Most microbiologists consider used flasks, laden with splotches of colonizing bacteria, simply more dishes to wash. Paul Rainey sees more. For Rainey, ecologist and evolutionary biologist at the University of Auckland in New Zealand and the University of Oxford in Britain, those clusters of bacteria may help demonstrate evolutionary principles at work. He is one of many investigators looking to microbes to see how cooperation and sociality evolve.
Microorganisms within a colony may produce by-products not for their own feeding or reproduction, but simply to promote the colony. That individuals in a clonal, or even closely related, microbial population would incur costs to benefit their neighbors' genes and increase the group's fitness is a compelling notion. So-called cheaters may opt out of the "group mentality" for individual gain, but understanding the cooperative mechanisms and even the ways in which cheaters are dealt with could lend new insight into how complex ...
