Fig. 2: Adding mutation restores extinct strategies, reproducing outcomes from large populations.
From: Mutation mitigates finite-size effects in spatial evolutionary games
The figure shows the frequencies of cooperators (C, blue), defectors (D, orange), and loners (L, green) over time in the spatial optional public goods game on a network of size N = 2002. The top panels (a, b) correspond to a synergy factor of r = 2.02 and bottom panels (c, d) to r = 4.6. The left panels (a, c) display results without mutation, where certain strategies occasionally go extinct due to finite-size effects. The right panels (b, d) show outcomes with mutation introduced at a fixed rate of μ = 10−6, which reintroduces extinct strategies and restores stable coexistence. Horizontal dashed lines represent the stable frequencies of each strategy observed in large populations (N = 20002), as reported in ref. 32.
