Figure 8.
Importance of the speed of change. Reducing the amount of available growth factor increases the threshold from h1 = 0.4 to h2 = 0.8; d = 3, c = 0.01, s = 20. If the change occurs immediately (in the following generation), the +/+ type goes extinct; if the change takes 100 generation per cell to be completed, the population moves to a new equilibrium with a higher fraction of +/+ cell and higher fitness (the contrary of the desired effect); if the change takes 20 generations per cell, results are intermediate.