Kyle, Randians apparently believe in what philosophers call contra-causal, or “true” free will. That is magic because it somehow puts human will outside of the normal web of cause-effect. Ironically, that’s what Christians do as well.
Of course humans do have will, meaning the ability to make decisions, and of course it evolve because it was advantageous, nobody but fundamentalist Christians deny that.
As for introspection, modern psychology has shown it to be highly unreliable, so I wouldn’t count on it as evidence of “free” will.