Well I've never heard of an animal wiping itself out. I don't think it will be us doing it to ourselves. Even if we do nuke ourselves I don't think that would be enough to kill all of us, and we would rebuild. That might take hundreds of years in a "dark age" full of little tribes, but I think we'll be fine.
The only thing I could see wiping out humanity would be something along the lines of a meteor or cataclysmic event that defastates the planet.
Edit: If you're talking about just civilization being devistated to the point of being unrecognisable then there are a lot of options...
PS. Sorry about the spelling, no spell check on this shitty work computer...
The only thing I could see wiping out humanity would be something along the lines of a meteor or cataclysmic event that defastates the planet.
Edit: If you're talking about just civilization being devistated to the point of being unrecognisable then there are a lot of options...
PS. Sorry about the spelling, no spell check on this shitty work computer...