Genes and tone languages, yet again
Below is a guest post by Bob Ladd.
Long-time readers of Language Log may recall a couple of posts from 2007 (here and here) about a possible link between population genetics and tone languages. That year, Dan Dediu and I published a paper in PNAS showing that there’s a significant geographical correlation between the distribution of tone languages and the distribution of older and newer variants (alleles) of two genes known to be involved in brain development, ASPM and Microcephalin 1. For ASPM in the Old World (where tone languages are found predominantly in sub-Saharan Africa and Southeast Asia), you can eyeball the correlation on the map below: the lighter the dot, the rarer the new variant of the gene. Our PNAS paper put this eyeballing on a reasonably sound statistical basis.
Read the rest of this entry »