Jul 23, 2011

Butterfly Study Sheds Light On Convergent Evolution: Single Gene Controls Mimicry Across Different Species

For 150 years scientists have been trying to explain convergent evolution. One of the best-known examples of this is how poisonous butterflies from different species evolve to mimic each other's color patterns -- in effect joining forces to warn predators, "Don't eat us," while spreading the cost of this lesson.

Now an international team of researchers led by Robert Reed, UC Irvine assistant professor of ecology & evolutionary biology, has solved part of the mystery by identifying a single gene called optix responsible for red wing color patterns in a wide variety of passion vine butterfly species. The result of 10 years of work, the finding is detailed in a paper that appears online July 21 in the journal Science.

"This is our first peek into how mimicry and convergent evolution happen at a genetic level," Reed said. "We discovered that the same gene controls the evolution of red color patterns across remotely related butterflies.

"This is in line with emerging evidence from various animal species that evolution generally is governed by a relatively small number of genes. Out of the tens of thousands in a typical genome, it seems that only a handful tend to drive major evolutionary change over and over again."

The scientists spent several years crossbreeding and raising the delicate butterflies in large netted enclosures in the tropics so they could map the genes controlling color pattern. UCI postdoctoral researcher Riccardo Papa (now an assistant professor at the University of Puerto Rico, Rio Piedras) then perfected a way to analyze the genome map by looking at gene expression in microdissected butterfly wings.

Finding a strong correlation between red color patterns and gene expression in one small region of the genome was the breakthrough that led to discovery of the gene. Population genetics studies in hybrid zones, where different color types of the same species naturally interbreed, confirmed it.

Read more at Science Daily

Egyptian names his daughter Facebook

WIKINEWS claims: An Egyptian man in his early twenties has named his newborn daughter ‘Facebook’ following the 2011 Egyptian Revolutionwhich was almost solely organized on the social-networking site Facebook. The father, Gamal Ibrahim, told the Egyptian newspaper Al-Ahram that he gave his child the name to “express his joy at the achievements made by the January 25 youth.”

Full story here

Jul 22, 2011

Fool's Gold Gives Scientists Priceless Insight Into Earth's Evolution

Fool's gold is providing scientists with valuable insights into a turning point in Earth's evolution, which took place billions of years ago.

Scientists are recreating ancient forms of the mineral pyrite -- dubbed fool's gold for its metallic lustre -- that reveal details of past geological events.

Detailed analysis of the mineral is giving fresh insight into Earth before the Great Oxygenation Event, which took place 2.4 billion years ago. This was a time when oxygen released by early forms of bacteria gave rise to new forms of plant and animal life, transforming Earth's oceans and atmosphere.

Studying the composition of pyrite enables a geological snapshot of events at the time when it was formed. Studying the composition of different forms of iron in fool's gold gives scientists clues as to how conditions such as atmospheric oxygen influenced the processes forming the compound.

The latest research shows that bacteria -- which would have been an abundant life form at the time -- did not influence the early composition of pyrite. This result, which contrasts with previous thinking, gives scientists a much clearer picture of the process.

More extensively, their discovery enables better understanding of geological conditions at the time, which informs how the oceans and atmosphere evolved.

The research, funded by the Natural Environment Research Council and the Edinburgh Collaborative of Subsurface Science and Engineering, was published in Science.

Dr Ian Butler, who led the research, said: "Technology allows us to trace scientific processes that we can't see from examining the mineral composition alone, to understand how compounds were formed. This new information about pyrite gives us a much sharper tool with which to analyse the early evolution of the Earth, telling us more about how our planet was formed."

Read more at Science Daily

Diamonds Pinpoint Start of Colliding Continents

Jewelers abhor diamond impurities, but they are a bonanza for scientists. Safely encased in the super-hard diamond, impurities are unaltered, ancient minerals that can tell the story of Earth's distant past. Researchers analyzed data from the literature of over 4,000 of these mineral inclusions to find that continents started the cycle of breaking apart, drifting, and colliding about 3 billion years ago. The research, published in the July 22, 2011, issue of Science, pinpoints when this so-called Wilson cycle began.

Lead author Steven Shirey at the Carnegie Institution's Department of Terrestrial Magnetism explained: "The Wilson cycle is responsible for the growth of the Earth's continental crust, the continental structures we see today, the opening and closing of ocean basins through time, mountain building, and the distribution of ores and other materials in the crust. But when it all began has remained elusive until now. We used the impurities, or inclusions, contained in diamonds, because they are perfect time capsules from great depth beneath the continents. They provide age and chemical information for a span of more than 3.5 billion years that includes the evolution of the atmosphere, the growth of the continental crust, and the beginning of plate tectonics."

