Which puts it smack, dab in the middle of a debate in ........
philosophy
That is not science. Science can deal with the mechanical and explain how, but is useless beyond that.
Yet it is a source of constant amazement the number of scientists who have the arrogance to make pronouncements about subjects outside their expertise using a tool totally inappropriate for the job.
Notice that they qualified the intelligent agent as in the *natural* world? Can't have any of that God creating stuff now, can we?
philosophy
That is not science.
Which is why, until there is "non-religiously based, verifiable evidence of meaningful and purposeful acts of creative intelligence in the natural world," ID belongs in philosophy class, not science class. I'm glad you've finally come around.
Note that the author of the posted piece apparently agrees that functions evolve (though he seems to prefer the terms "come about" or "are produced," probably because "evolve" has all those nasty connotations to it). And as you say, "Science can...explain how." The author's only argument is whether intelligence directed the production or not. But that's a question for philosophy, as you and IDers both have stated.