Microbial cooperation

Microorganisms engage in a wide variety of social interactions, including cooperation. A cooperative behavior is one that benefits an individual (the recipient) other than the one performing the behavior (the actor). This article outlines the various forms of cooperative interactions (mutualism and altruism) seen in microbial systems, as well as the benefits that might have driven the evolution of these complex behaviors. Microorganisms engage in a wide variety of social interactions, including cooperation. A cooperative behavior is one that benefits an individual (the recipient) other than the one performing the behavior (the actor). This article outlines the various forms of cooperative interactions (mutualism and altruism) seen in microbial systems, as well as the benefits that might have driven the evolution of these complex behaviors. Microorganisms, or microbes, span all three domains of life, including bacteria, archaea, viruses, and many unicellular eukaryotes (e.g., some fungi and protists). Typically defined as unicellular life forms that can only be observed with a microscope, microorganisms were the first cellular life forms, and were critical for creating the conditions for the evolution of more complex multicellular forms.