From reading some Jewish Kabbalist references, there's some argument in those quarters that Adam and Eve were the first "spiritually aware" humans (which is used to explain things like "who did cain marry" and "who went to live in the city that he built", etc), and that non-spiritually-aware humans pre-existed
Reminds me of the email going around titled "God's Answering Machine", where, among other items of info (Press "1" for English, "2" for Hebrew, "3" for Aramaic, "4" for other), the instructions are: "For information concerning questions like "How did Noah's Ark float", just wait till you get here.