Today, right near the end of The Ape That Understood The Universe (pp. 275-276), I had another What He Said moment:
… Earlier I mentioned that humans have an innate capacity to learn language, but that the specific languages we learn evolve culturally to mesh with our language-hungry brains. There may be a twist in the plot, however. It’s possible that our languages themselves helped to wire a language-learning instinct into the human genome. Here’s what might have happened. It all began with the cultural evolution of a rudimentary proto-language: a system of grunts and gestures not too far removed from what we see today in wild chimps. We didn’t have a dedicated language faculty at that time, so we acquired this proto-language via general learning mechanisms. (This is presumably what captive apes do when they learn to communicate with signs.) The proto-language wasn’t nearly as useful as our modern ones. But as anyone who’s visited a foreign-speaking country knows, even a little language is better than none. As such, any ancient human who acquired the proto-language more easily, mastered it at a younger age, or used it more adroitly, would have had an advantage over her more linguistically ham-fisted contemporaries. And what an advantage! Language is useful in virtually every sphere of human life: communicating needs and wants, organizing hunts and other cooperative ventures, entertaining mates, conveying useful information to offspring, finding out who to trust and who not to. In these areas and others, better language-users would have had a definite edge. Given the evolutionary importance of these activities, such individuals would plausibly have had more offspring, and their linguistic advantage would have spread through the population. As humans became more verbally adept, this would have triggered the cultural evolution of a more complex proto-language. That in turn would have created a selection pressure for even greater linguistic giftedness, which would have spurred the cultural evolution of an even more complex language – the usual story. In short, the cultural evolution of language resulted in the biological evolution of a language-learning instinct, and vice versa.
If so, this has an interesting implication. We saw earlier that genes for lactose tolerance were a consequence of milk drinking, rather than a cause. The same may be true of language. We tend to assume that genes for language came first, thereby making language possible. It’s equally likely, however, that it’s the other way around: that language came first and then created a selection pressure for genes promoting the rapid acquisition of language. In other words, our gift of the gab may have started with a cultural mutation, rather than a genetic one.
I worked out this notion, that culture creates new evolutionary spaces for genetic evolution to move into, several years ago, but it is good to have it confirmed by SS-W. I presume that this means that, what with culture hurtling towards new evolutionary spaces all the time, that means that genetic evolution is hurtling onwards, faster than ever before.