Social insects like honeybees and army ants are cool, there is no denying it. But how, and why, do they exist at all? Sociality represents a major transition in evolution: understanding the mechanisms and function of social behaviour provides important insights into one of the most fascinating phenomena in the natural world.
Why do animals live together in societies? How did this evolve, and what are the mechanisms by which sociality and social behaviour arise? These are the questions we go to work thinking about. We are addressing these questions by taking a holistic view of social behaviour, from the differences in gene expression to the observable phenotypes we see in the field. Our favourite study organisms are wasps, bees, ants and termites.
Some of the questions our group are currently addressing include…
How do identical genomes produce phenotypic and behavioural diversity?
Social insects (bees, wasps, ants and termites) are great models for addressing this: a single genome can give rise to remarkably different phenotypes, in the form of queen and worker castes. Such differences are underlain by differential expression of shared genes. We are exploring the molecular basis of social castes in a range of eusocial wasps and bees through genome sequencing, RNAseq transcriptomic analyses combined with field-based behavioural ecology.
Wasps, in particular, display incredible diversity, in life-history, sociality and hunting behaviour. What is the molecular machinery underpinning these traits, and how do these innovations evolve? We are sequencing lots of wasp genomes to address these questions. These data are revealing the genes underpinning different types of behaviours in solitary and social wasps. Read more about this here.
Losses in behavioural plasticity and the evolution of altruism
A trade-mark of sociality is the evolution of specialist task-performers, who show life-time commitment to a specific role. Social insects are great study organisms for understanding how and why this happens. The prime example is the highly eusocial species, the honeybee, where each individual larvae retains the ability to develop as a queen or a worker up until a certain point in development, after which it is committed to one or the other for the rest of its life. Conversely, in simpler societies of insects, each individual retains the plasticity to change caste/phenotype throughout life. This means a female can start life off as a worker, but end up as a queen if the right opportunity arises. Loss of caste plasticity is an important way to view the mechanisms of social evolution.
We have been studying the limitations of plasticity and its implications on social evolution and behaviour in paper wasps from around the world. We are interested in determining to what extend all females are equal in their capacity to switch castes and become egg layers or foragers; are males really limited to being packages or flying sperm, or are they able to express some behavioural plasticity to improve their personal fitness; how and why do seemingly paradoxical behaviours such as nest-drifting behaviours evolve, and how does the environment influence the evolution of altruism?
What roles do wasps play in nature?
Social insects perform vital ecosystem services; for example, bees are important pollinators, ants disperse seeds and termites toil the soil. The role of wasps in ecosystems is less well understood, and this is one of the reasons why people generally dislike wasps. We lack estimates of the ecological and economic value of wasps to ecosystems and their contributions to planetary health, as pollinators, pest-controllers and provisioners.
As voracious predators that are abundant and diverse across the globe, wasps hold much promise as agents of biocontrol. Yet, this service has gone largely unappreciated. We are interested in exploring the potential that wasps hold as contributors to sustainable pest-control, especially for farming communities in developing countries.