Sportive Thoughts

FOXP2 is probably the single most important gene a non-biologist with an interest in language should be interested in. Discovered in 1998, FOXP2 has now been bred into laboratory mice by the Max Plank Institute for Evolutionary Anthropology. (Max Plank, by the way, is under the co-direction of Michael Tomasello, a comparative psychologist whose work on language offers a strong alternative to Chomskian linguistics.)

First some background. The gene is essential in embryonic development; all mammals have it and depend on it for proper formation of the lungs, stomach and brain. As with many genes, there are slight variations between the species. Hence, humans have one version of FOXP2 and mice have a different version. As it happens, a non-fatal mutation in the human version causes specific deficiencies in linguistic ability--a discovery that led biologists to believe that the human gene enables necessary brain developments that allow for speech. So they carefully replaced the version naturally found in mice with the human FOXP2 to see what happens.

The result of this experiment is fascinating, and Nicholas Wade does a superb job in explaining the outcomes:

Despite the mammalian body's dependence on having its two FOXP2 genes work just right, Dr. Wolfgang Enard's team found that the human version of FOXP2 seemed to substitute perfectly for the mouse version in all the mouse's tissues except for the brain.

In a region of the brain called the basal ganglia, known in people to be involved in language, the humanized mice grew nerve cells that had a more complex structure and produced less dopamine...humanized baby mice, when isolated, made whistles that had a slightly lower pitch, among other differences.

That "slightly lower pitch"--though one might be unexcited upon first hearing of it--has enough scientific relevance to show that there are observable differences in the human genome which are by themselves responsible for language.

It's truly mind boggling, especially if you think about it as follows. Imagine we discover all the genes necessary for human speech. Theoretically, we would then be able to trace the activation of those genes to specific tissue development, and from there we could definitively say what structures in the brain are responsible for the production of speech, and how. We could then infer the functional mechanisms of language, and possibly build machines to mimic those functions.

All that is only sci-fi for now; but as of today we know with certainty that FOXP2 is the first of many new bio-linguistic discoveries to come.

Image from: St. Clair, R. et al "The Basal Ganglia and Serial Order of Communicative Signs"