Nov 1, 2014

Lack of oxygen delayed the rise of animals on Earth

Geologists are letting the air out of a nagging mystery about the development of animal life on Earth.

Scientists have long speculated as to why animal species didn't flourish sooner, once sufficient oxygen covered Earth's surface. Animals began to prosper at the end of the Proterozoic period, about 800 million years ago -- but what about the billion-year stretch before that, when most researchers think there also was plenty of oxygen?

Well, it seems the air wasn't so great then, after all.

In a study published Oct. 30 in Science, Yale researcher Noah Planavsky and his colleagues found that oxygen levels during the "boring billion" period were only 0.1% of what they are today. In other words, Earth's atmosphere couldn't have supported a diversity of creatures, no matter what genetic advancements were poised to occur.

"There is no question that genetic and ecological innovation must ultimately be behind the rise of animals, but it is equally unavoidable that animals need a certain level of oxygen," said Planavsky, co-lead author of the research along with Christopher Reinhard of the Georgia Institute of Technology. "We're providing the first evidence that oxygen levels were low enough during this period to potentially prevent the rise of animals."

The scientists found their evidence by analyzing chromium (Cr) isotopes in ancient sediments from China, Australia, Canada, and the United States. Chromium is found in Earth's continental crust, and chromium oxidation is directly linked to the presence of free oxygen in the atmosphere.

Specifically, the team studied samples deposited in shallow, iron-rich ocean areas, near the shore. They compared their data with other samples taken from younger locales known to have higher levels of oxygen.

Oxygen's role in controlling the first appearance of animals has long vexed scientists. "We were missing the right approach until now," Planavsky said. "Chromium gave us the proxy." Previous estimates put the oxygen level at 40% of today's conditions during pre-animal times, leaving open the possibility that oxygen was already plentiful enough to support animal life.

In the new study, the researchers acknowledged that oxygen levels were "highly dynamic" in the early atmosphere, with the potential for occasional spikes. However, they said, "It seems clear that there is a first-order difference in the nature of Earth surface Cr cycling" before and after the rise of animals.

"If we are right, our results will really change how people view the origins of animals and other complex life, and their relationships to the co-evolving environment," said co-author Tim Lyons of the University of California-Riverside. "This could be a game changer."

"There's a lot of interest right now in a broader discussion surrounding the role that environmental stability played in the evolution of complex life, and we think our results are a significant contribution to that," Reinhard said.

Read more at Science Daily

Rare Dwarf Buffalo Charges Against Extinction

The population of the Philippines' dwarf buffalo, one of the world's rarest animals, has grown to its largest since efforts to save them from extinction began, conservationists said Friday.

An annual survey counted 382 tamaraws in a protected mountain area this year, an increase from 345 in 2013, according to data from the World Wildlife Fund (WWF).

The tamaraw, famed for its distinct v-shaped horns, can be found only in the mountains of Mindoro, a farming island in the central Philippines.

The stocky tamaraw, with its chocolate brown coat, runs wild in the forest and weighs half as much as the more common carabao, which is used by farmers in the Philippines to plough rice fields.

"The tamaraw is the flagship species of the Philippines. It is our moral obligation and international commitment to preserve them," forest ranger Rodel Boyles, who heads a joint government and private sector conservation effort, told AFP.

"If they are not protected, the species might get wiped out in five years," he said.

The tamaraw is considered "critically endangered" -- two steps away from extinction -- by the International Union for Conservation of Nature.

Hunting and the destruction of their habitat to make way for grazing areas for cattle led to their near decimation, as the population fell from 10,000 in the 1900s to just 154 by 2000, according to the WWF.

The government and private sector's Tamaraw Conservation Programme aims to double the dwarf buffalo's population from 300 in the mid-2000s to 600 by 2020, Gregg Yan, a local spokesman for the WWF told AFP.

This requires ramping up forest patrols to ward off poachers and installing hidden cameras in the mountains to better understand the behaviour of the beast, Yann said.

A team of 30 forest rangers patrol a 37-acre portion of a mountain that is considered the buffalo's "core habitat", Boyles said.

"They are hunted down for food and trophy. When a species is rare, their price in the black market also goes up," he said.

Read more at Discovery News

Oct 31, 2014

First Afghan Fanged Deer Seen in More Than 60 Years

A fanged creature not seen in Afghanistan for more than 60 years has been spotted by a research team in the northeast part of the country.

The Kashmir musk deer was last seen in Afghanistan in 1948. But a team headed up by the Wildlife Conservation Society (WCS) reports in the October 22 issue of the journal Oryx that it made five sightings in a range of land that included alpine meadows and steep, rocky outcrops.

The sightings featured a solitary male that was spotted three different times in the same area, as well as one female with a juvenile deer and one solitary female. The area where they were seen was scattered with dense bushes of juniper and rhododendron.

Unfortunately, the extremely skittish deer, already difficult to spot, did not remain in place long enough to be photographed, the team said.

The Kashmir musk deer is one of seven similar species in Asia and is considered endangered due to habitat loss and poaching. The deer's scent glands are a high-ticket black market item -- deer musk has been used for ages in perfume, incense, and medical applications -- and can be worth more than $20,000 per pound.

The male of the distinctive herbivores has telltale fangs used during mating season as weapons to joust for mates. For deer, they are small and a bit stocky, topping out at barely more than 2 feet tall at the shoulder.

"Musk deer are one of Afghanistan's living treasures," said Peter Zahler, co-author of the study and WCS deputy director of Asia programs. "This rare species, along with better known wildlife such as snow leopards, are the natural heritage of this struggling nation. We hope that conditions will stabilize soon to allow WCS and local partners to better evaluate conservation needs of this species."

From Discovery News

Ancient Stone Circles in Mideast Baffle Archaeologists

Huge stone circles in the Middle East have been imaged from above, revealing details of structures that have been shrouded in mystery for decades.

Archaeologists in Jordan have taken high-resolution aerial images of 11 ancient "Big Circles," all but one of which are around 400 meters (1,312 feet) in diameter. Why they are so similar is unknown but the similarity seems "too close to be a coincidence" said researcher David Kennedy.

The Big Circles (as archaeologists call them) were built with low stone walls that are no more than a few feet high. The circles originally contained no openings, and people would have had to hop over the walls in order to get inside.

Their purpose is unknown, and archaeologists are unsure when these structures were built. Analysis of the photographs, as well as artifacts found on the ground, suggest the circles date back at least 2,000 years, but they may be much older. They could even have been constructed in prehistoric times, before writing was invented, scientists say.

Though the Big Circles were first spotted by aircraft in the 1920s, little research has focused on these structures, and many scientists are not even aware of their existence, something these archaeologists hope the new aerial images will help to change.

The "most important contribution is simply to collect and make known a large group of rather remarkable sites," writes Kennedy, a professor at the University of Western Australia, in an article published recently in the journal Zeitschrift für Orient Archäologie.

In addition to the 11 photographed circles, researchers have identified another similar circle in Jordan, which appears to have been only partially completed, Kennedy noted. Old satellite imagery also reveals two circles, one in Jordan and another in Syria, which have both been destroyed. The circle in Syria was destroyed within the last decade and the one in Jordan a few decades ago. A separate research team, from Durham University, investigated the Syria circle before it was completely gone.

While there are many smaller stone circles in the Middle East, what makes these 11 Big Circles stand out is their large size and ancient age, Kennedy said.

Kennedy has been leading the Aerial Archaeology in Jordan Project (AAJ) since 1997 and also co-directs the Aerial Photographic Archive for Archaeology in the Middle East (APAAME).

Building the Big Circles

The circles would not have been hard to build, Kennedy said. They were constructed mainly with local rocks, and a dozen people working hard could potentially complete a Big Circle in a week, Kennedy told Live Science in an email.

However, building the circles in a precise shape would have taken some planning. "In the case of those circles that near-precise circles, it would have required at least one person as 'architect,'" Kennedy said, adding that this architect could simply have tied a long rope to a post and walked in a circle, marking the ground as he or she moved around. "That would also explain the glitches [in the circles] where the land was uneven," as the architect wouldn't have been able to keep walking in a perfect circle at those spots.

