Evolution is a fact.

In any developing science there are disagreements. But scientists—and here is what separates real scientists from the pseudoscientists of the school of intelligent design—always know what evidence it would take to change their minds. One thing all real scientists agree upon is the fact of evolution itself. It is a fact that we are cousins of gorillas, kangaroos, starfish, and bacteria. Evolution is as much a fact as the heat of the sun. It is not a theory, and for pity’s sake, let’s stop confusing the philosophically naive by calling it so. Evolution is a fact.
--Richard Dawkins

So there.