Spatial snowdrift game in heterogeneous agent systems with co-evolutionary strategies and updating rules*
Xia Hai-Jiang, Li Ping-Ping, Ke Jian-Hong†, Lin Zhen-Quan
       
Snapshots of spatial patterns of cooperators and defectors for different cost-to-benefit ratios: (a) and (b) r = 0.12 and (c) and (d) r = 0.82. Besides, panels (a) and (c) are original scattergrams of the strategy and type distribution, which consist of A -type cooperators (blue), B -type cooperators (black), A -type defectors (red), and B -type defectors (yellow); while, panels (b) and (d) are referenced scattergrams of the strategy distribution without regard to the agent type, which consist of cooperators (dark green) and defectors (orange). Here, the other model parameters are the same, ν T = 3 and f a 0 = 0.5. Obviously, almost all of B -type agents will occupy the D -strategy sites in the chessboard-like pattern of strategies; while in the small- r case, a few of the B -type agents might also occupy the inner sites of “ C lines” (dark green) embedded in the chessboard.