Is Plasticity facilitating or impeding Adaptive Evolution?

Again. I know that we discussed this topic not too long ago, but I feel that the issue is not satisfyingly resolved and I got a bit stuck with it... Therefore, I would like to discuss a paper by Dayan et al., 2015, Mol Ecol, that tackles this controversy. The authors are trying to assess the role of phenotypic plasticity in evolution by comparing gene expression patterns in killifish (Fundulus spp.). They are contrasting divergent populations and test to what extent their ability to acclimate to different temperatures varies. They address questions such as whether plasticity and genetic divergence operate in parallel on the same set of genes, or what the magnitude of the plastic response is compared to the evolved response. I think these are exciting questions and I hope you enjoy reading the paper and discussing their ideas (don't get scared by the stats!).

Link to the paper is here and there is also a little commentary on it here.

When: Tuesday, 16th of Feburuary 2016, 10 am
Where: Argumentet

Title: Phenotypic plasticity in gene expression contributes to divergence of locally adapted populations of Fundulus heteroclitus

Abstract: We examine the interaction between phenotypic plasticity and evolutionary adaptation using muscle gene expression levels among populations of the fish Fundulus heteroclitus acclimated to three temperatures. Our analysis reveals shared patterns of phenotypic plasticity due to thermal acclimation as well as non-neutral patterns of variation among populations adapted to different thermal environments. For the majority of significant differences in gene expression levels, phenotypic plasticity and adaptation operate on different suites of genes. The subset of genes that demonstrate both adaptive differences and phenotypic plasticity, however, exhibit countergradient variation of expression. Thus, expression differences among populations counteract environmental effects, reducing the phenotypic differentiation between populations. Finally, gene-by-environment interactions among genes with non-neutral patterns of expression suggest that the penetrance of adaptive variation depends on the environmental conditions experienced by the individual.

...and yes, there will be fika :-)