earth-her uniqueness

The Compound Heat Shield of the Saharan Silver Ant

vova_mirnyy5 — Wed, 22 Mar 2017 19:41:50 GMT

The Compound Heat Shield of the Saharan Silver Ant

THE Saharan silver ant (Cataglyphis bombycina) is one of the most heat-tolerant land animals known. When the midday Saharan sun forces the ant’s predators to seek shade, the ant makes brief forays from its burrow in search of food, which consists of other insects killed by the intense heat.

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Consider: The silver ant’s assets include a compound heat shield made up of a covering of special hairs on the top and sides of its body and a hairless underside. The hairs, which give the ant a silvery sheen, are tiny tubes with a triangular cross section. Their two outward-facing surfaces have microscopic corrugations that run the length of the hair, while the inward-facing surface is smooth. This design serves two functions. First, it enables the hairs to reflect solar radiation in the visible and near-infrared ranges. Second, it helps the ant to dissipate body heat absorbed from the environment. Meanwhile, the ant’s hairless underside reflects radiation that is in the mid-infrared range and emanates from the desert floor. *

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The Saharan silver ant’s compound heat shield helps the insect to keep its body temperature below the maximum it can tolerate—128.5 degrees Fahrenheit (53.6°C). Inspired by that tiny creature, researchers are working to develop special coatings that enhance passive cooling—that is, cooling without the aid of fans or other devices.
What do you think? Did the compound heat shield of the Saharan silver ant come about by evolution? Or was it designed?

The Sea Otter’s Fur

vova_mirnyy5 — Wed, 22 Mar 2017 19:40:04 GMT

The Sea Otter’s Fur

MANY aquatic mammals that live in cold waters have a thick layer of blubber under the skin to help them stay warm. The sea otter relies on another insulation method—a thick fur coat.
Consider: The fur of the sea otter is denser than that of any other mammal, with some one million hairs per square inch (155,000 per sq cm). When the otter swims, its coat traps a layer of air close to its body. That air acts as an insulator, preventing the cold water from coming into direct contact with the animal’s skin and sapping its body heat.
Scientists believe that there is a lesson to be learned from the sea otter’s fur. They have experimented with a number of artificial fur coats, varying such factors as hair length and hair spacing. The researchers have concluded that “the denser and the longer the hairs are, the dryer or the more water-repellent the hairy surface is.” Put another way, sea otters can boast a truly efficient fur coat.
Researchers hope that their studies will lead to technological advances in the design and production of novel water-repellent textiles. This may lead some to wonder whether people who have to dive in cold waters may not be better off wearing a hairy wet suit—one similar to that of the sea otter!
What do you think? Did the heat-insulating fur of the sea otter evolve? Or was it designed?

The Landing Strategy of the Honeybee

vova_mirnyy5 — Wed, 22 Mar 2017 19:38:38 GMT

The Landing Strategy of the Honeybee

HONEYBEES can safely land at virtually any angle without problems. How do they do it?
Consider: A safe landing requires that the honeybee reduce its approach speed to nearly zero before contact. One logical way to do this would be to measure two factors—flight speed and the distance to the target—and then reduce speed accordingly. However, that method would be difficult for most insects because they have close-set, fixed-focus eyes that cannot directly measure distance.
The vision of honeybees is very different from that of humans who use binocular vision. Honeybees seem to use the simple fact that an object appears to get bigger as they approach it. The closer they get to an object, the faster it seems to increase in size. Experiments conducted at the Australian National University indicate that the honeybee decreases its flight speed so that the rate of apparent enlargement of an object remains constant. By the time the honeybee reaches its target, its speed has decreased to almost zero, allowing it to land safely.
The journal Proceedings of the National Academy of Sciences reports: “The simplicity and generality of this landing strategy . . . [make] it ideal for implementation in the guidance systems of flying robots.”
What do you think? Did the honeybee’s landing strategy evolve? Or was it designed?

The Whales Are Here!

vova_mirnyy5 — Wed, 22 Mar 2017 19:37:10 GMT

The Whales Are Here!

