In South Africa there is a tribe "hoansi San", whose members speak the language spoken by their ancestors thousands of years ago. This language consists of clicking sounds produced by the tongue, and consonants. Scientists suggest that 40 thousand years ago in a language spoke all mankind.
On the question of what has caused the appearance of this unusual language, scientists answer clearly: only hunting and the need to silently sneak up on the prey has forced people to communicate in this way. Because the animals, afraid of human speech, not react to clicks, mistaking them for the language of animals or birds.
By the way, like languages in Africa, there are about 30.