New "Destroyer" Dinosaur Found, Was T. Rex Relative

A 29-foot-long (9-meter-long) "destroyer" dinosaur once reigned over the Wild West, according to a new study of a fossil T. rex relative found in New Mexico.

Two nearly complete skeletons of the new species, Bistahieversor sealeyi—eversor means "destroyer" in Latin—were discovered in the desolate badlands of New Mexico's Bisti/De-na-zin Wilderness.

A "teenager's" skeleton was found between 1989 and 1990, and an adult was unearthed in 1998, researchers say. The fossils had been on display at the New Mexico Museum of Natural History until recently, so scientists hadn't previously had a chance to study the remains.

Discovering that B. sealeyi is a primitive Tyrannosaurus rex relative—and, like T. rex, part of a group called the tyrannosauroids—is a "big deal," said study co-author Thomas Carr, director of the Carthage College Institute of Paleontology in Kenosha, Wisconsin.

"In and of itself, a relatively complete dinosaur from 75 million years ago in New Mexico is not common," he said. But "it's doubly rare to have a predator like this.Dinosaur Development

Scant tyrannosauroid teeth and scraps of bone had previously been found in the Southwest. But they all had come from tyrannosauroid species known to live in the northern Rocky Mountain region.

But B. sealeyi is a completely new species, found nowhere else—proving that the Southwest had its own top predator stalking the tropical forests and rivers of the late Cretaceous period.

When Carr first heard a new tyrannosauroid fossil had been found, "I was very excited, because I knew that if it was complete, we would actually finally know tyrannosauroids were living in the Southwest," he said.

What's more, finding the teenaged B. sealeyi skeleton and partial skull gives the scientists "a really unique snapshot of the biological development of this particular dinosaur," he said.

For instance, the team found that a hole above the adult's eyes—one of many air sacs common in tyrannosaur skulls—was not present in the young dinosaur's skeleton.

This suggests that the hole developed in adulthood, he said, although scientists aren't sure what the hole's function might have been.

B. sealeyi also had a deep snout like T. rex, though the two species are not closely related, Carr said.

Mystery of the Dinosaur Snout

Deeper—or shorter—snouts may have evolved in concert with a more powerful bite and smaller forearms in tyrannosauroids in western North America andAsia, which were connected during the Cretaceous.

"The main implement of killing was the head, and they needed the power for that," Carr said. 

But for some reason, tyrannosauroids in eastern North America retained the more primitive features of shallow snouts and large arms.

For B. sealeyi to have a deep snout suggests that the adaptation evolved early in tyrannosauroids—opening up new mysteries in tyrannosaur evolution.

GRASS-FED BEEF HAS BIGGER CARBON FOOTPRINT

Red meat has a bad reputation among the green-minded for its emissions of heat-trapping gases that exacerbate climate change. Fertilizer derived from fossil fuels is required for growing grain to feed cattle, and cows' digestion produces large amounts of the potent greenhouse gas methane, which is 25 times more heating than carbon dioxide.

But a new study of the Australian livestock industry finds that the seemingly greener alternative to grain-fed beef -- beef from cows grazed on grass -- produces more greenhouse gases per pound than beef from feedlots.

"The reason for that is that, on the one hand, the grain-based diet can be digested better by the animals, so that reduces the enteric methane production by the animals," said study lead author Matthias Schulz of the University of New South Wales Water Research Center in Australia.

Grain-finished beef produced 38 percent less methane, the researchers found, though other studies have reported as much as 70 percent less. 

"Also, although the (total) emissions are higher on the feedlot, the animals gain weight quicker," Schulz said, so the animals are slaughtered sooner, emitting less gas overall. "On a per-kilogram-of-meat basis, the feedlot performs better," he saidEmissions from grass-fed cows were about 20 percent higher than grain fed, according to the study, which was published in Environmental Science and Technology, and funded by Meat and Livestock Australia.

Schulz' study also concluded that raising sheep produced less greenhouse gas emissions than beef, largely because the animals have about half the lifespan of cattle.

Other studies have made the same comparison between beef from grass versus grain-fed animals and found that the higher methane emissions from grass-fed cows tip the carbon scales in favor of feedlot beef.

