Inducible defenses and environmental tolerance: A model system for the evolution of phenotypic plastic responses

Short-term dynamics and the long-term evolution of predator-prey-systems can be strongly influenced by inducible defenses. The objective of this sabbatical proposal is to develop models and theory on inducible defenses using the concepts of environmental tolerance and adaptive phenotypic plasticity. The model should be able to predict plastic responses depending on the biotic and abiotic environmental conditions. The focus will be on reversible inducible defenses, e.g. for Daphnia fast reversible behavior changes in vertical migration, reversible physiological states like alertness, slowly reversible morphological defenses like helmets and neckteeth formation, and only partly reversible life history decisions. These reversible defenses appear simultaneously and in addition to constitutive defenses. The goal is find general conditions for the evolution of reversible plastic responses and to predict the intensity of each induced defense depending on the predation regime and its variability.