Evolution
Communication is an adaptive dance, its form evolving based upon antecedent employment. A natural tendency is reuse, modifying from an existing mechanism. Mating signals of water mites and fruit moths are recycles of a signal even stronger than the urge to reproduce: the need to eat.
A receiving channel must exist for a sending signal to have any chance. Receptiveness readies the prospect and practically dictates the type of signal used for communication.
