Fig 3. Optimal fragmentation modes for fecundity and survival landscapes (costless fragmentation).

A Life cycles achieving the maximum population growth rate for n = 4 under fecundity landscapes (i.e., d₁ = d₂ = d₃ = 0). In this scenario, fragmentation mode 2+2 is optimal for most fitness landscapes. B Life cycles achieving the maximum population growth rate for n = 4 under survival landscapes (i.e., b₁ = b₂ = b₃ = 1). In this scenario, fragmentation modes emitting a unicellular propagule (1+1, 2+1, 3+1) are optimal for most parameter values. We use ratios of birth rates and differences between death rates as axes because one can consider b₁ = 1 and min(d₁, d₂, d₃) = 0 without loss of generality (S1 Text, Appendix D). Shaded areas are obtained from the direct comparison of numerical solutions, lines are found analytically (S1 Text, Appendix F).