Fitness of damage repair and segregation strategies with increasing damage accumulation rates. The fitness of both the completely symmetric (S, blue) and completely asymmetric (A, red) damage segregation strategies increased when combined with repair (solid lines with no repair, N, dash-dotted lines with optimal repair, O). As expected, optimal repair was always fittest, and in this combination symmetric was best. Fitness differences were much smaller when damage was inert (A, C) than when it was toxic (B, D). Note that in the constant environment (A, B), single-strategy fitness is determined by specific growth rate, while in the dynamic environment (C, D), it is determined by the ability to persist at the lowest substrate concentration. Error bars show standard deviations (n = 400). concn, concentration.