Figure 1.

Equilibrium frequency of the fully functional wildtype form of a parasite as a consequence of the number of parasites within the human host (its clonal population size) and number of parasite erythrocyte cycles (each of which lasts two days) which elapse prior to transmission. Computational details are as described in the main text i.e. dysfunctional mutation rates = 10^-5, beneficial mutation rates = 10^-8, and the selective disadvantage of the mutation is 10% per erythrocytic cycle.