Byssus Threads

            The Byssus of the Marine Mussel

     LIKE barnacles, marine mussels attach themselves to rocks, wood, or ship hulls. However, unlike barnacles, which fasten themselves tightly to a surface, marine mussels dangle by a network of thin filaments called byssus threads. While this method increases the mussel’s flexibility for feeding and migration, the threads seem too flimsy to withstand the impact of ocean waves. How does the byssus allow the mussel to hang on and not be swept out to sea?

Consider: Byssus threads are stiff on one end, yet soft and stretchy on the other. Researchers have found that the precise ratio used by the mussel—80 percent stiff material to 20 percent soft—is critical for providing the strongest attachment. Hence, the byssus can handle the force of dramatic pulling and pushing by marine waters.

Professor Guy Genin calls the results of this research “stunning,” adding: “The magic of this organism lies in the structurally clever integration of this compliant region with the stiff region.” Scientists believe that the design of the byssus threads could have uses as diverse as attaching equipment to buildings and underwater vessels, connecting tendons to bones, and sealing surgical incisions. “Nature is a bottomless treasure trove, as far as adhesion strategies go,” says J. Herbert Waite, a professor at the University of California in Santa Barbara, U.S.A.

What do you think? Did the byssus of the marine mussel come about by evolution? Or was it designed?

Butterfly's Mystery

        The Painted Lady—A Mystery Revealed

EUROPEAN observers have long admired colorful painted lady butterflies (Vanessa cardui) and have wondered what happened to them at the end of each summer. Do they simply perish with the onset of cold weather? Fresh research reveals an extraordinary story. The butterflies make an annual journey between northern Europe and Africa.

Researchers combined results from sophisticated radar with thousands of sightings reported by volunteers across Europe. The results revealed that as the summer ends, millions of painted lady butterflies migrate south, mostly flying at an altitude of more than 1,600 feet (500 m)—therefore hardly ever seen by humans. The butterflies wait for favorable winds, which they ride at an average speed of 28 miles per hour (45 km/h) on the long trip to Africa. Their annual migration is up to 9,300 miles (15,000 km) long, beginning from as far north as the fringes of the Arctic and terminating as far south as tropical West Africa. The trip is almost double that of  the North American monarch butterfly. It takes six successive generations of painted ladies to complete the round-trip.

Professor Jane Hill of the University of York, in England, explains: “The Painted Lady just keeps going, breeding and moving.” Annually, those steps take the whole population from northern Europe to Africa and back again.

“This tiny creature weighing less than a gram [0.04 oz] with a brain the size of a pin head and no opportunity to learn from older, experienced individuals, undertakes an epic intercontinental migration,” states Richard Fox, surveys manager at Butterfly Conservation. This insect was “once thought to be blindly led, at the mercy of the wind, into an evolutionary dead end in the lethal British winter,” Fox adds. Yet this study “has shown Painted Ladies to be sophisticated travellers.”

Blood Clotting

 The Human Body’s Ability to Repair Wounds

AMONG the numerous mechanisms that make human life possible is the body’s ability to heal wounds and regenerate damaged tissue. The process begins as soon as an injury occurs.

Consider: The healing process is made possible by a cascade of complex cellular functions:

• Platelets adhere to tissues around a wound, forming a blood clot and sealing damaged blood vessels.
• Inflammation protects against infection and removes any “debris” caused by the injury.
• Within days, the body begins to replace injured tissue, make the wound contract, and repair damaged blood vessels.
• Finally, scar tissue remodels and strengthens the damaged area.

Inspired by blood clotting, researchers are developing plastics that can “heal” damage to themselves. Such regenerating materials are equipped with tiny parallel tubes containing two chemicals that “bleed” when any damage occurs. As the two chemicals mix, they form a gel that spreads across the damaged areas, closing cracks and holes. As the gel solidifies, it forms a tough substance that restores the material’s original strength. One researcher admits that this synthetic healing process currently under development is “reminiscent” of what already exists in nature.

What do you think? Did the body’s ability to repair wounds come about by evolution? Or was it designed?

Fascinating lesson in Teamwork

           The Extraordinary Clown Fish       

FEW fish grab our attention the way the clown fish does. Perhaps it wins our hearts with its fancy coloring, which may remind us of a circus clown. Or maybe we are struck by its surprising choice of home—among the stinging tentacles of a sea anemone. Not surprisingly, another name for the clown fish is anemonefish.

Like many Hollywood actors, clown fish are not averse to photographs. Divers and snorkelers can usually expect clown fish to “pose” for pictures, since they rarely stray far from home and are not particularly shy.

But what makes clown fish extraordinary is their seemingly risky lifestyle. Living among poisonous tentacles would seem to be comparable to setting up home in a nest of serpents. Still, clown fish and their anemone of choice are inseparable. What makes this strange partnership possible and successful?

