Microbes have amazing social lives, often at our expense.
Microbes are master manipulators of their environment. Working together in highly social collectives, microbes produce a diverse array of extracellular chemicals and building-blocks to make their environment more favourable for their growth and survival. However, because these secreted factors are shared (i.e. they are public goods, external to individual microbes), microbes are vulnerable to social conflict. ‘Cheats’ that exploit too much, or produce too little of these resources, or manipulate their neighbours, may prosper at the expense of more cooperative individuals. In turn, the local prevalence of cooperators will have important consequences for the nature and degree of environmental change engineered by the microbial ensemble, and consequently for ensemble productivity. When the local environment is a host, ‘environmental change’ is more often referred to as virulence (damage to host), and productivity can be linked to transmission.
We aim to develop and test novel theory on the evolution of sociality and virulence, rooted in an empirical understanding of microbial social interactions on a molecular and cellular level. Building on empirical insights into microbial social interactions, we generate and test theoretical predictions of relevance on both the host (pathology) and population (epidemiology) levels, informing medical and public-health decision-making on both short-term (ecological) and long-term (evolutionary) scales. The output is also interpreted in the light of basic questions in evolutionary ecology, such as ‘why cooperate?’ and ‘why kill your host?’