and what happens is that if an embryo has the single gene for being male, it happens to have a white chromosome not surprisingly, it turns on thousands of other genes that then make the embryo into a male, but, but that single gene has to be there to act as a switch and that's   that gene is also present in alligators and crocodiles   so the point i'm making is it is just wrong to say that, that all these discoveries about genetics cut no ice with human evolution, because human things cannot be influenced by single genes.