Signals in family conflicts

Although the role of animal signals in the resolution of family conflicts has been thoroughly studied, it has been typically analysed in isolated two-player interactions. For instance, parents are usually considered as the sole receivers of offspring begging signals or mates the receivers of sexual displays. However, this view does not wholly encompass the dynamic and complex nature of the family scenario. In this essay, we review for the first time the clearest evidence of animal signals found to play a role in more than one family context (e.g. mate–mate, parent–offspring and sib–sib interactions). We then argue that these signals might have coevolved in multiple family contexts because the whole network of related individuals shares genes and similar physiological mechanisms underlying signal expression and perception abilities. Finally, we propose candidate traits that we would expect to function in multiple family contexts and we consider questions that could be addressed in further studies to understand better the evolution of family signals.