Oct 25, 2014

Florida lizards evolve rapidly, within 15 years and 20 generations

Scientists working on islands in Florida have documented the rapid evolution of a native lizard species -- in as little as 15 years -- as a result of pressure from an invading lizard species, introduced from Cuba.

After contact with the invasive species, the native lizards began perching higher in trees, and, generation after generation, their feet evolved to become better at gripping the thinner, smoother branches found higher up.

The change occurred at an astonishing pace: Within a few months, native lizards had begun shifting to higher perches, and over the course of 15 years and 20 generations, their toe pads had become larger, with more sticky scales on their feet.

"We did predict that we'd see a change, but the degree and quickness with which they evolved was surprising," said Yoel Stuart, a postdoctoral researcher in the Department of Integrative Biology at The University of Texas at Austin and lead author of the study appearing in the Oct. 24 edition of the journal Science.

"To put this shift in perspective, if human height were evolving as fast as these lizards' toes, the height of an average American man would increase from about 5 foot 9 inches today to about 6 foot 4 inches within 20 generations -- an increase that would make the average U.S. male the height of an NBA shooting guard," said Stuart. "Although humans live longer than lizards, this rate of change would still be rapid in evolutionary terms."

The native lizards studied, known as Carolina anoles or green anoles, are common in the southeastern U.S. The invasive species, Cuban anoles or brown anoles, are native to Cuba and the Bahamas. Brown anoles first appeared in South Florida in the 1950s, possibly as stowaways in agricultural shipments from Cuba, and have since spread across the southeastern U.S. and have even jumped to Hawaii.

This latest study is one of only a few well-documented examples of what evolutionary biologists call "character displacement," in which similar species competing with each other evolve differences to take advantage of different ecological niches. A classic example comes from the finches studied by Charles Darwin. Two species of finch in the Galápagos Islands diverged in beak shape as they adapted to different food sources.

The researchers speculate that the competition between brown and green anoles for the same food and space may be driving the adaptations of the green anoles. Stuart also noted that the adults of both species are known to eat the hatchlings of the other species.

Read more at Science Daily

Century-Old Notebook From Antarctic Expedition Found

Hidden in ice for more than 100 years, the photography notebook of a British explorer on Captain Robert Falcon Scott's ill-fated expedition to Antarctica has been found.

The book belonged to George Murray Levick, a surgeon, zoologist and photographer on Scott's 1910-1913 voyage. Levick might be best remembered for his observations of Cape Adare's Adélie penguins (and his scandalized descriptions of the birds' "depraved" sex lives). The newly discovered book also shows he kept fastidious notes, scrawled in pencil, about the photographs he took at Cape Adare.

Levick's "Wellcome Photographic Exposure Record and Dairy 1910" had been left behind at Captain Scott's last expedition base at Cape Evans. Conservationists discovered the notebook outside the hut during last year's summer melt.

"It's an exciting find," Nigel Watson, executive director of the New Zealand-based Antarctic Heritage Trust, said in a statement. "The notebook is a missing part of the official expedition record. After spending seven years conserving Scott's last expedition building and collection, we are delighted to still be finding new artifacts."

The book has notes detailing the date, subjects and exposure details from his photographs. In his notes, Levick refers to a self-portrait he took while shaving in a hut at Cape Adare and shots he took of his fellow crewmembers as they set up theodolites (instruments for surveying) and fish traps and sat in kayaks.

Levick was one of six men in Scott's Northern Party, who summered (1911-1912) at Cape Adare and survived the winter of 1912 in a snow cave when their ship was unable to reach them. Levick was not part of the team that accompanied Scott on his doomed quest to be the first to reach the South Pole.

After an arduous two-and-a-half month trek, Scott and his crew did make it to the South Pole on Jan. 17, 1912. But they discovered that the Norwegian explorer Roald Amundsen had beat them to it. Scott and his team died on the way back to their base, faced with a blizzard and dwindling supplies.

