One of the traits that sets us, as humans, apart from the rest of the animal kingdom, is our ability to communicate in a variety of ways. Granted, other animals communicate in one form or another. But it is our ability to use language, both written and spoken, complex symbolism, and deliver these through other systems, such as radio, telephone, pictures.., to communicate with other human beings. But it was not always so. The history of communication begins with hand signs and body language to communicate to others the most elemental things like hunger or pain. From there, a long, winding road stretches to our times. Here are 10 milestones in human communication.