polygenesis n.

word-forming element meaning "many, much, multi-, one or more," from Greek polys "much" (plural polloi), from PIE root *pele- (1) "to fill," with derivatives referring to multitudinousness or abundance. Equivalent to Latin multi-, it is properly used in compounds only with words of Greek origin. In chemical names, usually indicating a compound with a large number of atoms or molecules of the same kind (such as polymer).

word-forming element meaning "birth, origin, creation," from Greek genesis "origin, creation, generation," from gignesthai "to be born," related to genos "race, birth, descent" (from PIE root *gene- "give birth, beget," with derivatives referring to procreation and familial and tribal groups).

1864, in anthropology, "the doctrine that the human race is not one but consists of many distinct species" (opposed to monogeny or monogenism), from Late Greek polygenēs "of many kinds," from polys "many" (see poly-) + -genēs "born" (from PIE root *gene- "give birth, beget"). By c. 1970 the same word was used in a different sense, in reference to the theory that multiple genes contribute to the form or variant of some particular trait of an organism. Another word for the anthropological theory was polygenism (1857).