So... I'm confused by Genesis and/or it's apologists. When scientists found mitochondrial Eve in Africa a few years back...
Mitochondrial Eve - Wikipedia, the free encyclopedia
...the raving evangelical types lept on it as "proof" of a singular Adam and Eve.
1) They wanted to believe such a find had been made;
2) They suddenly and conveniently found science tolerable and believable;
3) They assigned her identify as the biblical Eve, totally mis-reading the conclusions and evidence of the find to suit their fantasy interpretation (typical);
4) They had a problem though: the discoverers dated her as being 170,000 years old;
and...
5) They could not fathom that many many generations of humanoids had lived long
before this Eve, and the Y-chromosome Adam also noted by paleontologists had lived in an
entirely and vastly different time, and did not "know"
[wink wink, nudge nudge] this
mt-mrca Eve.
(Look that
underlined one up; you'll learn something).
Being as how the entire biblical account of Genesis is so obviously riddled with implausibilities and contradictions and
ooopsee omissions, we can safely conclude there simply is no rational explanation for how the children of Cain & Abel arose.
Because? It didn't happen is why.
QED
(Oh, go ahead, while you're "Googling", look that up too. It'll expand your encased mind. What, you don't want to be educated? Doesn't surprise me)