And once you have one form of communication, the pressure to develop a second is almost none.
I agree with almost all of your post, but not this, given the huge number of channels of communication that animals have. Sound, sight, smell and touch are all important bidirectional communication channels between many social animals.
I agree with almost all of your post, but not this, given the huge number of channels of communication that animals have. Sound, sight, smell and touch are all important bidirectional communication channels between many social animals.