Read more at Discovery News

Oct 24, 2014

Swimming Mammoths Beat Humans to California

A fossil tusk rescued from the sea proves mammoths swam to Southern California's Channel Islands much earlier than thought.

The new fossil is one of two recently discovered tusks that challenge the idea that climate change killed off the Channel Islands' pygmy mammoths, said Daniel Muhs, a geologist with the U.S. Geological Survey in Denver, who described the find Sunday (Oct. 19) here at the Geological Society of America's annual meeting. The pint-size beasts disappeared from the islands about 12,000 years ago. Most researchers blame either the Earth's warming climate or the arrival of humans on the islands for the mammoth's demise, he said.

But pygmy mammoths likely survived a steamier, more severe climate swing about 125,000 years ago. "This new find suggests they had to have lived during a period even warmer than the present," Muhs told Live Science.

Muhs and his collaborators discovered an 80,000-year-old pygmy mammoth tusk half-buried in the edge of a sea stack on Santa Rosa Island's northwest coast. With a few more storms, the rare fossil — just 3 inches (8 centimeters) wide and 2 feet (62 cm) long — might have disappeared forever into the Pacific, washed out of the rock pedestal. "It was a miracle," Muhs said of the well-timed find. The tusk is now in the Santa Barbara Museum of Natural History, he said.

Fossil corals buried with the tusk allowed scientists to date the find. But 80,000 years ago, sea level was higher than today. So Muhs said he thinks that mammoths crossed during an earlier glacial period, some 150,000 years ago. "We're going on the assumption that they only swim when the distance [to the mainland] is at a minimum," Muhs said. "Sea level was really low only at 150,000 years ago."

Scientists think mammoths reached the four northern Channel Islands when sea level dropped during past ice ages. At their peak, the planet's giant ice sheets socked away ocean water like sponges, lowering sea level around the Channel Islands nearly 400 feet (120 meters). Twice in the past 150,000 years, when the ice sheets expanded, the islands joined together into one large island, called Santarosae. The distance to the mainland near the city of Oxnard, along the coast of Southern California, shrank to about 4.5 miles (7.2 kilometers), easily reachable by a swimming, 10-ton (9,000 kilograms) Columbian mammoth. The island where the tusks were found, Santa Rosa, now sits about 26 miles (42 km) offshore.

Modern elephants, which share a common ancestor with mammoths, can cover at least 30 miles (48 km) with their ungainly underwater crawl. There are anecdotal reports of elephants swimming to islands in search of food, guided by the scent of ripe fruit.

During the late Pleistocene epoch, winds blew from the northwest across the islands, carrying the scent of unmunched forests to the mainland.

"Mammoths could have swum over to the Channel Islands several times during different glacial periods, because mammoths have been in North America for 1 million years," Muhs said. However, despite more than a century of searching, no one had found older mammoth fossils on the islands until now.

Recently, Muhs and his collaborators uncovered a second pygmy mammoth tusk from a different rock layer, in sand and landslide deposits. Dating of snail shells with the tusk, and an older marine layer below the sand, reveal that this mammoth died sometime between 46,000 and 100,000 years ago. Even that broad age range is helpful to scientists piecing together the history of these pony-size mammoths.

Until now, researchers had thought the most recent ice age transformed the Channel Islands mammoths into pipsqueaks. That glacial period peaked about 20,000 years ago, and then Earth's climate started to gradually warm.

As the ice sheets melted, sea level rose and trapped the mammoths on separate islands. Once the animals were confined, the competition for a limited food supply favored smaller mammoths, and the animals shrunk until they were half the size of their ancestors. These pygmy mammoths are a unique species, called Mammuthus exilis, found so far only on San Miguel, Santa Rosa and Santa Cruz islands.

"There is every good reason to get small because of reduced forage, and no particularly good reason to stay large, because they've lost the predators," Muhs said. "Fortunately, the big predators do not swim."

