How can bacteria that forage on organic particles survive in vast ocean regions where such particles are extremely sparse? A new study by researchers from ETH Zurich and Queen Mary University of London shows that variability at the level of individual bacteria plays a central role. Using a probabilistic population model linking mathematics and microbiology, the team demonstrates that rare, high-impact encounters sustain bacterial populations even when average conditions suggest decline. The paper is published in the Proceedings of the National Academy of Sciences.