Olaya Garcia-Rendueles, who just joined our lab, got a grant from FRM to study the evolution of bacterial capsules. Bacterial capsules are well-known major virulence factors varying greatly within and across species. Yet capsular prevalence, mechanisms of variation and cost-benefit trade-offs (in terms of virulence and metabolism) have not been thoroughly addressed from an evolutionary perspective. Olaya’s interdisciplinary approach will integrate multiple scales from macroevolutionary analyses, population genetics, and experimental evolution. A better understanding of the extremely fast evolution of capsules should shed light on capsular functionality in the environment and in the human host.