The purpose of the Big Circles is a mystery, Kennedy said. It seems unlikely that they were originally used as corrals, as the walls were no more than a few feet high, the circles contain no structures that would have helped maintain an animal herd and there's no need for animal corrals to have such a precise shape, he said.

One of the circles contains three cairns, or rock piles, on its edges that may have been used for burial. However, Kennedy said, "my inference is that the cairns [were built] later, when the enclosure was no longer significant."

Solving the circle mystery

In order to solve the mystery, archaeologists must conduct more actual fieldwork, Kennedy said, noting that aerial images are helpful but can't replace excavation.

Archaeologists Graham Philip and Jennie Bradbury, both with Durham University in England, have examined a Big Circle they found near Homs in Syria. While the circle was "badly damaged" when the researchers found it, they completed their fieldwork before land development completely destroyed the structure.

This Big Circle was positioned in such a way that it could give someone standing inside it a "panoramic" view of a basin that would have held crops and settlements, the researchers reported in a 2010 paper in the journal Levant. This "may have played an important part in the location of the enclosure," the two archaeologists wrote in the Levant article.

Recent satellite imagery shows that the circle near Homs is now virtually destroyed, Kennedy wrote.

Read more at Discovery News

Humans Would Beat Neanderthals in Marathon

Humans, versus other great apes, are built for running fast and long as opposed to very impressive strength, but what about Neanderthals? If a modern human and a Neanderthal competed in a marathon, who would win?

In a short sprint, the Neanderthal might have had a chance, but most fit humans would always win longer races, suggests research in the Journal of Human Evolution.

Anthropologist David Raichlen of the University of Arizona and his colleagues determined that our modern human ancestors were better runners. The researchers did this by studying the hominids'fossilized remains.

Recent research suggests that the energy cost of running at a given speed is strongly related to the length of certain limb bones. The longer these bones (Achilles tendon moment arm and calcaneal tuber from the calcaneus are, the more energy it takes for the individual to run.

The scientists' measurements of such bones determined that Neanderthals were lousy at endurance and distance running when compared to modern humans. The sturdy Neanderthal bones, however, were built for long-distance walking and strength.

"Endurance running is generally thought to be beneficial for gaining access to meat in hot environments, where hominins could have used pursuit hunting to run prey taxa into hyperthermia," Raichlen and his team conclude. "We hypothesize that endurance running performance may have been reduced in Neanderthals because they lived in cold climates."

Since there is an inherent trade-off between speed and strength in species throughout the animal kingdom, it is likely that Neanderthals were built more for brawn, with humans evolving lighter, more aerodynamic bodies for running. (This doesn't take into account food consumption and other behavioral factors that can add heft.)

Read more at Discovery News

Hubble Sees the Eerie Ghosts of Long-Dead Galaxies

See that blue glow? That’s the ghostly remains of once-dazzling galaxies that have since been blended in a Cosmic grinder. It may sound like a gruesome Hallowe’en space slasher movie, but this is actually a stunning portrait of galactic evolution as captured by the Hubble Space Telescope.

Abell 2744, or “Pandora’s Cluster,” consists of 500 galaxies over 4 billion light-years away from Earth. The stunning array of galaxies of all shapes and sizes are a sight to behold. But in this case, scientists studying this Hubble observation aren’t admiring the beautiful elegance of the spiral galaxies or arcs of light bent by gravitational lensing, they’re focused on the long-lost stars cast adrift in intergalactic space, released like tiny sparkles after an immense galactic smashup that occurred billions of years ago.

The blue glow has been detected by Hubble’s sensitive optics and represent cosmic forensic evidence of the galactic violence — it is caused by countless billions of stars that are no longer gravitationally bound to their galaxies, forever drifting alone.

“The Hubble data revealing the ghost light are important steps forward in understanding the evolution of galaxy clusters,” said Ignacio Trujillo of The Instituto de Astrofísica de Canarias (IAC), Santa Cruz de Tenerife, Spain. “It is also amazingly beautiful in that we found the telltale glow by utilizing Hubble’s unique capabilities.” This finding has been published in the Oct. 1 edition of the Astrophysical Journal.

When Abell 2744 was forming, huge numbers of galaxies coalesced under a powerful mutual gravitational well. As each galaxy careened toward one other, intense tidal forces would have ripped some of the galaxies to shreds. Computer models have predicted that this mechanism likely occurs in large clusters of galaxies and, in the case of Abell 2744, over 200 billion stars were scattered throughout the cluster, contributing to 10 percent of the cluster’s brightness.

“The results are in good agreement with what has been predicted to happen inside massive galaxy clusters,” said lead author Mireia Montes also of the IAC.

Interestingly, Hubble wasn’t being used to study this ghostly glow. As a part of the Frontier Fields project, Hubble’s sensitive optics used large galactic clusters like Abell 2744 to study the phenomenon of gravitational lensing. The arcs of light in this observation are examples of lensing artifacts where light from galaxies behind the clusters is being warped and magnified by the cluster’s immense gravity.

Read more at Discovery News

Oct 30, 2014

Does Uber-Ancient Earth Water Mean Life Started Earlier?

Just 14 million years after the start of the solar system, Earth and the rest of the inner planets were inundated with water, setting back the clock for when life could have evolved, a new study shows.

Analysis of meteorites from the mini-planet Vesta, located in the main asteroid belt between Jupiter and Mars, show hydrogen isotope ratios that match what has been found in ancient, unaltered meteorites known as carbonaceous chrondrites.

Scientists already had a match between the chemical fingerprints of Earth’s hydrogen and the carbonaceous chrondites, but what they didn’t know is when the water would have been available to accrete into Earth.

The new analysis pushes water’s first appearance in Vesta and presumably on other rocky, planet-like bodies including Earth to just 14 million years after the start of the solar system.

“All the the planets could have gotten their water very early, which means the planets could have been habitable immediately after they formed. They weren’t just sitting there and looking at their watch, waiting for water to come,” Adam Sarafian, a geophysics doctorate student at the Woods Hole Oceanographic Institution in Massachusetts, told Discovery News.

Water is necessary for life as we know it.

Geologic activity on Earth has destroyed the earliest records of the planet’s formation, with its oldest rocks dating back to about 200 million years after the formation of the solar system some 4.6 billion years ago.

Analysis of rocks from the moon, retrieved during the 1969-1972 Apollo missions, show water was available in the inner solar system about 150 million years after the solar system’s formation.

The Vesta meteorites, known as eukrites, date back to 14 million years after the start of the solar system. Sarafian and collegues measured a mineral called apatite in the samples to determine their water content.

“This is the oldest water that anyone has measured that has accreted to something that resembles a planet,” Sarafian said.

The scientists plan additional studies on an ever rarer group of meteorites called angrites that date back to just 2 million years after the formation of the solar system.

The findings aren’t at odds with the idea that comets delivered water to Earth, said astronomer Donald Brownlee, with the University of Washington, the lead researcher in NASA’s Stardust comet sample return mission.

“The early solar system contained tens of Earth masses of materials that could be considered carbonaceous chondrites or comets -- they were the most common planetesimals in the solar nebula. Almost all of them are gone, but surely there were great numbers of comets that formed close enough to the sun to have (hydrogen isotope) ratios similar to carbonaceous chondrites and Earth,” Brownlee wrote in an email to Discovery News.

“Many people consider (comets and carbonaceous chrondites) to be quite different beasts, but I am more impressed with how similar they are to each other. Surely there was a continuum of rocks that were identical to carbonaceous chondrites and rocks (planetesimals) that contained very low temperature ices and would be considered comets,” he said.

Read more at Discovery News

How Diseases Inspired Movie Monsters

Terrifying tales of monstrous creatures such as the Wolfman, zombies, and Count Dracula originated from a poor understanding of medical maladies, according to a forensics expert.

Dracula’s appearance and behavior, for example, matches with a disorder called porphyria that affects the skin and nervous system. Symptoms include sensitivity to sunlight, insomnia, and skin redness, which might make the skin look bloody.