But some people claim that the math comes out the opposite way if carbon stored in the soil by grazing animals is incorporated: Grass-fed beef mow the pastures, fertilize the ground with their manure, and tramp around, creating healthy soil that acts as a carbon sink.

If the carbon storage is incorporated, they claim, grass-fed beef produces no net emissions, and can even capture carbon overall.

The problem, said Christopher Weber of Carnegie Mellon University, is that accurately quantifying how much soil carbon contributes is difficult, and it can vary dramatically from place to place -- even in locations just a few feet away. This uncertainty can swing the calculation one way or another.

To Weber's knowledge, no study published in a scientific journal has come to the conclusion that grass-fed beef is better from a greenhouse gas perspective.

"There's a lot of range of what the emissions are from beef, and that is real variability," agreed Rita Schenck, Executive Director of the Institute for Environmental Research & Education in Vashon, Wash., who has also studied this question.

"It is different in different places. It is different in different growing regimes. It's just different. I think the numbers are really close," she said, so the scales can tip one way or another depending on the specific circumstances.

"To some extent, all of this bickering about carbon footprint is missing the forest for the trees," Weber said. ""In terms of air pollution, water pollution and odor, concentrated feedlots are a disaster. In terms of other environmental impact, there is no question that grass fed is better. My problem is that people really play on the carbon footprint angle, when it's really not clear. "

According to a 2006 United Nations report, livestock accounts for 18 percent of the world's greenhouse gas emissions.

Grass-fed cattle require fewer antibiotics and other chemicals than grain-fed cows, and the resulting beef is higher in healthy omega-3 fatty acids.

For biologists searching for the presence of Asian carp in the twisting rivers and channels that flow into Lake Michigan, it's helpful to view the entire Great Lakes watershed as a crime scene.

Asian carp, the invasive species that has left a trail of destruction on its 30-year migration up the Mississippi River and into Illinois, naturally leave behind tiny cells as they move through the water. These cells, most commonly found in fish scales, feces and urine, contain carp DNA that distinguishes them among millions of other fish in Chicago waterways.

Like investigators reconstructing a crime scene using fingerprints on a doorknob or lipstick smudges on a wine glass, biologists are using Asian carp DNA found in these cells to track the carp's movement. Using DNA to monitor aquatic life is not new, but this method has never been used in a freshwater environment like the Great Lakes, officials said.

Because experts haven't yet seen an Asian carp within about 40 miles of Lake Michigan, the DNA evidence is central to the legal and political firestorm that has put Illinois' carp crisis in the national spotlight. That has brought the reliability of environmental DNA, or eDNA, under scrutiny and prompted some to wonder if bad science is perhaps driving the Asian carp controversy.

"Some people hear about carp DNA being found near Lake Michigan and they just think the threat is imminent, which isn't exactly the case," said state Sen. Susan Garrett, D-Lake Forest. "We need to be careful about how we talk about what we've found and what it means."

An invasive species expert and one of the architects of this eDNA method told Garrett and other state lawmakers that the science is sound. It's the interpretation of the DNA evidence that's up for debate.

"In terms of reliability, we know what we're picking up is big head or silver carp DNA. We're confident in our methods," said Lindsay Chadderton, the aquatic invasive species director at the Nature Conservancy. "The question people seem to be asking is whether the DNA could have gotten there by other means."

Since summer, researchers have combed Chicago's waterways north of the underwater electric barrier near Romeoville collecting more than 700 DNA samples. Water is scooped up in two-liter bottles and taken to a laboratory for analysis. Water, which acts like liquid cement keeping the cell structure intact, is filtered through a fine glass filter paper. The remaining solids are examined for the presence of DNA under a microscope, Chadderton said.

When DNA from one of the four varieties of Asian carp is detected, the results are compared with known carp DNA markers and matched against a global database for aquatic DNA. The results are independently verified by the U.S. Environmental Protection Agency, Chadderton said.

Asian carp DNA has now been located in five locations north of the electric barrier, built in 2002 to keep the carp from advancing into Lake Michigan. One sample has been found in Calumet Harbor, inside the rim of the lake, a troubling sign that the millions of dollars spent to deter the fish haven't worked.

