Was It Designed?

The Surface of the Butterfly’s Wing

● The striking metallic colors on the wings of some butterflies change depending on the angle from which they are viewed. The wing color of one species is so pure and intense that it can be seen from a half mile (805 m) away. What makes the butterfly’s wing remarkable?

Consider: Rows of tiny concave surfaces on the wings of a green swallowtail butterfly (Papilio blumei) reflect light in various ways. For example, the center of each concavity reflects yellow-green light, while the edges reflect blue light. Also, light at the center of a concave surface is reflected directly, but light striking the sides first bounces through a surface of multiple layers, which amplifies and partially polarizes, or rotates, the light waves. The final mix is called structural color because of the complex way in which it is produced.

It took ten years for researchers to produce a simplified replica of the butterfly’s wing surface. Such technology, they hope, will lead to bank notes and credit cards that are harder to forge and solar cells that are more efficient at collecting energy from the sun. However, duplicating the surface of a butterfly’s wing is challenging. “Despite the detailed scientific understanding of optics,” writes Professor Ullrich Steiner of Cambridge University’s Nanoscience Centre, “the astonishingly varied colour palette found in nature often surpasses the optical effects that can be generated by technological means.”

What do you think? Did the butterfly’s wing surface come about by chance? Or was it designed?

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Green swallowtail butterfly

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Microscopic view of a butterfly’s wing

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Butterfly: Faunia, Madrid; microscopic view: © Eye of Science/​Photo Researchers, Inc.