Destabilizing mutations encode nongenetic variation that drives evolutionary innovation

Evolutionary innovations are often achieved by repurposing existing genes to perform new functions; however, the mechanisms enabling the transition from old to new remain controversial. We identified mutations in bacteriophage ’s host-recognition gene J that confer enhanced adsorption to ’s native receptor, LamB, and the ability to access a new receptor, OmpF. The mutations destabilizeparticles and cause conformational bistability of J, which yields progeny of multiple phenotypic for