Abstract
Geographic variation in selection pressures creates the potential for intraspecific divergence and ecological speciation. However, we are still far from fully understanding the mechanisms that underlie ecological speciation. Three major areas of research have been ignored so far. First, plasticity in the traits under divergent selection has been thoroughly neglected and thus the role of plasticity in ecological speciation remains unknown. Second, the genetic architecture of traits under divergent selection is poorly known, but theoretical work shows this is a crucial factor in determining the conditions under which ecological speciation can occur. Third, the emphasis has been on morphological traits, whereas life-history traits are known to be closely related to reproduction and therefore potentially of more importance for ecological speciation. The proposed project addresses these gaps in current research by studying divergence in temperature plasticity across habitats and its consequences at the population level. It is my conviction that the role of phenotypic plasticity in the process of speciation will become a major issue in evolutionary biology in the coming years. Therefore, I choose to study population divergence in temperature plasticity of juvenile growth rate, and its genetic basis in the springtail Orchesella cincta, with an evolutionary perspective addressing the consequences for ecological speciation. The research will use 1) laboratory and field experiments to study the effect of plasticity on population divergence; 2) molecular techniques such as suppression subtractive hybridization and linkage mapping to study the genetic architecture of temperature plasticity; and 3) spatially explicit modelling to demonstrate the wider applicability of my findings. In addition, collaboration with three international research institutes will incorporate their specific expertise into the project. I aim to initiate a new line of research in the fast-moving fields of molecular ecology and ecological speciation.
Netherlands