Oct 25, 2014
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
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
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
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 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
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.
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.
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.
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
|Don’t you give me that it-wasn’t-me-who-grew-up-eating-my-mother’s-unfertilized-eggs look.|
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.|
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.|
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.|
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.|
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
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
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
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
Agarikon is hard to find and grows only on trees in old-growth forests in North America and Europe. The Agarikon may be the longest-living shroom on Earth and is sometimes referred to as the quinine conk because of its bitter taste (no relation to actual quinine.)
Agarikon mushrooms are most promising in the treatment of drug-resistant tuberculosis. The mushrooms were used to treat TB by Ancient Greeks and by some indigenous peoples in North America. Today in the lab, researchers say, compounds extracted from Agarikon mushroom show encouraging early results in fighting tuberculosis bacteria.
You can see Stamets go on the hunt for Agarikon mushrooms in the video below.
Oct 22, 2014
The discoveries, presented in the latest issue of the journal Nature, unravel a nearly 50-year-old mystery concerning the dinosaur, Deinocheirus mirificus. Fossils for the dinosaur's 8-foot-long arms were found in 1965, but little else, leaving paleontologists with a lot of unanswered questions concerning "Horrible Hands."
With two almost complete skeletons now pieced together, most of the mysteries have been resolved, yet the dinosaur has lost none of its shock value.
Lead author Yuong-Nam Lee told Discovery News that the dinosaur had "a peculiar humpbacked form with a duckbill-like skull. It measured 36 feet long, weighed 14,000 pounds and lived 70 million years ago."
Lee is director of the Geological Museum at the Korea Institute of Geoscience and Mineral Resources. He and his colleagues came to the conclusions after studying the newly found fossils.
The fossils were originally located at the Nemegt Formation in Mongolia. Poachers not associated with the research team found some of the parts that wound up in private hands before being repatriated to Mongolia, making the recent study possible.
"Horrible Hands" turns out not to have been so horrible. Because its arms are the longest on record for any two-legged animal, paleontologists suspected that the dinosaur could have been a ferocious predator on par with meat-loving hunters like T. rex and Allosaurus.
The dinosaur, however, lacked an important feature that would have completed such an imagined picture: teeth.
Toothless Deinocheirus instead sported a beak. Stomach remains suggest that the dinosaur died with a belly full of fish and probably plants too. Gastroliths (small swallowed stones) helped to pulverize all of the edibles grabbed by the dinosaur's beak and claws.
Instead, they believe it frequently stood on very wet substrates, which can be like quicksand for animals. To support such a lifestyle, the dinosaur evolved sink-repellent squared-off toes that functioned similar to snowshoes.
"The tips of the pedal unguals (toe bones) are wide and flattened," he explained. "Much less downward force per unit area causes the blunt unguals not to sink in deeper on substrates. Some fossils show that theropod (two-legged carnivorous) dinosaurs died after becoming mired in mud."
As for the dinosaur's prominent hump, he and his team believe it was primarily for display. The intricate system of ligaments within it also likely helped to support the dinosaur's abdomen from the hips and hind limbs "in a manner similar to an asymmetrical cable-stayed bridge."
"The new finds help close a chapter on a mystery," said vertebrate paleontologist Thomas Holtz, Jr., of both the University of Maryland and the National Museum of Natural History. "We've known about Deinocheirus as long as I've been alive. Basically every book on dinosaurs featured these enormous theropod arms with the statement, 'Some day we may know what the whole dinosaur looks like.' Well, now we do."
Read more at Discovery News
This research unexpectedly revealed that ancient Europeans started dairying thousands of years before they evolved genes to make the most of milk in adulthood, investigators added.
Scientists examined ancient DNA extracted from 13 individuals in archaeological burial sites unearthed during highway construction in the Great Hungarian Plain in Central Europe. This crossroads for Eastern and Western cultures experienced significant transformations in culture and technology known to have shaped European prehistory. The bones at the site span about 5,000 years, from 5,700 B.C. to 800 B.C., ranging across the Stone, Copper, Bronze and Iron Ages.
