Signal function drives phenotypic and genetic diversity: the effects of signalling individual identity, quality or behavioural strategy.

Animal coloration is influenced by selection pressures associated with communication. During communication, signallers display traits that inform receivers and modify receiver behaviour in ways that benefit signallers. Here, we discuss how selection on signallers to convey different kinds of information influences animal phenotypes and genotypes. Specifically, we address the phenotypic and genetic consequences of communicating three different kinds of information: individual identity, behavioural strategy and quality. Previous work has shown signals that convey different kinds of information differ in terms of the (i) type of selection acting on signallers (e.g. directional, stabilizing, or negative frequency dependent), and (ii) developmental basis of signals (i.e. heritability, genetic architecture). These differences result in signals that convey different information having consistently different phenotypic properties, including the amount, modality and continuity of intraspecific variation. Understanding how communication influences animal phenotypes may allow researchers to quickly identify putative functions of colour variation prior to experimentation. Signals that convey different information will also have divergent evolutionary consequences. For example, signalling individual identity can increase genetic diversity, signalling quality may decrease diversity, and signalling strategy can constrain adaptation and contribute to speciation. Considering recent advances in genomic resources, our framework highlights new opportunities to resolve the evolutionary consequences of selection on communication across diverse taxa and signal types.This article is part of the themed issue 'Animal coloration: production, perception, function and application'.