Research

We work on questions of phenotypic and genomic evolution.

A lot of our work revolves around the question how the genetic encoding of traits constrains their evolution. We address this question mainly in the context of adaptive conflicts between the sexes. Males and females share a common genome and homologous traits in the two sexes are usually genetically coupled to at least some degree. This poses a problem whenever the sexes’ reproductive roles diverge and shared male and female traits aresubjevct to opposing selection pressures. The combination of genetic coupling and divergent selection pressures then sets the scene for adaptive conflicts between males and females, where ‘sexually antagonistic’ alleles that benefit one sex but harm the other can be favoured by selection. The conflict can only be resolved by mechanisms that uncouple male and female traits, such as such as sex-specific gene expression. In their absence, sexual antagonism causes maladaptation and a genetic load in both sexes and can contribute to the maintenance of quantitative genetic and allelic sequence variation.

Sexually antagonistic variation in fruit flies

The main aim of our work is to better understand the function and evolution of sexually antagonistic variation. To do so, we use different approaches (GWAS, experimental evolution) in fruit flies to identify sexually antagonistic loci. We characterise candidates based on functional information and validate them using genome editing. In parallel, we use computational population genomic approaches and public sequence data to study their dynamics and assess their contribution to genome-wide genetic variance. This work aims to infer the presence of balancing selection maintaining antagonistic polymorphisms and shed light on the timescales over which they are maintained. In combination with scans for balancing selection, we are also inetersted in learning about the role that sexual antagonism plays in the maintenance of genetic variation more generally.

Our empirical work on sexual antagonism is complemented by evolutionary theory. A number of collaborations with theoreticians (Ewan Flintham and Charles Mullon at the University of Lausanne and Tim Connallon at Monash University) explore specific questions related to our work, such as the conditions under which sexual antagonism and other mechanisms generate stable polymorphisms and those under which such balanced polymorphisms are detactable using current inference methods.

The genetic architecture of stress tolerance in fission yeast

A parallel strand of experimental research investigates the evolution of genetic correlations and plastic genotypes more generally. Sexual dimorphism and sexual antagonism is conceptually related to other instances where genomes do or fail to express different phenotypes in response to genetic or environmental cues. We are interested in the evolution of genetic correlations among traits and novel regulatory mechanisms that allow plasticity. In collaboration with Jürg Bähler, we study the genetic architecture of stress tolerance and how the genetic correlation among traits is shaped by the interplay between mutational input and selection.