After several years of experimentation with a variety of kinds of bones, the researchers discovered the best place to recover ancient DNA for analysis in humans is the petrous bone, a pyramidal bone at the base of the skull. The name petrous comes from the Latin word "petrosus," meaning "stonelike." The petrous bone is the hardest bone in the human body and very dense, forming a protective case for the inner ear.
"The high-percentage DNA yield from the petrous bones exceeded those from other bones by up to 183-fold,"the study's joint senior author Ron Pinhasi, an archaeologist at University College Dublin in Ireland, said in a statement. "This gave us anywhere between 12 percent and almost 90 percent human DNA in our samples, compared to somewhere between 0 percent and 20 percent obtained from teeth, fingers and rib bones."
The DNA the scientists recovered helped them systematically examine the skeletons. "Our findings show progression towards lighter skin pigmentation as hunter-and-gatherers and nonlocal farmers intermarried," Pinhasi said in the statement.
The scientists also found that great changes in prehistoric technology, such as the adoption of farming, and the first use of hard metals such as bronze and then iron, were each associated with the substantial influx of new people.
In the Neolithic or New Stone Age, ancient central Europeans did not look anything like modern central Europeans, "but were closer to Sardinians," or people from the Italian island of Sardinia, Pinhasi told Live Science. "With the Bronze Age, you get a total shift into populations that look more like Western Europeans, and in the Iron Age you get another shift, with people genetically coming from the East, such as the Caucasus or Asia. These shifts were probably associated with major migrations and population turnovers in Central Europe."
Surprisingly, Pinhasi and his colleagues found that ancient Central Europeans apparently remained intolerant to lactose, the natural sugar in the milk of mammals, until the Bronze Age, about 4,000 years after these people began dairying. Artifacts that archaeologists previously unearthed suggest ancient Europeans started dairying 7,500 years ago in the Neolithic period. Most of the world is lactose intolerant, unable to digest lactose as adults, and the evolution of the ability to break down this sugar in adulthood helped Europeans take advantage of animal milk, a highly nutritious food.
"These ancient Europeans would have raised domesticated animals such as cows, sheep and goats without having yet developed the genetic tolerance for drinking milk from mammals without problems," Pinhasi said.
Pinhasi suggested ancient Europeans may have practiced dairying "not to drink milk, but to consume milk products such as cheese and yogurt," he said. "The processes that make cheese and yogurt break down lactose. Nowadays, in the Caucasus region, most people eat cheese and yogurt, but milk drinking is not a big thing."
Read more at Discovery News
The man, who lived 45,000 years ago, was definitely related to both humans and Neanderthals, the study published in the journal Nature reports. His DNA showed that the two human groups first mated around 60,000 years ago.
Project leader Chris Stringer of the Natural History Museum in London explained to Discovery News that the Siberian man belonged to a population that was closely related to the ancestors of today’s Europeans and Asians. He carried only slightly more Neanderthal DNA than they do.
“But his genomic segments of Neanderthal ancestry are on average about three times the length of those found in genomes today,” Stringer said.
This is highly informative, he continued, “as the chunks of Neanderthal DNA have been gradually broken up each generation since the time of interbreeding.”
He and his team charted the rate of that change to the present, when all living non-Africans possess 2 percent Neanderthal in their DNA. Going backwards in time, the researchers could then see that the mating with Neanderthals took place 7,000–10,000 years before the Siberian man lived. This means the human/Neanderthal interbreeding happened no more than 60,000 years ago.
A simple explanation would then be that Homo sapiens first left Africa at around 60,000 years ago, but other finds dispute that. Anthropologists have found 100,000-year-old skeletons for our species in the Israeli caves of Skhul and Qafzeh.
Putting the pieces together results in two possible scenarios:
1- People left Africa sometime around 100,000 years ago but failed to have successful, lasting settlements. A later group left Africa approximately 60,000 years ago, resulting in a successful dispersal. This group gave rise to all of today’s non-Africans.