“In the 10th or 11th century, Romanians at the time often didn’t bury their dead in very deep graves,” Greg McDonald, director of forensic medicine at Philadelphia College of Osteopathic Medicine, was quoted as saying in a press release. “Sometimes, the bodies would shift.”

“So imagine you’re a peasant,” he continued, “and you come across a body that is pale and looks like it has blood around the mouth. You might think he’d been walking around, feasting on the blood of others.”

That’s how Porphyria helped to create the myth, which took on a life of its own via oral tradition and folktales before Bram Stoker penned his famous novel “Dracula” in 1897, bringing the tale to the masses.

Observation of individuals on drugs, as well as graveyard-shifting bodies, probably contributed to the origin of zombies.

Yet another illness that took on Hollywood proportions was the still-dreaded rabies. Its symptoms of panting and foaming at the mouth helped to inspire the Wolfman, McDonald said.

Read more at Discovery News

Freaked Out Fish Grind Their Teeth and Produce Odd Noise

When in distress, a fish called the French grunt produces a jarring sound akin to fingernails-on-a-blackboard, and now a new study reveals how and why the fish do it.

The sound isn’t grunting at all — it’s produced by the fish grinding their teeth. The research, published in The Journal of Experimental Biology, demonstrates how this fish (Haemulon flavolineatum) can audibly communicate with others without a voice box.

The clever fish makes the most of its limited sound-producing anatomy.

“Sound production is probably an adaptation of the food-processing mechanism in this species,” lead author Frédéric Bertucci and colleagues from the Universities of Liège and Antwerp wrote.

The researchers recorded the calls, which are produced when the fish feels threatened. You can hear one of the fish making the sound as a fisherman grasps it.

Bertucci and his team tested French grunts’ hearing and examined high-speed X-ray movies of their heads.

All of this determined that the sound has a pitch of about 700 Hz, but that their hearing sensitivity was strongest at 300 Hz. This doesn’t mean that the fish can’t hear each other. They just don’t specifically tune into the distress calls of their own species, perhaps because the teeth grinding is a relatively new phenomenon. They also must listen for other sounds, such as prey movements.

The fish have what are known as pharyngeal jaws, meaning a second set that’s located in the throat which manipulate prey and aid in its swallowing. And now we know that these jaws have another function.

Read more at Discovery News

5 Spooky Spider Myths Busted

Just the facts, please.
Spiders: they creep, they leap, they haunt the nightmares of arachnophobic humans. But a lot of the fear surrounding spiders is based on myths, not facts, according to the experts who study these eight-legged creatures.

Did you know, for example, that the venom of most tarantulas would hardly make adult humans flinch, let alone kill them? And all those stories you've heard about spiders laying eggs inside an open wound are the stuff of urban legend, not reality.

Here are five more spider myths that irk arachnologists and spider-lovers alike.

Didn't see what bit you? It was probably a spider.

"Unquestionably, the most pernicious of all spider myths is the idea that if you didn't see what bit you, it was a spider," said Rod Crawford, curator of arachnids at the Burke Museum of Natural History and Culture in Seattle.

Spiders are blamed for all kinds of bites, bumps, rashes and growths that they likely had nothing to do with, according to Crawford. The myth that spiders tend to bite people when they least expect it — like when they're lying in bed — has been making the rounds for well over a hundred years, but it's not clear how it got started, he said.

While it is certainly possible for spiders to bite people in bed, Crawford said this doesn't happen often. Unlike mosquitos or ticks, spiders don't feed on human blood, so they have no reason to venture near a slumbering human on purpose. And even if you were to roll on top of a spider in your sleep, it would be tough for the critter to bite you since its fangsare located underneath its body, Crawford said.

The notion that spider bites are extremely common is also a potentially dangerous myth. Several conditions that are wrongly labeled as spider bites — particularly skin infections and skin cancer — are actually much more serious than spider bites and require immediate medical attention, Crawford said.

Spiders are Insects.

Spiders are not insects, even though both spiders and insects belong to the same phylum (Arthropoda). In fact, spiders and insects are members of different classes: Spiders belong to the class Arachnida, while insects belong to the class Insecta. This means that spiders and other arachnids are as far removed from insects as birds are from fish, Crawford said.

To distinguish a spider from an insect, you can start by counting how many pairs of legs it has, Crawford said. Spiders have four pairs, whereas insects have three. A spider also has two main body parts — the cephalothorax at the front (the legs are attached to this part of the body) and the abdomen in the rear. Insects have three body parts: a head, thorax and abdomen.

Misidentifying spiders as insects can be more than just a harmless mistake.

"It leads indirectly to a lot of environmental pollution because it results in unnecessary pesticide use," Crawford said. Pest control companies often use insecticides to kill off the spiders inside a house, but these chemicals aren't formulated to kill spiders and so they don't typically work, he added. Instead of insecticides, sticky traps can be a more effective way to rid your home of eight-legged creatures.

If you see a spider in your house, you should put it back outside.

You may think you're being kind by putting a spider you find in the bathroom sink outside on the lawn, but this isn't necessarily the case. Putting a house spider outside is a little like "freeing" a lion that has spent its whole life inside a zoo: the odds that it'll survive a return to its "native habitat" aren't very good.

This is because most of the spiders found in homes — about 95 percent — have adapted to life indoors, according to Crawford. While spiders may wander into your home from outside every once in a while, this isn't the norm. Spiders found indoors likely belong to a small number of species, dubbed house spiders, that have been living with humans since at least the days of the Roman Empire, Crawford said.

In Seattle, for example, there are approximately 137 species of spiders that live outdoors and there are approximately 25 known species of house spiders. Only eight of those species, however, can survive both inside a house and outside in the garden, Crawford said.

So what should you do when you see a spider in your house? Crawford suggests leaving the critter alone, but if that's not your style, he recommends trying to keep spiders out of certain areas of your home where you'd rather not run into them, such as the bedroom. Seal any gaps in floorboards, cracks in walls or other holes or crevices through which the spiders may access these spaces, Crawford said.

Read more at Discovery News

Oct 29, 2014

New Frog Species Discovered in NYC

New York City is the most populous city in the United States, and yet a newly discovered frog species living there has gone unnoticed until recently.

The Manhattan-dwelling amphibian is the leopard frog Rana kauffeldi, which is described in the latest issue of PLOS ONE. The frog looks suitably fashionable, with its distinctive leopard-print skin in shades of brown and green.

"The discovery of a new frog species from the urban Northeast is truly remarkable and completes a journey that began six years ago with a simple frog call in the wilds of New York City," researcher Jeremy Feinberg from Rutgers University was quoted as a saying in a press release.

Feinberg and his team, familiar with frog calls, wondered, "What the heck is that?" when they first heard the call, which consists of a short, repetitive croak. The calls of other leopard frogs have been described as sounding like a "long snore" or even a human, throaty laugh.

The scientists traced the call to the leopard frog. DNA testing revealed that it was a previously undocumented species.

The researchers believe that, in addition to NYC, the frog exists in other parts of New York, as well as in coastal lowland regions from Connecticut to northeastern North Carolina. This video, produced shortly after Feinberg and his team began to investigate the mysterious NYC frog, shows more about leopard frogs in the U.S. and where they are found.

The frog favors "open-canopied wetlands interspersed with upland patches," but it's also seen in muddy NYC puddles, including around Yankee Stadium. The frog's fashionable skin serves as the perfect camouflage, perhaps explaining how a busy New Yorker could walk right by the cleverly nature-disguised amphibian without even noticing it.

Read more at Discovery News

Koala Chlamydia Vaccine Successful in Early Tests

Australian scientists said Wednesday they have successfully tested a vaccine against chlamydia in wild koalas, in what they believe is a breakthrough in combating the sexually-transmitted disease ravaging the native marsupial.

The much-loved furry animal has been under increasing threat, with the government classifying it as a vulnerable species amid a plunge in population numbers from habitat loss, disease and other factors.

