Rapid evolution and sexual signals

Surprisingly few examples of rapid evolutionary change in behavioral traits have been documented in nature, yet circumstances favoring rapid evolution in other traits apply equally well to behaviour, including animal signals. This chapter considers the role of signals in rapid evolution and the way behavior influences evolutionary change. Because communication involves interactions between individuals, changes in signal structure or production must be accompanied by change in the receiver, which means that behaviour itself can constrain evolution. Alternatively, behaviour may facilitate contemporary evolution. The chapter reviews the literature as well as work presented in this chapter with a field cricket in which pre-existing behavioural plasticity apparently facilitated spread of a mutation that silences males, simultaneously eliminating their sexual signal and protecting them from a parasitoid.