Abstracts (first author)
A new perspective on phenotypic plasticity: taking into account physiological mechanisms challenges classic plasticity theory
Phenotypic plasticity is ubiquitous but we have poor knowledge about the underlying mechanisms. The reason for this is that classical studies of phenotypic plasticity developed and tested theory only for organismal traits, such as morphology or life history. However, a new and upcoming perspective on plasticity encompasses also transcriptional and physiological flexibility in an effort to study the underlying mechanisms of phenotypic plasticity. This raises the question how plasticity at different organisational levels interacts to produce the optimal phenotype in different environments. Here, I will focus on the evolution of temperature-induced plasticity as a case study to show that greater phenotypic plasticity at one organisational level is associated with environmental canalization (lack of plasticity) at the other level. More specifically, my work shows that strong physiological flexibility in response to temperature correlates with low sensitivity to temperature for fitness traits. In this context, I will discuss costs of plasticity and the evolution of plasticity as a means of adaptation to changing thermal conditions. I will also identify candidate physiological pathways underlying variation in thermal response. Ultimately, taking into account the mechanism underlying plasticity will challenge the classical dichotomy between phenotypic plasticity and environmental canalization. Instead, the key question is at what level of biological organization phenotypic plasticity will evolve.