Social wasps are important ecosystem servicers as predators of insect pests and ‘back-up’ pollinators in disturbed habitats. However, like other insects, they are on the decline in the UK. An understanding of how and why social wasp populations have changed over the last hundred years, when land-use has changed significantly, is essential in order to better manage and conserve these important (yet under-appreciated) insects. This studentship will determine how populations have changed over time and identify any genes or genomic regions under selection in the common yellow jacket, Vespula vulgaris. The student will use high coverage next-generation sequencing to sequence DNA from historic samples in Natural History Museum and from current samples collected across the UK by the Big Wasp Survey project (www.bigwaspsurvey.org). Using linkage disequilibrium for pairs of loci of different genomic locations (thus of different recombination rates), the trajectories of effective population size over about 200 generations before the current and ancient sampling points can be estimated. The consistency of estimates for the overlapping period from both ancient and current samples acts as a check of the reliability of the analyses. Current population structure, including the number of UK wasp populations, their genetic differentiations and migration rates, can be inferred from the genomic data of the current samples. The temporal changes in allele frequencies between ancient and current samples can be used to identify loci under selection and to estimate the corresponding selection coefficients.