It's all based on the Sumerian texts, written 2000 years before the Bible was written. In that version, we were genetically engineered by mixing DNA from the alien Sumerians and human apes, to make gold mine slaves. All the workers were male, until two of the genetic engineers felt sorry for the slaves and created someone who could THINK independently..a woman.
The first try, Lilith, had too much royal Draco DNA, so was too vicious to mate with the slave men, so they ditched her and made Eve instead.
In Genesis chapter 1 there is an entire creation story of man & woman being created at the same time by gods (plural]. In chapter 2, god (singular) creats Adam & the garden...then Eve (Lilith should be in there)...so Cain's wife was from "the others" who were in the land of Nod, or outside of Eden. (Oh & this is TOTAL blasphemy)