Joanna Mountain: Stanford University Department of Anthropological Sciences

In the 1960’s linguist Joseph Greenberg classified all languages spoken primarily in Africa into four families. One of those families, Khoisan, includes not only the languages of the Khoe and San peoples of southern Africa, but also the languages of the Hadzabe and Sandawe peoples of Tanzania. Primary criteria for including languages in the Khoisan family were the presence of click-consonants and the absence of evidence of recent borrowing of such clicks. In 1998 we set out to compare the genetic variation of the Hadzabe with that of a San population of Namibia in order to better understand both the linguistic and population history of this broad region of Africa. Our analyses of mitochondrial DNA and Y chromosomal variation indicated deep genetic divergence between these click-speaking populations, with implications for the evolution of the click languages. More recently Sarah Tishkoff of the University of Maryland and I have teamed up to investigate how the Sandawe fit into the picture. Intriguingly, even the geographically proximate click-speaking populations, the Hadzabe and Sandawe, are relatively divergent in terms of genetic variation. Furthermore, the haplotypes of some Sandawe individuals indicate a deep but unique link with the San. The correspondence with the conclusions of linguist Bonny Sands is striking.
http://www.bec.ucla.edu/papers/Mountain_3-7-05.pdf