The best analogy I've seen (sorry can't remember who it was or I'd credit) is that creationists accept 'micro' evolution, where small changes, say dog breeding occur, but reject large change. If you take change and use actual money it's akin to saying that if you add pennies you'll get small change, but you'll never get dollars or hundreds.
Yet, if you keep adding pennies, you can eventually get to a million dollars. (obviously).
There is probably a fallacy for it, fallacy of large numbers or some such.