'Supergene' is key to copycat butterflies

Aug 12, 2011
This undated handout photo released by the CNRS shows butterflies, Melinaea mneme (top) and Heliconius numata. The mystery of how a butterfly has changed its wing patterns to mimic neighbouring species and avoid being eaten by birds has been solved by a team of European scientists.

Since Charles Darwin, biologists 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 Friday, lies in an astonishing cluster of about 30 genes in a single chromosome.

"We were blown away by what we found," said Mathieu Joron of France's , who led the probe into what is being called a "supergene".

"These 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 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 investigated by French and British scientists, who focussed on a species of Amazonian rainforest butterfly, Heliconius numata.

It is able to copy the colour patterns of several species of the Melinaea butterfly which are unpalatable to birds.

The "supergene" comprises a tightly packed region of genes on a single chromosome which control different elements of the wing pattern.

This image shows Melinaea (left) and Heliconius numata mimetic forms. Credit: Mathieu Joron

"By changing just one gene, the butterfly is able to fool its predators," explained Richard ffrench-Constant of the University of Exeter, southwestern England.

Even more astonishing is that three versions of the chromosome exist within this species, with each version controlling distinct wing-pattern forms.

Even though the butterflies look quite different from each other, they have the same DNA.

The supergene apparently transmits in a block from generation to generation, rather than go through recombination -- the mingling of genes from both parents.

The "supergene" also appears important in other species, say the authors.

One such , the peppered moth, developped black wings in 19th-century Britain as a means of gaining camouflage in the sooty industrial environment.

"It's a gene that really packs an evolutionary punch," said ffrench-Constant.

The paper is published online by the British science journal Nature.

Explore further: High-pitched sounds cause seizures in old cats

Related Stories

Painting by numbers

Sep 29, 2006

Professor Richard ffrench-Constant of the University of Exeter in Cornwall has worked with an international team of experts to ‘decode’ the patterns on butterflies’ wings.

How the butterflies got their spots

Feb 05, 2010

(PhysOrg.com) -- How two butterfly species have evolved exactly the same striking wing colour and pattern has intrigued biologists since Darwin's day. Now, scientists at Cambridge have found 'hotspots' in ...

An eye gene colors butterfly wings red

Jul 21, 2011

Red may mean STOP or I LOVE YOU! A red splash on a toxic butterfly's wing screams DON'T EAT ME! In nature, one toxic butterfly species may mimic the wing pattern of another toxic species in the area. By ...

Butterfly study sheds light on convergent evolution

Jul 21, 2011

For 150 years scientists have been trying to explain convergent evolution. One of the best-known examples of this is how poisonous butterflies from different species evolve to mimic each other's color patterns – in effect ...

Recommended for you

High-pitched sounds cause seizures in old cats

46 minutes ago

When the charity International Cat Care asked veterinary neurologists at Davies Veterinary Specialists, UK, for help with several enquiries it had received regarding cats having seizures, seemingly in response ...

Bumblebees use nicotine to fight off parasites

5 hours ago

Researchers from Queen Mary University of London (QMUL) and Royal Holloway, University of London (RHUL), gave bumblebees the option to choose between a sugar solution with nicotine in it and one without. ...

ANZAC grevillea hybrid marks centenary celebrations

7 hours ago

Through an intense breeding program of native flora, Kings Park botanists have provided the Western Australian RSL with a commemorative grevillea (Proteaceae) in time for the Anzac Centenary.

Secret life of penguins revealed

10 hours ago

To mark World Penguin Day (25 April 2015) citizen science project Penguin Watch will release 500,000 new images of penguins and reveal secrets from a year of spying on penguins. ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.