"As a tool, we're excited by what (eDNA) has been able to show us," Chadderton said. "But the results have been bittersweet since it's showing us something we never wanted to see."

While eDNA cannot definitively say whether a carp is alive or dead, Chadderton, who helped develop the science in partnership with the University of Notre Dame, believes the samples indicate the presence of live fish. Some have speculated that passing boats may have collected carp tissue in their ballast water downriver, where Asian carp are known to be in abundance, and carried it across the electric barriers. Others say Asian carp being used as bait in the canals and along the lakefront may trigger a positive result.

Chadderton said those scenarios are unlikely. Cell tissue, he said, typically breaks down between six and 48 hours, meaning there is a small window to collect usable tissue. An even bigger indication, though, is that positive samples have been found in locations that follow the known movement of Asian carp upriver, Chadderton said.

"The other (scenarios) people are talking about simply don't explain that pattern," he said.

DNA sampling has other limitations as well, like determining the sex of the fish or shedding light on how many there are in one location. Those are important details, Chadderton said, to understand the scope of the problem.

Now that the Asian carp crisis has caught the attention of the U.S. Supreme Court and the White House, a large-scale effort is under way to confirm these DNA findings with a sighting of the fish. Crews could hit the water as early as this week with nets, using electric shock to stun fish and bring them to the surface. Without that confirmation, Chadderton said, the science will always have its detractors.

'DOGS OF WAR' SAVE LIVES IN AFGHANISTAN

THE GIST:

• "Dogs of War" are deployed to Iraq, Afghanistan to assist in finding bombs, lost soldiers.
• Bomb squads prefer Labradors. The dogs start training when they're puppies.
• These military dogs save lives and boost morale among troops.

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For the U.S. Marines patrolling the dusty footpaths of southern Afghanistan, a bomb-sniffing black Labrador can mean the difference between life and death.

These "dogs of war" have saved countless lives and their record for finding hidden explosives has won them a loyal following.

"They are 98 percent accurate. We trust these dogs more than metal detectors and mine sweepers," says handler Corporal Andrew Guzman.

Trained to detect five kinds of threat, from military grade C-4 plastic explosive to common chemicals used by the Taliban to make improvised explosive devices (IEDs), the dogs play a vital role alongside their human comrades.

Bomb expert Sergeant Crush is all concentration as he leads a foot patrol by two squads of US Marines deployed to Afghanistan as part of Washington's fresh surge to end an eight-year insurgency by the Taliban.

His job along with Corporal Goodwin is to lead the men to safety through dusty footpaths and compounds where Taliban militants plant deadly bombs that have left many troops dead in recent months.

They are from a group of four Labradors, who are on average four years old and have all seen action in Iraq and Afghanistan.

"These dogs are great. They keep our Marines alive," says First Lieutenant Aaron MacLean, 2nd Platoon commander of the Marines 1st Battalion, 6th Regiment Charlie Company, to which the dog team is attached.

Crush suddenly goes on a swift bound, sniffing out a corner of a compound in the outskirts of a Taliban stronghold in Helmand province.

There is a quick change in his demeanour, his muscles tense up, he freezes, sticks out his tail and then lies down with his paws extended up front.

Mammals "Rafted" to Madagascar, Climate Model Suggests

Only in the movies could a lion, a zebra, a giraffe, and a hippo wash ashore onMadagascar to start a new life.

But a new computer model suggests there may be a grain of truth in the animated fiction: The ancestors of ring-tailed lemurs, flying foxes, and other mammals that live on the Indian Ocean island got there aboard natural rafts.

(Related: "Three New Lemurs Discovered, Add to Madagascar's Diversity.")

The model supports a 70-year-old theory that mainland mammals from southeastern Africa "rafted" to the island on large logs or floating carpets of vegetation after being swept out to sea during storms.

The ancient refugees were carried to Madagascar by ocean currents, drifting on the open seas for several weeks before finally coming ashore, the model says.

Based on genetic and ecosystem evidence, this theory makes more sense than the alternative, which holds that Madagascar's mammals arrived via a land bridge that was later destroyed by shifting continents.

One of the problems with the rafting theory was that ocean currents and prevailing winds around Madagascar today move east to west—away from, not toward, the island.

