Hobbit Humans Had Big Brains

Hobbit humans, the tiny folks who lived on the remote Indonesian island of Flores until about 12,000 years ago, had bigger brains than previously thought, according to a new paper that strengthens the theory that hobbits evolved from own own ancestor, Homo erectus.

Homo erectus, in turn, is thought to have evolved into our own species in Africa. The new study, published in the latest Proceedings of the Royal Society B, reveals how location and environment could mean the difference between an individual who looked like us, and someone who wound up a hobbit.

"They were extremely short (about 3'6"), much shorter than any healthy living humans," co-author Yousuke Kaifu told Discovery News. "Their legs were short relative to their arms and feet, (features that) some researchers think were primitive."

Kaifu, a senior researcher at the National Museum of Nature and Science in Tokyo, conducted the study with lead author Daisuke Kubo and Reiko Kono.

The three used high-resolution micro-CT scanning to study the brain regions of hobbit human skulls. The scans found that the brains measured 426 cc, as opposed to earlier estimates of around 400 cc. The former is still not huge by modern standards, and was about the same size as a chimpanzee's brain.

Nevertheless, the difference means it was possible for a Homo erectus population to have evolved such brains. The prior estimate ruled that out, since there is only so much shrinkage that could have taken place.

The researchers believe H. erectus, living on the mainland, either intentionally or unintentionally -- such as due to a storm -- made it to the isolated island of Flores.

The hobbits' "unique evolution suggests they did not go out of the island once they got there," Kaifu said.

He explained that "a popular theory is that big mammals tend to reduce and small mammals tend to increase their body sizes on an isolated island because of energetic demands."

Elephants, for example, tend to get smaller, since without many carnivores, they have no need to maintain such big, bulky bodies. Remains suggest that the hobbits hunted primitive elephants called Stegodon.

In contrast to the pygmy elephants, a type of stork and lizard evolved larger bodies on Flores, probably because predators were few and food was plentiful.

Known distribution of Homo erectus extends all the way from Africa to parts of Europe and Asia. Thus far, it looks like they could not survive the extreme cold of the North, but they did reach at least the one isolated island.

"So there are chances that they were also present on other near-shore islands of that region, such as Sulawesi and possibly the Philippines," Kaifu said.

Yet another likely regional population of Homo erectus, called "Peking man," inhabited the Asian continent, but it is still unclear if they evolved into more advanced humans or even interbred with Homo sapiens arriving from Africa. DNA analysis of what are known as Denisovans from Melanesia, Australia and the Philippines suggest that some interbreeding did indeed take place.

As for the hobbit human's contribution to the mix, much hinges on the brain size, given how that either strengthens or weakens the possible relationship to Homo erectus.

Dean Falk, whose team previously estimated the brain to be smaller, told Discovery News that the new measurement is “the most precise estimate available to date because it has been calculated with improved methods and great care." Falk, a Florida State University professor of anthropology, hopes that the "thoughtful and thorough analysis" will move "the discussion forward" about H. floresiensis.

William Jungers, professor and chairman of Stony Brook University Medical Center's Department of Anatomical Sciences, said, "this is the normal brain of a very small and now extinct human relative that evolved in isolation for at least a million years on Flores Island."

Read more at Discovery News

Big Bang? This Is What It Really Sounds Like

In the beginning, there was a righteous bass.

So says physicist John Cramer, who has not only found evidence of the sound created during the Big Bang, but has also created a simulation of the low, deep noise emitted as the universe came into being.

After the Big Bang, the universe expanded so rapidly that matter itself resonated to create a deep bass noise, and sound waves themselves became stretched and warped. "As the early universe expanded, sound waves propagated through the dense medium that closed back on itself, so that the hypersphere of the universe rang like a bell," Cramer, a professor of physics at the University of Washington, explained.

The effect would have been similar to that of a magnitude-9 earthquake that caused the entire planet to actually ring, Cramer said. However, in this case, the ringing covered the entire universe.

That sound is long gone, of course, but it left its imprint on the cosmic microwave background, which is a thermal echo of the energy released during the Big Bang.

