Stochasticity, Selection, and the Evolution of Cooperation in a Two-Level Moran Model of the Snowdrift Game

Figure 5

Simulation results of within-group Moran process. Each panel shows the evolution of cooperation in each of nine different groups over the course of 100 generations within each group. Within a panel, groups are all the same size but vary in their r-values. The range of r-values that were simulated was , where b was set to 10 and c ranged from 1 to 9 in increments of 1. The jagged lines represent the frequency of cooperators in a group. As r-values get larger, the equilibrium frequency of cooperators gets smaller; thus, is black, while is teal. Each horizontal line of a corresponding color represents the equilibrium frequency of cooperators for that r-value given by (7).

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