Mutation or just trait selection, not evolution. Words mean something. I promise you no scientist goes to bed at night wondering what species will be in the dish tomorrow or even next year. (Unless it is some artificial boundary created just to generate a headline.)
Traits get selected for, just like when we're breeding dogs. That's how it works, no matter how much you and Behe go "nuh-uh!"
Trait selection works on already-present genes. No matter how many dogs I cross I am never going to get something that is not a dog.
Define "dog."
Um... evolution proceeds through the accumulation of DNA changes, aka mutation. You simply cannot talk about mutation and pretend it has nothing to do with evolution, any more than you can talk about architecture and pretend it has nothing to do with building construction. And there are plenty of scientists who *do* wonder what will happen to a population if they put selective pressure on it. Oh, yeah--since literal creationists place so much emphasis on the word "species", I'll just point out that it *is* pretty much a human concept, and one that is not easy to define in a scientific manner. If the offspring of A+B is fertile, and the offspring of B+C is fertile, but the offspring of A+C is sterile, then where do you draw the species line? It gets even trickier with bacteria--they give DNA to each other whether they belong to the same (human defined) species or not.
Trait selection works on already-present genes. No matter how many dogs I cross I am never going to get something that is not a dog.
Sure. And every one of these dog breeds looks exactly like the original wild dogs < /sarcasm >. Dog breeds look so different from each other because they have genes that never existed in wild dogs, because their genes mutated and humans made sure they survived. From a scientific point of view, I would call teacup poodles and great danes different species--they certainly can't breed together, so they fit the definition.
You know corn, that yummy yellow grain that we use for so many things? The corn species does not exist in the wild. It exists because humans 10,000 or so years ago started selectively breeding a kind of wild grass, and they ended up with a whole new species, corn.