happen that way.”

That claim is unfalsifiable.