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
Hamish Peacock and made the final in each. In the 2007 World Youth Championships in Ostrava Peacock finished second in the javelin. Peacock is the older brother of fellow athlete Huw Peacock. Huw was selected, along with Hamish, to participate in the 2014 Commonwealth Games in Glasgow. Huw's event is the Hammer throw. Huw is ranked 15th on the Australian all-time hammer throw rankings, with a personal best of 68.48m. Huw is two years younger than Hamish. Both are coached by their father Evan, and are based at the Domain Athletics Centre in Hobart, Tasmania. Hamish Peacock Hamish Peacock (born 15 October