Coevolution in Communication

Sender-Receiver Coevolution in Communication

All communication requires both a sender and a receiver. The sender must be equipped to produce a signal and the receiver to perceive it.

Signals and perceptive organs rarely, if ever, arise de novo, just because animals have a “need” to communicate. Perceptive mechanisms arose in evolution because selection favored animals which could perceive the physical characteristics of their environment. Perceptual mechanisms for light, temperature, vibration, and electricity and magnetism are deeply rooted in the evolution of animals.

The first signals were probably chemical and functioned to coordinate activities with cells. Chemical communication among primitive unicellular organisms, such as bacteria, was probably the first type of interindividual communication to evolve. When multicellularity arose, chemical signals were easily adapted to between-cellular communication, as well as for communication between organisms.

Working from the basic assumption that in most cases perceptual mechanisms preceded signals in evolution, then the first step of signal evolution is the use of signals which are unintentional, physiological byproducts, or which evolved in interspecific contexts, such as defensive movements or chemicals, as information sources. If use of information in this way confers survival advantage, then selection will favor animals which use this information.

From this basis signals and perceptual systems may then evolve for intraspecific communication. Species and gender identification, because these are critical to avoiding wasting gametes in cross-species fertilization, was probably one of the earliest contexts in which communication arose. Kin selection may also have favored warning or alarm signaling early in evolution, if closely related animals lived in groups or clusters. Other forms of communication arise from complexities of mating systems or living in larger social groups.

The next steps in the evolution of signals are ritualization, the adaptation of cues into signals with specific meanings, and stereotypy, the refinement of cues so that extraneous information and noise are reduced.