‘I CANNOT LIVE WITHOUT YOU’

           Two-banded clown fish

Like most good partnerships, clown fish and anemones give and take. The relationship is not merely convenient for the 

 

clown fish; it is vital. Marine biologists have confirmed that clown fish cannot live in the wild without a host anemone. They are poor swimmers and would be at the mercy of hungry predators without the anemone’s protection. However, by using the anemone as a home base and as a safe shelter when threatened, the clown fish may reach ten years of age.

The anemone provides a safe nesting site as well as a home. The clown fish deposit their eggs at the base of the host anemone, where both parents keep careful watch over them. Later, the clown fish family can be seen swimming around that same anemone.

What does the anemone get out of this relationship? The clown fish serve as marine bodyguards, driving away butterfly fish that like to feed on anemone tentacles. At least one species of anemone cannot live without resident clown fish. When researchers removed the clown fish, within just 24 hours, the anemones had disappeared completely. Apparently, butterfly fish had consumed them.

It seems that clown fish even provide their host with energy. The ammonium that clown fish excrete helps spur growth in the host anemone. And as the clown fish swim among the tentacles, they help circulate oxygen-rich water to the anemone.

GOING WHERE OTHERS FEAR TO SWIM

             Pink skunk clown fish

In the case of clown fish, protection is skin-deep. They have mucus on their skin that keeps them from being stung. Thanks to this chemical coating, it seems the anemone considers the clown fish one of its own. As one marine biologist put it, the clown fish becomes “a fish in anemone’s clothing.”

Some studies suggest that when selecting a new host, the clown fish has to go through a process of adaptation. It has been observed that when the fish approaches an anemone for the first time, it touches the anemone intermittently for a few hours. Apparently, this on-and-off contact allows the clown fish to modify its protective coating to conform to the new anemone’s particular poison. Possibly the clown fish gets stung a little during this process. But after that, the two get along fine.

The collaboration of such different creatures offers a fascinating lesson in teamwork. In so many human endeavors, people from diverse cultures and backgrounds achieve remarkable results by pooling their resources. Like the clown fish, we may take a little time to adapt to working with others, but the results are well worth it.  Was it evolved or designed?

CuttleFish

The Color-Changing Ability of the Cuttlefish

       CUTTLEFISH can change their color and camouflage themselves, becoming almost invisible to the human eye. According to one report, cuttlefish “are known to have a diverse range of body patterns and they can switch between them almost instantaneously.” How do cuttlefish do it?

Consider: The cuttlefish changes color by using the chromatophore, a special kind of cell found under its skin. Chromatophores contain sacs that are full of colored pigment and that are surrounded by tiny muscles. When the cuttlefish needs to camouflage itself, its brain sends a signal to contract the muscles around the sacs. Then the sacs and the pigment within them expand, and the cuttlefish quickly changes its color and pattern. The cuttlefish may use this skill not only for camouflage but also to impress potential mates and perhaps communicate.

Engineers at the University of Bristol, England, built an artificial cuttlefish skin. They sandwiched disks of black rubber between small devices that function like cuttlefish muscles. When the researchers applied electricity to the skin, the devices flattened and expanded the black disks, darkening and changing the color of the artificial skin.

Research on cuttlefish muscles—“the soft structures that nature is so good at making,” according to engineer Jonathan Rossiter—could lead to clothing that changes color in a fraction of a second. Rossiter says that people might wear cuttlefish-inspired clothes for camouflage—or simply for fashion.

What do you think? Did the ability of cuttlefish to change color come about by evolution? Or was it designed?

Katydid

 The Katydid’s Remarkable Hearing

THE South American bush katydid (Copiphora gorgonensis) has ears less than a millimeter long, yet they work in a way very similar to human ears. The insect can distinguish a wide range of frequencies from long distances. For example, it can tell the difference between the sound of another katydid and the ultrasound of a bat that is hunting.

KATYDID’S EAR

Consider: The katydid’s ears are located on its two front legs. Like the human ear, the ear of the katydid collects sound, converts it, and analyzes the frequency. But scientists have discovered a unique organ inside the ear of this insect—a pressurized fluid-filled cavity that looks like an elongated balloon. This organ, which they named the acoustic vesicle, works like the cochlea of mammals but is much smaller. The acoustic vesicle is responsible for the katydid’s remarkable hearing.

Professor Daniel Robert, of the University of Bristol’s School of Biological Sciences in the United Kingdom, says this discovery will help engineers “develop bio-inspired hearing devices that are smaller and more accurate than ever before.” Researchers believe it will also contribute to the next generation of ultrasonic engineering technology, including imaging systems for hospitals.

What do you think? Did the remarkable hearing of the katydid come about by evolution? Or was it designed?

