July 10, 2013 | David F. Coppedge

Animal and Plant Tricks

There’s no end of amazing tricks in the living world – adaptations that aid their success.  Finding them is one thing.  Explaining them is another.

Electric webs:  There’s electricity in the air around spider webs, Science Now says in “Spider Silk Grabs Electrically Charged Insects in Midair.”  Flying insects pick up static eletricity as they fly (a honeybee can pick up 200 volts).  Spider silks get a charge out of greeting the food service, flexing up to 2 mm at a fast rate of 7 m/s when the prey approaches.  More study is needed, Live Science cautioned, to see if all flying insects, such as the spiders’ preferred diet of flies, pick up static electricity.

Jumping fish:  A swamp dweller called the mangrove rivulus has a unique hopping method, Live Science reports.  Unlike the largemouth bass that flexes into a C-shape and jumps but gets nowhere fast, the rivulus does a unique tail flip that sends it on the path to progress (see video clip in the article).  On land, the mostly-hermaphroditic fish can live for up to two months feeding on insects while absorbing oxygen through its skin.

Self-cleaning guillemot eggs:  The eggs of the guillemot, a seabird, are covered in small conical pimples that shed water, the BBC News reported.  This helps them avoid the saltwater and detritus in the birds’ crowded colonies.  The roughness of the shell may also give the eggs a better foothold on the rocky cliffs where the females lay their eggs.

Bat battery:  Using elastic energy stored in their wing tendons, fruit bats get better mileage, Science Daily reports.  When taking off, this “recycled energy” stored from previous wing flaps gives them an extra boost.  This ability is apparently unique among small mammals.  The article ends with a touch of biomimetics: “This research will likely have relevance for the development of autonomous micro aircrafts and potentially also amphibious search and rescue vehicles.”

Jerboa jumps:  Jerboas are little desert rodents that look like a cross between a mouse and a kangaroo (see picture in Science Daily).  The small bipedal jumpers have not been studied much.  Science Daily says that their hops, skips and jumps allow them to compete with four-footed rodents in Old World deserts.  The unpredictability of their trajectories gives the jerboas a way to coexist in the niche occupied by quadrupedal rodents.

RNA regulates flowering time:  There’s new insight into how perennial plants know they are old enough to flower, and that the right season has arrived.  An article on Science Daily reports that “Alpine Rock Cress Uses a Ribonucleic Acid to Measure Its Age and Tell When It’s the Right Time to Flower.”  The concentration of a small RNA “works like an hourglass,” the article explains.

One can hypothesize about the origins of these adaptations by considering horizontal and vertical axes of information.  The horizontal axis represents variations of existing genetic information.  The vertical axis would require gain or loss of information.  With that in mind, we might suspect that the guillemot egg did not require intelligent design, since it represents accentuation of existing dimples in the eggshell.  The most-dimpled ones survived the salty, steep environment to bring a new generation of birds, whereas others were more susceptible to damage or falling.  The RNA hourglass in flowering plants, though, appears to be a system that required programming from the beginning.  There’s nothing about a particular small RNA molecule that would signal a plant to flower unless other systems exist to measure its concentration and use that metric to signal downstream processes.  Try your skill with each organism to see where on the axes the adaptations might lie, realizing that scientific explanations are not necessarily part of science, especially when speculation exceeds testability.  Avoid just-so stories.


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