Listen to Cramer's Big Bang simulation here.

In 2003, NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) satellite gave scientists an unprecedented picture of the cosmic microwave background. In an article for science-fiction magazine Analog Science Fiction and Fact, Cramer wrote how this thermal data could be extrapolated into wavelengths of sound.

In other words, the universe's cosmic microwave background is kind of like a recording of the Big Bang's phat beat.

Two years after Cramer published his findings, the mother of an 11-year-old elementary school student wrote to Cramer, asking if there was an actual recording of the sound that her son could use for his school science-fair project. Cramer responded that there wasn't — but there could be.

To recreate the Big Bang's sound, Cramer converted WMAP’s wavelength data into sound using a computational program called Mathematica.

The resulting sound is low, creaky, and almost unassuming.

Read more at Discovery News

Sharks Dive By the Moon

The moon and water temperature affect the diving behaviour of sharks, researchers reported Tuesday, in a discovery that could help prevent fishermen from catching the marine predators inadvertently.

A team from the University of Western Australia's Oceans Institute and the government-run Australian Institute of Marine Science spent nearly three years monitoring grey reef sharks off Palau in the Pacific.

They tagged 39 sharks -- common on coral reefs throughout the Indo-Pacific region -- and used acoustic telemetry to follow them, finding they stayed in deep water on full moon nights but rose to the shallows with the new moon.

Similar patterns have previously been recorded in species such as swordfish, yellowfin and big eye tuna, suggesting the reef shark behaviour was related to feeding.

The study also said it may be an anti-predator response where reef sharks seek to avoid increased light nearer the surface that may aid the hunting abilities of larger sharks.

"We also found that the diving behaviour of grey reef sharks was related to water temperature," said lead researcher Gabriel Vianna.

The sharks, mostly adult females, dived to an average depth of 35 metres (114 feet) in winter when deeper water was colder and 60 metres in spring when temperatures warmed up.

In summer, when the warmer layer of surface water expanded, the sharks tended to move in a broader range of depths.

The authors said that because sharks were cold-blooded, they may prefer warmer waters to conserve energy.

The research, published in the science journal PLOS ONE, also found that the time of day could affect how deeply sharks dive.

"We were surprised to see sharks going progressively deeper during the morning and the exact inverse pattern in the afternoon, gradually rising towards the surface," Vianna said.

"This matches how light changes on the reef during the day. To our knowledge, this is the first time such patterns have been observed in detail for reef sharks."

Read more at Discovery News

Mayan Calendar End Date Confirmed

Carbon-dating of a structural beam from a Guatemalan temple confirms that the Mayan Long Count calendar did end on December 2012, leaving no room for further doomsday prophecies and miscalculations claims.

The Long Count is a complex system of bars and dots that consists of five time units: Bak’tun (144,000 days); K’atun (7,200 days), Tun (360 days), Winal (20 days) and K’in (one day).

The days are counted from a mythological starting point.

The Long Count proliferated to more than 40 different centers across the Mayan lowlands between 600–900 A.D. and was used to anchor major historical events in time.

However, those historic events comprising royal successions, rituals, victories and defeats, could not be precisely ordered by date as scholars were unable to set the date of the mythical starting point.

Indeed, the Long Count system fell into disuse before European contact in the 16th century, moreover the Spanish colonizers destroyed any evidence that could have helped correlate the Maya and European calendars.

“Many solutions to the problem have been proposed, employing a variety of historical and astronomical data,” an international team of researchers led by Douglas J. Kennett, professor of environmental archaeology at Pennsylvania State University, wrote in the journal Scientific Reports.

However, “correlation constants can vary up to 1,000 years and remain controversial,” they said.

To place the Long Count dates into the European calendar in order to understand when things happened in the Maya world relative to historic events elsewhere, Kennett’s team turned to an elaborately carved wooden beam from a temple in the ancient Maya city of Tikal.

The carvings depict Tikal’s king, known as Jasaw Chan K’awiil. A related text describes his defeat of King Yich’aak K’ahk’ , known as “Claw of Fire,” from a rival kingdom at Calakmul.

