>There is obviously a gap between humans and other non-human primates.
However, Savage-Rumbaugh's research with Kanzi (a language-trained bonobo)
indicates, at least, that Kanzi can comprehend some grammatical utterances
and relationships. She also suggests (although not very conclusively, in my
opinion) that Kanzi also produces some grammatical utterances. The gap may
not be as wide as we think.
I would say that the gap between human and ape language is huge (if one
defines language as the symbolic communication via words, either made by
hands or voice). Bickerton notes:
"However, there are still striking differences between ape
vocabularies and human vocabularies. The most obvious is sheer
size. No ape has so far succeeded in acquiring more than a few
hundred elements, as opposed to the many thousands of words that
are found in the vocabularies of the average human. But a less
obvious fact is perhaps even more significant. In chapter 3, we
saw that a full half of the words used in normal conversation are
grammatical items (articles, auxiliaries, prepositions, and the
like). With trivial exceptions (such as if/then element used by
David Premack in his work with chimpanzee Sara), the vocabularies
of apes are strictly limited to lexical items."~Derek Bickerton,
Language & Species, (Chicago: University of Chicago Press, 1990),
p. 107-108
Given these limitations, one can hardly claim that apes have learned speech
in the same sence that a child learns speech.
glenn
Adam, Apes, and Anthropology: Finding the Soul of Fossil Man
and
Foundation, Fall and Flood
http://www.isource.net/~grmorton/dmd.htm