Coauthor and longtime colleague Stephen Richardson of the University of Cape Town added: "It is astonishing that we can use the smallest mineral grains that can be analyzed to reveal the origin of some of Earth's largest geological features."

The largest diamonds come from cratons, the most ancient formations within continental interiors that have deep mantle roots or keels around which younger continental material gathered. Cratons contain the oldest rocks on the planet, and their keels extend into the mantle more than 125 miles (200 km) where pressures are sufficiently high, but temperatures sufficiently low, for diamonds to form and be stored for billions of years. The diamonds arrived at the surface as accidental passengers during volcanic eruptions of deep magma that solidified into rocks called kimberlites. The inclusions in diamonds come in two major varieties: peridotitic and eclogitic. Peridotite is the most abundant rock type in the upper mantle, whereas eclogite is generally thought to be the remnant of oceanic crust recycled into the mantle by the subduction or sinking of tectonic plates.

Shirey and Richardson, using their own work with other coinvestigators published in more than 20 papers over a 25-year period, reviewed the data from more than 4,000 inclusions of silicate -- Earth's most abundant material -- and more than 100 inclusions of sulfide from five ancient continents. The most crucial aspects were to look at when the inclusions were encapsulated and the associated compositional trends. Compositions vary and depend on the geochemical processing that precursor components underwent before they were encapsulated.

Two systems used to date inclusions -- the rhenium-osmium and samarium-neodymium techniques -- were compared. Both rely on natural isotopes that decay at exceedingly slow but predictable rates -- around one disintegration every ten years on the scale of an inclusion -- making them excellent atomic clocks for determining absolute ages.

Read more at Science Daily

Mass Extinction Caused by Deadly 'Earth Burp'

Micha Ruhl and researchers from the Nordic Center for Earth Evolution at the University of Copenhagen in Denmark have found that the mass extinction of half of Earth's marine life over 200 million years ago was likely the result of a giant release of carbon methane in the atmosphere.

This massive methane "burp" led to an increase in atmospheric temperature around the globe -- and organisms and ecosystems were simply unable adapt to their hotter environment.

"We measured the isotopes of carbon in plants, from before the mass extinction event and then after the mass extinction. We found two different types of carbons and the molecules that were produced during that event," Micha Ruhl told FoxNews.com. "So we started thinking of other sources of carbon that could have changed the atmosphere."

The original theory blamed the extinction and atmospheric change on carbon released during a period of intense volcanism -- a large surge in volcanic activity brought about by continental shift when Pangaea broke apart. But Ruhl and his partners discovered that this volcanic episode occurred 600,000 years prior to the end of the Triassic Period. The mass extinction occurred only 20,000 to 40,000 years prior.

Extensive calculations and research by Ruhl's team revealed that the burp pumped over 12,000 gigatons of methane into the atmosphere during the final years of the Triassic. While volcanism was revealed not to have caused the extinction itself, the researchers believe that the volcanoes indirectly set the events in motion by triggering the methane release.

"A small release of carbon dioxide from volcanism initiated global warming of the atmosphere, increasing temperatures in the oceans," Ruhl told FoxNews.com. "Methane is stored in the sea floor -- it's a molecule which is caught in some kind of ice structure. As soon as the temperatures got above a certain threshold, the ice melted and that methane was released."

For those unconcerned with an event hundreds of millions of years in the past, Ruhl's research is a little more than a history lesson. Ruhl argues that better understanding the Triassic period extinction could help with further research in the field of climate change.

"People are worried nowadays that the release of carbon dioxide from fossil fuel burning could melt glaciers in the same way," Ruhl told FoxNews.com. "That's the big question of course" -- and a big leap to make. "People are worried nowadays that the release of carbon dioxide from fossil fuel burning could melt glaciers in the same way," Ruhl told FoxNews.com. "That's the big question of course" -- and a big leap to make.

Ruhl noted that events far back in history when the planet was dramatically different are hardly comparable to the modern world.

Read more at Discovery News

Jul 21, 2011

Mass Extinction Easier to Trigger Than Thought

The cataclysmic extinctions that scoured Earth 200 million years ago might have been easier to trigger than expected, with potentially troubling contemporary implications.

Rather than 600,000 years of volcanic activity choking Earth’s atmosphere with carbon dioxide, just a few thousand years apparently sufficed to raise ocean temperatures so potent greenhouse gases trapped in seafloor mud came bubbling up.

