@heidilifeldman There was apparently a student in my tenth-grade biology class who belonged to a Christian sect that truly and sincerely believed that men have one less rib than women, because Eve was made from Adam's rib. The teacher went into this long laborious explanation in which he noted that the father of another student was a combat veteran who had lost a leg, but that the student herself had two legs, because, see, acquired traits are not inherited, and the same goes for Adam and the rib, so it's ok to believe that men and women have the same number of ribs and still believe that God took one of Adam's to make Eve out of. Post-Mahmoud, I gather that any biology teacher who's going to say that men have 12 ribs needs to provide advance notice so parents who believe otherwise can protect their precious babies from hearing such blasphemy.