I'm passionately interested in Darwin and evolution, but have been bashing my head against the wall recently, over the objection that 'survival of the fittest' is a tautology. The answers to this that I've read state that 'fitness' doesn't mean:
"those that survive, but those that could be expected to survive because of their adaptations and functional efficiency"
But then the reply to this seems to be:
"This charge is not repelled by substituting "most adaptable" or "best designed," etc., for "fittest," because these too are determined by survival. (That is, how do we determine that a species, or members of a species, is "most adaptable" or "best designed"? By the fact that it survived.)"
As an aside following on from this, I know that you can then say that there is a lot of evidence. But isn't this evidence for evolution, not the specific theory of natural selection?
My question is:...
My understanding of the supposed tautology to which you refer isthis: In the theory of evolution, only the most fit organisms survive. But the fitness of an organism can only be determined by the fact that it survived. So, we conclude: 'In the theory of evolution, only those that survive survive' The statement in (3) is indeed quitemeaningless. If this were indeed the basis of evolution, then itwould have no predictive power, and fail a key test of beingscientific. Because the primary object that evolution seeks tounderstand is the past through the fossil record (and similarevidence), and it is successful species that leave such traces, it isindeed the case the palaeontologists have to work backwards fromsurvival to fitness. There are several problems with theabove reasoning, however. First, 'fitness' is not an attribute of anorganism or of its genes. Rather, it is a relation of the heritablecharacteristics of an organism to its environment ...