Butterfly Wing Shimmer Done With 3-D Crystals
Those shimmering flashes of light seen on butterfly wings are not done with pigments. They’re done with tiny, geometric crystals called gyroids stacked in 3-D patterns, scientists have found. They are so effective at concentrating color, the scientists want to imitate the trick.
“A precise characterization of color-producing biological nanostructures is critical to understanding their optical function and development,” the authors of the paper in PNAS said.1 “Structural and developmental knowledge of biophotonic materials could also be used in the design and manufacture of biomimetic devices that exploit similar physical mechanisms of color production.” Prior studies of the photonic crystals in butterfly wings did not reveal the 3-D nature of the structures. By studying five tropical butterfly species with small angle X-ray scattering, they found that the crystals begin as double gyroid precursors “as a route to the optically more efficient single gyroid nanostructures.” The paper has been summarized by Live Science and PhysOrg.
Lead author Vinodkumar Saranathan [Yale U] told Live Science that these intricate structures “evolved over millions of years of selection for optimal function.” Did the original paper in PNAS elaborate on how that might have happened? Here are the only mentions of evolution in the paper:
By initially developing the thermodynamically favored double gyroid nanostructure, and then transforming it into the optically more efficient single gyroid photonic crystal, these butterflies have evolved to use biological and physical mechanisms that anticipate contemporary approaches to the engineering and manufacture of photonic materials…..
Butterflies have apparently evolved a diversity of photonic nanostructures by using membrane energetics to arrive at different stable, self-assembled states.
It appears that Saranathan and his team made butterflies into engineers that used “evolution” as a tool with a purpose.
1. Saranathan et al, “Structure, function, and self-assembly of single network gyroid (I4132) photonic crystals in butterfly wing scales,” Proceedings of the National Academy of Sciences, published online before print June 14, 2010, doi: 10.1073/pnas.0909616107.
It is painful to put Amazing and Dumb awards together, but as long as Darwinists insist on putting wonders of nature alongside the phrase “it evolved,” what more can one do? The Darwin attack dogs are sure to call this “science bashing” again, but show us where the science is in a statement like “butterflies have evolved to use biological and physical mechanisms that anticipate contemporary approaches to the engineering and manufacture of photonic materials,” and we will certainly honor it here. In the meantime, we would not wish to dishonor our engineers and manufacturers by attributing their work to happenstance.