Jon Jones is a great MMA fighter, probably one of the best ever, however Klitschko would annihilate him in a boxing match, it would not even be close, I'm talking first or second round KO.
When boxers open their traps about how MMA isn't a real sport, human cockfighting, etc it's lame as hell but the reverse is also just as bad. Just be quiet and stick to MMA guys, there are absolutely no MMA fighters in the UFC who could get near to challenging the best boxers at their weight in a boxing match right now. None.