Microbiologists from the University of the Sunshine Coast in Queensland hope to be able to protect some of the remaining population after successfully trialling a chlamydia vaccine that they spent five years developing.

"It's all very promising and it's not just that it's doing the right thing from an immune response point of view, but it's actually protecting a significant number of them out in the wild climbing around trees," professor Peter Timms told AFP of the field trial, believed to be the first of its kind.

Chlamydia can lead to blindness, infertility and death among koalas. The risk of infertility also exacerbates the impact of other factors that are already reducing population levels.

Thought to number in excess of 10 million before British settlers arrived in 1788, there are now believed to be as few as 43,000 koalas left in the wild, though their existence high in the treetops makes them difficult to count.

In the trial, microbiologists Timms and Adam Polkinghorne gave 30 koalas the vaccine while 30 others were left unvaccinated against the disease, which is endemic in some koala populations.

All 60 koalas were fitted with radio collars so they could be monitored in their natural habitat at Moreton Bay north of Brisbane.

Of the 30 vaccinated, some were healthy, some were already infected with chlamydia, and some were showing signs of the disease, typically eye infections and reproductive tract infections.

For the trial, seven out of eight koalas suffering from eye infections who received the vaccine showed an improvement. In the unvaccinated group, four of the six koalas with eye infections saw their conditions worsen.

The researchers also found that koalas infected with the chlamydia strain who were then vaccinated did not go on to develop the full-blown disease.

"In the unvaccinated group, three of the animals have already got the disease, but in the vaccinated group, none of them got the disease," Timms said.

Read more at Discovery News

70,000-Year-Old Mammoth Skeleton Found in Idaho

The skeleton of a mammoth was discovered this month on the banks of a reservoir in Idaho. Paleontologists have rescued part of its skull and a tusk, but there could be a lot more buried below the surface.

"We may even have a complete mammoth," said Mary Thompson, a vertebrate paleontologist and senior collections manager at the Idaho Museum of Natural History. "This is very unique for us."

Every year, when water levels drop in Idaho's American Falls Reservoir, teams of paleontologists and volunteers with the Bureau of Reclamation walk the beaches in search of fossils. The ancient bones of camels, bison latifrons, giant ground sloths, saber-toothed cats and other extinct Ice Age beasts sometimes poke out of the freshly eroded reservoir banks.

Earlier this month, one volunteer stumbled upon the mammoth fossil on a cliff face about 30 feet (9 meters) below the reservoir's high-water mark. Thompson said she could tell it was from a mammoth as soon as she got the pictures in her email inbox. She and a team of students and volunteers mounted a quick, two-and-a-half-day excavation to dig up the bones as they raced rising water levels.

"I've been here since 1990, and we haven't gotten anything this complete from that site since then," Thompson told Live Science. "Out of this area, we have one other complete mammoth."

The excavators used plaster casts to remove most of the mammoth's right tusk, which was about 7.5 inches (19 centimeters) in diameter. They also found part of its skull, a chunk of its mandible and two jagged upper molars. The specimen was transferred to the Idaho Museum of Natural History at Idaho State University in Pocatello.

Read more at Discovery News

Scientists Resurrect 700-Year-Old Virus

When researcher Eric Delwart read about the many things that could be preserved in ice cores, he told NPR he realized he might be able to find buried treasure: caribou poop.

Now, the work has paid off. The well-preserved, 700-year-old remains of, yes, caribou poop that Delwart found contained DNA that he and some colleagues were able to extract. Eventually, they used it to reconstitute an entire plant virus.

"I mean we're constantly shoving viruses down our throat and if you look at poo samples from humans and from animals you will find a lot of viruses," Delwart, a researcher at Blood Systems Research Institute in San Francisco, told NPR.

The news, published in Proceedings of the National Academy of Sciences, is both exciting and scary: The virus "time capsules" found in Canada will undoubtedly help inform research on the evolution of viruses. But it also raises the possibility of unleashing ancient viruses as ice melts or Arctic regions are drilled.

"The find confirms that virus particles are very good 'time capsules' that preserve their core genomic material, making it likely that many prehistoric viruses are still infectious to plants, animals or humans," Jean-Michel Claverie, of the Aix-Marseille University School of Medicine in France, told New Scientist. "This again calls for some caution before starting to drill and mine Arctic regions at industrial scales."

Although Delwart's team was able to get the buried virus to infect a type of tobacco plant, he told NPR that this particular virus isn't dangerous.

"There's a theoretical risk of this, and we know that the nucleic acid of the virus was in great shape in our sample," Delwart told New Scientist. "But old viruses could only re-emerge if they have significant advantages over the countless perfect viruses we have at present."

From Discovery News

Fantastically Wrong: The Real-Life Journey to the Center of the Earth That Almost Was

Sucks for you, Greenland.
Back in 1818, some 500 heads of state, scientific societies, and universities got what could generously be called one of the more singular letters they’d ever received. The immediate giveaway, perhaps, was the attached document proving the sanity of the sender, an American eccentric named John Symmes.

“I declare the earth is hollow,” Symmes began, “and habitable within; containing a number of solid concentrick [sic] spheres, one within the other, and that it is open at the poles 12 or 16 degrees; I pledge my life in support of this truth, and am ready to explore the hollow, if the world will support and aid me in the undertaking.”

He added with aplomb: “I ask one hundred brave companions, well equipped, to start from Siberia in the fall season, with Reindeer and slays [sic], on the ice of the frozen sea: I engage we find a warm and rich land, stocked with thrifty vegetables and animals if not men, on reaching one degree north-ward of latitude 62; we will return in the succeeding spring.”

There were no takers. But Symmes would eventually earn an enormous audience for his theory in the US, touring tirelessly in the 1820s. He was largely ridiculed, sure, but miraculously managed to get a congressman to petition his colleagues in Washington for the funding to reach the North Pole and discover the 4,000-mile-wide entrance to the “hollow.” And while he never got his expedition, dying an early and penniless death, he helped jump-start a glorious new era of exploration—and arguably helped transform American science as we know it.

The Man and the Myth

John Symmes was born in New Jersey in 1780 and grew up on his family’s farm. After a rather valorous career as a captain in the Army, Symmes retired to St. Louis in 1816 to sell supplies to soldiers and Native Americans. It was here where Symmes, a prolific reader who pulled information from all manner of encyclopedias and compendiums, would solidify and unleash his theory that there are entire inhabited worlds underground.

The impetus of it all, according to Peter Sinnema in his essay “10 April 1818: John Cleves Symmes’s ‘No. 1 Circular,’” were studies of Saturn’s rings. Using these to make a bit of a leap in judgement, Symmes reasoned that the planet’s concentric circles must necessarily be duplicated elsewhere in the solar system, including Earth. Our circles are just underground, in the form of at least five hollow spheres that each have their own atmosphere, which forms by clouds (and, we’re to assume, the occasional penguin or seal) pouring into two giant holes, one at the North Pole and the other at the south.

These openings are so enormous, in fact, that the northern one unfortunately seems to reach all the way down into Canada and Iceland and Greenland and such, according to Duane A. Griffin in his own essay “Hollow and Habitable Within: Symmes’s Theory of Earth’s Internal Structure and Polar Geography.” (One of Symmes’ few surviving diagrams of his Earth, shown at the top of this story, appeared in The Southern Bivouac in 1887). This would come as some surprise to folks who live in those regions. No problem at all, argued Symmes.

Writes Griffin: “Refraction, Symmes claimed, would bend light rays down into the planet, where reflection among the spherical surfaces would provide a soft, never-ending daylight more than sufficient to light the inner world and warm it well above freezing.” Thus the phenomenon provided not only the light required to sustain life down there, but served as a kind of optical illusion, which tricked the denizens of places like Greenland into thinking they were part of our world as we know it.

The polar holes would also explain how we get wind. James McBride—Symmes’ “patron and collaborator,” according to Sinnema—wrote in his glowing manifesto on the theory that the “long continuation of winds, or regular monsoons, which occur in some parts of the earth, may be supplied by winds sucked into one polar opening and discharged through the other.” (Wind is actually caused by changes in air pressure, or if TV meteorologists are to be trusted, angry clouds blowing on you.)

