ENVIRONMENT CHANGE, GEOGRAPHIC MIGRATION AND SICKLE-CELL-ANEMIA

The classic model describing the interaction between sickle cell anaem ia and malaria is one of the most notable achievements of population g enetics. Nevertheless, only panmictic populations in steady environmen ts have been studied theoretically to date. In this paper, environment change and geographic inhomogeneity are introduced. The rate of decre ase of mutation after environment improvement is obtained. The kinetic s of the spread of disease after the initial mutation, together with t he genetic composition profile near the borders of malaria areas, are calculated. The results are compared with the empirical data on the mu tation level in African and African-American populations. It is shown that the spread of disease and decrease in mutation are highly asymmet ric: the mutation level increases exponentially and decreases much mor e slowly (as a power function). The mathematical and biological reason s for this behaviour are discussed.