Notice it says , later… there is no account that Adam had sex again and she had a second pregnancy. This appears to be one event. Eve had one baby and oh look, here comes another. There is an almost identical story in Sumeria about Emesh and Enten that predates the biblical story. I found a blog with that story if you want to check it out (no need to for me to go into it here) . I’ve even heard some say that the forbidden fruit was sex and that Eve had sex with the devil and that Cain was one offspring and Abel was the son of Adam. (its possible to have fraternal twins by two different fathers if the sex engagement is close enough). And why would “God” prefer animal sacrifice over produce? Could it be that the god they were worshipping was eating this sacrifice? Is it possible that their god was carnivorous? The thing is this… most people don’t know the full story and like with everything… mindless accept it without question.