2. People left Africa 100,000 years ago and were successful. Members of their group took a while to disperse, with one wave reaching southern Asia before 75,000 years ago, eventually reaching Australia and New Guinea. Then, Stringer said, describing this scenario, “a second wave at around 60,000 years ago carried the ancestors of present day Eurasians and Native Americans out of Africa.”
So which scenario is the one that really happened? The Siberian man provides a constraint on the theories, indicating that interbreeding with Neanderthals is unlikely to have happened before 60,000 years ago.
Read more at Discovery News
A commentary in the latest issue of Nature theorizes that the Hobbit Human could have descended from a more ancient pre-human group called Australopithecus, of which the 3.2-million-year-old skeleton “Lucy” is the most famous representative. Lucy might have to share the spotlight with the Hobbit, though, if the theory is proven to be correct.
A quick refresher: The Hobbit Human, aka Homo floresiensis, was a 3 1/2 foot tall species with huge feet that lived on the remote Indonesian island as early as 13,000 years ago.
The prevailing theory has been that the Hobbit was a member of our family tree, belonging to the genus Homo and having descended from a population of Homo erectus that made its way to the island and shrunk in stature over evolutionary time due to the “island effect.” (Because islands are relatively closed communities, evolution tends to lead to smaller forms.) Remains for a handful of Hobbits were found with stone tools and bones of a pygmy form of the now-extinct, elephant-like Stegodon.
Renowned paleoanthropologist Chris Stringer from the Natural History Museum in London questioned some parts of this theory.
In his Nature commentary, Stringer wrote that the tiny brain of one of the excavated Hobbits as well as its body shape and individual bones “look more primitive than those of any human dating to within the past million years.”
The Hobbit jaw and chin are “most like those in pre-human fossils more than 2 million years old,” Stringer wrote.
The Hobbit therefore shares traits with Australopithecus. This presents a real mind blower.
We’ve tended to assume that only Homo sapiens left Africa, interbred with locals in Europe and Asia (like Neanderthals and Denisovans), resulting in today’s non-Africans.
But what if other species, like Australopithecus, also left Africa, made it to places like Indonesia, and successfully settled there until more recent times? The plot thickens.
Read more at Discovery News
|A couple hundred feet down, a couple hundred thousand miles to go.|
Sure, now we know where they go, but our forebears really struggled with the problem of birds disappearing every winter. There were all kinds of theories, but none was more bizarre than that of English minister and scientist Charles Morton, who in the 17th century wrote a surprisingly well-reasoned, though obviously totally inaccurate, treatise claiming birds migrate to the moon and back every year.
That’s right. To the moon and back. And Morton was even aware of how epic this journey would be. He estimated the one-way trip to be 179,712 miles (he wasn’t so far off—the moon varies between 226,000 miles and 252,000 miles away, on account of its elliptical orbit), and reckoned it would take the birds 60 days to reach our satellite flying a dizzying 125 mph. Still, Morton reasoned, they pulled it off. And, really, because some species seem to disappear entirely, the only logical conclusion is that they set off into space. “Now, whither should these creatures go, unless it were to the moon?” he asked.
Whither should they go indeed.
Flock and Awe
Before we get to the particulars of Morton’s strange theory of migration, it’s worth noting the many other theories of antiquity, beginning with Aristotle, who reckoned that some birds hibernate while others simply transform into different species when winter comes around. Redstarts, for instance, morph into robins in winter—a fantastical claim that’s easier to understand when you consider that redstarts indeed migrate to Africa as robins make their way to Greece.
|A pygmy battles his ruthless enemy, the crane, with nothing but a stick and a sombrero.|
|Barnacle geese hatch from a tree.|
In the 16th century, the great cartographer and writer Olaus Magnus championed the theory that swallows disappear in the winter not because they travel to tropical climes to pick up coconuts, but because they bury themselves in the clay at the bottom of rivers. They come together in the fall in huge swarms, then sink down into the mud en masse, only to reemerge in the spring. But in his famous map the Carta Marina, Magnus also echoed the tale of the barnacle goose with an illustration of ducks being born from a tree.