Halley’s model of the hollow Earth.
Now, Symmes’ wasn’t an entirely original idea. None other than the famed astronomer Edmond Halley was the first to put forward a scientifically reasoned theory of a hollow Earth (and the idea had been bouncing around in various folk traditions for thousands of years before that). Halley argued that “the Earth is represented by the outward Circle, and the three inward Circles are made nearly proportionable to the Magnitudes of the Planets Venus, Mars, and Mercury, all which may be included within this Globe of Earth.” In between those circles, a sort of luminous ether provided the light that allowed life to flourish.

Whether or not Symmes was influenced by this is unclear. Griffin says no in his essay, while Sinnema claims the eccentric picked up the idea from Cotton Mather’s The Christian Philosopher, which focuses extensively on Halley’s theory. Neither Griffin or Sinnema address it, but Symmes also believed the giant entrances to the underworld to be responsible for the aurora borealis. Halley, too, though the phenomenon was due to the ether escaping through cracks in the Earth. (It’s actually the sun’s particles slamming into our magnetic field.)

Either way, the American people didn’t give a hoot where the theory came from. They ate it up.

Have You Heard the One About There Being Giant Holes in the Earth and There Being, Like, Critters Running Around Down There and Stuff?

To drum up support for his unprecedented journey to the North Pole, Symmes toured much of the Midwest—to mixed reviews. The press largely ridiculed him, but the more gullible in the audiences bought it. Symmes, it seems, was a convincing speaker. And in 1825, he set out east on his most popular tour yet. “Audiences packed halls expecting high amusement from a madman,” writes Griffin. “They went home wondering if Symmes might not be right after all.”

This was not, though, simply a bamboozling of the plebs, à la Dr. Oz. He earned the support of Ohio newspaper editor Jeremiah Reynolds, as well as Major Thomas H. Long, “one of America’s foremost military engineers,” according to Griffin. Symmes even got an invitation from the chancellor of Russia, Count Romanoff, to join him on his polar expedition. Quite cleverly, he told the press that he’d have to accept if his own country couldn’t foot the bill for his own expedition. Writes Griffin: “The ploy tapped a fierce streak of nationalism and bought Symmes—dubbed ‘the Newton of the West’—a new degree of legitimacy and popularity that boosted lecture attendance, earning the team enough to commission new globes and charts for their demonstrations.”

A portrait of John Symmes by the famed painter John Audubon, the man responsible for the most gorgeous work of ornithology ever. Yeah, he pretty much phoned this one in.
Even learned types bought into the theory. In his plea to world leaders and intellectuals, Symmes had vaguely declared: “I select Doctor S.L. Mitchill, Sir H. Davy and Baron Alex. de Humboldt as my protectors.” The latter two of these superstar scientists ignored Symmes’ letters. But Mitchill wrote back, according to Griffin, “giving the Captain ‘great credit for the ingenuity and originality’ of his hypothesis and noting that he ‘should exceedingly rejoice’ if polar exploration were to prove it correct, an outcome that would earn Symmes honor as ‘one of the most profound theorists that ever addressed a wondering people.’” Students at Harvard also lined up behind him (“You’re doing what now?” asked their professors), and he also “apparently fared well at other colleges and learned societies.” Even his coverage in the press finally improved.

The Crank That Changed American Science

At the peak of his momentum, though, Symmes’ health failed, and he died in 1829. With him went his theory—but not his influence.

Griffin argues that Symmes had a deep and lasting impact on American science, which at the time was decidedly empiricist, that is, science as we know it, with careful collection of specimens and experimentation and whatnot. Symmes, he writes, provided “a model of a way of thinking that went beyond empiricism toward explanations of the unknown.” The eccentric had spiced up science with that can-do, adventurous American spirit. Sure, that’s a bit cliched at this point, but by harnessing that ethos, Symmes helped kick off a new era of scientific exploration.

Read more at Discovery News

Oct 28, 2014

Galapagos Island Giant Tortoises Stage a Comeback

Endangered giant tortoises have staged a remarkable population comeback on Espanola Island in the Galapagos.

A new study published today in the journal PLOS ONE reports that giant tortoises on the island now number about 1,000 self-sustaining creatures, after nearly disappearing in the 1960s, when just 15 were counted.

"The population is secure," said James P. Gibbs, professor of vertebrate conservation biology at the SUNY College of Environmental Science and Forestry and lead author of the paper, in a press release. "It's a rare example of how biologists and managers can collaborate to recover a species from the brink of extinction."

Captive-bred tortoises were originally reintroduced to the island about 40 years ago by the Galapagos National Park Service. The study reports that about half of the tortoises released there since 1975 were still alive as of 2007, and that the tortoises' risk for extinction in the future was low, "with or without continued repatriation."

Gibbs and his team gauged the current population on the island by poring over 40 years of data about tortoises that had been monitored, marked and recaptured on a regular basis for measuring.

While Gibbs called it "a true story of success and hope in conservation," the scientist said there is another hurdle yet to be cleared, if the tortoises are to continue growing their numbers -- recovery of the landscape.

"Population restoration is one thing but ecological restoration is going to take a lot longer," he said. In the late 19th century, feral goats brought to the island ravaged the vegetation. Even after their removal from the island, today resources are more scarce, as small trees and shrubs have taken root whose numbers crowd out the growth of cactus, a key component of the tortoises' diet.

"This is a miraculous conservation success accomplished by the Galapagos National Park Service," said Gibbs, "but there is yet more work to fully recover the ecosystem upon which the tortoises and other rare species depend."

From Discovery News

Prehistoric Art Highlights 'Supernatural' Sound Effects

Depictions of interesting sounds, such as echoes and natural amplifications, appear to have made their way into everything from cave art to Stonehenge, according to new research presented today at the Meeting of the Acoustical Society of America in Indianapolis.

Among other things, the discovery could help to explain why so much early cave art showed human hands and images of herds of running animals. Steven Waller of Rock Art Acoustics suggests that the echoes and reverberation of things like hand clapping in a cave would have been misinterpreted as being “supernatural.”

“Ancient mythology explained echoes from the mouths of caves as replies from spirits, so our ancestors may have made cave paintings in response to these echoes and their belief that echo spirits inhabited rocky places such as caves or canyons,” Waller explained in a press release.

Echoes of clapping hands can sound similar to hoof beats, he said, which could be why so many running herds of animals were featured on cave walls.

“Many ancient cultures attributed thunder in the sky to ‘hoofed thunder gods,’ so it makes sense that the reverberation within the caves was interpreted as thunder and inspired paintings of those same hoofed thunder gods on cave walls,” he said.

Waller added, “This theory is supported by acoustic measurements, which show statistically significant correspondence between the rock art sites and locations with the strongest sound reflection.”

Sounds like this are now called “auditory illusions.” Early leaders appear to have often used them. For example, prior research determined that hand clapping at the pyramid of Kukulkan in Chichen Itza, Mexico, produces an echo resembling the call of the quetzal, a sacred bird thought to hold mythical powers. Priests clapped and then interpreted what the “mystical” echo meant.

Waller even thinks that the placement of stones at Stonehenge could have been done with “supernatural” sound effects in mind. He traveled to the megalith and had two flute players play the same note at the same time in a nearby open space. Other blindfolded individuals listened to the results.

Read more at Discovery News

When Spirits 'Dictate' Books: What's to Believe?

Just in time for Halloween, there are several recent books out that are claimed to have been written by dead people through living writers. One is by musician David Young called “Channeling Harrison,” in which he claims that the spirit of ex-Beatle George Harrison is in contact with him, guiding his songwriting and teaching him life lessons.

There is nothing new about this; so-called “channeled” books were very popular in New Age circles in the 1970s and 1980s. Among the most popular was the 1970s book series “Seth Speaks,” dictated by Jane Roberts, who claimed that an energy named Seth possessed her body and dictated esoteric information through her about the soul, the nature of consciousness, spiritual truths, higher planes of reality, and so on.

