Super Designs in Amazing Animals, Part I
Animals of all kinds, sizes and shapes have mastered physical principles in astonishing ways.
Peacock spiders, those incredibly fast-moving dancers with colorful fantails to impress females, know another trick to make their shimmering abdominal displays stand out. Phys.org reports, “Bumps on peacock spider make dark spots super-dark.” The fantails of these tiny (4mm) Australian spiders seem to almost glow, not because of pigment, but because of optical tricks.
The researchers report that part of the reason the colors were so striking on the abdomen was because the black, velvety parts next to them were incredibly black. When they took a very close look at the black parts, they observed bumps with a unique structure. When they reproduced the bumps in a simulation, they found that they manipulated light in two ways to reduce reflection. First, their curved surfaces made light bounce in random directions, directly reducing reflection. And second, they found that each of the bumps was a tiny microlens—each forced light that entered to take a longer path as it interacted and was ultimately absorbed by the black melanin pigment. Together, the features of the bumps reflected less than 0.5 percent of the light that struck them.
How did these spiders learn both pigments and structural colors to do this? If you haven’t seen them perform, by all means take a look at some of the YouTube videos posted by Peacockspiderman (Jurgen Otto), the biologist who brought their ‘spiders’ got talent’ dances to light in 2008 for the enjoyment of millions of viewers. His latest new video was posted just a week ago.
Kingfishers are kings at fishing partly because of their aerodynamic beaks that plow through water smoothly and silently. Scientists at Bangor University, according to Phys.org, searched all species for the champions. Not unexpectedly, the species that spend the most time diving after fish had the best beaks.
Asked why this research was valuable, Kristen explained that although designers use the natural world as inspiration and that the kingfisher beak shape had been used to redesign bullet trains to remove a sonic boom as they compressed air when entering tunnels, the design solution had come through observation, but no one had actually validated the kingfisher beak shape under lab conditions.
Achieving a greater understanding of how shapes behave could lead to more bio engineering solutions in the future.
The article makes a common mistake in evolutionary theory by claiming that “Some kingfishers forage rather than dive for food, so their beaks have not evolved to break the water so seamlessly.” No animal part “evolves to” do something or not do something. Evolution is blind and purposeless. A better explanation is that the kingfishers that found other ways to eat than diving for fish lost the ideal beak shapes of their champion counterparts.
Color Vision in Total Darkness
How do deep-sea fish get around and find their prey? They have amazingly adapted eyes. Scientists studied the eyes of five species of fish that live below the photic (light) zone, and found retinas rich in highly-sensitive rods and cones, layered in a way that accentuates light – not light from the sun, but light from bioluminescent organisms. Elizabeth Pennisi exclaims in Science, “Jeepers, Creatures, Where’d You Get Those Peepers”?
When the ancestors of cave fish and certain crickets moved into pitchblack caverns, their eyes virtually disappeared over generations. But fish that ply the sea at depths greater than sunlight can penetrate have developed super-vision, highly attuned to the faint glow and twinkle given off by other creatures. They owe this power, evolutionary biologists have learned, to an extraordinary increase in the number of genes for rod opsins, retinal proteins that detect dim light. Those extra genes have diversified to produce proteins capable of capturing every possible photon at multiple wavelengths—which could mean that despite the darkness, the fish roaming the deep ocean actually see in color.
The finding “really shakes up the dogma of deep-sea vision,” says Megan Porter, an evolutionary biologist studying vision at the University of Hawaii in Honolulu who was not involved in the work. Researchers had observed that the deeper a fish lives, the simpler its visual system is, a trend they assumed would continue to the bottom. “That [the deepest dwellers] have all these opsins means there’s a lot more complexity in the interplay between light and evolution in the deep sea than we realized,” Porter says.
Where’d you get those peepers, indeed. One could claim that existing opsins just got duplicated and enhanced. Perhaps. But it would be far less costly for fish to stay in the light. Duplication, furthermore, does not add information any more than photocopying does. The real question is the origin of opsins in the first place in animals without the neurons and brains to use the information. Why would an organism evolve a light-sensitive spot when it doesn’t even know what light is? Opsins alone do not create vision. Many interacting genes, proteins, and organs have to be present simultaneously. Since eyes presuppose foresight to use it, the sensible explanation is that the Eye-Maker gave organisms ability to adapt to different environments.
No matter where you look in the biosphere, animals have superpowers that our engineers drool over. One thing is clear: these animals did not design themselves. Something more clear: the Stuff Happens Law did not hit on these designs by sheer dumb luck.