Gary Marcus, author of The Birth of the Mind, has a pithy piece in The New York Times, From Squeak to Syntax: Language’s Incremental Evolution, which sketches out the refinements that the new science of genomics is adding to our understanding of the origins of language. In fact, one could argue that it isn’t adding, it is actually building the initial foundations. Many of you probably also know that the Linguistic Society of Paris banned the discussion of the origin of language in 1866 because it seemed to be simultaneous attractive and intractable. Though Noam Chomsky was one of the major drivers in conceiving of language as being facilitated by a biologically undergirded “organ,” he has also been resistent to a more thorough evolutionary and adaptive explanation in a standard Neodarwinian (read: adaptive) framework.
But as Marcus notes the discovery of necessary genetic loci like FOXP2 allows us to explore the contigencies of how language develops in the present. Additionally, evolutionary genomic models have been able to show that the human variant of FOXP2 is highly derived, that it is more distinct (in the number of mutational steps) from other orthologous genes than it “should” be based on phylogenetic distance alone. In other words, it seems evolution “sped it up,” which suggests positive selection as background mutations are driven toward fixation. Of course it seems very likely that FOXP2 is a necessary precondition for language acquisition capacity, but it is not sufficient, and, the locus itself seems to be pleiotropic in its impact. Not only is it implicated in language, but it has correlations with general intelligence, and it is likely an important upstream regulatory node for a host of traits.1 The lesson is that the “origin of language” isn’t going to be an easy puzzle to solve, but over the last 5 years a new and very formidable detective has come on the scene, so things should get hot. Cognitive psychologists like Marcus and Steven Pinker have been whipping out FOXP2 right from the get-go, their conception of how language is structured on the genetic level predisposed them to expect the existence of a gene such as FOXP2, the only worry is that the public might believe that this is the end of the story when in fact it is simply the prologue.
1 – I am hearing there might be non-trivial levels of polymorphism on FOXP2 coming out of the HapMap project.