Evolutionary Biology
Evolutionary Genetics
The field of evolutionary genetics is concerned with understanding evolutionary changes over relatively small time scales ('microevolution'). We are particularly interested in traits that are involved in sexual selection. Mate choice and intrasexual competition are the two key components of sexual selection and together constitute a driving force that contributes to biological diversity. Traits of interest include morphological ornaments (such as the 'Popeye arms' of Gomphocerus sibiricus), acoustic signals (such as insect song), behavioral traits (such as display behaviors) and fitness traits (such as laying dates in birds). We employ a range of methods that include pedigree analyses as well as molecular genetics techniques.
Quantitative Genetics
Important insight into evolution can be gained from rather simple data. One very powerful framework for doing so is called quantitative genetics. Two types of information are sufficient for predicting short-term evolution: data on the heritability of traits and data on the strength of selection. The two components can be estimated from data on phenotypes from related individuals and data on reproductive success. The correlation between trait values and reproductive success in a population allows estimating the strength of selection, while the similarity of phenotypes between relatives allows estimating the amount of genetic variation within a population. Heritable variation is required for evolutionary change to occur.
We are particularly interested in cases where evolution does not follow the predicted patterns. For example, the genetic architecture of heritable variation might constrain evolution if traits under directional selection are genetically correlated to traits under stabilizing selection. But populations might also fail to respond to apparent selection when selection is acting on the environmental component rather than the (genetically) heritable component of trait variation. On the other hand, apparent response to selection might also be sufficiently explained phenotypic plasticity, i.e. the ability of animals to adjust their phenotype to the current environment, without any need for genetics changes of allele frequencies in a population.