Using a combination of high-resolution accelerator mass spectrometry carbon-14 dates and a statistical model of tree growth rates estimated from changing calcium concentrations, the researchers established that the lintel was carved sometime around 658-696 A.D.

The estimate closely matches the most popular method in use, the Goodman-Martinez-Thompson (GMT) correlation, initially put forth by Joseph Goodman in 1905 and subsequently modified by others.

According to the GMT estimate, the K’awiil’s victory occurred around 695-712 A.D. The date was determined in the 1950s by carbon dating on two other wooden beams from Tikal.

Kennett and colleagues believe the discrepancy between the two dates can be explained by the fact that the beam was taken from a tree called the sapotilla whose hard wood would have required years to carve.

The date of the Mayan battle would work like a Rosetta stone for the chronology of the ancient civilization.

“Anything that has a Mayan date on it, we can be more certain about what the European date is,” Kennett told U.S. News & World Report.

Read more at Discovery News

Saturn's System May Contain 'Born Again' Moons

The Saturnian system, with its majestic rings, icy moons, and mysteriously veiled Titan, is the gemstone of the solar system. Ironically the system is full of clues that it was born, or rather reborn, out of a violent demolition derby less than 4 billion years ago.

A clue is the giant moon Titan, larger that the planet Mercury. Every month NASA’s prolific Cassini orbiter unveils more details about this orange hued moon that make it look intriguingly earthlike. Just last week scientist reported seeing a cap of ice clouds forming over the moon’s south pole as a harbinger of the approaching southern hemisphere winter.

With its massive nitrogen atmosphere, hydrocarbon seas, ice continents, tropical methane rain, and cryovolcanoes, Titan has been dubbed “Earth II.” What are the odds that potentially habitable Titan-sized worlds exist around the estimated billions of gas giant planets in our galaxy? And, why doesn’t Jupiter have such a massive moon?

Adding to the mystery is that Saturn’s family icy moons, once dismissed as dead snowballs, look geologically young and active. The moon Enceladus is spewing water geysers from a subsurface ocean that could be an abode for life.

The moons are small enough that they should have been blasted apart in a “baptism by fire” period called the Late Heavy Bombardment (LHB) 4 billion years ago. This tore up Earth’s moon with massive impacts, and blasted out giant impact basins on Mercury and Mars, and presumably Venus and Earth.

The LHB was triggered by final gravitational shuffle of the giant planets. They first moved inward and then outward under a gravitational tug-of-war. The giants shifting orbits forced asteroids and comets onto destructive high-speed eccentric orbits.

Erik Asphaug of Arizona State University and co-authors have tied Saturn observations together to propose that the planet shuffle lead to a major makeover of Saturn’s satellite system. Their research was published in the journal Icarus.

Computer modeling by Asphaug suggest that Saturn started out with several primordial moons that were the size of Jupiter’s four major satellites (first discovered in 1609 by Galileo Galilei). The theory is that during the LHB their orbits were disrupted and they collided to merge and form Titan in place of Jupiter’s Galilean-style system. Perhaps not coincidentally, Titan is similar in mass to all of the Galilean satellites put together. “The original physics a satellite formation may have been the same around Jupiter and Saturn,” Asphaug writes.

This smashup also left behind Saturn’s family of oddball major icy satellites that that would have been formed after the LHB. The moons’ chemical diversity and geology tell what parts of the larger parent moons they came from, say the researchers. The idea is that denser moons like Enceladus, with its silicate core under a water ocean, came from deep inside the parent body. Low density, purely ice moons like Tethys could have come from a water-ammonia mantle of the lost Galilean sized satellites.

The model predicts that the icy moons should have had their own rings and subsatellites that decayed and crashed onto the moons. This could explain the puzzling equatorial bulge on walnut-shaped Iapetus (pictured right) where a shattered moon might have literally rained out of the sky.

Read more at Discovery News

Proton Mass Mystery Could Mean New Physics

The size of a proton, long thought to be well-understood, may remain a mystery for a while longer, according to physicists.

Speaking on Saturday (April 13) at the April meeting of the American Physical Society, researchers said they need more data to understand why new measurements of proton size don't match old ones.

