Adaptive parental effects in predictable and unpredictable environments: Integration of experimental evolution, neurogenetics, physiology and theoretical modelling

In order to predict the adaptive capacity of species in our rapidly changing world, accurate models for evolutionary change are needed, based on the mechanisms underlying such change. Here, we propose to investigate a hotly debated pathway for adaptive plasticity – non-genetic heritability via parental effects. If parental and offspring environments are correlated, then parental phenotype can provide developing offspring with information regarding their future environment and trigger a matching developmental trajectory in the offspring. However, the role of parental effects in adaptive plasticity is poorly understood due to 1) lack of evolutionary theory that incorporates non-genetic determinants of development; 2) experimental studies that vary transgenerational environmental correlations and quantify parental effects; 3) lack of knowledge of the underlying genetic architecture and physiological mechanisms.
In this project we will study parental effects from all three angles by integrating theoretical modeling, experimental evolution, (neuro) genetic analysis, and physiological studies, building on experimental data and the genetic toolbox of Drosophila melanogaster. Flies will be subjected to different regimes of between-generation temperature transitions (zero, positive or negative correlations). We will measure the contribution to adaptation of parent and offspring through a fully factorial match-mismatch design. The genetic basis of evolved parental effects and offspring plasticity will be studied with an evolve-and-resequence approach, complemented by candidate gene approach and physiological analyses related to heat shock proteins and egg composition. Building on our recent theoretical work, we will construct evolutionary models specifically tailored to Drosophila life history, the experimental environmental fluctuations, and the genetic architecture and mechanisms of parental and offspring traits uncovered by our study. Thus, by an innovative integrative approach we will critically advance our understanding of transgenerational adaptive plasticity and quantify its importance for adaptation in a rapidly changing world.