How Does a Zebrafish Grow a New Tail?

If a zebrafish loses a chunk of its tail fin, it will grow back within a week. Like lizards, newts, and frogs, a zebrafish can replace surprisingly complex body parts. A tail fin, for example, has many different types of cells and is a very intricate structure. It is the fish version of an arm or leg.

Scientists have discovered some of the genes and cell-to-cell communication pathways that enable zebrafish to restore their tail fins. The ability involves creating cells that can take any number of new roles. This can be done by re-programming cells that already have a given function or by activating resident stem cells. Through a series of signals, cells waiting for their calling learn which spot to take to help form the embryo, what kinds of cells to become there, and how many cells like themselves should be reproduced.

Amazing Parrot

A captive African grey parrot named N'kisi has a vocabulary of 950 words, and shows signs of a sense of humor! He invents his own words and phrases if he is confronted with new ideas with which his existing repertoire cannot cope - just as a human child would do. Only about 100 words are needed for half of all reading in English, so if N'kisi could read he would be able to cope with a wide range of material. He uses words in context, with past, present and future tenses, and is often inventive.

One N'kisi-ism was "flied" for "flew", and another "pretty smell medicine" to describe the aromatherapy oils used by his owner, an artist based in New York. When he first met Jane Goodall, the renowned chimpanzee expert, after seeing her in a picture with apes, N'kisi said: "Got a chimp?" When another parrot hung upside down from its perch, he commented: "You got to put this bird on the camera."

UPDATE:

This page has a link to a "conversation" between N'kisi and his trainer. She is using a musical children's toy with buttons as a training aid.

New Zealand Fossil Challenges Scientific Theory

A team of scientists has discovered a unique, primitive type of land mammal that lived at least 16 million years ago in New Zealand. The discovery of tiny fossilized bones of a mouse-like creature in the Central Otago region is the first hard evidence that New Zealand once had its own indigenous land mammals. The finding could prompt a major rewrite of pre-history textbooks.

Scientists have long believed that New Zealand had an unusual avian biota that lived on the ground because there were no mammals to impede or compete with birds. It appears that this little mouselike animal was part of the fauna on the ancient Gondwana supercontinent and it got stuck on New Zealand when it separated from the continent more than 80 million years ago. The discovery also challenges geological claims that New Zealand was entirely submerged beneath the sea from 25 to 30 million years ago and re-colonized by plant and animal species from nearby land masses like Australia once it re-emerged.

Newly Discovered Sea Critters

Creatures thriving at the hot and cold extremes of the marine environment have amazed scientists who are celebrating the discovery of 500 previously unknown species in the oceans in the past year.

They have been found beneath ice shelves, in the darkest, deepest abysses and in scalding water around hydrothermal vents on the sea bed. They have smashed records for distance, numbers and sheer tenacity in the most inhospitable habitats imaginable.

Among the most astonishing discoveries is a shrimp living within inches of the hottest water yet found at the bottom of the oceans. The animals live on a thermal vent at the equatorial floor of the Atlantic Ocean that spews out water and a soup of heavy metals heated to 765F — more than hot enough to melt lead! The shrimps dependent on the vent live in a narrow band of water at 140F and because of swirling currents are frequently washed with water at 176F or hotter. Scientists are intrigued about how they survive at such extreme temperatures and are trying to find out why their proteins do not break down. The species has yet to be determined, but is very similar to the Rimicaris exoculata shrimp seen at cooler vents.

At other oceanic extremes scientists discovered dozens of animals, including jellyfish, living beneath ice 2,300ft thick and 125 miles from open water. Among the biggest surprises discovered this year by census takers in the Coral Sea, northeast of Australia, was Neo glyphea neocaledonica, a shrimp previously thought to have died out 50 million years ago. It has been dubbed the “Jurassic Shrimp”. The biggest marine animal to be discovered was Palinurus barbarae, a rock lobster located off Madagascar. It weighed 4lbs and its body, excluding legs and pincers, was more than 18in long.

