Actually it started with the idea we that spawned from some kind of mud...and I don't believe that either. We have a lot to learn about how we got here and we certainly don't have all the answers - I for one am content with not knowing for the present time, however, I would like to see at least part of the puzzle solved in my lifetime. It is just as plausible, however, to believe we are the spawn of ancient aliens as we are the spawn of an ancient gods. Either way, you either believe we are the product of something beyond our current level of knowledge or that we are the product on an incestuous relationship between Cain and his sisters.
Not exactly, any astute student of the Bible knows that by the time Cain killed Abel, there were cities that Cain fled to. Adam and Eve had other children, Seth is another son
that comes to mind. So we are the product of any number of Adam's children.