developmental bias - genetics - epigenetics
In the traditional framework of evolution, mutations are regarded as the ultimate source of genetic variation and natural selection as the filtering process determining which variants are conserved for future generations and which are not. Effects of the environment as well as developmental processes on the way genotypes translate to phenotypes are regarded random and not affecting evolution. However, the developmental system organisms are subject to is also shaped by evolution, therefore the way genes and the environment affect the phenotype are coordinated and can be directional and even functional. The evolutionary trajectory a species takes is therefore affected by development. This developmental bias is often marginalized as anecdotal. In this project we will use meta-analysis to investigate how widespread developmental bias is, whether cryptic genetic variation — which is released in novel environments — is non-random and how phenotypic plasticity plays a role in these processes. This project is part of the Extended Evolutionary Synthesis research program.
social networks - genetics - epigenetics
The amounts of genomic and phenotypic data collected in ecology and evolution are surging. The collection of more and new types of data require new analytical techniques; generalized linear mixed models do not always offer the right tools and therefore more flexibility is needed. Among other benefits, Bayesian statistical techniques offer tremendous flexibility of model structure and the integration of uncertainty. I use Stan, a general-purpose Bayesian inference library and language, which utilizes novel algorithms to efficiently deal with highly dependent data structures. I develop and use novel model structures to analyze high dimensional dependent data structures to for instance infer extra-genetic or indirect genetic effects.
4/2018: Presentation. Inference in ecology and evolution beyond generalised linear mixed models. Presentation at Bayes@Lund 2018 conference. Presentation at a conference on applied Bayesian statistics, for researchers and professionals of all disiplines working with or interested in Bayesian methods.
The transgenerational tolerance of Daphnias to cyanobacteria
epigenetics - life history
When exposed to cyanobacteria, daphnids are known to build up resistance to microcystin — a toxin produced by cyanobacteria — over (clonal) generations. This could be a positive maternal effect in which mothers prepare their offspring to the environment they will encounter, by for instance adding particular proteins to the eggs. However, a toxic environment also affects the growth of mothers, which ultimately affects the amount of resources they can provide to their offspring and therefore the offspringâs fitness. In this project we investigate the interplay between those two (positive and negative) maternal effects. We investigate the effect of different levels of toxicity on different genotypes and life phases. As part of this project we also test whether DNA methylation can act as a mechanism of inheritance for this resistance to microcystin.
Radersma R, Hegg A, Noble DWA, Uller T, 2018. Timing of maternal exposure to toxic cyanobacteria and offspring fitness in Daphnia magna: implications for the evolution of anticipatory maternal effects. Ecology and Evolution. Early view: .
Paredes U, Radersma R, Cannell N, While GM, Uller T, 2016. Low Incubation Temperature Induces DNA Hypomethylation in Lizard Brains. Journal of Experimental Zoology Part A: Ecological Genetics and Physiology. 325: 390-395.