| Definition -
The hypothesis that unrelated human languages emerged spontaneously at different places and at different times.
1. As opposed to monogenesis, which hypothesizes that all human languages derive from a single source language.
2. If you believe this, you are a polygenist.
Etymology - The term means "multiple births" in Greek.
Oxford English Dictionary - Its first citation is from 1936:
"At various times scholars have raised the question of monogenesis as opposed to polygenesis of human speech: whether it had a single origin at a given time and place, whence it spread over the rest of the earth, or whether it was independently evolved by different branches of the human family."
(Science & Society I. 23)