Some complex things in the universe evolved. But plenty didn't. The 'fine-tuning' of physical constants arguments is quite fashionable at the moment.

Is interesting how easy it is to project a certain assumption onto arguments, though. Because your atheist response assumed natural selection, while a response above protests that the theist hasn't experienced enough universes to generalise about them, so presumably interprets the statement to refer to the universe as a whole. All the more reason to make sure you understand what people mean, I suppose!