title: On the origin of sexual behavior.
mesh_terms: D000818:Animals; D003307:Copulation / Q000502:physiology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000502:physiology*; D008116:Lizards / Q000502:physiology*; D008297:Male; D010060:Ovulation; D010312:Parthenogenesis; D012726:Sexual Behavior, Animal / Q000502:physiology*
chemical_list: D012739:Gonadal Steroid Hormones