Other previously unknown species include a squid from the mid-Atlantic that rather than simply bite and swallow chunks of prey is thought to be able to chew its food, and Kiwa hirsuta, a furry crab living on a hydrothermal vent 900 miles from Easter Island.

In the Sargasso Sea, 200 zooplankton species, 12 previously unknown, were found three miles beneath the surface while in the air the sooty shearwater broke the record for migratory distance by flying a round trip of 46,000 miles!

Tiny Animals On Fingers

The title of this Flickr group says it all. Below are some neat examples:

Honda's New "Ultra-Clean" Diesel Fuel System

Honda has announced a new "ultra-clean" diesel fuel system. Diesel engines now power half of Europe's new cars and are slowly becoming popular with fuel-conscious consumers around the world. They typically get 30% better mileage than gasoline cars, but their weakness has been the higher exhaust levels of nitrogen oxide (NOx), a greenhouse gas.

Honda said its new diesel system has a unique method that generates and stores ammonia within a two-layer catalytic converter to turn nitrogen oxide into harmless nitrogen.

The company plans to introduce the new engine in the United States within three years.

Man builds 105 MPG car

For only $2,339 and 1,000 hours of labor, Jory Squibb built a 105 MPG car using two old Honda motorcycles. The car is capable of a 53 MPH top speed and returns over 80 MPG in the city and over 105 MPG on highway. He calls his car Moonbeam. Although it’s a two-seater, it’s best for one adult and one child. It’s practical as a grocery-getter with its space for storage behind the seats and on both sides of the engine. Plus, it’s a convertible.

World's tallest man saves two dolphins

In Beijing, China the long arms of the world's tallest man reached in and saved two dolphins by pulling out plastic from their stomachs. The dolphins got sick after nibbling on plastic from the edge of their pool at an aquarium. Veterinarians asked for help from Bao Xishun, a 7-feet-9 herdsman from Inner Mongolia with 41.7-inch arms. Xishun was confirmed in 2005 by the Guinness Book of World Records as the world's tallest living man.

Flying Mammal From 125 Million Years Ago

Scientists have discovered an extinct animal the size of a small squirrel that lived in China at least 125 million years ago and soared among the trees. It is the earliest known example of gliding flight by mammals, and the scientists say it shows that mammals experimented with aerial life about the same time birds first took to the skies, perhaps even earlier.

From an analysis of the fossil, the researchers concluded that this gliding mammal was unrelated to the modern flying squirrel and unlike any other animal in the Mesozoic, the period best known for dinosaurs living in the company of small mammals. They announced today that the species qualified as a member of an entirely new order of mammals.

Until now, the earliest identified gliding mammal was a 30-million-year-old extinct rodent. The first known modern bat, which is capable of powered flight, dates to 51 million years ago, but it is assumed that early bats were probably gliding much earlier.

Archaeopteryx, the earliest known bird, lived about 145 million years ago, though scientists are not sure if it could flap its feathered wings in fully powered flight. But it lived about the time birds did take off in flight.

The discovery of the new flying mammal was made last year in Inner Mongolia, a region of northern China. Farmers found the delicate fossil embedded in sandstone.

Creature Camouflage

According to Nature magazine, The molecules that make octopus skin so successful as a camouflage could one day provide scientists with a new way to make super-reflective materials.

Octopus, squid and cuttlefish have developed sophisticated skins so they can hide in an ocean full of hungry predators. Scientists have studied this skin and have identified a new group of proteins with remarkable properties. The bottom layer of octopus skin, made up of cells called leucophores, is composed of a translucent, colorless, reflecting protein.

These proteins are very unusual in the animal kingdom. They reflect all wavelengths of light that hit at any angle. The material looks very white in white light, and blue in the bluish light found beneath the ocean's waves. They also match the intensity of the surrounding light, all of which helps the creatures to blend into their surroundings.

The pictures show an octopus (top) and a cuttlefish (bottom) blending into their surroundings.

How do you draw an extinct animal?