Now, using computer simulations normally employed to study global warming, scientists think the currents might have been more favorable for drifitng to Madagascar 50 million years ago.

"The biologists were right all along," said study team member Matthew Huber, a paleoclimatologist at Indiana's Purdue University.

Lemurs on a Log

One weakness of the land-bridge theory is that today only four major groups of mammals live in Madagascar. These animals are distantly related to mammals in mainland Africa, and they are all relatively small.

"If there was a land bridge between Africa and Madagascar, why didn't large animals like elephants or lions cross?" Huber said.

In addition, genetic evidence suggests Madagascar's mammals arrived in discrete waves spaced several million years apart.

Lemurs started the migration about 50 million years ago, followed by hedgehog-like tenrecs, then mongoose-like carnivores such as the fossa, and finally rodents 24 million years ago.

(Related: "Lemurs Hunted, Eaten Amid Civil Unrest, Group Says.")

Since rafting fits the biological evidence, Huber and co-author Jason Ali of the University of the Hong Kong wanted to find out if currents around the island might have changed over time.

In fact, 50 million years ago Africa and Madagascar sat about 1,000 miles (1,600 kilometers) south of their current positions due to continental drift, the pair note in the paper, appearing today in the online edition of the journal Nature.

By plugging data about the ocean and atmosphere of ancient Earth into modern climate models, Huber and Ali found that ocean currents around the two land masses once flowed eastward, toward Madagascar, after all.

Rafting Debate Settled?

Huber predicts the 270-mile (430-kilometer) ocean voyage may have taken about three weeks when the currents were flowing at their swiftest.

"The simulation suggests that these very fast currents occurred very rarely, maybe one month every hundred years," Huber said. And small mammals with naturally low metabolisms could have survived for weeks without much food or fresh water, Huber and Ali suggest.

Anne Yoder, director of the Duke University Lemur Center, said she was "very excited" about the new findings.

"Although I am not surprised by the results, I am gratified to see them," said Yoder, who was not involved in the research but who reviewed the study for publication in Nature.

"For me the debate is settled: Madagascar's mammals arrived in Madagascar via ... overwater rafting from Africa."

The new computer simulation might also help solve other biological mysteries, study co-author Huber added.

"We're going to see if we can explain how monkeys made it to South America, because as far as paleontologists can tell, they arrived there sometime during the Eocene"—55.8 to 33.9 million years ago—"when South America wasn't connected to anything," he said.

PARASITE SPREADING BETWEEN ANIMALS, ZOOKEEPERS

• A parasite associated with diarrhea and irritable bowel syndrome has been identified among many zookeepers and animals.
• Zoos can be hot spots for interspecies spread of infectious disease.
• Experts advise that zoos regularly monitor their staff and animals for infections.

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A common parasite associated with diarrhea and irritable bowel syndrome appears to be spreading among animals, and from animals to zookeepers, at several zoos worldwide, according to a new study.

The resulting infection, called Blastocystis, has been identified in humans, non-human primates, elephants, giraffes, quokkas (a small, Australian mammal), southern hairy nosed wombats and western grey kangaroos at zoos in Australia, Belgium, Japan, Malaysia, The Netherlands and Spain, and scientists believe the bug is prevalent "in most zoos."

While this parasitic illness is not usually serious, its presence at so many zoological parks, and among so many different species, demonstrates the need for zoos to closely monitor the health of their staff and animal charges.

"Zoos are indeed a hot spot for interspecies spread of infectious diseases," co-author Bruno Levecke told Discovery News.

Levecke, a parasitologist at Ghent University and the Royal Zoological Society of Antwerp, and his colleagues collected fecal samples from zookeepers and various animals at The Perth Zoological Gardens in Western Australia, the Melbourne Zoo, the Werribee Open Range Zoo in Victoria, Australia, and unidentified zoos from Amsterdam and Antwerp.

The study, accepted for publication in the journal Veterinary Parasitology, concluded that the parasite was present in most of the test subjects. Sixty-three percent of zookeepers tested positive and up to 82 percent of certain animal populations were infected with Blastocystis.

Prior studies at Osaka Zoo in Japan, Malaysia's Zoo Negara, Spain's Pena Escrita, and zoos in the United Kingdom and Denmark also reported infections with the parasite, some of which were found in birds.

