Since the time of Charles Darwin's origin of species , scientists have pondered the mystery of “mimicry butterflies”, which survive by copying the wing patterns of other butterflies that taste horrible to their predators, birds.
The answer, according to a study released on this Friday, lies in an astonishing cluster of about 30 genes in a single chromosome.
“We were blown away by what we found,” said scientist Mathieu Joron of France’s National Museum of Natural History, who was head of the team into what is being called a “supergene”phenomenon.
“These butterflies are the ‘transformers’ of the insect world,” said Joron.
“But instead of being able to turn from a car into a robot with the flick of a switch, a single genetic switch allows these insects to morph into several different mimetic forms.
“It is amazing, and the stuff of science fiction. Now we are starting to understand how this switch can have such a pervasive effect.”
The trick, known as Muellerian mimicry, was by French and British scientists, who focused on a species of Amazonian rainforest butterfly specie, Heliconius numata.
It is able to copy the colour wing patterns of several species of the Melinaea butterfly which are unpleasant to predator birds.
The “supergene” comprises a tightly packed genes on only one chromosome which control different elements of the wing pattern.
“By changing just one gene, the butterfly fools birds ,”explained Richard ffrench-Constant of the University of Exeter, southwestern England said .