Honeycomb

THE HONEYCOMB

       HONEYBEES (Apis mellifera) construct their honeycombs with wax secreted from glands found on the underside of their abdomen. The honeycomb is regarded as an engineering marvel. Why?
Consider: For centuries, mathematicians suspected that partitions in the shape of hexagons were better than equilateral triangles or square—or any other shape—for maximizing space with the least amount of building material. But they could not fully explain why. In 1999, Professor Thomas C. Hales provided mathematical proof for the advantage of what he termed “honeycomb conjecture.” He demonstrated that regular hexagons are the best way to divide a space into equal parts with minimal structural support. By using hexagonal cells, bees can make the best use of all the space available to them, produce a light but sturdy honeycomb with a minimum amount of wax, and store the maximum
amount of honey in a given space. Not surprisingly, the honeycomb has been described as “an architectural masterpiece.” Today, scientists mimic the bees’ honeycomb to create structures that are both resilient and space efficient. Aircraft engineers, for example, use panels patterned after the honeycomb to build planes that are stronger and lighter and thus use less fuel. What do you think? Did the superior structure of the honeycomb come about by evolution? Or was it designed?

Hawaiian Bobtail Squid

THE LIGHT ORGAN OF THE HAWAIIAN BOBTAIL SQUID

           A NOCTURNAL hunter, the Hawaiian bobtail squid creates its own light—not to be seen, but to be unseen—to blend in with the ambient moonlight and starlight. The animal’s secret is its partnership with light-emitting bacteria. That partnership may also hold secrets that could benefit us, but in a seemingly unrelated way. It may benefit our health.

      Consider: The Hawaiian bobtail squid lives in the clear coastal waters of the Hawaiian Islands. Light from the moon and the stars would normally make the silhouette of the creature stand out to predators below. The bobtail squid, however, emits a glow from its underside that mimics ambient night light in both intensity and wavelength. The result is stealth—no silhouette, no shadow. The squid’s “hightech” apparatus is its light organ, which houses bioluminescent bacteria that produce just the right glow to camouflage their host. The bacteria may also help to regulate the squid’s sleep-wake pattern. This interests researchers because the bobtail squid may not be the only creature where there is a link between bacteria and circadian cycles, or daily rhythms in activity. In mammals, for example, bacteria that play a role in digestion may also be associated with circadian rhythms. Disturbances of these rhythms have been linked to depression, diabetes, obesity, and sleep disorders. Hence, the study of the squid’s bacteria-host system may furnish insights into human health. What do you think? Did the light organ of the Hawaiian bobtail squid come about by evolution? Or was it designed?

Wings of Soaring Birds

The Upturned Wing Tip of Soaring Birds

       AJET plane in flight creates rapidly spiraling swirls of air at the tips of its wings. These vortices cause drag, increasing fuel consumption. They also buffet planes that may be following closely. Thus, flights departing from the same runway must be sufficiently spaced to allow time for the vortices to dissipate.  Airplane engineers have discovered a way to reduce these problems. Their solution? Winglets, inspired by the upturned wing-tip feathers of soaring birds, such as buzzards, eagles, and storks.

Consider:   During flight, the feathers on the wing tips of those large birds bend upward until they are almost vertical. This configuration balances maximum lift with minimum wing length. It also improves performance. Engineers have designed airplane wings with a similar shape. Using innovative wind-tunnel testing, they found that if the modified wings were precisely curved at the tip and properly aligned with the airflow, they improved aircraft performance—nowadays by up to 10 percent or more. The reason? Winglets minimize drag by reducing the size of the vortices. Moreover, winglets also create a form of thrust that “counteracts some of the normal drag of the airplane,” says the Encyclopedia of Flight. Winglets thus enable airplanes to fly farther, carry a greater load, have shorter wings—which also facilitates parking—and save fuel. In 2010, for example, airlines “saved 2 billion gallons [7,600 million L] of jet fuel worldwide” and contributed to large reductions in aircraft emissions, says a NASA news release. What do you think? Did the upturned wing tip of soaring birds come about by evolution? Or was it designed?

Crocodile's Jaw

 CROCODILE'S JAW

     THE crocodile has the most powerful bite ever easured for animals that are now living. For example, the saltwater crocodile, found near Australia, can bite nearly three times as hard as a lion or a tiger. Yet, the crocodile’s jaw is also incredibly sensitive to touch—even more sensitive than the human fingertip. How can that be, considering the crocodile’s armored skin? The crocodile’s jaw is covered with thousands of sense organs. After studying them, researcher Duncan Leitch noted: “Each of the nerve endings comes out of a hole in the skull.” This arrangement protects the nerve fibers in the jaw while providing sensitivity that in some spots is greater than instruments could measure.  As a result, the crocodile can distinguish between food and debris in its mouth.  That is also how a mother crocodile can carry her hatchlings in her mouth without accidentally crushing them. The crocodile’s jaw is a surprising combination of power and sensitivity. What do you think? Did the crocodile’s jaw come about by evolution? Or was it designed? 