While it is difficult to determine exactly how the parasite is spreading, project leader Unaiza Parkar told Discovery News, "Blastocystis can be transmitted directly -- contact with infected stool -- or indirectly -- consumption of contaminated food and/or water. Given the housing conditions for the non-human primates, usually four to six primates sharing an enclosure, there is definitely transmission occurring between the animals."

Acclimating Your Coral

Regardless of your light setup, place all new corals on the bottom of your aquarium until they begin to adjust. If you employ metal halide lights, place some sort of screening material above your coral during the first few weeks of acclimation. The screen could be egg crate light paneling or fiberglass mesh. Also, reduce the photoperiod by a quarter for the first week and gradually add an hour each week to reduce the risk of light shock. A good indication your coral has adjusted is when it appears fully expanded and displays full coloration.

Slowly inch the coral to its preferred location over the next month or so. Generally, brighter colored corals should be nearer to the lights. Bright colors signify tissue pigment development that helps protect coral from the UV-light present in shallower depths. Though proper light acclimation is a slow process, it can be the difference between a home reef that simply sustains and one that thrives for years to come.

'Survival of the Cutest' Proves Darwin Right

Domestic dogs have followed their own evolutionary path, twisting Darwin's directive 'survival of the fittest' to their own needs -- and have proved him right in the process, according to a new study by biologists Chris Klingenberg, of The University of Manchester and Abby Drake, of the College of the Holy Cross in the US.   The study, published in The American Naturalist on January 20,  2010, compared the skull shapes of domestic dogs with those of different species across the order Carnivora, to which dogs belong along with cats, bears, weasels, civets and even seals and walruses.

It found that the skull shapes of domestic dogs varied as much as those of the whole order. It also showed that the extremes of diversity were farther apart in domestic dogs than in the rest of the order. This means, for instance, that a Collie has a skull shape that is more different from that of a Pekingese than the skull shape of the cat is from that of a walrus.

Dr Drake explains: "We usually think of evolution as a slow and gradual process, but the incredible amount of diversity in domestic dogs has originated through selective breeding in just the last few hundred years, and particularly after the modern purebred dog breeds were established in the last 150 years."

By contrast, the order Carnivora dates back at least 60 million years. The massive diversity in the shapes of the dogs' skulls emphatically proves that selection has a powerful role to play in evolution and the level of diversity that separates species and even families can be generated within a single species, in this case in dogs.

Much of the diversity of domestic dog skulls is outside the range of variation in the Carnivora, and thus represents skull shapes that are entirely novel.

Dr Klingenberg adds: "Domestic dogs are boldly going where no self respecting carnivore ever has gone before.

"Domestic dogs don't live in the wild so they don't have to run after things and kill them -- their food comes out of a tin and the toughest thing they'll ever have to chew is their owner's slippers. So they can get away with a lot of variation that would affect functions such as breathing and chewing and would therefore lead to their extinction.

"Natural selection has been relaxed and replaced with artificial selection for various shapes that breeders favour."

Domestic dogs are a model species for studying longer term natural selection. Darwin studied them, as well as pigeons and other domesticated species.

Drake and Klingenberg compared the amazing amount of diversity in dogs to the entire order Carnivora. They measured the positions of 50 recognizable points on the skulls of dogs and their 'cousins' from the rest of the order Carnivora, and analyzed shape variation with newly developed methods.

The team divided the dog breeds into categories according to function, such as hunting, herding, guarding and companion dogs. They found the companion (or pet) dogs were more variable than all the other categories put together.

According to Drake, "Dogs are bred for their looks not for doing a job so there is more scope for outlandish variations, which are then able to survive and reproduce."

Dr Klingenberg concludes: "I think this example of head shape is characteristic of many others and is showing it so clearly, showing what happens when you consistently and over time apply selection.

"This study illustrates the power of Darwinian selection with so much variation produced in such a short period of time. The evidence is very strong."

"FAUX" FUR ON CLOTHING MAY CONTAIN DOG HAIR

So-called "faux" fur may actually contain dog hair, according to Humane Society of the United States investigations.

Inspectors for the Humane Society say fur from a canine species known as the raccoon dog (Nyctereutes procyonoides) was found on garments labeled as being "faux-fur."