Fly Me to the Moon
But back to Morton. According to Thomas P. Harrison in his essay “Birds in the Moon,” Morton quite rightly noted that migrating avians recognize “changes of the air where they are,” or notice the “alteration of abatement of their daily food,” and are therefore stirred to “obtain what is more suitable to them or to avoid what is offensive” and begin their migration. He refutes, however, the position of Olaus Magnus that birds make their way into the clay at the bottoms of rivers. There’s the rather glaring problem of the lack of air, he notes, not to mention frigid temperatures.
|A woodcock passionately denying rumors that it migrates to the moon. Yes, this is what it looks like when birds passionately deny rumors.|
But how could they get back and forth between the celestial bodies? Luckily, in space the birds “encounter no air resistance and are unaffected by gravitation,” writes Harrison. “They are sustained by excess fat,” which turns out to be true in migrating birds, “and they sleep most of the journey of two months.” (Definitely not true, though migrating birds do indeed nod off for a few seconds at a time.)
Now, it’s important to note that it was a widely held belief in Morton’s time that all of the planets in our solar system must necessarily be inhabited, since a higher power wouldn’t take the trouble of creating planets and moons and have them just sit there all lonely-like. Even the discoverer of Uranus, William Herschel, went so far as to argue in 1795 that the sun held life as well. And even as late as the early 1900s, American astronomer Percival Lowell claimed he had discovered alien-built canals on Mars, which turned out to just be an optical illusion.
So Morton’s birds would find the moon quite well-appointed with vegetation and water. Indeed, according to Harrison, Morton’s inspiration for all of this likely came from John Wilkins, a founder of the famed Royal Society, who in 1638 published “The Discovery of a New World in the Moon.” In it, Wilkins argued “that the moon, with its borrowed light, is like our earth with its seas, streams, mountains, and so on,” writes Harrison. Wilkins goes on to suggest humans might get to the moon by attaching wings to our arms, or train birds to take us there.
|The adventurous Domingo Gonsales and his flying machine made of swans.|
They were on their way to the moon. And when they arrived Gonsales found trees three times as high and five times as thick as our own. But more importantly, there was wildlife, none of which compared to ours, “except swallows, nightingales, cuckows, woodcocks, batts, and some kind of wild fowl,” birds that “spend their time, in their absence from us, in that world.”
Such fiction became science in the 1600s, according to Harrison, and greatly influenced Morton’s theory of the moon migration. But in 1676, a man named Francis Willughby set us down the path to avian truth when he published Ornithologia, a masterwork of bird science we can file with such classics as John James Audubon’s Birds of America. While Willughby, like Morton, refuted Aristotle’s notion that swallows hibernate, he wasn’t under the impression that they instead went to the moon. More modestly, it was to the warmth of northern Africa.
Read more at Wired Science
Oct 21, 2014
Built before writing was invented, the temple is about 60 by 20 meters (197 by 66 feet) in size. It was a "two-story building made of wood and clay surrounded by a galleried courtyard," the upper floor divided into five rooms, write archaeologists Nataliya Burdo and Mykhailo Videiko in a copy of a presentation they gave recently at the European Association of Archaeologists' annual meeting in Istanbul, Turkey.
Inside the temple, archaeologists found the remains of eight clay platforms, which may have been used as altars, the finds suggested. A platform on the upper floor contains "numerous burnt bones of lamb, associated with sacrifice," write Burdo and Videiko, of the Institute of Archaeology of the National Academy of Sciences of Ukraine. The floors and walls of all five rooms on the upper floor were "decorated by red paint, which created ceremonial atmosphere."
The ground floor contains seven additional platforms and a courtyard riddled with animal bones and pottery fragments, the researchers found.
The temple, which was first detected in 2009, is located in a prehistoric settlement near modern-day Nebelivka. Recent research using geophysical survey indicates the prehistoric settlement is 238 hectares (588 acres), almost twice the size of the modern-day National Mall in Washington, D.C. It contained more than 1,200 buildings and nearly 50 streets.
