Data from: Biotic interactions govern genetic adaptation to toxicants

The adaptation to a new environment through microevolution has been shown to accelerate in the presence of unrelated environmental stressors. However, the consequences of interactions between different stressors for microevolution have not been considered. Moreover, the microevolutionary effects of environmental stressors have been studied for the genetic recovery after pesticide exposure, but not for the actual genetic adaptation during pesticide exposure. Here we show that stress through intraspecific competition accelerates microevolution because it enhances fitness differences between adapted and non-adapted individuals. In contrast, stress through interspecific competition or predation reduces intraspecific competition and thereby delays microevolution. In mosquito populations (Culex quinquefasciatus) exposed to the pesticide chlorpyrifos, non-selective predation through harvesting and interspecific competition with Daphnia magna delayed the selection for individuals carrying the ace-1R resistance allele. Under non-toxic conditions, susceptible individuals without ace-1R prevailed. Likewise, predation delayed the reverse adaptation of the populations to a non-toxic environment, while the effect of interspecific competition was not significant. Using a simulation model, we further identified how microevolution is generally determined by the type and degree of competition and predation. We conclude that the manipulation of species interactions within communities may potentially be used to manage the development of resistance to toxicants.