Most fossils of pygmy and full-size mammoths discovered so far on the islands are between 20,000 and 12,000 years old, Muhs said. A handful hit 30,000 years old. And one spectacular, 5.5-foot-tall (1.7 m), nearly complete skeleton was uncovered in 1994, dating to about 13,000 years ago.

Read more at Discovery News

Ancient Humans May Not Have Been Redheads

Ancient humans found with red hair weren't necessarily redheads in life, but may have acquired their carrot tops after death, a new study finds.

A team of researchers examined the processes that degrade locks, ranging from exposure to the sun's powerful rays or being eaten away by microbes. These processes, many of which begin while a person or animal is still alive, can leave hair with an unnatural, reddish hue.

The findings are not only important for archaeology, but also for conservation efforts and forensic investigations, according to the study published Oct. 21 in the journal Proceedings of the Royal Society B.

Silvana Tridico is a forensic scientist at Curtin University in Perth, Australia, and co-author of the study. She's been studying hair for the past 30 years. "There aren't too many people who do it at the level I do it at," Tridico said.

In the study, Tridico and her colleagues examined about 450 hairs from a variety of animals, including ancient humans, modern humans and woolly mammoths. The researchers first examined the hairs under a microscope at low magnification, recording the locks' color, length and physical profile. Using a scanning electron microscope, the scientists examined a fraction of the hairs in much greater detail, revealing the strands' surface contours.

They found that many of the processes that degrade hair occur not only after death, but also in living animals. Microbes, especially fungus, appear responsible for much of the degradation, but sunlight and other factors also play roles.

Hair today, gone tomorrow

Hair contains two kinds of pigments, one that produces dark hair and one for red hair. The sun degrades these pigments in a process known as photo-oxidation, but the hair pigment for darker hair isn't as stable as the one for red hair, so hair turns a reddish color when exposed to sunlight for long periods of time. This is why the hair of ancient aboriginal people in Australia has a reddish tint, Tridico said.

The researchers also found that fungi had invaded many of the hairs they studied. Some of the hairs were "just covered by fungus," Tridico said. When a layer of tiny fungal filaments called hyphae coats a hair, it can give the strand a reddish color, she said. And since fungi need heat and moisture to grow, finding them reveals something about the environment in which an animal lived.

Sometimes, hair can pick up red pigmentation from its environment. Iron from soil or permafrost can seep into hairs, staining them red, Tridico said. For example, some of the "bog people" who have been found preserved in peat marshes in Northern Europe have reddish hair. But the bogs contain a lot of tannins, the bitter substance in tea or wine, which can degrade the pigments in hair, Tridico said. While she hasn't examined the hairs from the bog people herself, she said, "I strongly suspect tannins have infiltrated them and given them a reddish tinge."

Like human hair, animal fur can redden after death, too. Some scientists say that woolly mammoth fur was a strawberry-blond color. But "that garish orange color can't possibly be natural," Tridico said. Instead, the animals probably had a layer of colorless hair that soaked up iron from the permafrost, she said.

Read more at Discovery News

The Science (and Non-Science) of the Ouija

The new supernatural horror film “Ouija” hits theaters soon, and is expected to scare up big numbers at the box office this weekend.

The Oujia board, also known as a witch board or spirit board, is simple and elegant. The board itself is printed with letters and numbers, while a roughly heart-shaped device called a planchette slides over the board. The game was created in the 1890s and sold to Hasbro in 1966. It began as a parlor game with no association with ghosts until much later, and today many people believe it can contact spirits.

“Ouija” is only the most recent in a long line of movies featuring the board. Since the Oujia board’s film debut in the 1920 Max Fleischer film “The Ouija Board,” it has appeared in hundreds of films including “The Uninvited” (1944);”The Changeling” (1980); “Witchboard” (1986); and “Paranormal Activity” (2007).

