I'll agree with you about humanity in the sense of our culture and other sociological interpretations, and even go a step further and say that the human mind can't just be reduced to the perpetuation of genes, but I'm afraid I'm a little more evolutionist with the brain - it is just as much a physical piece of our body built by the recipe written in our genes and influenced by our environment. Cartesian dilemma solved or unsolved, the brain is a physical organ. I will say, though, that the brain is the most complex thing ever studied and many (if not all) of its functions are pretty much only very far-removed and indirectly related to gene survival. Our brains had to serve a near infinite set of purposes, many that were compounded by the existence of other brains and brain(mind)-products, so that gene survival is only an ultimate explanation, almost never a proximate one.
Chomsky's talking about the just-so stories endemic to the arena of adaptationist explanation of observed facts. I want to mention that this isn't restricted to EP, though - plenty of evolutionary explanations, human or non-human, are susceptible to being just-so stories; it's inherent in the nature of abductive reasoning. This is why evolutionary research (conceding the point: especially with human psychology, since it's already sometimes difficult to assure construct validity there) needs to be careful and cautious across the board. Also, holy crap - I am almost certain I had The Evolution of Language out of the local library too this summer! I ended up having to return it unopened (I had borrowed one called Proust and the Squid with it and opened that first) because my reading list for class was too heavy to let me get in some leisure too.
Anyway, broad conclusions based on just western uni students are unreliable. I could defend an argument for their (limited) usefulness despite that, but the point is inarguable.
We will totally be interdepartmental bros.