While we know a lot about the processes affecting mutation accumulation in E.coli in a laboratory setup, less is known about processes governing it in the course of evolution of natural lineages. This is what we depict in the image with three strains of E. coli with known mutational profiles in the Petri dish, and the wild roaming E. coli for which the major mutational processes are unknown. Image idea: Sofya Garushyants Drawing: Sarah R.A. Stone. To know more about the mutational signatures in E. coli, click on this link: https://doi.org/10.1093/gbe/evae035