What makes you think he won't evolve anymore? He's 25 years old and has shown complete dominance in all his fights. At this age guys like Anderson/Fedor were only a few fights in their career and weren't even close to having any titles tied to their name. Jones is already the best LHW ever and has 5 title defenses.
My point being that he's evolved beyond most fighters today in a very short amount of time. There's no reason to not think that as he ages/fights he will get more techniques, more experience and refine his game. If anything I'd say he's evolving faster and at a higher rate than anyone else in MMA right now, the guy has been fighting for 5 years and is the most dominant LHW in the sports history and has 5 title defenses under his belt, I mean seriously, that's insane.