(Federalist) Bill Nye, who has been recently spending time yelling at people that gender is fluid and has nothing to do with DNA, used to tell everyone that science says chromosomes determine if a person is a boy or a girl.
In an episode of his show “Bill Nye the Science Guy,” circa 1996, the message is loud and clear: biology says chromosomes determine if people are male or female.
“Inside each of ourselves are these things called chromosomes, and they control whether we become a boy or a girl,” a teenage narrator explains. “There are only two possibilities: ‘XX,’ a girl, or ‘XY,’ a boy.”
Bill Nye in '96: Chromosomes determine gender