Now that we've become so smart with our opposable thumbs and our web 2.0, we're probably going to halt evolution in its tracks with unnecessary surgery and/or ostracism of the higher evolved, leading to either suicide, genocide, alcoholism or X-Men style drama.
Then we will regress to the caveman stage in which we don't know how to maaro-pair-pe-kulhaadi anymore.
Then we will evolve back to this stage and repeat the process all over again.
Rubber-band evolution. Bouncing back and forth, back and forth.
Or maybe the next time around, the cavemen will sprout wings and have green skin so we can photosynthesize. In mid air. So cool.
Now this all makes sense.