Nope. Omega Man is '71, and The Last Man on Earth is '64.
Not to mention one is color, the other is b/w, and different production values, they even "sound" differently. Movies from the 50s and 60s have a certain sound to the dialogue that was lost in the 70s, as we became more technologically savvy.
Listen to a movie like The Thing From Another World, or truly listen to The Last Man on Earth. Listen as they talk about science. Most sci-fi movies of the time sounded like that. That was untrue of the 70s.
Yeah, I'm only a little bit of a movie buff/geek.