Ecological Genetics and Adaptation

Phenotypic Selection and Quantitative Evolutionary Responses in Immune Defence

Immune defence is considered as an important trait for organisms’ fitness as it eliminates harmful parasites. Therefore, a strong immune defence is often assumed to evolve as a response to parasitism. However, since immune defence is energetically costly to maintain and use, immune defence could be under stabilising selection. Although understanding the type and strength of natural selection on immune defence traits is in high demand for predicting their evolutionary responses, this information is still generally lacking in most natural systems. In this project, phenotypic selection and its relation to quantitative genetic variation in host immune defence traits (i.e. their expected evolutionary responses) is studied in natural populations of a freshwater snail Lymnaea stagnalis. The research concentrates on novel aspects of evolution of immune defence by examining, for example, the role of variation in infection risk and amount of genetic variation (estimated using neutral markers) among host populations, and different parasite types in these processes.