A number of other prehistoric sites, of similar size, have been found in Ukraine and other parts of Eastern Europe. These sites are sometimes referred to as belonging to the "Trypillian" culture, a modern-day name. The name is derived from the village of Trypillia in Ukraine, where artifacts of this ancient culture were first discovered.
Archaeologists found that when this prehistoric settlement was abandoned, its structures, including the newly discovered temple, were burnt down, something that commonly occurred at other Trypillian culture sites.
Fragments of figurines, some of which look similar to humans, were also found at the temple. Like findings at other Trypillian sites, some of the figurines have noses that look like beaks and eyes that are dissimilar, one being slightly larger than the other.
Ornaments made of bone and gold were also discovered at the temple. The gold ornaments are less than an inch in size and may have been worn on the hair, researchers say.
Read more at Discovery News
In the flesh, King Tut had a club foot, a pronounced overbite and girlish hips, says a “virtual autopsy” built using more than 2,000 computerized tomography (CT) scans of the pharaoh’s body.
Built for the BBC documentary, “Tutankhamun: the Truth Uncovered,” the shocking 3-D computer model could shed new light on the death of the boy pharaoh at the age of 19.
Previous theories suggested King Tut may have died as a result of a chariot accident, but the virtual reconstruction showed a different scenario.
“It was important to look at his ability to ride on a chariot and we concluded it would not be possible for him, especially with his partially clubbed foot, as he was unable to stand unaided,” Albert Zink, head of the Institute for Mummies and Icemen in Italy, told the U.K. daily The Independent.
According to Ashraf Selim, an Egyptian radiologist, King Tut “also developed Kohler’s disease or death of the bones, during adolescence, which would have been incredibly painful.”
Indeed, about 130 walking sticks found in King Tut’s treasure-packed tomb would support the theory that the boy pharaoh had to rely on canes to get around.
Zink believes the pharaoh’s early death was most likely caused from his weakened state — a result of genetic impairments inherited from his parents, who were siblings.
Indeed, in 2010 an international genetic study produced a five-generation pedigree of Tutankhamun’s immediate lineage. In the study, the mummy known as KV55 — most likely the “heretic” Akhenaten — and KV35YL, also known as the Younger Lady, were identified as siblings, as well as King Tut’s parents.
The study confirmed the frail king was afflicted by malaria and suffered a badly broken leg, above his knee, just before he died.
“It is difficult to say whether malaria may have been a serious factor in the cause of death,” Zink said.
The boy pharaoh has been puzzling scientists ever since his mummy and treasure-packed tomb were discovered on Nov. 22, 1922, in the Valley of the Kings by British archaeologist Howard Carter.
Read more at Discovery News
The quake, likely a magnitude 9.0, sent the mighty waves toward Hawaii sometime between 1425 and 1665, the study found. It's possible that another large Alaskan earthquake could trigger a comparable tsunami on Hawaii's shores in the future, experts said.
The tsunami was at least three times the size of the damaging 1946 tsunami, which was driven by an 8.6-magnitude earthquake off the Aleutian Islands. Mammoth tsunamis, like the one described in the study, are rare, and likely happen once every thousand years. There's a 0.1 percent chance it could happen in any given year, the same probability that northeastern Japan had for the 9.0-magnitude 2011 Tohoku earthquake and related tsunami, said Gerald Fryer, a geophysicist at the pacific Tsunami Warning Center in Ewa Beach, Hawaii, who was not involved in the study.
Results of the study have already prompted Honolulu officials to revise their tsunami evacuation maps, Fryer said. The new maps, which will affect nearly 1 million people who live in Honolulu County, would include more than twice the area of evacuation in some areas, Fryer said in a statement. County officials hope to distribute the new maps by the end of 2014, Fryer said.
"You're going to have great earthquakes on planet Earth, and you're going to have great tsunamis," said the study's lead researcher, Rhett Butler, a geophysicist at the University of Hawaii at Manoa. "People have to at least appreciate that the possibility is there."
Evidence of the colossal tsunami surfaced in the late 1990s during the excavation of the Makauwahi sinkhole, a collapsed limestone cave on the south coast of Kauai. About 6.5 feet (2 meters) below the surface, study researcher David Burney found a bounty of old debris that must have come from the ocean.
