Do you believe in the alien ant farm theory?
It is likely that the aliens planted apes as well, to confuse us about our origins. The first people who lived on Earth had no scientific knowledge. Perhaps on a planet far away the cave-dwellers still exist, while their cousins (mankind) evolved. Earth is a planet favorable for great evolution. It is possible that religious scribes believed in our alien masters, and because alien life was controversial, they invented the story of God.
As our population grows out of control and resources are overconsumed, it is likely the aliens will be back. Is that a metaphor of the second-coming of the Messiah?