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
S-comma this reason, almost all Romanian texts still use S-cedilla (or even S), despite the recommendation to migrate from cedilla to comma. The letter is placed in Unicode in the Latin Extended-B range, under "Additions for Romanian", as the "Latin capital letter S with comma below" (U+0218) and "Latin small letter s with comma below" (U+0219). In HTML these can be encoded by codice_1 and codice_2, respectively. S-comma S-comma () is a letter which is part of the Romanian alphabet, used to represent the sound , the voiceless postalveolar fricative (like "sh" in "shoe"). The letter was proposed in the "Buda