Curiously, the sinkhole's mouth is 328 feet (100 m) away from the present-day shore, and 23 feet (7 m) above sea level, suggesting the enormous quantities of corals and shells were probably carried there by a gigantic wave, Burney, a paleoecologist at the National Tropical Botanical Garden in Kalaheo, said. But he needed more evidence to back up his claim.
The debris remained a mystery until the 2011 Tohoku earthquake hit Japan. The earthquake triggered a rapid surge of water that stood 128 feet (39 m) above sea level and pummeled the Japanese coast. Soon after, researchers revisited Hawaii's tsunami evacuation maps. The maps are largely based on the 1946 tsunami, which caused water to rise 8 feet (2.5 m) up the side of the Makauwahi sinkhole.
"[The Japan earthquake] was bigger than almost any seismologist thought possible," Butler said. "Seeing [on live TV] the devastation it caused, I began to wonder, did we get it right in Hawaii? Are our evacuation zones the correct size?"
Butler and his colleagues assembled a wave model to predict how a tsunami might flood Kauai's coastline. They simulated earthquakes ranging between magnitudes 9.0 and 9.6 along the Aleutian-Alaska subduction zone, a 2,113-mile-long (3,400 kilometers) ocean trench where the Pacific tectonic plate slips under the North American plate.
In the aftermath of a large earthquake, the eastern Aleutians' distinctive geography could send a large tsunami toward Hawaii, the researchers found. In fact, a magnitude- 9.0 earthquake in just the right spot could easily direct water levels of 26 to 30 feet (8 to 9 m) high toward Kauai, carrying debris into the Makauwahi sinkhole, they found.
The researchers also looked for tsunami evidence in other places. Radiocarbon dating showed that the marine deposits in the sinkhole, on Sedanka Island off the coast of Alaska and along the west coasts of Canada and the United States all date back to the same time period, and may have come from the same tsunami.
"[The researchers] stitched together geological evidence, anthropological information as well as geophysical modeling to put together this story that is tantalizing for a geologist, but it's frightening for people in Hawaii," Robert Witter, a geologist at the U.S. Geological Survey in Anchorage, Alaska, who was not involved in the study, said in the statement.
More evidence is needed to determine whether the deposits came from the same tsunami, Witter said. For instance, radiocarbon dating, which the study researchers relied on, only gives a rough time estimate. It's possible that multiple tsunamis between 350 and 575 years ago deposited the debris at the three locations, he said.
Read more at Discovery News
By now we know that the vast majority of galaxies have supermassive black holes in their cores. These galactic behemoths generate some energetic phenomena, especially when matter falls onto their accretion disks and event horizons. Often, the energy generated by active galactic nuclei (where these rambunctious black holes reside), will regulate the star formation processes in their host galaxy.
Now, in a new study published in the journal Monthly Notices of the Royal Astronomical Society, researchers believe that they’ve found the reason why maturing galaxies seem to “switch off” star formation all together.
“When you look into the past history of the universe, you see these galaxies building stars,” said Tobias Marriage, of Johns Hopkins University and co-lead author of the study. “At some point, they stop forming stars and the question is: Why? Basically, these active black holes give a reason for why stars stop forming in the universe.”
Marriage and his colleagues used an established method for studying large clusters of galaxies and applying it to single galaxies. By doing this, they discovered that supermassive black holes are driving “radio-frequency feedback,” which is heating up the galaxies, preventing interstellar gases from cooling, clumping and forming new stars.
In short, massive black holes, at a certain age, act like a switch and are snuffing out star formation before it can even take hold.
Normally, the Sunyaev–Zel’dovich (SZ) effect signature is used to study how the primordial cosmic microwave background radiation (the ‘echo’ of the Big Bang) interacts with the electrons inside interstellar gases locked in clusters of hundreds of galaxies. But for the first time, this method has been down-scaled to gauge the interstellar environment of single galaxies.