Speaking to the Dead

People in all cultures have long believed that communication with the dead is possible, and throughout the ages many people have claimed to speak to the dear departed. Ghosts and spirit communication shows up often in classic literature, including in mythology, the Bible, and Shakespeare’s plays.

In Victorian England it was fashionable in many circles to conduct séances; Ouija boards, three-legged tables, and candles were used to try to contact the dead. A century ago mediums “in touch with the spirit” during séances would write pages and pages of “automatic writing,” the psychic’s hands allegedly guided by ghosts to convey lengthy handwritten messages.

Since that time ghosts seem to have lost their will (or ability) to write—or even communicate effectively. These days the spirits (as channeled through mediums) seem to prefer a guessing game and instead offer only ambiguous, vague information: “I’m getting a presence with the letter M, or J in the name? A father, or father figure perhaps? Did he give you something special to remember him by, something small?” The Ouija board seems to cut out the middleman and let you communicate directly with the dead.

Fearing the Ouija

There’s a reason that scary movies are based on the Ouija game and not, for example, Monopoly or Scrabble. Many evangelical groups believe that playing with Ouija boards can lead to demonic possession. The Bible is pretty clear about its position on the occult (Exodus 22:18 commands that “Thou shalt not suffer a witch to live”), and because witchcraft is seen as an abomination in the eyes of God, anything associated with it, like the Ouija board, is by association evil. Obviously not every person who buys, owns, or uses a Ouija board is thought to practice evil, but many believe it’s a clear invitation to demonic temptation and children are especially vulnerable.

As the mythology and folklore of the Ouija board evolved over time, so did its representation in entertainment. Horror films began to reflect the public’s belief and concern that Ouija boards could not only contact the dead, but invite possession by evil spirits. In the 1973 classic “The Exorcist,” for example, twelve-year-old Regan MacNeil is first contacted through a seemingly innocent encounter with a Ouija board. The entity she thought she was communicating with (and whom her mother chalked up to as an imaginary friend) called himself Captain Howdy but is later revealed as the demon Pazuzu that would soon possess her (and terrify millions).

Many supposedly haunted locations forbid the use of Ouija boards on the premises. For example at the St. James Hotel, said to be among New Mexico’s most haunted buildings and a very popular destination with ghost hunters features a sign from the hotel management explicitly prohibiting the spirit board.

Others fear the Ouija board not because they believe that there’s anything demonic about it, but instead because it seems so mysterious. After all, something moves the planchette around the board, giving answers and spelling out phrases. If it’s not the people touching the planchette—and they often swear it’s not—then what could possibly be doing it, if not some unknown and possibly supernatural force?

Psychology of the Ouija

There’s no real mystery to how the Ouija board works: it is a psychological process called the ideomotor effect. What happens is that the people touching the planchette unconsciously move it around the board without knowing they’re doing it. Since they don’t know that they’re moving it (and believe others aren’t either) they assume that some unknown force must be at work. So how does the planchette give accurate answers if it’s just being moved unconsciously by one or more of the participants?

It doesn’t. The problem is that little if any of the information from the board can be verified. For example let’s say that a group of college kids plays with a Ouija board one night and asks if there are any spirits around. The planchette slowly moves over to Yes; they then ask the spirit’s name and, after some stuttering, it spells out “Tom” (a more likely name to appear like than, say, “Benedict Timothy Carlton Cumberbatch”), and after someone asks how old Tom was at his death the board indicates 54.

Does that mean that the group truly contacted the dead spirit of a man named Tom who died at age 54? It might—if much more specific, detailed information was revealed and recorded, and then compared with historical records that confirmed the validity of the information. Otherwise it’s just a few random bits of information which may or may not have anything to do with anything; the board might have just as easily spelled out “Tim” and slid over to 183 when asked his name and age at death.

The fact that people must be touching the board for it to work offers an obvious clue: if ghosts or spirits (instead of people) are moving the planchette to spell out messages, there would be no reason anyone would need to touch it. Anyone can test the Ouija board to see whether the messages it spells out are real or not: Simply put blindfolds on the participants, or block their view of the board with a cloth or piece of cardboard. The results become gibberish.

