Live to 140 would mean working to 120 or thereabouts.... and the world could not afford it without measures to control population,,,,,, because people would know they had so much time the motivation to do things would be far less ..... Extending the lives of key people might be worthwhile..but who would chose....a lesser extension might be nice if the aging process was slowed too but at the moment we probably live far longer than we were meant to....as far as I am aware there are few other cases in nature where members of a species survive so long after their reproductive lives are over,,,,I believe only elephant, and possibly the larger primates but not to the extent we have managed it.....