“The SZ is usually used to study clusters of hundreds of galaxies but the galaxies we’re looking for are much smaller and have just a companion or two,” said Megan Gralla, also of Johns Hopkins.
“What we’re doing is asking a different question than what has been previously asked,” Gralla said. “We’re using a technique that’s been around for some time and that researchers have been very successful with, and we’re using it to answer a totally different question in a totally different subfield of astronomy.”
So, while studying the SZ effect signature in galaxies, the researchers found that all the galaxies displaying radio-frequency feedback coincided with galaxies that also lacked signs of star formation. It just so happened that these particular galaxies were large and mature elliptical galaxies, where their heated interstellar gas was prevented from cooling down.
“If gas is kept hot, it can’t collapse,” said Marriage. If the gas cannot collapse, no new stars can form.
Read more at Discovery News
Oct 20, 2014
"When I turned on the light, I couldn't quite understand what I was seeing," said Naskrecki, an entomologist and photographer at Harvard University's Museum of Comparative Zoology.
A moment later, he realized he was looking not at a brown, furry mammal, but an enormous, puppy-size spider.
Known as the South American Goliath birdeater (Theraphosa blondi), the colossal arachnid is the world's largest spider, according to Guinness World Records. Its leg span can reach up to a foot (30 centimeters), or about the size of "a child's forearm," with a body the size of "a large fist," Naskrecki told Live Science. And the spider can weigh more than 6 oz. (170 grams) — about as much as a young puppy, the scientist wrote on his blog.
Some sources say the giant huntsman spider, which has a larger leg span, is bigger than the birdeater. But the huntsman is much more delicate than the hefty birdeater — comparing the two would be "like comparing a giraffe to an elephant," Naskrecki said.
The birdeater's enormous size is evident from the sounds it makes. "Its feet have hardened tips and claws that produce a very distinct, clicking sound, not unlike that of a horse's hooves hitting the ground," he wrote, but "not as loud."
When Naskrecki approached the imposing creature in the rainforest, it would rub its hind legs against its abdomen. At first, the scientist thought the behavior was "cute," he said, but then he realized the spider was sending out a cloud of hairs with microscopic barbs on them. When these hairs get in the eyes or other mucous membranes, they are "extremely painful and itchy," and can stay there for days, he said.
But its prickly hairs aren't the birdeater's only line of defense; it also sports a pair of 2-inch-long (5 centimeters) fangs. Although the spider's bite is venomous, it's not deadly to humans. But it would still be extremely painful, "like driving a nail through your hand," Naskrecki said.
And the eight-legged beast has a third defense mechanism up its hairy sleeve. The hairs on the front of the spider's body have tiny hooks and barbs that make a hissing sound when they rub against each other, "sort of like pulling Velcro apart," Naskrecki said.
Yet despite all that, the spider doesn't pose a threat to humans. Even if it bites you, "a chicken can probably do more damage," Naskrecki said.
Despite its name, the birdeater doesn't usually eat birds, although it is certainly capable of killing small mammals. "They will essentially attack anything that they encounter," Naskrecki said.
The spider hunts in leaf litter on the ground at night, so the chances of it encountering a bird are very small, he said. However, if it found a nest, it could easily kill the parents and the chicks, he said, adding that the spider species has also been known to puncture and drink bird eggs.
Read more at Discovery News
A magnetic field shift is old news. Around 800,000 years ago, magnetic north hovered over Antarctica and reindeer lived in magnetic south. The poles have flipped several times throughout Earth's history. Scientists have estimated that a flip cycle starts with the magnetic field weakening over the span of a few thousand years, then the poles flip and the field springs back up to full strength again. However, a new study shows that the last time the Earth's poles flipped, it only took 100 years for the reversal to happen.
The Earth's magnetic field is in a weakening stage right now. Data collected this summer by a European Space Agency (ESA) satellite suggests the field is weakening 10 times faster than scientists originally thought. They predicted a flip could come within the next couple thousand years. It turns out that might be a very liberal estimate, scientists now say.
"We don't know whether the next reversal will occur as suddenly as this one did, but we also don't know that it won't," Paul Renne, director of the Geochronology Center at the University of California, Berkeley, said in a statement.