Every year, beginning in July, female southern right whales (Eubalaena australis) arrive at the southern coast of Santa Catarina, Brazil. They come from as far as the subantarctic, thousands of miles away, to give birth and nurse their calves in shallow waters. For several months residents and tourists at the beaches or on the cliffs are thrilled to watch the whales—mothers and calves resting or frolicking in the water! *

Giant Acrobatic Marine Creatures
A female can be 52 feet (16 m) long, about the size of an articulated bus, and weigh up to 80 tons! Its massive body is generally black, sometimes with white patches on the belly. The head is enormous, a quarter of the entire body length. The mouth is long and arched. This whale has no dorsal fin as do some other species. To swim forward, it flexes its broad and deeply notched tail up and down, instead of side to side as fish do. To change direction, it moves its flippers. This is similar to the way an airplane is steered.

Curiously, despite their immense proportions, right whales have considerable flexibility, performing some amazing acrobatics. You can see them sailing, the tail sticking out of the water for long periods; lobtailing, raising the tail and slapping the water hard; and breaching, thrusting themselves out of the water and then falling back with a great splash that can be seen from far away.

Distinctive Physical Characteristics
On and around the head, the right whale has a series of whitish or yellowish callosities—roughened patches of skin covered by colonies of small crustaceans (cyamids) known as whale lice. “Each callosity pattern is unique,” explains Karina Groch, coordinator of the Brazilian Right Whale Project, “just as each person’s fingerprints are unique, enabling the identification of individual right whales. We take photos of whales’ callosity patterns when they visit our shores and keep these photos in a directory.”

Biologists say that it is difficult to tell the right whales’ age when they die because this species of whale has no teeth. They estimate the whale’s life expectancy to be at least 65 years on average. *

Curious Eating Habits
Right whales feed on tiny crustaceans. On each side of the whales’ upper jaw are filtering structures made up of hundreds of baleen plates that are fringed with fine hairs. As they swim, their open mouth allows water to filter through the baleen plates, capturing the tiny prey in the baleen hairs. By this means each whale can consume up to two tons of crustaceans a day.

Southern right whales spend the summer (January/February) feeding in the Antarctic Ocean, building up blubber. This thick layer of fat provides excellent insulation when they are in cold waters and serves as food reserves when they migrate.

How Did They Get Their Name?
From the 18th century onward, whalers hunted these whales extensively in the Southern Hemisphere. They were considered the “right” whales to hunt. Why? Being slow swimmers, they were an easy catch, even for whalers in frail wooden boats that were equipped with only handheld harpoons. Besides, unlike other whales, right whales float when they are killed because of their extraordinary amount of blubber. Thus, whalers could easily drag them to the beach.

In addition, blubber and baleen were important commodities at the time. Blubber was used in street oil lamps and as a lubricant. Baleen was fashioned into things such as corset stays, buggy whips, and umbrella ribs. In fact, baleen plates obtained from one whale alone would cover the expenses of an entire expedition!

In the early 20th century, over-intensive hunting greatly reduced the right whale population, and eventually whaling was no longer commercially viable. In Brazil, the last whaling station was closed down in 1973. While there has been a slow recovery of some species, others remain critically endangered.

The right whale is definitely an outstanding example of the intricacy and great

The Flipper of the Humpback Whale

vova_mirnyy5 — Wed, 22 Mar 2017 19:35:27 GMT

The Flipper of the Humpback Whale

THE adult humpback whale is bigger and heavier than a city bus. Still, this colossal mammal is remarkably agile when diving and turning. How can the humpback whale be so nimble? Part of the secret lies in the bumps on its flippers.
Consider: Most whales and other cetaceans have flippers with smooth leading edges. However, the humpback whale is different. It has uniquely large bumps (called tubercles) on the leading edge of its flippers. As the humpback swims, water flows over the bumps and breaks up into a multitude of vortices. The bumps channel the water flow and create turbulence. This “tubercle effect” provides the whale with more lift, allowing it to tilt its flippers at a high angle without stalling. At high angles these bumps also reduce drag—an important benefit for the humpback’s long flippers, each being about one third of the whale’s body length.
Researchers are applying this concept to make more-efficient boat rudders, water turbines, windmills, and helicopter rotor blades.
What do you think? Did the flipper of the humpback whale come about by evolution? Or was it designed?

