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
Quarter-comma meantone are observed for all interval types, except for unisons and octaves, and they are all multiples of ε, the difference between the quarter-comma meantone fifth and the average fifth. Notice that, as an obvious consequence, each augmented or diminished interval is exactly 12"ε" cents (≈ 41.1 cents) wider or narrower than its enharmonic equivalent. For instance, the diminished sixth (or wolf fifth) is 12"ε" cents wider than each perfect fifth, and each augmented second is 12"ε" cents narrower than each minor third. This interval of size 12"ε" is known as a diesis, or diminished second. This implies that "ε" can