Most of everything alive on Earth was soon wiped out. Another half-million years of vulcanism were just icing on the cake. The immediate question: What lessons, if any, can be drawn?

“Scientists have been worried about the current release of methane from seafloors. What this study shows is that it already happened in the past,” said paleoecologist Micha Ruhl of Utrecht University, whose findings are published July 21 in Science. “It could happen again. It’s only the boundary conditions that we don’t know.”

In what scientists call the end-Triassic mass extinction, at least half of all living species simply disappear from the fossil record. The die-off didn’t merely cause ecological disruption. It was so sudden and profound that planetary chemical cycles went haywire for the next several million years.

The leading explanation for the extinction invokes extended, climate-altering volcanic activity caused by splitting continental plates, but earlier research by Ruhl suggested a more nuanced and jarring narrative.

By calculating how changes in ancient sediment composition corresponded to natural cyclesin Earth’s distance to the Sun, he could study the end-Triassic’s onset in fine-grained chronological detail.

Ruhl found that limestone — the geological remains of corals and shellfish — vanishes within the first 20,000 years. Similar terrestrial disruption can be inferred from changes in fossilized plant spores. The end-Triassic extinction must have occurred far more suddenly than believed.

In the latest study, Ruhl’s team examined chemical traces left by dying plants on the shores of the Tethys Sea, a body of water that separated the ancient continents of Laurasia and Gondwana. Today those shores are sedimentary layers in the Austrian Alps.

The researchers concentrated on changes to carbon isotopes, or subtly different elemental formations that betray whether carbon in plants came from carbon dioxide or methane. At 201.4 million years ago, in that narrow 20,000-year window of their updated end-Triassic cataclysm, they found a rise in CO2 followed by a tremendous spike of methane.

“A small release of CO2 from volcanoes triggered a small change in the global climate, raising land and ocean temperatures. That led to the release of methane from the seafloor,” said Ruhl.

Methane, familiar to most people as the main component of natural gas fuels, is a greenhouse gas less common than carbon dioxide in the atmosphere but far more potent. Most of Earth’s supply is contained in soils and seabeds.

Scientists have raised the possibility that rising global temperatures could release trapped methane into the atmosphere, further raising temperatures and releasing more methane in a feedback loop of warming and planetary disruption. That’s apparently what happened during the end-Triassic extinction.

According to paleobiologist Jessica Whiteside of Brown University, a leading researcher on end-Triassic vulcanism, more evidence is needed before Ruhl’s interpretations are conclusively supported. It’s possible that the new study reflects localized rather than planetary patterns.

But though Whiteside is uncertain about methane’s end-Triassic role, she said the possibility of a CO2-methane warming loop is real and likely fueled climate change leading into the Eocene, an epoch lasting from 55 to 35 million years ago.

“It was a very hot time, so hot there were crocodiles in the Arctic Circle and palm trees extending to the North Pole,” said Whiteside. “It’s the most recent time in Earth’s history that greenhouse gases were at the level where we’re predicted to be in the next century.”

Read more at Wired Science

Physicists Confirm Existence of New Particle

Physicists working at Fermilab’s particle accelerator have confirmed the observation of an entirely new particle — the the Xi-sub-b baryon.

Baryons are particles formed of three quarks, in different configurations. The proton is a baryon that consists of two up and one down quark, and the neutron is two down and one up. The Xi-sub-b has an up quark, a strange quark (yes, that’s its real name) and a heavy bottom quark (again, real name), meaning that it weighs around six times as much as a proton or neutron.

Its existence has been predicted for some time, but hadn’t previously been observed. It doesn’t stick around long, though — traveling a fraction of a millimeter before decaying into lighter particles.

Happily, Fermilab has smashed together almost 500 trillion sets of particles, so researchers were able to verify the particle’s existence multiple times over. The Xi-sub-b has been spotted 25 times.

More at Wired Science

The Beautiful Violence of Exoplanet Aurorae

If you think the auroral displays we have on Earth are impressive, spare a thought for aurorae erupting in the atmospheres of massive gas giant exoplanets orbiting close to their parent stars.

Through a combination of close proximity to the star and powerful magnetic fields, aurorae on so-called "hot-Jupiters" could be 100-1000 times brighter than the displays we see on Earth. Also, as an added bonus, these aurorae are predicted to ripple across entire exoplanetary atmospheres and not just be restricted to the polar regions, according to a new study.

