What is polygenesis theory?

Polygenesis theory in human evolution and linguistics posits that different human populations evolved independently in separate geographic locations, suggesting that various groups of early humans developed into distinct species rather than originating from a single common ancestor. In linguistics, this theory asserts that human languages evolved separately in multiple regions, leading to different, unconnected language lineages. This contrasts with monogenesis, which proposes a single origin for both human species and languages. Polygenesis suggests multiple migrations out of Africa and independent language development across different human populations. Some scholars also believe that writing independently emerged in at least four ancient civilizations: Mesopotamia, Egypt, China, and Mesoamerica.