Premise: The Hitchhiker's Guide to the Galaxy is a 2005 British-American comic science fiction film directed by Garth Jennings, based upon previous works in the media franchise of the same name, created by Douglas Adams. It stars Martin Freeman, Sam Rockwell, Mos Def, Zooey Deschanel and the voices of Stephen Fry and Alan Rickman.
Hypothesis: The Hitchhiker's Guide to the Galaxy was based upon previous media creation under a different name.