Abstracts (first author)
Introducing diversity? Variable strategies in new environments and consequences for infection dynamics
Invasion of new habitats is an important natural process known to require phenotypic plasticity of migrating individuals to cope with their new environments. It is poorly understood though how the potential for plasticity among individuals changes during an invasion. Increased trait variation among phenotypes of individuals experiencing a new environment could indicate the use of different strategies for coping with stress and a disruption of previously adaptive patterns. On the other hand, more uniform patterns in groups subjected to environmental changes would suggest a homogenizing effect of high stress levels. We investigate this question with a particular focus on immunity and immune related genes. The three-spined stickleback (Gasterosteus aculeatus) is known for its repeated and parallel invasion of different freshwater habitats from marine environments throughout the Northern hemisphere. In a lab-based study, we mimic transition from brackish water to freshwater and vice versa. Taking into account multiple biological levels as well as standing genetic variation and phenotypic plasticity, we explore the effects and patterns of variation caused by habitat invasion. Furthermore, we subject fish to experimental infection with the monogenean parasite Gyrodactylus gasterosteus and investigate differences in parasite susceptibility entailed by the mimicked invasion.