Spontaneous emergence of groups and signaling diversity in dynamic networks
Sending and receiving signals is ubiquitous in the living world. It includes everything from individual molecules triggering complex metabolic cascades, to animals using signals to alert their group to the presence of predators. When communication involves common interest, simple sender-receiver games show how reliable signaling can emerge and evolve to transmit information effectively. These games have been analyzed extensively, with some work investigating the role of static network structure on information transfer. However, no existing work has examined the coevolution of strategy and network structure in sender-receiver games. Here we show that coevolution is sufficient to generate the endogenous formation of distinct groups from an initially homogeneous population. It also allows for the emergence of novel "hybrid'' signaling groups that have not previously been considered or demonstrated in theory or nature. Hybrid groups are composed of different complementary signaling behaviors that rely on evolved network structure to achieve effective communication. Without this structure, such groups would normally fail to effectively communicate. Our findings pertain to all common interest signaling games, are robust across many parameters, and mitigate known problems of inefficient communication. Our work generates new insights for the theory of adaptive behavior, signaling, and group formation in natural and social systems across a wide range of environments in which changing network structure is common. We discuss implications for research on metabolic networks, among neurons, proteins, and social organisms.