Fig. 11.1 I Maps showing discordant variation in the distribution of 

 blood group genes (above, gene A; below, gene B) in aboriginal human 

 populations. Degree of shading indicates areas occupied by populations 

 with approximately the same frequency for the gene in question. ( From 

 Mourant, 1954, The Distribution of Human Blood Groups, Blackwell 

 Scientific Publications, Oxford; F. A. Davis Company, Philadelphia.) 



