A major reference for the analysis of geographic variation in human gene frequencies is the tabulation compiled by Mourant et al. (1976). It provided also the stimulus for developing quantitative methods of displaying and testing gene frequency distributions (Piazza et al. 1981a). They have been applied in detecting possible effects of evolutionary forces (Menozzi et al. 1978; Piazza et al. 1981b). The aim of this note is to give a summary of some results obtained with these techniques.