"I'd love to get a reservation on a tour to see these aurorae!" said lead author Ofer Cohen, a SHINE-NSF postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics (CfA).

Living With a Star

Space weather is of increasing importance to our planet as we send delicate electronics into space. The satellites that deliver everything from cable television to GPS coordinates are susceptible to being disrupted by the high-energy particles blasting from the sun.

But it's not only the circuit boards of satellites that are at risk. The large-scale circuitry of entire national power grids are also prone to failure.

As energetic particles slam into our planet's magnetosphere, the condition could arise that huge quantities of high-energy solar particles (mainly protons) are injected into the magnetic field of Earth. When this happens, aurorae will erupt at high latitudes (generating the famous Northern and Southern Lights -- a.k.a. the Aurora Borealis and Aurora Australis, respectively), and powerful currents are generated through the atmosphere. Power grids can be overloaded, causing widespread blackouts.

But what if a gas giant was orbiting its star only a few million miles from its star, as opposed to Earth's "safer" 90 million miles from the sun?

Stellar Blowtorch

Using computer models to simulate this extreme space weather environment, Cohen and his team simulated what it would be like if a coronal mass ejection (CME) were to hit a hot-Jupiter with a compact orbit.

In a word: Fireworks.

Firstly, as the exoplanet is so close to its star, the CME will be far denser than the CMEs than plow into our little world. After CMEs have traveled nearly 100 million miles to Earth's doorstep, their density drops as the CME cloud expands. Cohen's hot-Jupiter on the other hand is sitting right down the throat of a stellar blowtorch.

Although the physics is similar between aurorae on Earth and extreme aurorae on this particular exoplanet, that is where the similarities end.

"The impact to the exoplanet would be completely different than what we see in our solar system, and much more violent," said co-author Vinay Kashyap in the CfA press release.

Slamming into the exoplanetary atmosphere with an energy 100-1000 times greater than the aurorae we experience, the extreme illumination caused by the impact of the stellar plasma with atmospheric gases will rapidly engulf the whole globe. The CfA model predicts the resulting eruption will light up equatorial regions, rippling from the north to south poles over six hours, eventually fading as the geomagnetic storm energy is dissipated.

Read more at Discovery News

Nepal To Measure Everest

Nepal and China find themselves in a fierce battle over what seems like a simple question: Just how tall is Mount Everest?

Widely known as the tallest mountain in the world, Everest straddles the border between the two countries -- both of which claim slightly different measurements. Nepal stands by the measurement of 8,848 meters (29,029 feet), the result of a 1954 survey, but China often refers to the mountain as 8,844 meters in border talks.

Those 4 extra meters are causing quite a bit of confusion.

The solution: Nepal plans to re-measure Mount Everest, according to AFP.

"We have begun the measurement to clear this confusion," Gopal Giri, a spokesman for the Nepalese land reform and management ministry, told the news agency. "Now we have the technology and resources we can measure ourselves."

Giri said that the measurements were actually quite complex, requiring reference points to be set up on Everest; global-positioning system (GPS) satellites will then be used to calculate the precise measurement.

Read more at Discovery News

Jul 20, 2011

Iceman's 'Girlfriend' Found

Italian workers building an addition to a kindergarten have unearthed a well preserved female skeleton who might be relatively contemporaneous with Ötzi, the Iceman mummy discovered 20 years ago in a melting glacier in South Tyrol.

The "Lady of Introd" or "Ötzi’s girlfriend," as the skeleton was nicknamed in Italy, was found in the tiny Alpine village of Introd, in the Val d'Aosta, famous to be the preferred vacationing spot for both Pope John II and his successor Benedict XVI.

According to archaeologists and anthropologists, the woman has been lying on her right side, with her head facing west, for about 5,000 years.

The dating to the third millennium B.C. was based on the skeleton’s burial position and stratigraphy, said Vittorio Anglesio, mayor of Introd.

"She appears to have been buried without any grave goods. However, we are now going to extend the dig to better investigate the area," Anglesio told Discovery News.

Moved to a laboratory, the skeletal remains are now being analyzed in order to assess the diet, the age at death, possible diseases and causes of death.

According to Kristina Killgrove, a biological anthropologist at the University of North Carolina, further research into the woman's diet would be particularly interesting.

"Little direct evidence of human diet has been found from this time period. Ötzi's preservation, of course, provides unparalleled information about his diet, but it would be fascinating to see stable isotope analysis carried out on this skeleton, who lived around the same time and also died in the Alps," Killgrove told Discovery News.

