Has already happened. No I don't believe that, but it could be true. We could be living in the aftermath of an apocalypse, how else can you explain why their is so much pain and suffering in the world. When the end of the world happened, we were evolved from just a few worms that managed to escape.
Over the last 500 million years there have been five mass extinction events the likes man could not have survived The Permian mass extinction pretty much wiped-out 90% of all life Hotwater