Geologists still are not sure what causes the planet's magnetic field to flip direction. Earth's iron core acts like a giant magnet and generates the magnetic field that envelops the planet. This helps protect against blasts of radiation that erupt from the sun and sometimes hurtle toward Earth. A weakening magnetic field could interrupt power grids and radio communication, and douse the planet in unusually high levels of radiation.
While the ESA satellite studied the magnetic field from above, Renne and a team of researchers studied it from below. The researchers dug through ancient lake sediments exposed at the base of the Apennine Mountains in Italy. Ash layers from long-ago volcanic eruptions are mixed into the sediment. The ash is made of magnetically sensitive minerals that hold traces of Earth's magnetic field lines, and the researchers were able to measure the direction the field was pointing.
Renne and colleagues then used a technique called argon-argon dating — which works because radioactive potassium-40 decays into argon-40 at a known rate — to determine the age of the rock sediment. The layers built up over a 10,000-year period, and the researchers could pinpoint where the poles flipped in the rock layers. The last flip happened around 786,000 years ago.
The sediment layers also showed the magnetic field was unstable for about 6,000 years before the abrupt flip-flop. The period of instability included two low points in the field's strength, each of which lasted about 2,000 years.
Geologists don't know where the magnetic field is now in that reversal timescale or if this flip will even follow the same pattern as the last. The bottom line is that no one is sure when it's coming.
"We don't really know whether the next reversal is going to resemble the last one, so it's impossible to say whether we're just seeing the first of possibly several excursions (slight movements), or a true reversal," Renne told Live Science in an email.
While a pole flip could cause a few technical issues, there's no need to panic. Scientists have combed the geological timeline for any evidence of catastrophes that might be related to a magnetic flip. They haven't found any.
The only havoc that a reversal would wreak is interference in the global electric grid. No direct evidence remains of past catastrophes triggered by a magnetic flip.
Read more at Discovery News
The long left arm bones, dated at 200,000 years old, are the oldest human ancestor remains ever to be discovered in Tourville-la-Rivière, about 72 miles (116 kilometers) northwest of Paris. Fossils from this time period are rare, and may help fill in gaps about the evolution of humans and their close relatives, the researchers said.
"These are the oldest fossils found near Paris. It's the oldest Parisian, if you like," study researcher Bruno Maureille, at the Université de Bordeaux in Talence, France, told the BBC.
The bones, found in September 2010, consist of a humerus, radius and ulna from a left arm. Based on their size, the bones probably belonged to an adult or older adolescent, the researchers said.
The left humerus shows a curious injury that may indicate signs of muscle damage near the shoulder, possibly from doing a repetitive action, such as throwing or hammering, said study researcher Erik Trinkaus, a professor of anthropology at Washington University in St. Louis.
Trinkaus and his colleagues examined the humerus in detail, finding that it measures 9.1 inches (23.2 centimeters) and has a bony crest 1.6 inches (4 cm) long. Computer tomography scans suggest the crest may be evidence of an injury to the deltoid muscle at the owner's shoulder.
The individual may have gotten the injury from throwing a spear while hunting, even though all of the spears anthropologists have found from that time period are large and heavy, Trinkaus said.
If the injury is indicative of overuse from throwing, the newly found humerus would provide evidence that early humans and their relatives may have thrown spears 200,000 years ago, he said.
That interpretation is "controversial" but plausible, said Brian Richmond, a curator of anthropology at the American Museum of Natural History in New York, who was not involved in the study. "It looks like the bone kind of grew out [from the arm], probably from some damage where the muscle was attached to it," Richmond told Live Science.
It's unclear what caused the injury, but "they're arguing that this may be due to repetitive use, possibly throwing," Richmond said.
The guess isn't a bad one, he said. Humans are unusually good at throwing, whereas other animals, such as chimpanzees and apes, can't throw as accurately or as fast people can. "We seem to have an anatomy that's well designed for that," Richmond said. "And that anatomy probably goes back to as far as the Neanderthals."
Read more at Discovery News