The world would be comprised of the happiest group of hunter/gatherers that you can possibly imagine. Then again if you consider that there are no NT's then there would be a very heavy emphasis on gathering.
My wife and I made a game to teach kids about nutrition. Please try our game and vote for us to win. (Voting period: July 14 - August 14) http://www.revoltingvegetables.com
Seriously, I don't think it would make a difference if there were no NTs, or no people in general. Stuff just happens.
Accept the past. Live for the present. Look forward to the future. Robot Fusion
"As our island of knowledge grows, so does the shore of our ignorance." John Wheeler
"[A] scientist looking at nonscientific problems is just as dumb as the next guy." Richard Feynman
"[P]etabytes of  data is not the same thing as understanding emergent mechanisms and structures." Jim Crutchfield