Where does “一雄多雌” come from?

一雄多雌 (Japanese) comes from Japanese 一, from Japanese 始め, from Japanese 始める — begin; start; initiate; originate.

一雄多雌 (Japanese): polygyny

Definitions

一雄多雌 traces back through 3 separate lines of ancestry.

Step	Language	Word	Meaning
1	Japanese	一	one, 1; "term relating to the number one"; unity
2	Japanese	始め	beginning, the start of an activity or time...
3	Japanese	始める	begin; start; initiate; originate

Step	Language	Word	Meaning
1	Japanese	雄	male; something or someone excellent; man, male
2	Middle Chinese	雄	—

Step	Language	Word	Meaning
1	Japanese	雌	a female; a female person; an internal socket
2	Old Japanese	女	woman