Happy 2012 butterfly fans! In order to better celebrate the future, we’re taking a look back into the past: the ancient past. The earliest known butterflies and moths evolved about 50 million years ago (although there is some evidence that they might be even older and have coexisted with the dinosaurs). However since fossils are pretty drab, nobody really knew what the ancient butterflies looked like until recently.
Now scientists at Yale have used fossilized moth scales to figure out what color ancient moths and butterflies were. Butterfly wings get their vibrant hues from scales that reflect light to produce colors and patterns. These so called “strucutral colors” are produced by layers within the scales that reflect light like a prism. The research group, led by Professor Maria MacNamara, analyzed the structure of the fossilized moth scales to determine how they would have reflected light, and therefore what color the moths would have appeared.
The moths turned out to be bright green with blue wing tips, which means they would have been conspicuous as they fed on flowers in ancient forests. However, the closest living relative to the fossil moths, the forester moth, also uses bright colors to warn predators that it is toxic. MacNamara and her group think that ancient moths may also have been able to store toxins to ward off predators and used their colorful wings to deter attacks. These results are exciting to biologists as well as paleontologists because they show that predator-prey interactions were as important in the ancient past as they are today.
McNamara ME, Briggs DE, Orr PJ, Wedmann S, Noh H, & Cao H (2011). Fossilized biophotonic nanostructures reveal the original colors of 47-million-year-old moths. PLoS biology, 9 (11) PMID: 22110404