The polygenesis theories argue that hominids migrated out of Africa at different times and that many early human ancestors may have evolved in places other than Africa. Linguistically, polygenesis argues that whether humans evolved in one place or many, language use rose from multiple places, which may be supported by the wide variety of languages, and language families, in existence today. If polygenesis is correct, language development may have happened in a variety of ways across distance human populations. In the field of linguistics, polygenesis is the view that human languages evolved as several lineages independent of one another. It is contrasted with monogenesis, which is the view that human languages all go back to a single common ancestor.