I read once that we’ve been determined to have all come from a tribe of about 200 couples (breeding pairs). Don’t know if I believe it, don’t know that I believe this.
I can’t believe that all come from anything other than Adam and Eve...Seth the third son was Jesus ancestor. Cain killed Able then took a wife from land of NOD....wherever that is? Genesis. Abled died, no children. Cain married ?. Seth is most reasonable father of most of us. My next question ‘Why do some people have negative blood without the rhesus factor?