ABSTRACT
Many species of bacteria "form complex communities, hunt prey in groups and secrete chemical trails for the directed movement of thousands of individuals". As they grow, divide, and multiply, they reflexively release a species-typical signaling molecule known as an autoinducer. Desert locusts typically live as solitary animals. But when protein becomes scarce, their bodies change and they begin to move in coordinated bands. While the social interactions between swarming locusts are more robust than the interactions between bacteria, their collective behavior is a by-product of the flow of information between conspecifics. Natural selection tends to increase the frequency of genes associated with individual fitness, as individuals with such genes typically reproduce more frequently than those with rival alleles. In this chapter, the author has examined some ways that contextualized self-interest can generate stable forms of collective behavior in light of these facts.
