Adaptation to the environment is critical for the survival of individuals and the persistence of species. To understand this process, we must identify the genetic targets of natural selection and establish how they relate to potential drivers of selection. Doing so informs us about the origin and maintenance of organismal diversity, but is also essential to predict how species will cope with rapid change in their environment.
Studying the genetics of adaptation is now possible, through the analysis of rapidly accumulating sequence data. Population samples of whole genome sequences allow us to identify the signatures of natural selection in the genome. Together with environmental data, this information can be used to identify the potential evolutionary drivers.
This PhD project proposes to perform population genomic analyses of this kind to learn how abiotic and biotic factors drive genomic evolution. We are particularly interested in balancing selection, where genetic diversity is actively maintained. This can occur for example due to overdominance, frequency-dependent selection (typically from interactions with pathogens) or fluctuating selection (e.g. because of environmental variation in time and space). An additional and particularly interesting mechanism is sexual antagonism due to genomes facing different selective demands as they pass through males and females over generations.
We will initially focus on worldwide populations of the fruit fly. Drosophila provide a good model for understanding adaptation, as their genetics are well understood and they are amenable system for experimental validation. We will then investigate to what extent results obtained are transferable to other organisms.