The Crocodile’s Jaw

vova_mirnyy5 — Wed, 22 Mar 2017 19:32:40 GMT

The Crocodile’s Jaw

THE crocodile has the most powerful bite ever measured 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 desig

The Parrot Fish—A Sand-Making Machine?

vova_mirnyy5 — Wed, 22 Mar 2017 19:30:17 GMT

The Parrot Fish—A Sand-Making Machine?

WHERE does sand come from? There are many sources. But the one described in this article might surprise you. It is a fish that grinds coral into fine sand—the parrot fish!
Parrot fish live in various tropical waters throughout the world. After swallowing crushed coral, they extract tiny food morsels and then expel the rest in the form of sand. To do its job, the parrot fish uses its powerful beaklike jaws and strong back teeth. Some species can live as long as 20 years, without wearing out their teeth.
In some areas, by busily chomping away on dead coral, the parrot fish produces more sand than any other natural sand-making process. Some researchers estimate that a typical parrot fish produces hundreds of pounds (kg) of sand a year.

Swarthy parrot fish
The parrot fish performs another vital task. As it grazes intensively on dead, algae-coated coral and vegetable material, it also keeps the coral clean. The peculiar diet of parrot fish thus maintains the reef in good condition. Where they and other grazers (herbivores) are absent, the reef quickly gets choked with algae and seaweed. “Some suggest that modern reefs would not exist in their present form if it were not for herbivores,” explains the book Reef Life.
All this activity during the day requires a good rest at night, and here again parrot fish are unusual. Nighttime is dangerous on the reef, since many predators are at large. Parrot fish usually sleep concealed under a ledge, but such a hiding place will not always protect them from a hungry shark.
For additional safety, some parrot fish wrap themselves up for the night. They secrete a protective mucus that envelops them, looking somewhat like a transparent nightgown. Marine scientists believe that this foul-smelling wrapping protects them from predators.
The parrot fish is one of the most visible and attractive fish of the reef. Male and female parrot fish often come in a whole palette of vivid colors, which change as they grow to adulthood. But best of all, parrot fish become quite tame in areas where they are not overfished. So they are some of the easiest fish to observe.
Getting up close to a parrot fish while watching and listening to it munch on coral is something few explorers of a coral reef will ever forget. And as parrot fish parade their finery, they keep their environment healthy for other reef creatures and us humans to enjoy.
PARROT-FISH FACTS
Parrot fish (known to scientists as Scaridae) are a large family of some 80 different species that frequent coral reefs throughout the Tropics. Their name comes from their distinctive mouth that looks somewhat like a parrot’s beak. The length of parrot fish ranges from 20 to 40 inches (50 to 100 cm).

The Light Organ of the Hawaiian Bobtail Squid

vova_mirnyy5 — Wed, 22 Mar 2017 19:28:08 GMT

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 “high-tech” 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?

Big Eyes—Tiny Body!

vova_mirnyy5 — Wed, 22 Mar 2017 19:26:22 GMT

Big Eyes—Tiny Body!