Read more at Discovery News

Oldest High-Altitude Settlement Found in Andes

The oldest-known evidence of humans living at extremely high altitudes has been unearthed in the Peruvian Andes, archaeologists say.

The sites — a rock shelter with traces of Ice Age campfires and rock art, and an open-air workshop with stone tools and fragments — are located nearly 14,700 feet (4,500 meters) above sea level and were occupied roughly 12,000 years ago.

The discovery, which is detailed today (Oct. 23) in the journal Science, suggests ancient people in South America were living at extremely high altitudes just 2,000 years after humans first reached the continent.

The findings also raise questions about how these early settlers physically adapted to sky-high living.

"Either they genetically adapted really, really fast — within 2,000 years — to be able to settle this area, or genetic adaptation isn't necessary at all," said lead study author Kurt Rademaker, who was a University of Maine visiting assistant professor in anthropology when he conducted the study.

In follow-up work, the team plans to look for more evidence of occupation, such as human remains.

Coastal clue

The recent discovery of these high-altitude artifacts was made possible by work that started in the 1990s. At that time, Rademaker and his colleagues were studying a 13,000-year-old Paleoindian fishing settlement on the coast of Peru called Quebrada Jaguay. There, they found tools made of obsidian, a volcanic rock. There were no rivers or other geologic forces to carry the volcanic rock to the coast, and the closest volcanoes were in the Andes Mountains, roughly 100 miles (160 kilometers) away, said Rademaker, who is now a postdoctoral researcher at the University of Tübingen in Germany.

"This obsidian told us that early on, Paleoindians must have gone to the highlands," Rademaker told Live Science.

Rademaker and his colleagues analyzed the obsidian and determined that it likely came from around the Pucuncho Basin, an arid, cold plateau ringed by 21,000-foot-tall (6,400 meters) volcanoes, Rademaker said.

High life

After years of searching around the plateau, the researchers found a rock shelter with two alcoves, ceilings blackened with soot and walls decorated with rock art. The site also showed evidence of burnt detritus from ancient people's campsites. The rock shelter was used for thousands of years, starting around 12,400 years ago, and may have been a temporary base camp where herders sheltered from the rain, Rademaker said.

The coastal obsidian point likely came from a nearby outcropping, near what would've been an ancient open-air workshop at the time, the researchers said. The workshop contained hundreds of ancient tools, from spear points to scrapers to bifaces, or hand axes, some of which dated to 12,800 years old. The researchers also found large mammal bones from vicuña, the wild ancestors to alpacas, similar animals called guanacos, and taruca deer.

It's still not clear whether the people living along the coast and in the highlands were the same individuals, or whether they maintained trading networks across large distances, Rademaker said.

Early settlers

The findings suggest people were living at high altitudes earlier than previously thought.

"People were really settled in and using this environment at the end of the ice age around 12,400 years ago," said Michael Waters, an anthropologist at Texas A&M University in College Station, who was not involved in the study. "They were going back and forth between the coast and this high-altitude site."

People in modern culture, perhaps because of stories of pioneers going west and getting trapped in the mountains (and eating each other), tend to see the highlands as poor living environments, said Bonnie Pitblado, an archaeologist at the University of Oklahoma, who was not involved in the study.

"There was this cultural stereotype that mountains are just impediments, that they get in the way," Pitblado told Live Science. But for prehistoric cultures, "mountains are these places with just the most amazing array of resources."

For instance, the highlands may have had hot springs and ice caves, glacial melt streams and other water sources, and the rock needed for stone tools, such as quartz, chert and obsidian, Pitblado said.

