ABSTRACT
The rate of mutation, which is expressed as the amount of change to a specific mutant per gene per generation, to any specific hemoglobin or glucose-6-phosphate dehydrogenase (G6PD) variant is obviously much less than the usual mutation rates discussed in genetics textbooks for human loci. Those involving the G6PD deficiency are sex-linked, while the hemoglobin and thalassemia loci are autosomal. For many specific series of human populations, it is obvious that the clines for different loci are not the same. Since the populational phenomena, gene flow and gene drift, are the same for all loci, much of the differences in these clines must be due to the forces of selection and mutation, particularly if the clines are stable and hence presumably close to equilibrium. Natural selection is expressed by the concept of fitness. The range of fitness for the hemoglobin genotypes is perhaps as great as for any set of human loci.
