A handout photo obtained on June 1, 2016 shows patterns on a Heliconius melpomene butterfly wing, made up of tiles of overlapping coloured scales. A gene responsible for the colours and colour patterns on the wings of butterflies and moths has been independently identified in two separate studies published in this weeks Nature. This gene, and a mutation associated with it, controlled the darkening of the peppered moth that took place during the Industrial Revolution, and the gene is also responsible for the natural colour pattern variation in certain butterfly species, the studies find. / AFP PHOTO / HANDOUT / Nicola NADEAU / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / Nature / Dept. of Animal and Plant Sciences / University of Sheffield / Nicola Nadeau" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS / EMBARGOED UNTIL 17:00 GMT, June 1NICOLA NADEAU/AFP/Getty Images
