Fig. 2.

Model outputs illustrating variable outcomes of evolution of stress resistance and consequences for age-dependent mortality (b), age at death, and lifetime reproductive success (LRS) under three scenarios of environmental stress exposure, as labelled. Outputs were generated from a single simulation of each scenario. Parameter means (solid lines) and the 5th and 95th percentiles (dashed lines) are plotted across 500 consecutive generations. In this example, parameters were fixed as follows: rate of increase of extrinsic stressors = 0.03/generation; heritability = 0.8; and, maximum stress resistance = 6.