Genetic basis of local adaptation
Uncovering the genetic basis of adaptive phenotypic traits is a key goal in evolutionary biology. We have used population-scale genome sequencing to address this question in a range of species. For example, we have uncovered chromosomal inversions that govern adaption to high-elevation habitats in honeybees, and identified genes that permit some honeybees to reproduce asexually. Together with collaborators, we have also identified chromosomal rearrangements that govern multiple adaptive phenotypes in the common quail, and genes that govern beak shape in the iconic Darwin's finches. We are currently investigating the genetic basis of climate adaptation in honeybees, aiming to predict their resilience to climate change.
Evolution of germline mutation and recombination rates
Mutation and recombination are fundamental processes that provide the raw material for evolution. It has become clear that their rates vary on multiple scales: among species, among individuals, and along the genome. We are interested in uncovering the genetic basis of this variation, and the evolutionary forces that govern rates of mutation and recombination. Much of this work uses the honeybee as a model, which has the advantage that males are haploid, allowing recombination and mutation events to be mapped onto the genome.
Evolution of somatic mutation rate
Mutations in somatic cells contribute to ageing and risk of cancer and other diseases. However, somatic mutations are difficult to detect accurately because because they are rare and usually restricted to single cells. Social insects are exciting models for understanding ageing because different castes (e.g. queens and workers) differ greatly in lifespan. We are studying the role of somatic mutations in the ageing process using insects models using high-fidelity genome sequencing.
We are experiencing a loss of biodiversity on Earth. In particular many studies have reported drastic insect declines in terms of species diversity and total biomass. Population genomics provides tools to accurately determine population health that can be used to accurately infer a number of parameters of relevance to conservation including past fluctuations in population size, adaptive potential, inbreeding and genetic load. We have applied these approaches to study genetic variation in bumblebees and solitary bees in order to predict vulnerability.
How new species form is a major question in biology to which we still do not have a complete answer. Reproductive isolation is required for speciation, but the processes that generate barriers to gene flow and not well understood. We also do not know how commonly speciation occurs in sympatry (when new species live in the same place) compared to allopatry (when they are separated by a geographic barrier). We have investigated these questions using genome sequencing in a variety of species. Bumblebees are interesting subjects for studying speciation due to the presence of evolutionary convergence in colour patterns. Our studies of bumblebees from the Rocky Mountains revealed the presence of a previously-unknown species and uncovered signals of speciation under gene flow.