However, it might be the case that this "syntax" has developed in parallel to human syntax from some common protolanguage
What is interesting here is not the structure of the language, but the fact of it.
Granted, I---probably erroneously---took the statement to which I responded to be a claim that studying the monkey's language would be informative vis-à-vis human language. The "proto" prefix is typically used to mean "ancestral to contemporary human language".
Humans are possessed of a wide range of incredibly powerful, flexible and general linguistic mechanisms. Non-human animals are frequently held to be entirely non-linguistic.
I think (hope!) that this position is becoming outmoded among the newer generations of linguistics & cognitive scientists. The evidence for abilities that map fairly straightforwardly onto human linguistic abilities is pretty much overwhelming at this point. (The final chapter of Bridget Samuels' dissertation talks about this a fair bit, mostly in relation of phonology)
This is implausible on the most basic evolutionary grounds: evolution is an elaborative process, and to have such remarkable abilities amongst humans strongly suggests a lot of linguistic or proto-linguistic capability in our ancestral line, and probably in other animals too. Otherwise, it would be like humans having the ability to run fifty miles in one go in a world where no other animal has legs.
Well, maybe yes, maybe no. There's a big push now toward viewing Language as a cultural artifact, whose properties are emergents of cultural evolution (cf. anything going on at the LEC in Edinburgh, or Mort Christiansen's work). This viewpoint, to which I'm generally sympathetic, always leads me to thinking about cooking and recipes. Cooking is, to the best of my knowledge, a purely human endeavour; one that has presumably been considerably refined via cultural evolution since the day when someone accidentally dropped her hunk of meat in the fire. And yet, no one would be tempted to say that the seeds of cooking/recipes/soufflé can be found in the behaviours of some animals (or maybe they would...I'm not ethologist).
I had a point, but it seems to be gone now...probably that appeals either to innateness or evolution alone are by necessity oversimplifications. The kind of empirical work being discussed here is what will move this domain of knowledge forward.
While the sexual selection forces that drove the evolution of human intelligence are powerful and able to produce relatively rapid elaboration of new capabilities, those capabilities have to be elaborations of something that already existed, and so we should naively expect this kind of discovery.
I don't think I'm understanding what you've said here. Surely not everything is built on something that came before? Mutation and exaptation have clear---in fact vitally important for the former---roles in evolutionary processes.
Unfortunately, because linguists seem for some reason to think that human language is the only possible model for language (see the other comments from linguists in this thread, for example) it can be difficult to recognize the linguistic (or possibly linguist-ish) capabilities of non-human species that do not conform well to that model.
Given that our only unambiguous model for Language is human language, it should be unsurprising that that's what we take as our primary model. Nonetheless, see my earlier reference to Samuels 2009 for a clear indication that this trend is changing.
I now have the PNAS paper in hand (well, on-screen)...I may come back and say more...