The genetic architecture of ‘mimicry’ — a clever adaption that Common Mormon butterflies Papilio polytes use to fend off their predators – has now been deconstructed by scientists.
A single gene, they find, is responsible for radically changing the wing pattern in female Common Mormons, making them resemble another toxic genus that birds have learned to avoid.
In a research paper published today (March 6) in Nature, authors identify the doublesex gene as being singularly responsible for mimicry in female Common Mormons, which can uncannily resemble the toxic, red-bodied Crimson Rose and other butterflies of the Pachliopta genus. Mimetic wing patterns on Common Mormons are classic examples of ‘Batesian mimicry,’ where species such as butterflies, moths and snakes imitate toxic or poisonous counterparts to effectively dodge predators, lead author K. Kunte, of the National Centre for Biological Sciences told this Correspondent.
Mimicry is limited to females, which are heavier with eggs, slower in flight and therefore in greater need of adaptive protection, he added. “For almost 50 years now scientists believed that it was a cluster of genes (or a “supergene”) that caused mimetic polymorphism (multiple forms) in Common Mormons. It is indeed significant to find that in fact a single gene, with tightly linked mutations, can switch the entire wing pattern,” Dr. Kunte said.
The doublesex gene has so far been primarily known as the vital controller of sex differentiation in insects, and polymorphic mimicry is indeed a novel function that scientists have now discovered for this gene, he said.