Super Designs in Amazing Animals, Part 2
Organisms of all kinds, sizes and shapes have mastered physical principles in astonishing ways. Here are more examples.
Another spider story on Phys.org announces the first know case of a spider that can fling itself directly at prey. Just when you thought spiders could not get more terrifying,
A study published Monday has found that at least one arachnid species is capable of winding up its web to store up elastic energy, before releasing its grip and catapulting itself at furious speed toward its unsuspecting prey. The ability to store and amplify muscular energy in external devices like bows, bolt-throwers and catapults was long thought to be unique to humans. Now, though, we can add the triangle-weaver spider, or Hyptiotes cavatus, to the list, according to a study published Monday, May 13, 2019 that describes how the creature winds up its web to launch itself at prey.
Electric Sensors in Diatoms
A new kind of membrane channel was found in diatoms, the one-celled eukaryotic algae in oceans and fresh waters that live inside ornate houses of glass. Researchers publishing in Current Biology found that these previously-unknown channels conduct electricity that the diatom “reads” like an electrical message about its surroundings.
But what information does a single-celled organism such as a diatom obtain from action potentials and Ca2+ transients? The phytoplankton needs to sense its biological and non-biological environment to grow and survive. Information is required about nutrient availability, stress factors, and the nature of close neighbors to get in contact with or flee from. Diatoms are able to migrate towards sediment rich in nutrients.
This ability is remarkable, considering that the electrical nature in water differs markedly between salt water and fresh water. The new findings “open the door to the world of single, miniature, capsuled, photosynthetic plankton cells,” commentator Rainer Hedrich says, but many questions remain. What is the message conveyed by these action potentials, and how does the tiny diatom interpret them? How does that result in an action response, like migrate toward it or flee? Where are these abilities encoded in the genes? Hedrich even asks, “Can diatoms count and respond accordingly to the number of APs, similar to the Venus flytrap, an excitable, carnivorous plant?
Hippos as Silicon Pumps
The hippopotamus takes in silicon-rich grass and then – well, all that silicon has to go somewhere. “By eating huge amounts of grass and then defecating in water,” New Scientist says, “hippos are acting like living silicon pumps – and the health of their habitat may depend on it.” A single hippo can take in 40 kg of grass a day. A herd of hippos can transport 0.4 tons of it daily. Single-celled microbes and algae, the base of the food chain, depend on silica (silicon dioxide). “Hippos act as a kind of conveyor belt,” says reporter Ruby Prosser Scully, “transporting silica from land to water.”
Firefly Efficiency Experts
A Belgian physicist was intrigued by fireflies as he camped in Central America on a field trip. Watching their dazzling display at night, he wondered how the flying insects emitted so much light without waste heat. Jean-Pol Vigneron took some of the bugs home, a short video on the BBC News says. His team found that the translucent cuticle over the light-emitting organ has an unusual shape. Each “tile” of cuticle overlaps like roof shingles, protruding in different directions. In addition, they found that the cross sections of these overlapping scales form right angles, like the profile of a factory roof. The team used lasers to etch a similar shape on light-sensitive material, and placed it over their test LED bulb. They found that it increased the efficiency of the bulb phenomenally – by 50 percent!
No matter where you look in the biosphere, organisms have superpowers that our engineers drool over. One thing is clear: these organisms did not design themselves. Something more clear: the Stuff Happens Law did not hit on these designs by sheer dumb luck.