Read more at Discovery News

The Vampire Frog That Devours Its Mother’s Eggs

Don’t you give me that it-wasn’t-me-who-grew-up-eating-my-mother’s-unfertilized-eggs look.
In 2008, amphibian biologist Jodi Rowley ventured into the cloud forests of Southern Vietnam, where the mists are so thick you can see them creeping into the tiny shack you call temporary home. It’s a place far different than the sweltering Vietnamese jungles of Platoon or Forrest Gump. It’s wet alright, constantly wet, to the point you can’t stop fungus from growing all over your clothes. But Rowley was almost a mile high. It’s cold, it’s isolated. “Like an Antarctic base station,” she said.

Setting out at night, with lamps on their heads and leeches on their feet, Rowley and her team scanned the canopy for the reflection of eyeballs. And soon they found it: a brick-red frog they had a sneaking suspicion was an undiscovered  species. So they grabbed the critter and a few more specimens, along with their tadpoles, and headed back to the Australian Museum in Sydney.

The frog they’d found wasn’t particularly remarkable. As far as flying frogs go, its feet weren’t as comically large and webbed as, say, Helen’s flying frog (which Rowley also discovered, and named after her mother). But once Rowley got a tadpole under a microscope, she realized she’d found the most unique larval frog on Earth.

It had fangs. Incredibly sharp, black-as-night fangs. She emailed a photo to a world-renowned tadpole expert (yes, they exist) in Mississippi, who was so excited he formatted his reply in ALL CAPS.

“So we described it,” said Rowley, “and named it the vampire flying frog.”

The impressive fang of the vampire flying frog. That dripping liquid isn't venom, it's vodka. Just kidding. Tadpoles don't drink vodka.
Chitty Chitty Fang Fang

Now, it seems to be a rule in nature that the strangest tadpoles develop into the most ordinary-looking frogs, while the more ordinary-looking tadpoles develop into the most extraordinary frogs. The vampire flying frog is decidedly in the former camp. Even among other species in its family, which have “totally boring tadpoles,” the vampire flying frog has “completely out-there tadpoles,” said Rowley. So the question becomes: Why? Why go about things differently than any other tadpole on Earth? Well Rowley reckons the fangs help the tadpoles better eat their mother’s unfertilized eggs. You know, like ya do.

Life growing up in the cloud forest, you see, is rough. The incredible biodiversity means there’s an incredible number of creatures that would be interested in eating you. Frogs can take their chances dropping their kids off in a pool and leaving them to fend for themselves, or they can do like the vampire flying frog does and actually give a hoot about their survival.

The foamy mass that protects the eggs within.
Mom begins by seeking out a water-filled hole in a tree, no bigger than your fist, and lays her fertilized eggs just above it. Then she’ll “whip [the eggs] up with their back legs” to create a froth (shown at right), said Rowley, “like an egg milkshake that stays foamy.” Should a snake come along and make a grab for the babies, ideally it’ll get a mouthful of foul-tasting froth instead of dinner.

When the tadpoles hatch, perhaps as many as 45 of them, they release a secretion that liquifies the foam, allowing them to drop right into that tiny pond to mature. There is a rather glaring problem here, though: There’s no food in the water. But this is where mom comes to the rescue, by making the world’s most disturbing omelet. “The mother actually comes back and lays unfertilized eggs in these tiny little tree holes for the babies to eat,” said Rowley. “And they use the fangs to scoop the eggs into their mouths,” which are positively “ginormous,” likely an adaptation to accommodate such big meals.

The young slice through the egg’s dense mucus to get at the yolk, which they swallow whole. And they can get a lot of eggs in their time in the tree: “You can see that their belly is just packed full with little white round unfertilized eggs,” said Rowley, up to 40 each. In fact, the mother deposits so many eggs that the water becomes highly viscous with the extra mucus the tadpoles trim away with their fangs. Interestingly, this may have driven the tadpoles to evolve their unusually long tails, which provide them with more power to swim through the muck.

