Evolutionary Linguistics - Recent Developments

Recent Developments

Evolutionary linguistics as a field is rapidly emerging as a result of developments in neighboring disciplines. To what extent language's features are determined by genes, a hotly debated dichotomy in linguistics, has had new light shed upon it by the discovery of the FoxP2-gene. An English family with a severe, heritable language dysfunction was found to have a defective copy of this gene. Mutations of the corresponding gene in mice (FOXP2 is fairly well conserved; modern humans share the same allele as Neanderthals) cause reductions in size and vocalization rate. If both copies are damaged, the Purkinje layer (a part of the cerebellum that contains better-connected neurons than any other) develops abnormally, runting is more common, and pups die within weeks due to inadequate lung development. Additionally, higher presence of FOXP2 in songbirds is correlated to song changes, with downregulation causing incomplete and inaccurate song imitation in zebra finches. In general, evidence suggests that the protein is vital to neuroplasticity. There is little support, however, for the idea that FOXP2 is 'the grammar gene' or that it had much to do with the relatively recent emergence of syntactical speech.

Another controversial dichotomy is the question of whether human language is solely human or on a continuum with (admittedly far removed) animal communication systems. Studies in ethology have forced researchers to reassess many claims of uniquely human abilities for language and speech. For instance, Tecumseh Fitch has argued that the descended larynx is not unique to humans. Similarly, once held uniquely human traits such as formant perception, combinatorial phonology and compositional semantics are now thought to be shared with at least some nonhuman animal species. Conversely, Derek Bickerton and others argue that the advent of abstract words provided a mental basis for analyzing higher-order relations, and that any communication system that remotely resembles human language utterly relies on cognitive architecture that co-evolved alongside language.

As it leaves no fossils, language's form and even its presence are extremely hard or impossible to deduce from physical evidence. Computational modeling is now widely accepted as an approach to assure the internal consistency of language-evolution scenarios. Approximately one-third of all papers presented at the 2010 Evolution of Language conference rely at least in part on computer simulations.