MOST would call it cute; some might call it bizarre. It has spindly legs, soft fur, and huge shining eyes. Its body is about five inches (12.5 cm) in length, and it weighs about four ounces (114 g). What is it? It is the tarsier!
Let’s take a closer look at one of these creatures, the Philippine tarsier. Its eyes, ears, hands, feet, legs, and tail all seem too big for its tiny body. Yet, a closer look at this oddity reveals ingenious design.
HEARING: The tarsier’s paper-thin ears can furl, unfurl, and turn to pick up the faintest sounds. Its keen hearing helps it not only to avoid predators, such as wild cats, but also to locate prey. After dark, the tarsier’s ears will tune in to the sound of crickets, termites, beetles, birds, and frogs. Then its whole head will follow, directing those bulging eyes toward its prospective meal.
GRIP: The tarsier’s hands are tailor-made for grasping thin branches. Its fingertips have distinctive pads with ridges that grip like the tread on a tire. Even while sleeping, the tarsier needs to hang on tight. Ridges on the underside of its long tail help it to remain firmly propped in position until it wakes up.
VISION: No other mammal has eyes that are as large in comparison with the size of its body. In fact, each of the tarsier’s eyes is larger than the animal’s brain! The tarsier’s eyes cannot turn in their sockets; they always stare straight ahead. Is this design a disadvantage? Not really. The tarsier is adequately compensated, as it has a flexible neck that allows it to turn its head 180 degrees in either direction.
AGILITY: The tarsier’s long legs give it the strength to jump a distance of up to 20 feet (6 m)—more than 40 times its own length! When hunting, the little predator leaps into the darkness with fingers outstretched to grab its victim with pinpoint accuracy.
Tarsiers rarely survive in captivity, partly because of their voracious appetite for live insects as well as their aversion to being handled. Still, this unique creature continues to fascinate the Filipino people. Almost every part of this endearing bug-eyed forest dweller is a surprise.
Protecting the Tarsier
In 1997, the government of the Philippines declared the Philippine tarsier a “specially protected” species. Hence, it is illegal to hunt it, damage its habitat, or even keep it as a pet. The tarsier enjoys the affection of the Filipino people and is an icon for tour

Airborne Gardeners of the Tropical Rain Forest

vova_mirnyy5 — Wed, 22 Mar 2017 19:24:35 GMT

Airborne Gardeners of the Tropical Rain Forest

AS ANY gardener knows, successful cultivation depends on sowing seeds in the right place at the right time. Strange as it may seem, however, some of the most effective sowing in the rain forest is done at night—and from the air. The airborne gardeners doing the sowing are Old World fruit bats—some of which are known as flying foxes. *
Spreading the Seed
Most fruit bats fly around at night, scouring the forest for trees that offer them tasty fruit or flowers rich in nectar. As they go about their aerial foraging, the bats digest fruit and expel undigested pulp and seeds. To complete their gardening work, they also pollinate flowers while sipping the nectar they enjoy so much.
Since fruit bats may cover long distances during the night, they can disperse seeds over a wide area. And because the bats pass some seeds through their digestive tract, they also provide “fertilizer” that encourages seed growth. Not surprisingly, a variety of plants in the rain forest depend on bats to pollinate their flowers or disperse their seeds.
Since they range far and wide, fruit bats have to have navigational skills and exceptional eyesight. In poor light, they can see better than humans. They can even distinguish some colors. And they are not at all averse to flying by day as well as by night.
Family Life
DID YOU KNOW? Unlike many other bats, fruit bats locate their food, not by echolocation, but by sight and smell. Their large eyes are well-suited to their nocturnal activity
The Samoan flying fox (Pteropus samoensis) species mates for life. As observed in some species, the female bat cares well for her offspring, carrying it with her for a few weeks and suckling it almost to adulthood. In the case of two species of fruit bat, the female may even get the services of a “midwife” to assist her during birth.
Sadly, many fruit bats are threatened with extinction, partly because of the destruction of their habitat. In the islands of the South Pacific, the disappearance of fruit bats would be catastrophic because some plant species of these islands seemingly cannot be pollinated without bats. Clearly, the work of these airborne gardeners should never be taken for granted.
SAVING THE FOREST
Baobab tree blossoms have at most a 24-hour life span. But that is enough time for fruit bats to locate the large blooms full of nectar and transfer the pollen to other baobab trees
When an area of tropical forest is cleared, bats play a key role in helping trees reestablish themselves in the cleared area. Their ‘gardening work’ can sow seeds that eventually become new trees. “The quality of life for humans is directly related to a healthy global environment, and keeping that environment healthy requires bats,” says the book Bats of the World, by Gary L. Graham.