Human communication did not start from scratch. All living species need to communicate with others of their kind. The farther apart they are, the more sophisticated the modes of communication are.
Plants communicate with other plants via electrical signal transmissions to respond to environmental stress. Bees use dances to signal near by food sources.
While asleep, rats use neuron transmission not only to update their own long-term memory with fresh experiences, but also, by broadcasting this information, they update other rats' long-term memory. This results in group knowledge. While awake, rats emit two different kinds of signals -- low frequency calls in the 22 kHz range and high frequency 50 kHz calls. The low frequency calls are used as alarm cries, for instance emitted during exposure to predators, during male-male aggression and during social isolation. Thus they have a clear communicative aim.
Whales and dolphins use ultra sound. Compared to things like chemical signals, sound travels very rapidly underwater (about 1,500 meters/second) and much farther than in air, no matter how loud one of us screams up here on land. This is especially true for lower frequency sounds that are typically used by marine mammals for communication.
Man inherited communication skills from their ancestors. But with the growth of civilization, some of the natural communication skills were lost and others had to be invented. Establishing communication throughout an empire required a network of relay stations, used by runners, mounted horses, carriages and ships. Fire, light, smoke, sound, carrier pigeons could traverse distances faster than humans. See our defense page.

Check also this PDF file from Gerard Holzmann: Data Communications: The First 2500 Years