A recent study found that the prehistoric sea creature Dunkleosteus terrelli had the strongest jaws ever for a fish. Artists' drawings of the animal show an iron-jawed fish, sometimes with a nasty underbite. But how do artists draw animals that no one has ever seen? This article from Slate magazine looks at how scientists help artists to create images of such extinct creatures.

China's White Dolphin

An recent expedition searching for the rare Yangtze River dolphin (pictured right) ended without a single sighting and with the team's leader saying one of the world's oldest species was effectively extinct.

The white dolphin known as baiji, shy and nearly blind, dates back some 20 million years. Its disappearance is believed to be the first time in 50 years that a large aquatic mammal has been driven to extinction.

A few baiji may still exist in their native Yangtze habitat in eastern China but not in sufficient numbers to breed and ward off extinction. Around 400 baiji were believed to be living in the Yangtze in the 1980s. The last full-fledged search, in 1997, yielded 13 confirmed sightings, and a fisherman claimed to have seen a baiji in 2004. At least 20 to 25 baiji would now be needed to give the species a chance to survive.

The expedition also surveyed another dwindling species, the Yangtze finless porpoise (pictured right), finding less than 400 of them. The finless porpoises are declining at an alarming rate, and are also at risk of extinction.

Undiscovered life in Antarctica's ice caves?

Mount Erebus (pictured right) is a volcano located in Antarctica, and is the southernmost active volcano on Earth. According to this story from the Smithsonian Magazine, the volcano constantly sputters hot gas and lava which sculpt cool ice caves and create towers of ice that resemble chimneys.

The sides of Erebus are spiked with hundreds of these ice towers, called fumaroles. Gas and heat seeping through the side of the volcano melt the snowpack above, carving out a cave. Steam escaping from the cave freezes as soon as it hits the air, building chimneys as high as 60 feet! Below are examples of these neat ice chimneys and caves:





Erebus and the rest of Antarctica will be studied closely in 2007, as scientists head there for the fourth International Polar Year since 1882. They'll try out new monitoring techniques, study how Antarctica and the Arctic influence worldwide weather, and examine what kind of life could exist in the extreme cold and winter-long dark of the poles.

The ice caves at Mount Erebus are among the most promising places for undiscovered life in Antarctica. Though they grow or shrink depending on how much heat the volcano emits, inside they maintain a temperature of about 32 degrees (very warm for Antarctica!).

Undersea volcano-dwelling fish!

According to this BBC article, scientists have witnessed the extreme lifestyle of tonguefish that like to skip across pools of molten sulphur on the ocean floor. The animals - a type of flatfish - were filmed on three expeditions to undersea volcanoes in the western Pacific. Huge numbers were seen to gather around the sulphur ponds which well up from beneath the seafloor. Researchers are trying to figure out how they survive in such a hostile environment.

There are a lot of toxic heavy metals coming out of these active volcanoes. The water is very warm and can be very acidic, with pH levels as low as two (similar to sulphuric acid).

The area of interest is the Mariana Arc, a 745 mile chain of volcanic seamounts and islands between Guam and Japan. It hosts a number of hydrothermal vents - rock systems that draw water through cracks in the seafloor, heat it to temperatures which can be well above boiling, load it with dissolved metals and other chemicals, and then eject the hot fluid back into the ocean. This type of habitat will support a range of specialized animals such as crabs, shrimp, mussels, and worms - but very few fish. And the flatfish seen on the Mariana Arc seamounts are a first.

Sea Creature Photos

Below are just a few examples from this neat photo gallery of sea creatures called "Why We Dive":

Creature Origami

If you have always wanted to have a pet dancing crane, praying mantis, cicada, or owl, but could never seem to catch one in your backyard, now you can create your own with these neat origami crease patterns:

Animals in utero

According to this CNET article, scientists have used advanced ultrasound technology to capture three-dimensional images of animals inside the womb. Below are some of the pictures from the article. The scientists also hired artists to create models of the developing mammals (similar to production for a computer animation film), to create a video of the animals throughout gestation (click here for a brief preview). The video is featured in National Geographic's special entitled In the Womb: Animals.

