There isn't any ancient artifacts to trace back when dance started or why dance became part of human culture. There are only stories of traditions that tribes and clans have practiced over the years. Africa seems to be the place where all types of dance evolves from.
"The only way to preserve dance movements from generation to generation was by demonstration, imitation, practice and personal supervision" History of Dance ( Wikipedia, 2012)
"The only way to preserve dance movements from generation to generation was by demonstration, imitation, practice and personal supervision" History of Dance ( Wikipedia, 2012)