* Laboratoire de Génétique et Biométrie
Département d'Anthropologie et Ecologie, Université de Genève, Geneva;
† United Nations Environment Programme,
Global Resource Information Database (UNEP/GRID), Geneva; and
§ Laboratoire d'Anthropologie Biologique, Musée de l'Homme, Paris.

abstract

The human genome is composed of about hundred thousand different genes. Because of stochastic processes occurring during the transmission of genes from one generation to the other, each of these genes has its own more or less independent history. However, as shown in the eighties with the pionneering studies of Luca Cavalli-Sforza, Robert Sokal and their collegues, the affinities of human populations based on their genetic variability generally correspond with the classification of the languages spoken by these populations into linguistic families. A strong correlation of the processes of genetic and linguistic differentiation is thus suggested (see Cavalli-Sforza et al. (1988). Proc Natl Acad Sci USA 85: 6002-6006, and Chen et al. (1995). Hum Biol 67: 595-612).

There are two components of the genome whose story will also depend on the particular history of one sex: these are the non-recombining Y chromosome, strictly paternally transmitted, and the mitochondrial genome (mtDNA) strictly maternally inherited. Contrasting the genetic variability of these two genomic components has been shown to be usefull to infer resemblances or differences in the history of males and females (for a general review, see e.g. Owens and King (1999). Science 286: 451-453).

In a previous study, we compared the genetic and linguistic affinities of a small set of human population samples, as seen through the analysis of a male-specific genetic system (on the Y chromosome) and a female-specific one (on mitochondrial DNA). We observed that language classification was more correlated to the genetic affinities of populations based on the Y chromosome than on mitochondrial DNA. This result suggests that, to the end of reproducing, women may have moved more than men through linguistic borders, and doing so, women may have preferentially transmitted the language of the fathers to their progeny than their own language. We resumed this general pattern by suggesting the hypothesis that, on the long term, language is paternally transmitted (Poloni et al. (1997). Am J Hum Genet 61: 1015-1035).

However, the results of this previous analysis were based on a rather small set of population samples. Moreover, the process of human populations genetic differentiation is also correlated with the geographic distance that separates the populations. Language classification and geographic distance can thus be considered as two predictor variables of the genetic affinities among populations, but these two predictor variables are not independent since distinct linguistic families usually also extend on distinct geographic areas. In our previous work we estimated the proportion of populations genetic differentiation that is explained by language classification independently from geography. However, geographic distances were computed very roughly, so that they didn't represent very realistic migration routes between populations.

Thus our aim, here, is to re-examine the relation between genetics, linguistics and geography in males and females through a new analysis scheme, that is: (1) by extending our previous analysis to more population samples; (2) by testing alternative linguistic classifications; (3) by using a new procedure that takes into account different environmental variables such as topography, hydrography and vegetation to model more realistic migration routes between populations.

 Conference site: http://www.infres.enst.fr/confs/evolang/