Fig. 4

‘Pharaoh Dynamics’, a reduction of mortality may enable mutant invasion under the assumption that spore production is a saturating function of virulence: \( z=\left(\frac{B}{v+x}\right)\left(v+d\right) \). The y-axis represents the difference (Δk = k2-k1) of mutant to the resident propagule mortality. The x-axis represents the difference (Δv = v2-v1) of the mutant virulence to the resident genotypes virulence. The grey area represents the cases where mutant invasion fitness r > 0 and mutants can invade, as opposed to the white area, where r < 0 and mutants go to extinction. The point denotes the resident genotype, at which virulence mutants can only invade if virulence mutations are accompanied with a reduced spore mortality. The following parameter values were used in this simulation: β = 0.00083; m = 0.03; u = 0.07; C = 100; l = 0.33; d = 0.03; k1 = 0.0075; v1 = 0.03; x = 0.15; B = 750 000