Scientist believe that all life on Earth came from a single cell. Well, if scientists find life on Mars, doesn’t that disprove their theory. If they find a single cell on Mars, then why are there not other life forms, like on Earth. Where Is Marvin the Martian? Mars has been around just as long as Earth, yet we are the planet to have life? Just something for you to think about. Just because science thinks something is true, it doesn’t automatically make it true.