Did Language Evolve by Natural Selection?
In the Oct 14 issue of Nature,1 Gary Marcus (Dept. of Psychology, New York University) appears conflicted about how human language arose. He wants to attribute it to a Darwinian process:
If, as François Jacob famously argued, evolution is like a tinkerer who builds something new by using whatever is close at hand, then from what is the human capacity for language made?
Most accounts of the evolution of language have focused on characterizing changes that are internal to the language system. Were the earliest forms of language spoken or (like sign language) gestured? Did language arise suddenly? Or did it emerge gradually, progressing step by step from a simple one-word ’protolanguage’ (limited to brief comments about the ‘here and now’) into a more complex system that combined individual words into structured meaningful sentences encompassing the future, the past and the possible – as well as the concrete present?….
Yet in the last sentence, after considering several options of how language might have arisen and developed by natural processes, he cannot help but wonder at the result:
To the extent that the neural or genetic substrates of language and cognition overlap, language should be understood not just as an adaptation selected for effective communication, but also as a darwinian descendant with modification from pre-existing cognitive systems. Studying how linguistic systems may have descended with modification from cognitive precursors could in turn elucidate the oft-noted (but never satisfactorily explained) co-morbidity between language disorders and other cognitive impairments, in terms of overlap in genetic and neural machinery. At the same time, by highlighting how new mechanisms can be built on top of old, we may be able to make better sense of the mystery of how, within a relatively short period of time, with just a relatively small amount of genetic change, humans evolved the amazing gift of speech.
1Gary Marcus, “Concepts: Before the Word,” Nature 431, 745 (14 October 2004); doi:10.1038/431745a.
Can a schizophrenic psychologist understand human language? He sees the “amazing gift of speech,” with all its mystery and wonder, but wants to attribute it to a goddess tinkering with parts cobbled from whatever is at hand (shall we name the evolutionary goddess Charlotte, the fairy godmother of Charles Darwin)? He can’t have it both ways. Either language is an amazing gift, designed by intelligence, or it is a meaningless end product of a mindless, undirected natural process. How much evidence does Mr. Marcus have for his speculation about language arising by evolution? (Dead silence.)