Channeling remains immensely popular among New Agers; hundreds of books, audiotapes, seminars, and DVDs are devoted to the practice.

Ghost-Written Books

Earlier this year in her book “Conversations with History,” claimed psychic medium Susan Lander wrote that Betsy Ross, widely credited with sewing America’s first flag, came out to her as a lesbian about 175 years after her death. According to an interview on, “When Lander asked Ross why she contacted her, the American icon announced: ‘I am gay and I fly the flag of pride and liberty for all of us… I am gay, I am gay, I am gay… I am speaking now as a revolutionary act,” Ross explained [through Lander], saying she no longer wanted to carry this secret. ‘I want history to accurately reflect who I was.’”

It’s a surprising revelation from Ross — especially since many scholars doubt that she actually sewed the flag she’s famous for. According to “The Washington Post,” “There simply is no credible historical evidence that Ross… either made or had a hand in designing the American flag before it made its debut in 1777… it is all but certain that the story about her creating the American flag is a myth.” Given Betsy Ross’s interest in wanting history to accurately reflect who she was, it’s very strange that she would not have offered evidence defending her claim to fame.

Wendy Weir, sister of the Grateful Dead singer and guitarist Bob Weir, wrote a book titled “In the Spirit: Conversations with the Spirit of Jerry Garcia,” in which she offered 250 pages of what she says the dead singer told her about life, music, and the world, in a series of lessons from the cosmic beyond.

Unfortunately little of Jerry Garcia’s lyricism seems to have survived death, and most of his messages are indistinguishable from standard New Age platitudes; here’s a typical message: “Joy is love. Joy is peace. Joy is within each and every one of us if only we listen to it calling, follow its song, and open the doors to where we so often keep it hidden behind pressure, guilt, work, obligations, fear, and pain. Allow the light of joy to shine forth from within, allow it to penetrate the Universe, and you will be transformed, for life within you will be raised to a high vibration and the life without you will respond to this shift… This is a lesson we should incorporate into all of our lives, every day. Open up, allow your joy to shine forth, and feel the radiance, the joy, shining back to you.”

One of the problems with channeled books is that for the most part anyone can claim to communicate with the spirit of anyone, from Jesus to Napoleon to Michael Jackson, and write a book about it.

Verifying Ghostly Information

While the vast majority of information imparted through psychic mediums and channelers is impossible to independently verify, every now and then they do offer facts that can be examined.

For example before its demise in 2007 as a printed magazine, “Stuff” had a regular column called “Beyond the Grave: Interviews with Dead Celebrities.” It’s not clear how tongue-in-cheek the readers took it, but the psychic who wrote it, Victoria Bullis, was certainly serious about it. Bullis “interviewed” many dead celebrities including ex-model Anna Nicole Smith, and when Smith was asked about the then-hyped controversy over the paternity of Smith’s daughter Dannielynn, Smith was clear and unequivocal: “Please tell everyone it’s Howard K. Stern.”

However soon after the interview was published, DNA tests revealed that in fact Smith’s former boyfriend Larry Birkhead was the father. For Bullis and others who believe that people can talk to the dead, this presents an interesting problem, because the ghost said something that wasn’t true.

There are several possible explanations: 1) Smith did not know who the father of her child was, and therefore the dead don’t have any better information than the living (about paternity, cosmic truths, or anything else); or 2) Smith lied to Bullis and her readers (thus calling into question the truth of anything communicated by a ghost) or 3) “World-renowned psychic” Victoria Bullis cannot really talk with the dead as she claims.

The Psychology of Channeling

So are all these communications with dead people hoaxes or frauds? Not necessarily; surely some are cynically cashing in on dead celebrities, but most of them truly believe that they have been in contact with the dead or some unseen presence. This is neither pathological nor unusual: countless shamans, prophets, priests, and others claim to hear voices or receive supernatural knowledge or messages from the spirit world.

It’s an interesting phenomenon with a psychological explanation. When people meditate and relax, random thoughts, images, symbols, and messages may spontaneously arise. If we believe in ghosts or higher powers — and especially if we are actively trying to communicate with them — then in this harmless dissociative state we may interpret our own thoughts as coming from another consciousness outside the body.

David Young, author of “Channeling Harrison,” believes that George Harrison began communicating with him in his dreams, and Young soon began noticing what he considered to be significant coincidences in his life.

Read more at Discovery News

Murderers May Be Hardwired to Kill

Serial killers and other people who repeatedly commit violent crimes, such as assault and battery, may be hardwired to hurt others, suggests a new study that identifies two genetic variants tied to extreme violent behavior.

The findings, published in the latest issue of the journal Molecular Psychiatry, could help to explain why the majority of violent crimes are committed by a small group of antisocial, repeat offenders. The extensive study represents the first effort to investigate the genetic background of people exhibiting such repetitive, brutal behavior.

"I think that we have found two genes that have the largest effect in aggressive behavior, and that there are probably tens or hundreds of other genes having smaller effects," lead author Jari Tiihonen told Discovery News.

Tiihonen, a professor in the Department of Clinical Neuroscience at the Karolinska Institute in Sweden, and his colleagues screened 1004 prisoners in Finland. Of that group, 184 refused to participate in the study and 26 were excluded because of "a psychosis diagnosis." Blood samples for DNA extraction were taken from the remaining prisoners, whose crimes and backgrounds were also investigated.

The scientists determined that the prisoners who had repeatedly committed, or attempted to commit, violent crimes tended to have one or both of the following genetic variants: CDH13 and MAOA, a.k.a. the "warrior gene."

Tiihonen explained that MAOA metabolizes an important neurotransmitter called dopamine. The presence of this genetic variant and substance abuse helps to create a perfect storm.

"If this activity is decreased, it might lead to a larger dopamine burst in the brain when alcohol, cocaine or amphetamine is used," he explained. "It is known that these substances induce dopamine burst and aggression."

CDH13, on the other hand, is a gene that codes for neuronal adhesion protein, so it contributes to the development of neuronal connections in the brain. It is one of the most important genes associated with Attention Deficit Hyperactivity Disorder (ADHD).

People with both of these genetic variants have a 13-fold increase of committing a violent crime versus those who do not have the mutations, according to the study. Add substance abuse again to the mix and there is a likely recipe for disaster.

The study could also help to explain why most mass murderers are men.

"Since MAOA is located in the X-chromosome, men have only one copy of the gene and women have two copies," Tiihonen said, explaining that women have two X-chromosomes. "Therefore, females can have one low activity allele (alternative form of a gene that arises by mutation) and one high activity allele, but if males have a low activity allele, they cannot have another allele functioning more efficiently because they have only one copy of the gene."

Yet another recent study, conducted on a sample of about 100 inmates from a correctional institution in the Southern United States, also determined that MAOA is associated with higher rates of crime when the individual additionally experienced childhood adversity.

"These findings (published in the journal Psychiatric Genetics) indicate that gene-by-environment interactions are important for understanding variation in crime amongst populations with high base rates of criminal activity," said principal investigator Todd Armstrong of Sam Houston State University.

Read more at Discovery News

Oct 27, 2014

A Look Inside a Jumping Spider's Explosive Brain

The jumping spider, famed for its excellent vision and pouncing skills, has long been an enigma to neurobiologists. The arachnid's body is filled with a pressurized liquid that helps it move, and whenever curious scientists have tried to peer into its brain with surgical instruments, the spider exploded.

Now, with a new technique, scientists have recorded the electrical brain activity of these fascinating spiders, sans kaboom.

"What we've done is open up the brain basis of a very unusual animal," said researcher Ron Hoy, a professor of neurobiology and behavior at Cornell University.

The jumping spider (Phidippus audax) has a brain the size of a poppy seed, but vision almost on par with humans, making its visual system intriguing to researchers and robotic engineers who draw inspiration from nature.

Gil Menda, a postdoctoral researcher of neurobiology and behavior in Hoy’s lab, realized that if he made a tiny hole in the spider's head, the wound could self-heal around a tungsten-recording electrode as thin as a hair. He carefully inserted a microelectrode into the brains of 33 spiders, and watched how brain cells in their visual networks responded to pictures of white noise, flies and other jumping spiders.

