Yep, and this is how we "evolve"? I believe that humans were meant to be on this planet...nature created us just like everything else that is or has lived. We're not an invasive species...yet you have to wonder if "nature" has any order or is just totally random considering we're the only things it's every created that are just tearing shit up.
However...It may be that big brained things such as ourselves are the apex of nature's creations...and she put in a self destruct mechanism. Which would help explain why we don't see anything else tooling around the galaxy.