Each individual can survive in a changing and often harsh world, where the difference between life and death is one cell. These rugged individualists live a streamlined life, in which the drive to reproduce appears to rule. As soon as one cell divides into two, each strikes off on its own, foraging for food, seeking safety, and trying to become two once more. Yet scientists have gradually realized that diverse bacteria form coalitions to accomplish feats that individuals cannot perform. Once considered an oddity, this organizational ability appears to be a common occurrence.
Evolution seems to have distributed a standard kit of two genes to a variety of unrelated bacteria.
Armed with these tools, the various species exploit a similar tactic for mobilizing mass production of useful molecules. Then each bacterium begins to work toward the common goal. They're single-celled organisms, but they exhibit complex behavior. They're not only communicating, they're coordinating their behavior so that they behave in a uniform manner. S cientists first glimpsed this process, called quorum sensing, in the late 1960s.