Vampire flying frog tadpole, the overhead view.
Now, this may not seem like all that extreme parenting to you, but it’s important to remember that producing eggs is incredibly energy-intensive for ladies in the animal kingdom—not to mention that the eggs take up a lot of space in the body. Accordingly, the majority of animal species out there actually have larger females than males, whose sperm takes little energy to produce and little space to store. So by jettisoning eggs to feed her ravenous young, returning time and time again to that little hole in a tree, she’s making a huge commitment to ensure their survival.

I Believe I Can Fly

But once they’re all growed up and venture out of the pond, vampire flying frogs are on their own and at the mercy of the cloud forest’s many predators. They’re not toxic, like the famous poison dart frogs, but they do have a rather amazing trick to escape hungry mouths: They can fly. Well, if you want to be picky it’s more like gliding, but when threatened, the vampire flying frog will take its chances and leap out of a tree, ideally landing on another branch. At times they’ll even get into group skydiving sessions, as Rowley has seen firsthand.

“I’ve been in ponds in Southeast Asia in the beginning of the wet season when most of the flying frogs breed because the temporary pools start happening,” she said. “And literally there have been frogs flying out of the sky. It was the most amazing experience, sort of standing up to your knees in these ponds and you hear this plop plop plop, and it’s just frogs flying out of the sky at you.”

Their secret is their giant webbed hands and feet, which they manipulate along with twists of their body to slow their descent and achieve a good amount of maneuverability. They can even pull off banked turns like birds. Some snakes can do the same, as well as a particularly badass genus of ants known as Cephalotes, which leap from branches when threatened and skydive right back to the trunk with amazing dexterity.

Helen’s flying frog, a related species, has taken the gliding adaptation to the extreme with thoroughly webbed feet that look a bit like baseball gloves … I think? Sports confuse me.
But there is one threat against which the vampire flying frog has no defense, and you’ll be shocked to learn that it’s us. While the vampire flying frog is fortunate enough to live in some protected areas that also happen to feature rugged, hard-to-reach terrain, it’s still affected by habitat loss, and this year it was officially listed as endangered. Particularly beautiful species like this one also tend to fall victim to the pet trade, not to mention the trade in traditional medicines.

Climate change may also hit this species hard. “The vampire flying frog is in high-elevation cloud forests,” said Rowley. “And if there’s any shift in the cloud layer, which is one of the predictions of climate change, if it becomes more seasonal, more dry, then maybe these tree holes, for instance, won’t be full of water the whole year or for a long enough time.” Frogs are incredibly vulnerable to such shifts in temperature on account of their skin, which must stay moist. “So this is one of the places where we’re going to see potentially what happens” as the planet warms.

But let’s end on a positive note, shall we? You may have heard about a skin fungus that’s been devastating frog populations (this is going to be positive, I swear), particularly in Australia and Central and North America. But “we’re kind of lucky so far in that it doesn’t seem to have been the case in Southeast Asia,” said Rowley. “There was actually some evidence to suggest that maybe that fungus came from Asia, and a certain strain of it that was pretty devastating spread around the world.” Frogs in Asia that have evolved alongside the fungus, Rowley hopes, could in fact “have some great killer bacteria and peptides on their skin that prevent them from getting ill.”

Read more at Wired Science

Oct 23, 2014

Ancient Finned Predator Feasted on Sharks

With fangs and the first sawlike teeth on Earth, the biggest predator in the swamps of the early Permian Period ate anything it wanted.

But when Dimetrodon waddled on land 290 million years ago, there weren't enough tasty herbivores to go around, according to an idea proposed in the 1970s by famed paleontologist E. C. Olson. "There were too many meat eaters," said Robert Bakker, the curator of paleontology at the Houston Museum of Natural Science. "There was a meat deficit all over the world."

After 11 years of sifting through fossils in Baylor County, Texas, Bakker said he thinks he has proved Olson right, based on research presented Monday (Oct. 20) here at the Geological Society of America's annual meeting.

