To Parker this was not a mere collection of specimens, but "a treasure-trove of brilliant design." Every species, even those that have gone extinct, is a success story, optimized by millions of years of natural selection. Why not learn from what evolution has wrought? As we walked, Parker explained how the metallic sheen and dazzling colors of tropical birds and beetles derive not from pigments, but from optical features: neatly spaced microstructures that reflect specific wavelengths of light. Such structural color, fade-proof and more brilliant than pigment, is of great interest to people who manufacture paint, cosmetics, and those little holograms on credit cards. Toucan bills are a model of lightweight strength (they can crack nuts, yet are light enough not to seriously impede the bird's flight), while hedgehog spines and porcupine quills are marvels of structural economy and resilience. Spider silk is five times stronger by weight and vastly more ductile than high-grade steel. Insects offer an embarrassment of design riches. Glowworms produce a cool light with almost zero energy loss (a normal incandescent bulb wastes 98 percent of its energy as heat), and bombardier beetles have a high-efficiency combustion chamber in their posterior that shoots boiling-hot chemicals at would-be predators. The Melanophila beetle, which lays its eggs in freshly burned wood, has evolved a structure that can detect the precise infrared radiation produced by a forest fire, allowing it to sense a blaze a hundred kilometers away. This talent is currently being explored by the United States Air Force.
"I could look through here and find 50 biomimetics projects in half an hour," Parker said. "I try not to walk here in the evening, because I end up getting carried away and working until midnight."
In one such late-night creative burst eight years ago, Parker decided to investigate the water-gathering skills of a desert beetle by building an enormous sand dune in his laboratory. This tenebrionid beetle flourishes in the Namib Desert in southwestern Africa, one of the world's hottest, driest environments. The beetle drinks by harvesting morning fogs, facing into the wind and hoisting its behind, where hydrophilic bumps capture the fog and cause it to coalesce into larger droplets, which then roll down the waxy, hydrophobic troughs between the bumps, reaching the beetle's mouth. Parker imported several dozen beetles from Namibia, which promptly scampered all over the lab when he opened the box, but eventually settled contentedly on the dune. There, using a hair dryer and various misters and spray bottles, Parker simulated the conditions in the Namib Desert well enough to understand the beetle's mechanism. He then replicated it on a microscope slide, using tiny glass beads for the bumps and wax for the troughs.
For all nature's sophistication, many of its clever devices are made from simple materials like keratin, calcium carbonate, and silica, which nature manipulates into structures of fantastic complexity, strength, and toughness. The abalone, for example, makes its shell out of calcium carbonate, the same stuff as soft chalk. Yet by coaxing this material into walls of staggered, nanoscale bricks through a subtle play of proteins, it creates an armor as tough as Kevlar —3,000 times harder than chalk. Understanding the microscale and nanoscale structures responsible for a living material's exceptional properties is critical to re-creating it synthetically. So today Andrew Parker had arranged to view the skin of a thorny devil museum specimen under a scanning electron microscope, hoping to find the hidden structures that allow it to absorb and channel water so effectively.



Desktop Wallpaper
Buy NG Photos
Special Issues