The Asian elephant fetus (shown below) is unique for its 22-month gestation period, the longest pregnancy of all mammals. In the fetus, the elephant develops a unique mammalian feature called nephrostomes, or funnel-like ducts in the kidneys. These ducts can be found in freshwater fish and frogs, leading scientists to believe that elephants may have evolved from aquatic beginnings, when they used their trunks as snorkels. In fact, elephants can swim more than 15 miles without stopping by using their trunks to breathe!



Pictured below is a dog in the womb. At 60 days in the womb, three days before birth, the puppy has developed a full coat of hair, with nails and paw pads, and the body is covered with touch-sensitive nerve endings. It has also displayed its characteristic panting in the fetus, a behavior that helps the dog regulate its own body temperature in the absence of ample sweat glands.



Below is a dolphin in the womb. At one month in the womb, dolphins develop tiny leg-like limb buds that vanish within two weeks, and the animals swim in amniotic fluid for the next 11 months of gestation. Scientists say that evolutionary trick is a sign that the highly intelligent mammals descended from dog-like land creatures. At nine months, the dolphin has no more room in the mother's uterus, so the fetus curls inside the uterine wall. Hairs like tiny whiskers on the dolphin will fall out after birth as a result of water pressure, but the pores will remain open. At birth, the dolphin can see and swim, and has the musculature to follow its mother to the top of the ocean to get its first breath. When dolphins breathe, they exchange 80 percent of the oxygen in their bodies. Humans, in contrast, swap out only 17 percent.

Surprising Octopus Videos

This first video shows an octopus squeezing its body through a one-inch hole. Amazing what can be done when you're an invertebrate!



The next video was taken at an aquarium. Scientists there were confused as to why shark carcasses kept showing up at the bottom of the tank, so they stayed up late one night to learn something surprising and new about the culprit!

LEDs to start replacing light bulbs soon

Experts say that light-emitting diodes will become economically viable as replacements for conventional light bulbs in about two years, which could lead to massive conservation of electricity.

Light-emitting diodes, or LEDs, last about 100,000 hours, which is far longer than conventional filament bulbs. Unfortunately, the LEDs that can do this currently cost about $60. But prices have been declining by 50% a year, so two years from now the same LED should cost around $20.

Approximately 22% of the electricity consumed in the United States goes toward lighting, according to the U.S. Department of Energy. Conventional light bulbs are incredibly inefficient. Only about 5% of the energy that goes into them turns into light. The majority gets dissipated as heat.

If 25% of the light bulbs in the U.S. were converted to LEDs, the U.S. as a whole could save $115 billion in utility costs, cumulatively, by 2025, and it would alleviate the need to build 133 new coal-burning power stations. In turn, carbon emissions in the atmosphere would go down by 258 metric tons.

Bogs

A bog is a type of wetland that accumulates acidic peat, which is a deposit of dead plant material. Bogs are widely distributed in cold, temperate climes, mostly in the northern hemisphere. Some of the world's largest wetlands are the bogs of the Western Siberian Lowlands in Russia. Many bogs are also found in Europe, including Ireland, Scotland, the Netherlands, Sweden, Estonia, Finland, and northern Germany. They are also found in Canada and Alaska.

One of the interesting aspects of bogs is their ability to preserve organic material. This aspect has given rise to the term "bog bodies," as more than a thousand preserved human bodies have been found in bogs. These bodies have been dated as far back as 10,000 BC. Click here for Slate's "Explainer" podcast on how bogs are able to preserve organic material so well.

One of the most famous bog bodies is that of "Tollund Man" (pictured on the right). Radiocarbon dating has placed his death at approximately 350 BC, yet you can still clearly see is face and the rope around his neck that killed him. The man's stomach and intestines were also intact, and scientists discovered that his last meal had been a kind of soup made from vegetables and seeds, some cultivated and some wild: barley, linseed, gold of pleasure (Camelina sativa), knotweed, bristlegrass, and camomile.