With eight eyes, jumping spiders have an almost complete 360-degree view of their surroundings. Most spiders have poor vision and build webs to capture prey, but jumping spiders hunt nomadically much like a cat or a wolf stalks their prey, Hoy told Live Science.

He did note one small difference, however. Unlike cats, the spiders don't run after their prey. "They jump and seize their prey," Hoy said. "It's like a cat's pounce."

To keep the spiders still during the experiments, the research team created a small spider harness with a 3D printer. They covered the spiders' four back eyes, and inserted the electrode into the brain to help them look for brain cells associated with each spider's visual system. When the researchers showed the spiders an image of a fly, their natural prey, on a screen, the spiders' brain cells associated with their visual systems showed a burst of electrical activity.

In Chinese, the spider's name translates to "flying tiger." But they aren't dangerousto people. "They have venom, but it's reserved for their prey," Hoy said.

"You hear a very strong response from the brain when [the spiders] detect something that they recognize," Menda said.

To ensure the spiders weren't responding to certain parts of the fly, such as its wings or head, the researchers showed the spiders a jumbled picture of a fly. The scattered image didn't elicit a response. "They didn't respond at all to the pictures," Menda said. "It wasn't the small component of the picture, it was the image of the fly."

The jumping spiders also showed a neural response to the "white noise" static, but not to images of other spiders, according to the electrode recordings; it's possible that other neurons in their brains that weren't attached to the electrode showed a response to spider images, the researchers said.

Unlike humans, whose eyes detect both acuity and motion, the spider's large, primary eyes process acuity, and its small, secondary eyes see motion. Because researchers were unable to study the spiders' neural activity until now, they were unsure how the spiders' eyes worked together.

"You can imagine that you have four eyes that are all looking at the same thing, you get input one and input two, and you would add them together," speculated researcher Paul Shamble, a graduate student of neurobiology and behavior in Hoy's lab. "It turns out that for some of the neurons, that wasn't the case. It was much more complicated."

In the experiment, the researchers covered the spiders' front eyes and then their side eyes. The spiders showed little neural visual response to the images if either set of eyes was covered.

The spiders need both their large and small eyes to process visual information, the researchers found. "They need all of their eyes to detect the prey," Menda said.

Read more at Discovery News

Telltale Signs of Life Could Be Deepest Yet

Telltale signs of life have been discovered in rocks that were once 12 miles (20 kilometers) below Earth's surface — some of the deepest chemical evidence for life ever found.

Researchers found carbon isotopes in rocks on Washington state's South Lopez Island that suggest the minerals grew from fluids flush with microbial methane. Methane from living creatures has distinct levels of carbon isotopes that distinguish it from methane gas that arises from rocks. (Isotopes are atoms of the same element with different numbers of neutrons in their nuclei.)

In a calcium carbonate mineral called aragonite, the standard mix of carbon isotopes was radically shifted toward lighter carbon isotopes (by about 50 per mil, or parts per thousand). This ratio is characteristic of methane gas made by microorganisms, said Philippa Stoddard, an undergraduate student at Yale University who presented the research Tuesday (Oct. 21) at the Geological Society of America's annual meeting in Vancouver, British Columbia. "These really light signals are only observed when you have biological processes," she told Live Science.

The pale aragonite veins cut through basalt rocks that sat offshore North America millions of years ago. The veins formed after the basalt was sucked into an ancient subduction zone, one that predated today's Cascadia subduction zone. Two tectonic plates smash together at subduction zones, and one plate descends under the other, creating deep trenches.

Methane gas supplied the carbon as aragonite crystallized in cracks in the basalt, and replaced pre-existing limestone. The researchers think that microbes produced the methane gas as a waste product.

"We reason that you could have life deeper in subduction zones, because you have a lot of water embedded in those rocks, and the rocks stay cold longer as the (plate) comes down," Stoddard said.

But the South Lopez Island aragonite suggests the minerals formed under extreme conditions that push the limits of life on Earth. For example, temperatures reached more than 250 degrees Fahrenheit (122 degrees Celsius), above the stability limit for DNA, Stoddard said. However, the researchers think the higher pressures at these depths may have counterbalanced the effects of the heat. The rocks are now visible thanks to faulting, which pushed them back up to the surface.

Read more at Discovery News

Supervolcano Cleared in Neanderthals' Demise

Neanderthals disappeared from Europe 40,000 years ago, about the same time as the region's biggest volcanic blast in the last 200,000 years. But don't blame the volcano, a new study suggests.

Most of the eruption's climate-cooling pollution spread east, away from Neanderthal territory, according to research presented Monday (Oct. 20) here at the Geological Society of America's annual meeting.

"The pattern where the cooling was most intense doesn't overlap with where most of the Neanderthal sites are located," said study author Benjamin Black, a postdoctoral scholar at the University of California, Berkeley.

The Neanderthals' demise is an ongoing mystery. Their steep population decline followed the arrival of modern humans in Europe, studies show. Did our ancestors play a role in the Neanderthal extinction? Was it the onset of a cold, dry climate? Or did Italy's Campi Flegrei volcano deliver the final blow?

Campi Flegrei is an active volcano west of Naples that erupted in a tremendous explosion between 39,000 and 40,000 years ago. Superheated pyroclastic flows of volcanic gas and ash raced up nearby ridges more than 3,200 feet (1,000 meters) high and crossed miles of open water in the Bay of Naples, scorching the Sorrento Peninsula. The ash layers left behind are known as the Campanian Ignimbrite. The volcano also shot sulfur dioxide into the stratosphere, the layer of the atmosphere above the one we live and breathe in. In the stratosphere, sulfur dioxide is transformed into particles that reflect sunlight and cool the planet.

Black created a computer model of Campi Flegrei's global environmental effects, and then compared the extent of cooling and acid rain with locations of known Neanderthal and human archaeological sites of the same age. (Sulfur dioxide gas can also lead to acid rain.) The results suggest the volcano's fallout was brief and limited in Western Europe, where most Neanderthals met their end by 40,000 years ago, according to the latest studies. "The unusual climatic conditions may have impacted daily life, but the effects did not last long enough to trigger a catastrophic collapse of the Neanderthal population," Black told Live Science.

In Eastern Europe, temperatures fell by about 5.4 degrees Fahrenheit (3 degrees Celsius). This amount of cooling is similar to Europe's so-called "year without a summer" in 1816, which followed Mount Tambora's 1815 eruption. On the Volcano Explosivity Index, a scale that ranks eruptions, both Campi Flegrei and Mount Tambora rank a 7 out of 8.

The most intense cooling, of up to 11 degrees F (6 degrees C), was centered over Asia and North America rather than Europe, according to Black's model. And even then, the worst of the chill lasted about a year. Within five years, sulfur levels and temperatures in the Northern Hemisphere were nearly back to normal.

Scientists aren't sure how much ash and volcanic gas spewed from Campi Flegrei, so Black modeled both high- and low-emission scenarios and checked the results against 40,000-year-old sulfate levels preserved in the Greenland Ice Sheet. The best match comes from the low-emission scenario, with an estimated 55.1 million tons (50 teragrams) of volcanic sulfur dioxide used in the model.

Read more at Discovery News

Baby Stars' Twisted Magnetism More Chaotic Than Thought

As we zoom-in to stars light-years distant, we’re not only trying to understand the vast stellar menagerie that awaits our telescopic inquisitiveness, we’re also trying to decipher where we — and our bountiful solar system — came from.

Interestingly, the answer to how our unique planetary system came into being may be hiding in the magnetic configuration of a young sun that sparked to life over 4 billion years ago. Now, astronomers appear to have added another interesting finding to the magnetism surrounding a young star and how that may influence its ability at building a system of planets — thereby providing an insight to how our primordial solar system came to be.

