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
Comma (music) difference between the diatonic semitone and chromatic semitone is called the diesis. The widely used 12-tone equal temperament "tempers out" the diesis, and thus does not distinguish between the two different types of semitones. On the other hand, 19-tone equal temperament does not temper out this comma, and thus it distinguishes between the two semitones. Examples: A comma sequence defines a musical temperament through a unique sequence of commas at increasing prime limits. The first comma of the comma sequence is in the q-limit, where q is the nth odd prime, and n is the number of generators. Subsequent commas