"The discrepancy is rather severe," said Randolf Pohl, a scientist at the Max Planck Institute of Quantum Optics. The question, Pohl and his colleagues said, is whether the explanation is a boring one -- someone messed up the measurements -- or something that will generate new physics theories.

The Incredible Shrinking Proton

The proton is a positively charged particle in the nucleus of atoms, the building blocks of everything. Years of measurements pegged the proton at 0.8768 femtometers in radius (a femtometer is a millionth of a billionth of a meter).

But a new method used in 2009 found a different measurement: 0.84087 femtometers, a 4 percent difference in radius.

The previous measurements had used electrons, negatively charged particles that circle the nucleus in a cloud, to determine proton radius. To make the measurement with electrons, researchers can do one of two things. First, they can fire electrons at protons to measure how the electrons are deflected. This electron-scattering method provides insight into the size of the positively charged proton.

An alternative is to try to make the electron move. Electrons zing around the nucleus of an atom, where protons reside, at different levels called orbitals. They can jump from orbital to orbital by increasing or decreasing their energy, which electrons do by losing or gaining an elementary particle of light called a photon. The amount of energy it takes to budge an electron from orbital to orbital tells physicists how much pull the proton has, and thus the proton's size.

Pohl and his colleagues didn't use electrons at all in their measurements of the proton. Instead, they turned to another negatively charged particle called the muon. The muon is 200 times heavier than an electron, so it orbits the proton 200 times closer. This heft makes it easier for scientists to predict which orbital a muon resides in and thus a much more sensitive measure of proton size.

"The muon is closer to the proton and it has a better view," Pohl said.

Possible Explanations

These sensitive muon measurements are the ones that gave the smaller-than-expected result for the proton radius, a totally unexpected discovery, Pohl said. Now, physicists are racing to explain the discrepancies.

One possibility is that the measurements are simply wrong. Pohl said this "boring explanation" is the most probable, but not all physicists agree.

"I would say it's not the experimental side," said Massachusetts Institute of Technology physicist Jan Bernauer.

The electron-based measurements have been repeated many times and are well-understood, Bernauer said, and muon experiments have the advantage that if they're done wrong, they don't provide results at all.

If experimental error turns out not to be the culprit, there may be some calculation issue, "so we actually know everything that goes on but we are just not calculating it quite right," Bernauer told reporters.

Most exciting of all, the discrepancy could reveal some new physics not explained by the dominant physics theory, the Standard Model. Perhaps there is something unknown about how muons and electrons interact with other particles, said John Arrington, a physicist at Argonne National Laboratory in Illinois.

One possibility is that photons aren't the only particles that carry forces between particles — perhaps an unknown particle is in the mix, causing the proton-measurement discrepancies.

Next Steps

To find out what's going on, physicists are launching a new set of experiments across multiple laboratories. One major line of research involves testing electron-scattering experiments to be sure they've been done correctly and that all the facets are understood, Arrington said.

Another goal is to repeat the scattering experiments, but instead of shooting electrons at protons they'll shoot muons at protons. This project, the Muon Scattering Experiment, or MuSE, is set to take place at the Paul Scherrer Institute in Switzerland. The facilities there will allow researchers to simultaneously measure electron- and muon-scattering in one experiment.

Read more at Discovery News

Fish Prone to Melanoma Get DNA Decoded

Scientists at Washington University School of Medicine in St. Louis and elsewhere have decoded the genome of the platyfish, a cousin of the guppy and a popular choice for home aquariums.

Among scientists, the fish are meticulously studied for their tendency to develop melanoma and for other attributes more common to mammals, like courting prospective mates and giving birth to live young.

Known scientifically as Xiphophorus maculatus, platyfish sport a variety of spectacular colors -- brilliant oranges, yellows and a lovely iridescent silver -- and myriad striped and speckled patterns. And when melanomas develop, they are easy to spot, even to an untrained eye.

"In platyfish, melanomas typically develop as black splotches along the tail and fins," says senior author Wesley Warren, PhD, a geneticist at Washington University's Genome Institute. "These fish are an ideal model for exploring the many unknowns of cancer, including how, when and where it develops in the body as well as its severity."

