Appendix 5—figure 1. Evolution of irreversible somatic differentiation at unequal cell differentiation costs.

(A-C) The fraction of 200 random composition effect profiles promoting irreversible strategy at various cell differentiation costs ($c_{s\mathrm{\to }g}$, $c_{g\mathrm{\to }s}$) at fixed maturity size $n\mathrm{=}\mathrm{5}$ (panel A), 10 (B), and 15 (C). Larger maturity sizes promote the evolution of irreversible differentiation across all cell differentiation costs. (D-F) The fraction of composition effect profiles promoting irreversible strategy at unequal cell differentiation costs $c_{s\mathrm{\to }g}\mathrm{/}{c}_{g\mathrm{\to }s}\mathrm{=}\mathrm{2}$ (panel D), $c_{s\mathrm{\to }g}\mathrm{/}{c}_{g\mathrm{\to }s}\mathrm{=}\mathrm{1}$ (E), and $c_{s\mathrm{\to }g}\mathrm{/}{c}_{g\mathrm{\to }s}\mathrm{=}\mathrm{0.5}$ (F). Even with unequal differentiation costs, the minimal maturity size allowing the evolution of irreversible differentiation stays roughly the same — ${\mathrm{2}}^{\mathrm{5}}\mathrm{-}{\mathrm{2}}^{\mathrm{6}}$ cells. Dashed lines indicate overlap between panels. The legend is the same as that in Figure 2A–C.