But in this study, researchers explored a lesser-known evolutionary path: gene loss, reflective of the concept that ‘less is more’. To their surprise, it wasn’t a new gene or a mutation that made this strain dominant, but the loss of certain genes. Gene loss also produces weaker bacterial infections. The scientists thus believe that gene loss could be a common, powerful and underappreciated mechanism for adaptation in bacteria. “In our model species, it wasn’t mutation or gene gain that made the pathogen more successful: it was losing the right genes at the right time.”