Swallowtail butterfly tiger swallowtail), Y-linkage determines whether the females are either wild-type (yellow and black) or melanic (dark melanin replaces the yellow background). This genetic difference stems from the fact that melanism is controlled by a single gene, which controls the level of dopamine in the organism. The enzyme BAS, which assists dopamine in producing the yellow pigmentation, normally found on the wings' background, is suppressed. Without the pigmentation, the butterfly appears mostly black (the melanic form) and is a Batesian mimic of "Battus philenor", the pipevine swallowtail. There are also "Papilio glaucus" that are not wholly black; several possess an intermediate
C.D. Peacock C.D. Peacock C.D. Peacock, originally established as The House of Peacock, is a Chicago, Illinois-based retail jewelry store founded in 1837 by Elijah Peacock. The company is Chicago's oldest existing retailer. The company survived the Great Chicago Fire, despite its location in the middle of the city, as all of its merchandise was kept in a fireproof safe. In 1889, Charles Daniel Peacock assumed control of the business and changed the name to the current C.D. Peacock. They issued their first retail catalog in 1893, which coincided with the World's Columbian Exposition. Later, company president Walter C. Peacock became an