In creationist or ID circles, "survival of the fittest" is often accused of being a tautology and thus completely meaningless; of course the fittest survive! They're the fittest!
Setting aside for a moment the many problems with trying to whittle down the extremely complex theory of modern evolution to an oversimplified soundbite, I intend to show that "survival of the fittest" is only a tautology if evolution were a logical argument rather than a scientific argument. A logical tautology can be obvious or it can be subtle. "No vegetarian eats meat" is a tautology because by definition someone who eats meat cannot be a vegetarian. Recently I was told in an on-line discussion that "no conservative calls himself gay". Pointing out that there are many gay conservative pundits I was corrected; they are obviously not really conservative. Because to this commenter, the definition of conservative requires heterosexuality.
Well what about "survival of the fittest"? Is that a tautology? Logically, perhaps. By definition, an organism's level if fitness is directly related to the probability of its survival. But evolution isn't a logical exercise; it's a scientific endeavor. And evolution doesn't revolve solely around "survival of the fittest". In fact, it is only the second half of the true (and admittedly less impressive) soundbite: variations exist in nature and those organisms with more favorable variations survive.
Tautological or not, the "survival of the fittest" is merely an observation. But as a soundbite it obfuscates the truly fascinating observation underlying evolution: that organisms need to survive in the first place; that they vary, if ever so slightly, and that variation helps them interact with a changing environment. "Survival of the fittest" is indicative of the fact that the earth is not Eden. An organism may be best suited for the environment it finds itself in and less suited for a different environment. But since its environment isn't static, it finds itself in competition with other organisms for food, for shelter, for a mate.
Of course "survival of the fittest" is a painfully obvious observation. Evolution addresses why survival is necessary. Both a creationist and a "Darwinist" would say that it's because the earth is not Eden but only the evolutionist asks whether or not it is the imperfections in the world that create such changing diversity. In Eden, "survival of the fittest" would be meaningless because there would be no "survival"; there would be only life and death (if at all) in a regular cycle.
