<p>Summary of simulation parameters for Figs 2-4 and S1-S5 Movies.</p>

Parameters kept fixed are listed by a single value, other parameters are listed as ranges. The average number of sensitive cells S per deme at t = 0 () equals the metapopulation’s carrying capacity at t = 0 minus the constant threshold value for cooperation, , which depends on whether the system begins in a harsh or mild environment, (S1 Appendix Sec. 3.1). See Fig J (and Fig C) in S1 Appendix for the extended range in and , and S1 Appendix Sec. 5.5 for the discussion of results obtained on a periodic one-dimensional lattice (cycle) of length L = 100.