- Not Exactly Rocket Science
The Supergene That Paints a Liar
The females of the common mormon butterfly are masters of disguise. Some of them look like the black-and-white males, but others embellish their wings with white brushstrokes and red curlicues to mimic distantly related swallowtail butterflies that are toxic. By copying them, the delectable female mormons fool predators into thinking that they are similarly distasteful.
The picture below shows how varied these disguises can be. The right halves are all different butterfly species, and the left halves are all common mormon females.
British scientists Sir Cyril Clarke and Philip Sheppard studied these butterflies in the 1960s and, through cross-breeding experiments, showed that the insects never mix and match their patterns. You don’t get intermediate butterflies with red streaks from one