Alvin Plantinga leads with the idea that naturalism does not entail the observation of fine-tuning in the universe, whereas theism makes fine-tuning probable. I have to point out here that (as brilliant as he is) he gets this perfectly backwards. On naturalistic monism, observers cannot possibly exist unless at least part of some universe is so finely tuned as to allow for them to evolve naturally. On theistic dualism, observers exist as minds entirely apart from any sort of fine-tuned cosmos which might allow for the possibilty of organic matter walking about and pumping blood to their brains. In short, naturalism necessitates the observation of fine tuning, if naturalism is true and any actual observers exist at any time and place in any universe. By contrast, theism is not linked to fine-tuning at all, unless we include the downright bizarre premise that the god of theism is a bit of a deistic chap, and prefers to create a seemingly naturalistic world which runs all by itself according to fixed natural laws.
That aside, Plantinga came on the show not to confuse the listeners about cosmological fine-tuning, but rather to confuse them about the relationship between metaphysical naturalism, evolution, and the probability of some animals evolving reliable cognitive mechanisms. This he does quite well, by repeating the startingly claim that animal behavior is causally unrelated to animal beliefs about the world. Why does a cat or a dog or a human jump back and start pumping adrenaline when confronted by, say, an angry mama grizzly bear? Surely it is not because they believe themselves to be in danger. It must be for some other reason driven by neurology alone, without any regard to subjective experience. This decoupling of subjective experience and beliefs from behavior is the sort of thing that only a philosopher would dare to do, as it runs completely contrary to our actual experience of how these things really work.
Enough ranting. This was a reasonably good introduction to the evolutionary argument against naturalism, and one which I'd recommend if only because one is bound to run across this argument from time to time.