I’m reading the Fodor/Piatelli-Palmarini book now, but John Wilkins is not impressed.
Jerry Fodor is a smart guy in his field, but if this is his argument, it is childish. This, which is called “referential opacity” in philosophy (“You know your father. You do not know the Masked Man. Therefore the masked man is not your father.”) is a comment or fact about us the theorisers, not about the way the world works. It is about (as I italicised above) what we can say. The masked man might very well be your father, and the disconnect is in your words, not the world. Likewise natural selection works on whatever class of properties happen to confer differential fitness on their bearers; that we may be unable to identify what those properties are is a fact about us not about the organisms.