The evolution of condition-dependent mutation rates

Description

Mutation provides novelty, and thus the raw material for selection to act on. Previous evidence has shown that increased mutation rates can indeed lead to higher evolutionary rates and faster adaptation. However, when organisms are well adapted, most mutations are likely to be maladaptive – depending on the current degree of adaptation, increased mutation rates may thus be either beneficial or harmful. Particularly interesting in this context is stress-induced mutagenesis: a condition-dependent upregulation of mutation rates under stress. As stress may be a signal formal adaptation, stress-induced mutagenesis may allow mutations to occur predominantly in times of maladaptation, i.e. when they are more likely to be adaptive. Whilst this has received much attention in empirical work, comparatively few theoretical models have explored this topic.Here, we use individual-based simulations to investigate the evolution of condition-dependent mutation rates in fluctuating environments, where environmental change repeatedly leads to maladaptation and thus to stress. We show that condition-dependent mutation rates are indeed adaptive in this scenario – however, they only evolve under specific circumstances. We explore how this relates to initial conditions, selection strength, genome structure and patterns of environmental change. Overall, we discuss the relevance of condition-dependent mutation rates for evolvability, i.e.for the capacity for adaptive evolution.

Period	28-Jun-2022
Event title	Netherlands Society for Evolutionary Biology Meeting 2022
Event type	Conference
Conference number	5
Location	Ede, NetherlandsShow on map
Degree of Recognition	International