(Raccoon dogs in Japan; Credi: 663highland)

During the recent winter holiday shopping season, for example, Neiman Marcus advertised and sold animal fur online as being "faux." The item in question was a $1,300 Burberry women's jacket.

"Neiman Marcus has repeatedly sold garments where the animal fur was misrepresented or even described as fake fur," said Pierre Grzybowski, manager of the fur campaign for The HSUS. "How many of this latest jacket were sold to unsuspecting consumers who thought they were buying fake fur?"

Burberry has since changed its marketing for the item, but this is just one example in a long line of misrepresentations by other brands and retailers. In fact, "finnraccoon" is a well-known term used by the fashion industry to market fur from the raccoon dog, a canine indigenous to east Asia.

The problem also doesn't only impact individuals concerned about animal welfare. Buyers willing to shell out big bucks, thinking they are getting clothing made from the fur of exotic animals, may actually be wearing common farm animal hair.

Case in point- an HSUS investigation last August found that Neiman Marcus sold $1,500 fur-trimmed Manolo Blahnik boots that were advertised as "natural ocelot fur" — an endangered species that would be illegal to sell under the Endangered Species Act. After The HSUS brought this issue to the public's attention, a Neiman Marcus spokesperson admitted it was goat fur.

Bergdorf Goodman last year was also found to have sold unlabeled fur-trimmed jackets in violation of New York state law.

According to the HSUS, "false advertising or labeling of fur is punishable under the Fur Products Labeling Act by up to one year in prison and/or a $5,000 fine. The use of trade names on labels to describe the animals is prohibited."

The HSUS is pursuing a consumer protection lawsuit against Neiman Marcus and other retailers in the District of Columbia, and is also urging Congress to pass the Truth in Fur Labeling Act, S. 1076, by Sens. Robert Menendez, D-N.J., and Susan Collins, R-Maine, and H.R. 2480 by Reps. Jim Moran, D-Va., and Mary Bono Mack, R-Calif., to require accurate labeling of all animal fur-trimmed garments, regardless of dollar value.

Dollar value is mentioned because an apparent loophole in the federal law allows clothing manufacturers to not fully disclose information about fur if the item is valued at $150 or less.

If you have purchased items thinking they were fake fur, but now aren't sure, Grzybowski advises that you try the following home test:

1. First, look at the base of the "fur." If you see sewn threads, that's a good indication the material is indeed synthetic. Usually real animal hair will still be attached to its skin.
2. Pull a few strands of "hair" from the item.
3. Place them in a small fire-proof dish and light them with a match.
4. Smell the resulting fumes.
5. If you detect a plastic odor, the fur is probably fake. 
6. If you still can't tell, try burning a few strands of your own hair and compare the smell with that of the burnt strands from the clothing. They both should emit similar odors. (Mammal hair is made up of similar proteins, oils and other components.)

Earlier this week you might have seen the Discovery News slideshow on how experts struggle to identify forgeries from genuine artifacts. Here is a rare instance where authentic fakes are desired.

Coral Can Recover from Climate Change Damage, New Research Suggests

A study by the University of Exeter provides the first evidence that coral reefs can recover from the devastating effects of climate change. Published Jan. 11, 2010 in the journal PLoS ONE, the research shows for the first time that coral reefs located in marine reserves can recover from the impacts of global warming.Scientists and environmentalists have warned that coral reefs may not be able to recover from the damage caused by climate change and that these unique environments could soon be lost forever. Now, this research adds weight to the argument that reducing levels of fishing is a viable way of protecting the world's most delicate aquatic ecosystems.

Increases in ocean surface water temperatures subject coral reefs to stresses that lead quickly to mass bleaching. The problem is intensified by ocean acidification, which is also caused by increased CO₂. This decreases the ability of corals to produce calcium carbonate (chalk), which is the material that reefs are made of.

Approximately 2% of the world's coral reefs are located within marine reserves, areas of the sea that are protected against potentially-damaging human activity, like dredging and fishing.

The researchers conducted surveys of ten sites inside and outside marine reserves of the Bahamas over 2.5 years. These reefs have been severely damaged by bleaching and then by hurricane Frances in the summer of 2004. At the beginning of the study, the reefs had an average of 7% coral cover. By the end of the project, coral cover in marine protected areas had increased by an average of 19%, while reefs in non-reserve sites showed no recovery.

