In my TA class this semester we've just entered talking about Language Evolution, and combined with the recent discovery of this blog the topic has been on my mind a bit lately. Some general thoughts on reframing the overall discussion...
Some theories of language evolution postulate that ‘gestural language’ evolved prior to verbal language. While I am in support of the multimodal sentiment, parts of this rub me the wrong way.
First off, humans currently use both modalities concurrently in expression, which is offered as part of the evidence for its potential importance in evolutionary contexts. While the verbal form in most people uses more complex structure, both forms are in use at once in co-speech gesture. Why would it make sense for only one modality to develop dominantly then transfer into another? Should we perhaps be thinking in terms of concurrent development for concurrent usage?
Along these lines, humans also have the capacity to draw. While our primate cousins do have gestures and vocalizations for conceptual expression, none seem to manipulate the world for conceptual intent, which is at the heart of drawing. Yet, this is never mentioned alongside the discussions of the other modalities (though not surprisingly).
Also, I think it is largely a misnomer to say “gestural language” evolved first. As a cover phrase, I think it obfuscates the issues involved — namely, that there are various mental structures that contribute to a behavior of manual (verbal and visual) expressions.
This is even more problematic when various people use the word “language” in different ways — some refer to a communicative system, some to grammar, some to conceptual expression. Really, if the discussion is about the evolution of what we now know of as “language”, it may indeed be inappropriate to talk about its historical states as if they're the same thing as we have now.
It would be more useful to discuss the development and evolution of these structures (syntax, semantics, etc) than to talk about the capacity as if it were a whole thing. That is, we should be talking less about the evolution of “Language” and more about the development of the interacting cognitive structures that end up contributing to language as we know it in the modern context.