Seminar: Michael Hunter

How ecological interactions shape bacteriophage evolution

Bacteriophages (phages) are viruses that infect bacteria, and their evolutionary dynamics are shaped by interactions with their hosts, with other phages, and with their environments. Understanding how these ecological interactions influence evolutionary outcomes is important for fundamental questions in viral ecology and evolution, as well as for applications such as phage therapy. In this seminar, I will discuss three studies investigating how ecological interactions shape phage and bacterial (co-)evolution. I will first show how interactions between phages and bacteria can alter viral dispersal and shape the maintenance of genetic diversity during spatial expansion. Next, I will describe how interactions between phages, through superinfection exclusion, can favour short-term competitive success while limiting long-term adaptation. Finally, I will present experimental work showing how environmental osmolality changes the course of phage-bacteria co-evolution by favouring distinct bacterial resistance strategies. Together, these studies show how spatial structure, viral interactions, and environmental conditions can shape phage and bacterial (co-)evolution.