Stars form as large clouds of cold molecular gas collapse under mutual gravity, eventually creating an environment so dense that nuclear fusion can spark inside stellar cores. Surrounding these embryonic stars, disks of gas and dust collect, creating accretion disks. It’s from these accretion disks that planetary systems will eventually evolve.

However, a baby star’s emerging magnetic field is thought to have a huge impact on planetary formation and the magnetic field’s configuration can make a huge difference for the final outcome of that star system.

Until now observations of young stars’ magnetic fields have been hard to come by, but an international team of astronomers have now measured the magnetic field surrounding a T Tauri star only 1 million years old. Their research was published in the journal Nature last week.

T Tauris are stars that are currently undergoing gravitational contraction and it is thought that the magnetic field these T Tauri stars possess strongly influence the configuration of the stars’ accretion disks. Using the Combined Array for Research in Millimeter-wave Astronomy (CARMA) of radio telescopes in California, the researchers were able to capture the magnetic morphology of the T Tauri star HL Tau, which is located 450 light-years from Earth

Theoretical studies of baby star magnetic fields suggest they should either be “poloidal” (magnetic field lines that loop from the north to south poles of the protostar) or “toroidal” (wrapped around the circular accretion disk). What the observations of HL Tau appear to show, however, is a more complex picture — neither theoretical model fits the observation.

Read more at Discovery News

Stellar Fireball Captured in Action

The expanding fireball of a nova explosion has been observed in unprecedented detail for the first time.

The new observations, reported in the journal Nature, show these eruptions are far more complicated than previously thought.

"Bright novae go off every few years, but this is the first to have occurred in good weather since the development of reliable optical telescope interferometers," said one of the study's authors, Dr Michael Ireland of the Australian National University. "Everything has come together to give us a really good look at one."

A nova is the thermonuclear explosion of hydrogen on the surface of a dead star called a white dwarf. When a white dwarf comes into a very close orbit with a companion star, it can suck hydrogen off the other star onto its own surface.

Once this hydrogen ocean reaches a depth of around 200 meters, gravity produces enough pressure to trigger thermonuclear fusion -- essentially a stellar atomic bomb -- that is visible many light years away.

On Aug. 14, 2013 a nova exploded about 14,800 light-years away in the constellation Delphinus. The 'new' star was subsequently named Nova Delphinus 2013.

"This nova was bright enough to be seen with the unaided eye," said Ireland.

Within hours of its discovery, Ireland and colleagues pointed the telescopes of the CHARA array in California toward the expanding nova fireball.

The CHARA Array combines the light from six optical telescopes in a process called interferometery, to create very high resolution images. The first measurements, which were the earliest ever obtained for a nova, showed the fireball was already as big as Earth's orbit around the sun.

This dramatically expanded to the size of Neptune's orbit by the time of the final observations 43 days after the initial blast.

One of the big questions about novae is how the explosion happens. Astronomers suspect the blast must happen all over the star at once, but the process is very complex and not well understood.

"We found the initial nova explosion wasn't spherical, giving the fireball a slightly elliptical shape," said Ireland.

"This happens because the white dwarf's atmosphere is spinning, and there's a disk of accreted material falling onto it from the companion star, so there's a lot happening to prevent the system from being spherical when it goes bang."

This provides clues to understanding how material is ejected from the surface of the white dwarf during the explosion.

"The interesting thing for me, were the multiple shells seen as the nova explodes," said Ireland.

"There's a main shell expanding at about 600 kilometres per second, but then there were also semi-transparent shells further out going even faster. So we could see both the optically thick inner shell, and the transparent outer shells expanding at the same time."

Ireland and colleagues still don't know what these shells are.

"I think there's a very tenuous outer shell, and as you look deeper and closer into the star, things get denser until eventually you can't see through things," said Ireland. "It looks like there are multiple shells, but it could be a continuance of thicker stuff near the white dwarf and thinner stuff further out."

Read more at Discovery News

Oct 26, 2014

Some like it loud: Warning coloration paved the way for louder, more complex calls in poisonous frogs

Frogs are well-known for being among the loudest amphibians, but new research indicates that the development of this trait followed another: bright coloration. Scientists have found that the telltale colors of some poisonous frog species established them as an unappetizing option for would-be predators before the frogs evolved their elaborate songs. As a result, these initial warning signals allowed different species to diversify their calls over time.

Zoologists at the National Evolutionary Synthesis Center (NESCent), the University of British Columbia, and other research universities assembled an acoustic database to analyze more than 16,000 calls from 172 species within the poison frog family, Dendrobatidae. The paper, which will appear in the December issue of the Proceedings of the Royal Society B, is now available online.

The study included both frogs that display bright colors and others that rely on camouflage for protection. Each call was examined in terms of pitch and duration, and researchers also factored in the size of the frogs and their visibility to predators. They found that because warning coloration protected them from predators, they were better able to attract a mate with low-pitch, pulsing vocalizations in plain sight than their quieter, darker-hued relatives.

"This allows the frog to have a unique type of call -- a noisy call," said lead author Juan C. Santos, formerly of NESCent and now at the University of British Columbia. "These noisy kinds of calls, in general, are what the females really like."

Scientists already understood that predators shied away from brightly colored frogs because of visual cues, but Santos and his colleagues hypothesized that some species evolved to include audio signals, as well. Such a warning system is not unprecedented: Tiger moths emit ultrasonic chirps to communicate their unsavory taste to bats. Without a similar ability, frogs navigate a precarious dilemma in which they must either risk detection by predators or forgo possible courtship.

Initially the researchers expected that audio warnings predated coloration, but the results indicate the opposite. Using molecular data and statistical analyses, they were able to infer a phylogenetic tree and pinpoint which trait came first. Their findings indicate that visual traits established the frogs as poisonous and cleared the way for louder, more elaborate calls.

Species relying on camouflage for defense will not invite attention with boisterous calls, while their protected relatives -- including nonpoisonous frogs that mimic the appearance of their toxic counterparts -- can be loud and more nuanced.

"The type of color they have is in the range of the noisy ones," Santos said. "When you're mimicking somebody that's already protected, you have some freedom to be found by potential mates."

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Climate change caused by ocean, not just atmosphere

Most of the concerns about climate change have focused on the amount of greenhouse gases that have been released into the atmosphere.

But in a new study published in Science, a group of Rutgers researchers have found that circulation of the ocean plays an equally important role in regulating Earth's climate.

In their study, the researchers say the major cooling of Earth and continental ice build-up in the Northern Hemisphere 2.7 million years ago coincided with a shift in the circulation of the ocean -- which pulls in heat and carbon dioxide in the Atlantic and moves them through the deep ocean from north to south until it's released in the Pacific.

The ocean conveyor system, Rutgers scientists believe, changed at the same time as a major expansion in the volume of the glaciers in the northern hemisphere as well as a substantial fall in sea levels. It was the Antarctic ice, they argue, that cut off heat exchange at the ocean's surface and forced it into deep water. They believe this caused global climate change at that time, not carbon dioxide in the atmosphere.

"We argue that it was the establishment of the modern deep ocean circulation -- the ocean conveyor -- about 2.7 million years ago, and not a major change in carbon dioxide concentration in the atmosphere that triggered an expansion of the ice sheets in the northern hemisphere," says Stella Woodard, lead author and a post-doctoral researcher in the Department of Marine and Coastal Sciences. Their findings, based on ocean sediment core samples between 2.5 million to 3.3 million years old, provide scientists with a deeper understanding of the mechanisms of climate change today.

The study shows that changes in heat distribution between the ocean basins is important for understanding future climate change. However, scientists can't predict precisely what effect the carbon dioxide currently being pulled into the ocean from the atmosphere will have on climate. Still, they argue that since more carbon dioxide has been released in the past 200 years than any recent period in geological history, interactions between carbon dioxide, temperature changes and precipitation, and ocean circulation will result in profound changes.

Scientists believe that the different pattern of deep ocean circulation was responsible for the elevated temperatures 3 million years ago when the carbon dioxide level in the atmosphere was arguably what it is now and the temperature was 4 degree Fahrenheit higher. They say the formation of the ocean conveyor cooled Earth and created the climate we live in now.

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