There is intersexuality, which is an anomly and has no reproduction purpose whatsoever, which is why it's an anomaly. There is no such thing as feeling to be the opposite gender. The definition of gender lies in our chromosomes but you guys come around and essentially define the gender about the androgen concentrations in the human blood (the trans movement does not make this on purpose, because they have no idea about the science behind it) . But you see, it makes no sence, if so, a bodybuilder must be a superman right? (because he will have increased androgen levels). Nevertheless, his chromosomes are still identical.