Professor Peter Mumby of the University of Exeter said: "Coral reefs are the largest living structures on Earth and are home to the highest biodiversity on the planet. As a result of climate change, the environment that has enabled coral reefs to thrive for hundreds of thousands of years is changing too quickly for reefs to adapt.

"In order to protect reefs in the long-term we need radical action to reduce CO₂ emissions. However, our research shows that local action to reduce the effects of fishing can contribute meaningfully to the fate of reefs. The reserve allowed the number of parrotfishes to increase and because parrotfish eat seaweeds, the corals could grow freely without being swamped by weeds. As a result, reefs inside the park were showing recovery whereas those with more seaweed were not. This sort of evidence may help persuade governments to reduce the fishing of key herbivores like parrotfishes and help reefs cope with the inevitable threats posed by climate change."

Professor Mumby's research was funded by National Environment Research Council (NERC) and the Khaled bin Sultan Living Oceans Foundation.

SCORPION VENOM TAPPED AS PESTICIDE

Scorpion venom can paralyze, inflict pain, even kill. But instead of recoiling in fear from the arachnids, scientists are scrutinizing venom in the hopes of harnessing its power to fight insects, treat cancer and more.

In one approach, Israeli researchers have cloned the genes involved in producing specific toxic protein compounds. They have developed ways to produce and manipulate these toxins inside bacteria grown in their lab. They have also deciphered the three-dimensional structures of some of those compounds and figured out which surface of those structures bind to the nervous systems of insects.

These technical developments may eventually help scientists develop new, scorpion-inspired pesticides that would zero in on specific insect pests without harming people, the environment, or other animal bystanders.

"You should consider scorpions like a gift from nature," said Michael Gurevitz, of Tel Aviv University in Israel. "Nature has developed compounds during millions of years that show complete selectivity to various groups of animals. Understanding how these toxins affect the nervous system of animals may assist in preparing chemicals that mimic the toxin activity and can be produced industrially."

For decades, scientists have been probing the compounds in venom from scorpions, spiders, sea anemones, cone snails and other creatures. Plenty of studies have dissected venom to see what types of proteins are in it, what those proteins look like, and how they work -- by, for example, causing paralysis or breaking down cells.

A major goal has been to spin those findings into practical applications. For example, venom compounds are appealing candidates for pesticides because many of them are highly specialized to kill certain types of insects but have no effect on people, other mammals or beneficial insects, like honeybees.

The toxins that interest researchers are biodegradable, so they would not accumulate in the ground or drinking water, linger on vegetable skins, or endanger our health like modern chemical pesticides do. Translating scientific studies into practical applications, however, has been tough. For one thing, simply spraying venom compounds on crops doesn't do any good, because insects can swallow and digest the proteins in their guts without harm.

In order to kill, venom compounds need to enter an insect's blood, like what happens after a sting. Scientists can't sting individual insects. Finding a good delivery system is what they are struggling with now.

Venom toxins are "a resource with almost limitless potential," said Raymond St. Leger, an entomologist at the University of Maryland, College Park. "But you need a way of getting them into the insect."

Some researchers are experimenting with viruses and fungi as delivery systems. Gurevitz, who has been studying "the pharmaceutical factory in venom glands" for more than 20 years, is taking a different approach.

He is looking at the way these toxins interact with structures called sodium channels, which are located on the membranes of cells in nervous and muscular tissues. Essentially, he is getting at the molecular details of how toxic compounds in venom recognize sodium channels, bind to them, and then cause paralysis and death.

First, the scientists had to develop ways of producing the toxins and their target channels in the lab. To do that, they cloned related genes and established systems for expressing and mutating both the toxins and the channels they bind to.

Using bacteria, Gurevitz and colleagues are now producing their own venom compounds and manipulating their shapes to see what they do. Down the line, they aim to develop safe and powerful pesticides. They also hope that the knowledge they're acquiring will pave the way for production of chemicals that would mimic the toxins and be just as selective about which insects they kill.