Scientists at Washington University, the University of Würzburg in Germany and Texas State University led an international team involved in sequencing and analyzing the platyfish genome. Their findings are available online in Nature Genetics.

"Now that we have the genome in hand, we can tease apart the way genes interact with one another to cause melanoma," says co-lead author Manfred Schartl, PhD, of the University of Würzburg in Germany. "Just as in human melanoma, genes that play a role in pigment cells also influence the development of melanoma in platyfish."

The platyfish genome includes some 20,000 genes, roughly the same number found in the human genome. But unlike humans and other mammals, the chromosomes of the platyfish, like those in other fish, have remained remarkably intact over some 200 million years of evolution.

"It's very much a mystery as to why these chromosomes are so structurally similar among fish species over long time periods of evolution because they live in vastly different aquatic environments," says Warren.

The platyfish is a prolific breeder. But while most fish lay eggs, platyfish females give birth to live young, often in broods of more than 100.

Comparing the genes of platyfish to those in mice and other mammals that give birth to their young, the scientists found a number of altered genes in the fish involved in live-bearing birth.

"Surprisingly, we found that the platyfish retain some yolk-related genes typically found in fish that lay eggs to produce their offspring, and genes involved in placenta function and egg fertilization displayed unique molecular changes," says co-lead author Ron Walter, PhD, of Texas State University.

While humans are known for their higher-level thinking and behaviors, platyfish and other fish have evolved their own set of complex behaviors, like courting, schooling and avoiding predators that far exceed the abilities of amphibians, reptiles and other lower vertebrates. Looking through the platyfish genome, the researchers found a number of gene copies linked to cognition in humans and other mammals that could underlie these behaviors.

Read more at Science Daily

Hermit Arrests Shed Light On Extreme Solitude

Two of the country's most notorious survivalists -- the Hermit of North Pond in Maine, and The Mountain Man of Utah, were found and arrested in the last few weeks. And a case of a missing family, the McStay family of southern California, was effectively closed when investigators said the family appears to have gone to Mexico voluntarily.

So is it still possible to "disappear" in 2013?

"Is it more difficult? Yes," said Jim Biesterfeld, a former U.S. army counter-intelligence special agent who teaches private investigations at California State University-Fullerton Jim Biesterfeld. "Impossible? Not even."

For someone to hide away from society, he said, at least two things are essential: self-sufficiency, and desire.

"There are not that many people who want to stay hidden for that long" in solitude," Biesterfeld said. "Most people try to establish new identities."

That's why it's unusual for two cases of solitary survivalists to have been solved in such close succession.

Christopher Knight, 47, also known as The North Pond Hermit, appears to be one of those few who truly wanted to live on his own.

For 27 years, Knight avoided making a campfire for fear of drawing attention to himself. He stole what he needed to survive from campgrounds; in fact, everything he had was stolen except his eyeglasses. If there's not much reason to be found, as in Knight's case, costly police investigations are unlikely. But, eventually, Knight's thefts of food and survival supplies prompted local law enforcement to get involved.

It would take a possible federal criminal violation in addition to a disappearance, such as a fugitive or kidnapping situation, for the FBI to become involved, said FBI special agent Kathy Wright.

"The FBI requires an authorized law enforcement purpose to conduct an investigation," she said. "The mere fact that an adult disappears, is not, on its own, a violation of law."

In the end, a surveillance camera set up specifically to catch Knight triggered an alarm when he entered a campground kitchen looking for food, and Knight was arrested.

While technology -- such as thermal imaging that detects people by tracking body heat -- is helpful in pinpointing a location once a general area is mapped out, investigators haven't abandoned old-fashioned methods. In the case of Troy James Knapp, also known as The Mountain Man in Utah, it was snowshoe tracks that eventually gave him away.

Biesterfeld relies on the old adage of investigators and journalists: Keep It Simple, Stupid. Find out everything you can about the person.

