Info

0.2 0.4 0.6 0.8 Frequency of the A allele (p)

Figure 6.10 Mean fitness in a population (w) and change in allele frequency over a single generation (Ap) as a function of allele frequency for directional selection. Directional selection reaches allele frequency equilibrium at either fixation or loss, the point of highest mean fitness. Positive values of Ap (above the dashed line) indicate that allele frequency is increasing under selection while negative values of Ap (below the dashed line) indicate that allele frequency is decreasing under selection. The change in allele frequencies is faster when average fitness changes more rapidly (the slope of w is steeper). Here wAA = wAa = 1.0 and waa = 0.8 for selection against a recessive phenotype and wAA = wAa = 0.8 and waa = 1.0 for selection against a dominant phenotype.

0 0

Post a comment