"As we know more details about how these toxins bind and affect the sodium channels, we would be able to engineer toxins" and develop chemical mimics that would be easier for industry to produce, Gurevitz said.

These developments are not imminent, he said, but they are possible. Some drugs already fit the description, including one that was derived from cone snail venom and my help fight chronic pain.

Adding an effective and environmentally friendly battery of pesticides would be highly valuable, St. Leger said. Insects are incredibly good at developing resistance to the chemicals we thrown at them. The more options we have, the better

What is your favorite animal?

Poison dart frogs are by far my favorite animals.  

ALLIGATORS' LUNGS MAY EXPLAIN DINOS' DOMINANCE

Alligators have a one-way path for breathing that is similar to birds', new research shows. The findings, published in the Jan. 15 Science, could explain how dinosaurs' ancestors rose to prominence.

"It's absolutely transformational," comments Adam Summers of the University of Washington's Friday Harbor Laboratories. "It really makes us think hard about our interpretations of anatomy."

Unlike a mammal's breath, which exits the lungs from the same dead-end chambers it enters, a bird's breath takes a loopy one-way street through its lungs.

In mammals, air enters the lungs and flows through a network of branching tubes called bronchi, which culminate in small cul-de-sac chambers where blood vessels exchange carbon dioxide for oxygen. Air then exits the lungs via the same pathway.

But in birds' lungs, air moves constantly through a simpler network of tubes, making a single circuit before being exhaled. This unidirectional flow makes gas transfer much more efficient -- air can zip right past the blood vessels that need oxygen and then be on its way.

Conventional wisdom has held that only birds can do this because in addition to lungs, birds have air sacs that may steer the air unidirectionally through the lung. "People incorrectly believe that you must have avian-style air sacs in order to have unidirectional flow," says C.G. Farmer of the University of Utah, a coauthor of the new study. "Alligators don't have air sacs, so no one ever looked."

But a structural similarity in the way birds' and alligators' bronchi branch through the lungs caught Farmer's attention.

"If you look at the alligator lung, it's not hard to see how small modifications in this design could potentially lead to an avian lung," she says. She wondered if the similarities were more than cosmetic.  Farmer and her coauthor Kent Sanders of the University of Utah inserted flow meters called thermistors into the lungs of six living alligators to see how fast and in what direction the air moved. The primary bronchi each split into two branches shortly after the point where air enters each lung. Surprisingly, air moved through the first branch in each lung in the same direction whether the gator was inhaling or exhaling.

"That's the opposite of what you expect," Farmer says.

The researchers also pumped air in and out of the lungs of four dead alligators and pumped water containing tiny fluorescent beads through the lungs of another dead gator, to measure the flow.

All three lines of evidence showed the same unidirectional path through the gators' lungs. Farmer thinks that instead of entering the first bronchial branch, which veers off at a hairpin turn, air skips this tube and enters the second branch. Its passage past the first opening creates an aerodynamic valve that sucks air out of that branch. From the second branch, air passes through small tubes called parabronchi, where carbon dioxide is traded for oxygen in the blood. Finally, air flows from the parabronchi into the first branch, and then back out through the trachea.

Having three lines of evidence and careful measurements bolsters the researchers' claim, comments Elizabeth Brainerd of Brown University.

The finding could mean that this mode of breathing is far older than scientists suspected and that it may have helped archosaurs, the common forebearers of birds, alligators and dinosaurs, rise to a dominant ecological niche millions of years ago.

Archosaurs were the largest land animals on Earth from after the Permian-Triassic extinction 251 million years ago until the group split 246 million years ago into alligators and what would become dinosaurs and birds. To rise to prominence, archosaurs had to unseat large mammal-like reptiles called synapsids. But synapsids flourished after the dinosaurs went extinct, eventually leading to today's large land mammals. How archosaurs gained their brief time on top remains a mystery.

"There's a flip-flopping from synapsids, to archosaurs, back to synapsids in this one niche. Why did this happen?" Farmer says. "Our data suggest (archosaurs) had an advantage."

The trick of one-way breathing could have given archosaurs a boost. Other research has shown that the oxygen levels at the time were about half of what they are today, even lower than the air at the top of Mount Everest. A more efficient breathing system could have allowed archosaurs to flourish in that dizzying environment.