humans can evolve into many things, but they would be "evolving"

they can go to certain classes, like tyhm said, baddies for evil ones, but you can concitrate of certain things, like different races/classes

the intelligence (for complex NPC use)
the power (Evil = Baddies, good = *uhh you name it*)
speed (racers, uses advanced horses, other means of transportation better and faster)
and culture (for the spirit and such, uses mystiv npcs and powers! like some speed, power, ect.)