Stress-induced mutagenesis - increased mutation rates in stressed or maladaptated individuals - has been demonstrated in numerous species of bacteria, as well as in yeast and human cancer cells. However, the role of stress-induced mutagenesis in evolution is not yet clear.
We model a population crossing an "adaptive valley" with and without stress-induced mutagenesis. We show that in contrast to constitutive mutagenesis, stress-induced mutagenesis increases the population adaptation rate without reducing the population mean fitness.
Our results support the hypothesis that stress-induced mutagenesis is an adaptive trait and provide quantitative predictions on the expected difference between various mutational strategies in adaptive evolution.
