I don't agree with you about the interpretation of the DNA figures, but if we assume you're right, then the absurdity of trying to teach apes language is even more obvious. Would it be of any interest to train grad students to more or less mimic apes? We would learn nothing about apes from the fact that grad students can be trained to more or less mimic them -- try to get an NSF contract to study that -- just as we learn nothing about humans from the facts that apes can be trained to mimic humans in some respects. Language is a notorious failure, exactly as any biologist and paleo-anthropologist would have expected. But if, say, Nim had succeeded, we would still have learned nothing about language acquisition, gaining neither more nor less wonderment, though we would have a biological problem. Namely, if apes have this fantastic capacity, surely a major component of humans extraordinary biological success (in the technical sense), then how come they haven't used it? It's as if humans can really fly, but won't know it until some trainer comes along to teach them. Not inconceivable, but a biological problem, and about the only conceivable scientific consequence of the ape-language experiments, except what they might teach us about ape intelligence by training apes to deal with problems that are outside their normal cognitive range. This is all sentimentality of the worst sort.
Today, from what I can tell, scientific opinion is divided along disciplinary lines. Many researchers who work primarily with animals accept or at least are receptive to the idea that apes can be taught a rudimentary form of language. Linguists, on the other hand, dismiss the whole thing as nonsense. Personally I'm happy to concede that the boundary between animal and human communication isn't as sharply drawn as we once thought. Animals (not just primates--check out Alex the talking African gray parrot sometime) can use language in limited ways. They can respond to simple questions on a narrow range of subjects; they can express basic thoughts and desires. I'll even buy the possibility that some are capable of employing elementary syntax. However, all this strikes me as the equivalent of teaching a computer to beat people at chess--a neat trick, but not one that challenges fundamental notions about human vs nonhuman abilities. I've seen nothing to persuade me that animals can use language as we do, that is, as a primary tool with which to acquire and transmit knowledge. I won't say such a thing is impossible. But in light of the muddled state of the debate so far, the first task is to decide what would constitute a fair test.
The most famous was Koko (a chimpanzee)
I watched several videos with Koko and there were definitely signs and they definitely had meaning. As I said in the other thread, primitive and rudimentary, but something approximating communication.
I'll even buy the possibility that some are capable of employing elementary syntax.
And, as famed linguist Norm Chomsky points out.... if primates have developed this remarkable human ability, why wouldn't they use it themselves? It would be as if "humans can really fly, but won't know it until some trainer comes along to teach them".
There's no question that animals communicate and a combination of noises, gestures and body language communicate a lot of different things.
But they don't use language.
Yes, I think this is one of those issues where the terms have to be set pretty precisely to have a meaningful discussion.