Greater Wax Moth

Remarkable Hearing of the Greater WAX MOTH

     THE greater wax moth can hear high pitched sound better than any known creature in the world. Yet its ears are very simple in structure, each being about the size of a pinhead.

Consider:  For years, the greater wax moth’s hearing has been a subject of study. More recently, scientists at the University of Strathclyde, Scotland, tested the moth’s hearing with a wide range of

sounds. They measured the vibrations of these tympanal membranes and recorded the activity of their auditory nerves.  The “eardrums” still responded when exposed to sounds at a frequency of 300 kilohertz. By comparison, bat echolocation has been recorded at up to 212 kilohertz, the hearing of dolphins peaks at 160 kilohertz, and humans do not hear beyond 20 kilohertz.  Researchers would like to use the superior hearing capability of the greater wax moth as the basis for new technology.

How? “To help make better, and smaller, microphones,” says Dr. James Windmill of the University of Strathclyde.  “These could be put in a wide range of devices such as mobile phones and hearing aids.”  What do you think? Did the remarkable hearing of the greater wax moth come about by evolution? Or was it designed?

Cat Whiskers

The Function of Cat Whiskers

           DOMESTIC cats are mostly nocturnal. Whiskers apparently help them to identify nearby objects and catch prey, particularly after dusk. Consider: Cats’ whiskers are attached to tissues that have multiple nerve endings. These nerves are sensitive to even the slightest movement of air. As a result, cats can detect nearby objects without seeing them—obviously an advantage in the dark.  Since whiskers are sensitive to pressure, cats use them to determine the position and movement of an object or of prey. Whiskers also help cats to measure the width of an opening before they attempt to go through it. The Encyclopedia Britannica acknowledges that “the functions of the whiskers (vibrissae) are only partially understood; however, it is known that, if they are cut off, the cat is temporarily incapacitated.”  Scientists are designing robots equipped with sensors that mimic cat whiskers to help the robots navigate around obstacles. These sensors, called e-whiskers, “should have a wide range of applications for advanced robotics, human-machine user interfaces, andbiological applications,” says Ali Javey, a faculty scientist at the University of California, Berkeley.  What do you think? Did the function of cat whiskers come about by evolution? Or was it designed?

Plants

THE MATHEMATICAL ABILITY OF PLANTS

   

     PLANTS use a complex process called photosynthesis to extract energy from sunlight to create food. Studies on certain species have revealed that they perform yet another feat—they calculate the optimum rate at which to absorb that food overnight.

        Consider: By day, plants convert atmospheric carbon dioxide into starch and sugars. During the night, many species consume the starch stored during the day, thus avoiding starvation and maintaining plant productivity, including growth. Moreover, they process the stored starch at just the right rate—not too quickly and not too slowly—so that they use about 95 percent of it by dawn, when they start making more. The findings were based on experiments on a plant of the mustard family called Arabidopsis thaliana. Researchers found that this plant carefully rations its food reserves according to the length of the night, no matter whether 8, 12, or 16 hours remained until dawn. Evidently, the plant divides the amount of starch available by the length of time remaining until dawn, thus determining the optimal rate of consumption. How do plants ascertain their starch reserves? How do they measure time? And what mechanism enables them to do math? Further research may shed light on these questions. What do you think? Did the mathematical ability of plants come about by evolution? Or was it designed?

Ant

WAS IT DESIGNED?

                                         THE ANT'S NECK

           MECHANICAL ENGINEERS marvel at the ability of a common ant to lift weights many times heavier than its own body. To understand this ability, engineers at Ohio State University, U.S.A., reverse engineered some of the ant’s anatomy, physical properties, and mechanical functions by means of computer models. The models were created using X-ray crosssectional images (micro CT scans) and simulations of the forces an ant generates when carrying loads. A critical part of the ant’s anatomy is its neck, which has to bear the full weight of loads grasped in its mouth. Soft tissues within the ant’s neck bind with the stiff exoskeleton of its thorax (body) and head in a manner that mimics the interlocking of fingers in folded hands. “The design and structure of this interface is critical for the performance of the neck joint,” says one ofthe researchers. “The unique interface between hard and soft materials likely strengthens the adhesion and may be a key structural design feature that enables the large load capacity ofthe neck joint.” Researchers hope that a clear grasp of how the ant’s neck functions will contribute to advancements in the design of man-made robotic mechanisms. What do you think? Did the ant’s neck with its complex and highly integrated mechanical systems evolve? Or was it designed? 

Flight of Albatross