Briefly describe the three hypotheses formulated by 19th century-evolutionists in an effort to explain the origin of human language.

  the  "ding-dong" hypothesis .  language began when humans started naming objects, actions and phenomena after a recognizable sound associated with it in real life.  this hypothesis holds that the first human words were a type of verbal  icon ,  a sign whose form is an exact image of its meaning :   crash   became the word for thunder,  boom   for explosion
2) the  "pooh-pooh" hypothesis   holds that the first words came from involuntary exclamations of dislike, hunger, pain, or pleasure, eventually leading to the expression of more developed ideas and emotions.  in this case the first word would have been an involuntary  ha-ha-ha ,  wa-wa-wa  these began to be used to name the actions which caused these sounds.
3) the  "bow-wow" hypothesis   (the most famous and therefore the most ridiculed hypothesis) holds that vocabulary developed from imitations of animal noises, such as:   moo, bark, hiss, meow, quack-quack .  in other words, the first human words were a type of index, a sign whose form is naturally connected with its meaning in time and space.