"What was he like as a kid? Did he have mental health issues? Had he ever talked about it before?" Biesterfeld said. "In most cases, people crave human contact. The rare few who do not are the Maine guy and the unabomber" -- and, it appears, Utah's Mountain Man.

"He says, 'I don't hate people. I just don't like living with them,'" the Huffington Post quotes him telling Sevier County Sheriff Nathan Sheriff Curtis.

Read more at Discovery News

Dinosaur Swam a Strong Doggy-Paddle

Claw marks on a 100-million-year-old riverbed in China reveal how some dinosaurs doggy-paddled over long distances, scientists say.

"What we have are scratches left by the tips of a two-legged dinosaur's feet," study researcher Scott Persons, of the University of Alberta, said in a statement. "The dinosaur's claw marks show it was swimming along in this river and just its tippy toes were touching bottom."

Stretching over a distance of 50 feet (15 meters), the markings show that the dinosaur had a coordinated, left-right, left-right swimming style, Persons said. The researchers believe the scratches belong to a carnivorous theropod -- a type of dinosaur that walked on two legs -- that stood roughly 3 feet (1 meter) at the hip.

While it's tough to determine the identity of the swimming dinosaur from these marks alone, Persons suspects it could have been an early tyrannosaur or a Sinocalliopteryx, predators known to have roamed this prehistoric landscape in China.

The paddle-scratches were found in a dried-up river in China's Szechuan Province, which Persons described as a "dinosaur super-highway," full of the footprints of other Cretaceous-era theropods and long-necked, four-legged sauropods.

The research was detailed April 8 in journal Chinese Science Bulletin.

It's not the first time dinosaur paddle prints have turned up in the fossil record. In 2007, paleontologists found S-shaped prints on the bottom of what was a lake in the Cameros Basin in Spain 125 million years ago. The unusual tracks indicate the animal's body was floating in about 10 feet (3.2 m) of water when it scratched the lakebed, researchers said at the time.

Read more at Discovery News

Taste of Beer Triggers Good Feelings in Brain

The taste of beer, without its alcoholic effects, may be enough to trigger the release of the pleasure chemical dopamine in the brain, a study finds.

To see how the taste of beer affects the brain, researchers gave a group of men tiny tastes of beer, and as the men sipped the beer, the researchers scanned the men’s brains. After a taste of beer, the men's brains showed a notable release of dopamine, a brain chemical associated with the pleasurable experience of consuming alcohol and other drugs. The effect was even greater among men who had a family history of alcoholism.

The findings are not surprising, scientists say, but having a way to assess predisposition to alcohol abuse could be useful.

"We believe this is the first experiment in humans to show that the taste of an alcoholic drink alone, without any intoxicating effect from the alcohol, can elicit this dopamine activity in the brain's reward centers," the study's senior author, neuroscientist David Kareken of the Indiana University School of Medicine, said in a statement. The findings were detailed online today (April 15) in the journal Neuropsychopharmacology.

Dopamine, a brain chemical widely associated with pleasure, has long been linked to the consumption of alcohol and other drugs. Sensory cues — such as tastes, smells or the sight of a bar — can elicit cravings to drink and cause relapses in recovering alcoholics. Dopamine may be critically involved in such cravings, scientists believe.

In the study, researchers gave 49 male volunteers a tiny taste (half an ounce, or 15 milliliters) of their favorite beer over the course of 15 minutes — enough to taste the beer but not enough to cause a change in blood-alcohol level or intoxication. At other times, the volunteers were given a sports drink or water, for comparison.

To study the effect of beer's taste on dopamine receptors, the researchers scanned the volunteers' brains using Positron Emission Tomography, which uses the radiation emitted by a radioactive chemical to produce a 3D image of the brain.

The scans revealed higher increases in dopamine after the men tasted beer compared with tasting the sports drink or water — suggesting that the taste of alcohol is enough to prompt a pleasurable response in the brain. The men also reported higher beer cravings after tasting beer than water or the sports drink.

Furthermore, the men who had a family history of alcoholism showed an even greater spike in dopamine levels after they tasted the beer, so the dopamine response may be a heritable risk factor for alcoholism.

Read more at Discovery News