Oh, this is way over my head! But I do know that this story has been debunked.
On one hand you don't know. On the other you do know. Wow.
Hey, miss marmelstein, it is a known fact, chronicled in the Clan of the Cave Bear series, that Broud was hittin’ on Ayla every chance he got.
Proof of the puddling was the birth of Durc who was a half-breed.
There is so much evidence for this interbreeding in the record of that series that you can’t dismiss it out of hand.