Frank Kogan

It's very hard to come up with an explanation for language that doesn't involve it being an evolutionary advantage - and it's easy to see lots of ways in which it is, so I am not really inclined to doubt that. We could say the same about making tools - a few animals use tools in some simple ways, but none make them. There are quite a few things that have only evolved once, so the fact that it hasn't happened more than once is no evidence for it not being advantageous. I don't find it hard to believe that a combination of a particular environment, vocal apparatus that had some flexibility, a certain kind of social structure, brains big and complex enough and maybe other factors (a wide range of dangers from many directions, say) combined to make the start towards advanced language a useful and possible thing. I don't think we have any precise knowledge of when it evolved (hard to see how that could be determined), so the above is admittedly vague speculation.

If we assume that some such combination of factors might be needed to make it both possible and useful, and believe that they are rare, which I suspect they are, we don't have to explain why it didn't happen with, say, other primates. Evolution has never worked by finding one perfect solution, it works by sort of random (well, within complexity and chaos theory!) chance and some things working - the advantage may have been small at first, or it may be that other creatures managed the same sort of communication and cooperation in other ways, so didn't need it. Those ways may have been more limited, but enough to mean our kind of language in its early stages couldn't provide them with significant extra advantages, so wouldn't take hold.

I am strongly suspecting some teleological tendencies in the arguments you are quoting. Maybe not, but it reminds me of a lecture I went to some weeks ago about what alien life would be like, which succumbed to the usual tendency to think that what we have as evidence (life on Earth) is pretty much the way it inevitably has to be, so alien life will therefore be pretty similar to ours. Anything leaning towards universal grammar makes me think of that weak argument.