What's the difference between polygenist and polygynist?

Polygenist

Definition:

• (n.) One who maintains that animals of the same species have sprung from more than one original pair; -- opposed to monogenist.

Example Sentences:

Polygynist

Definition:

• (n.) One who practices or advocates polygyny.

Example Sentences:

• (1) A high proportion of the Yoruba women are in polygynous unions and most of those in monogamous unions are potential wives of polygynists.
• (2) The CAFN 1 survey shows that wives of polygynists tend to be older than those of monogamists.
• (3) Because of this the reported mean number of children ever born was higher for the wives of polygynists than for the wives of monogamists.