Figure 3
From: Spatial heterogeneity, frequency-dependent selection and polymorphism in host-parasite interactions
Outcome of GFG coevolution in a two-deme model linked by migration, in relation to the values of parameters in deme 2 (top lines for u 2 , b 2 and s 2 ) and migration rates (host and parasite migration rates are equal, m P = m H ). The behavior of the system was investigated for fixed parameters in deme 1: u 1 = b 1 = 0.05 and s 1 = 0.2), and was consistent for three initial frequencies of the resistant and virulent alleles (R 0 = a 0 ): 0.05; 0.1 and 0.2. When the migration rate had values below the black diamond, or above the white diamond, the host susceptibility and parasite virulence alleles became fixed. At intermediate migration rates, stable polymorphism in host and parasite populations was observed (for simplicity, c = 1).