Payoffs and resource acquisition.

Game payoffs (top) and basal resource acquisition (bottom) of cooperators (blue circles) and defectors (red squares). Equilibrium predictions for payoffs of cooperators (solid orange line) and defectors (dashed purple line) are also shown (top). The equilibrium prediction for basal resource acquisition for cooperators and defectors is the same and is shown by a solid orange line (bottom). In (a) a mixed non-viscous (q = 1) population, in (b) a structured non-viscous population, in (c) a viscous (q = 0.1) mixed population, and in (d) a structured viscous population is shown. While in a non-viscous population, payoffs and basal resource acquisition of cooperators and defectors are the same, in a viscous population, cooperators obtain a higher game payoff and a lower basal resource acquisition due to the formation of homogeneous domains. Parameter values: L = 100, η = 0.4, d = 2, λ = 0.6, c = 0.1, and ν = 10−4.