During the early Permian, carnivores greatly outnumbered herbivores on land, so Dimetrodon filled its belly by hunting in shallow water. In the bone beds, Bakker and his collaborators uncovered 30 Dimetrodons and only two herbivores. But the fossil hunters also found masses of freshwater shark fossils intermingled with Dimetrodon teeth. Dimetrodon shed teeth throughout its life, and the lost crowns are like bullets at a crime scene, Bakker said. "This is CSI," Bakker told Live Science. "Sharks were eaten by Dimetrodon in great numbers."

Dimetrodon resembled a sail-backed Komodo dragon on steroids, and probably hunted with ease in the water. But the shark, a Xenacanth, while nowhere near as large as aDimetrodon, fought to the death. Hundreds of shark coprolites (fossil poop) in the bone beds hold Dimetrodon bone fragments. Distinctive crescent-shaped shark bites were also discovered on intact Dimetrodon bones, although the marks suggest Xenacanthus sharks were too delicate to wrench off their foes' limbs.

In total, more than 60 Xenacanth shark fossils were intermingled with Dimetrodon teeth. (Cartilage is rarely fossilized, but the sharks left behind their protective head spines.) Three Dimetrodon teeth were imbedded in large pieces of shark cartilage. "Shark was the other red meat," Bakker said. Reptile and aquatic amphibian bones round out the chewed shark cartilage and mangled Dimetrodon bones. "We find Dimetrodon tooth marks on everything. They even ate each other," Bakker said.

Read more at Discovery News

Mysterious 4,000-Year-Old 'CD-ROM' Code Cracked

A fired-clay disk from the Second Millenium B.C. may finally have had some of its markings decoded.

The mysterious "Phaistos disk," found in 1908 in a palace called Phaistos on the island of Crete, contains symbols on both sides, in a spiral configuration meant to be read from the outside toward the center. It is estimated to date from about 1,700 B.C.

For better than a century, scientists have been trying to decode the meaning behind the symbols, and now Dr. Gareth Owens, of the Technological Educational Institute of Crete, says he has figured out some of its keywords and the general message it conveys.

The disk contains 241 "picture" segments created from 45 individual symbols. Owens argues that the disk -- about 6 inches in diameter -- contains a prayer to the mother goddess of the Minoan era.

"The most stable word and value is 'mother,' and in particular the mother goddess of the Minoan era," said Owens, according to Archaeology News Network.

Using specific groups of symbols Owens says one side of the disk contains the translated wording "great lady of importance" while the other uses the expression "pregnant mother." One side, Owens says, is dedicated to a pregnant woman and the other to a woman giving birth.

Owens spent six years working on the code with a colleague at Oxford University and says about 90 percent of one side of the disk can now be deciphered. In a talk, he jokingly referred to it as the first Minoan "CD-ROM" for its shape and hard-coded data.

From Discovery News

6 Pound Gold 'Butte Nugget' Goes on Auction Block

A massive gold nugget found in Butte County, Calif., will hit the auction block Thursday in San Francisco. The nugget weighs just over 6 pounds, comes with a price tag between $350,000 and $450,000 and may be the largest such specimen ever found in California by a private person.

After finding the nugget, the lucky prospector reached out to David McCarthy of Kagin’s Inc., a firm that specializes in such collectibles.

“Fortunately, the discoverer of the Butte Nugget photographed its excavation step by step," McCarthy said in a statement. "I was able to use his pictures to positively identify the location where the gold was discovered. Nuggets like this don’t come along every day -- I really didn’t believe that I would see a California nugget of this size unearthed during my lifetime.”

If you're considering breaking out the metal detector, take heart. The nugget was found, legally, on public land in the Butte County mountains.

“I can’t say the actual location of where this nugget was found, though I had to be blindfolded for the ride out to the location, so I couldn’t say exactly even if I wanted to,” McCarthy told the San Francisco Chronicle. “I’d call the spot rugged.”

From Discovery News