It’s a combination of Old Sumerian stories. Someone took elements of several different stories and put them together to make the Adam and Eve story. In the original stories a god named Enki created man with the help of a female god and the sacrifice of another god for his blood. The idea of taking a rib to create Eve is from another story about Enki again and another female goddess healing him (can’t remember the details) but do to a mistranslation the mentioning of a Rib is in that story.
Enki had a garden and a man who tended to this garden named Adamu. It’s was also in another story where Adamu was called to the sky gods and then offered immortality if he would eat of the food provided but Enki told him it was a trick so Adamu didn’t eat and therefore didn’t gain immortality. Enki is also the original god that warned man about a coming flood and to save yourself a and to build a boat, save living things.
Yes the alien connection is very tiresome.