[The Lone Ranger]

Apparently, you haven't read my entire post. (I amended it to clarify that "gender" isn't a word used in biology before your post, by the way.) Also, I specifically pointed out that there are at least two reasons for a genetically male fetus to develop into a phenotypic female: damage to the Y chromosome or failure of the mother's placenta to produce sufficient quantitites of the hormones that "activate" the developing testes.


But there is no sex change, since the undifferentiated fetus doesn't have ovaries and does have Mullerian ducts -- and so is neither male nor female in a gonadal or phenotypic sense. What happens is that it becomes one sex or the other. Even though the "default" sex is female (in humans), that in no way means that the fetus is a female until and unless acted upon by androgens.

Cheers,

Michael