Monkeys also have an evolution path, just not "snake->water serpent->dragon yaoguai->true dragon etc...." it's more like just different sizes, shapes, intellect like "猴(monke)->獼猴(macaque)->猨(ape)->玃猿(jueyuan/oozaru) etc...", and in myth, there's a 800/500 year evolution divide between each stage, not unlike how each tail of a fox or cat is grown, I guess