Read more at Discovery News

Footprints Show How Our Ancestors Walked

The oldest known human ancestor footprints, dated to 3.7 million years ago, reveal that some of the earliest members of our family tree walked fully upright with feet similar to ours, according to new research.

The findings, published in the Journal of the Royal Society Interface, push back the date for upright walking in our ancestry by nearly 2 million years. That's because previous studies had concluded this trademark gait emerged in the genus Homo about 1.9 million years ago.

The 3.7 million-year-old footprint maker, likely a species called Australopithecus afarensis (of the "Lucy" fossil fame), walked in an even less ape-ish way than some humans do today.

Lead author Robin Crompton told Discovery News that "some healthy humans produce more 'ape like' footprints."

Crompton, a professor in the University of Liverpool's School of Biomedical Sciences, explained that many researchers believed loss of the "so-called mid-tarsal break," a flexing of the side midfoot, "distinguished humans from non-human apes." This flexing can contact the ground and leave behind a mark in footprints. But Crompton and his colleagues found that certain people today create such footprints, while some of the ancient prints were lacking the distinguishing feature.

The researchers made this determination after studying the ancient footprints, found at a site called Laetoli in Tanzania. At least one, or possibly two, individuals left behind the footprints as they walked through damp volcanic ash.

Detailed imaging, based on methods employed in functional brain imaging, yielded clear, three-dimensional views of the 11 intact prints in the Laetoli trail. The scientists then compared these ancient footprints with prints made by modern humans and other living great apes.

It's now known that the prehistoric walker moved at just over 3 1/2 feet per second.

"Walking was completely erect," Crompton said. "Push off was substantially by the big toe and a medial arch was present. There was no collapse of the lateral side of the foot, as has been recently suggested."

The probable walker, A. afarensis, is best known via a partial skeleton named "Lucy." Lucy and other members of her species are thought to have lived at least some of their time in trees. Since Lucy was already walking upright in a very human-way, the new study strengthens the theory that erect, two-footed walking evolved in a tree-living ancestor of living great apes and humans.

Crompton explained that this way of moving was "probably faster than quadrupedalism on the ground in an animal built like great apes are." It also may have "enhanced feeding from low branches or bushes."

Upright walking on two feet additionally could have helped with visual displays and showing aggression, he said. All of this may have happened as forest canopies broke up, forcing A. afarensis to leave its tree homes for a more terrestrial way of life.

Unlike modern humans, however, this species had short legs and a long body. When compared to other animals, we have just the opposite: relatively long legs and a short body.

Sarah Elton of the Hull York Medical School told Discovery News, "Although there have been heated disagreements over how to interpret the Laetoli footprints, this incredibly detailed and well thought-out study must surely help to put some of the debate to rest."

Read more at Discovery News

Researchers Grow Tooth in Mouse Kidney

Japanese bio engineers have succeeded in growing a tooth from cells implanted into a mouse kidney, using a technique that could create replacement organs faster than previously tested methods.

Biologists have previously cultivated teeth in a laboratory and successfully transplanted them into the jaws of mice, but Japanese researchers have hailed the latest development as offering much faster growth rates.

The latest method "saves about 10 days" compared to earlier techniques, said Tokyo University of Science professor Takashi Tsuji, who led the research.

"It is our first step towards the goal -- to regenerate organs that could replace damaged or lost ones," he said.

"We still haven't got to the point where it can be used for humans," he added. "We have just completed our first step."

The research team, including scientists from Tokyo Medical and Dental University and Tohoku University, developed a "seed" by combining special cells necessary to form a tooth, their research showed.

The cells reacted to each other and started growing into tissues to create a real tooth.

The researchers then wrapped the "seed" in a tiny piece of plastic and implanted it in a mouse's kidney, where it grew to form a tooth, the study showed.

Read more at Discovery News

'Four-Eyed' Fish Sees Above and Below Water

A "four-eyed" fish swims along the surface with eyes appearing both in and out of the water.

New research explains how the fish simultaneously sees in these two very different environments.

The findings, published in the latest Royal Society Biology Letters, help to explain how animal visual systems, including human ones, evolve in response to different light environments.

In the case of the "four-eyed fish," or Anableps, and its sister species A. microlepis and A. dowei, the fish have two large eyes.

"The four-eyed name derives from the fact that it divides each pupil into two, one above the water and one below," lead author Gregory Owens told Discovery News.

For the study, Owens, a University of Victoria biologist, and his colleagues analyzed the eyes of the fish, focusing on light sensitive proteins called visual opsins. Each is most sensitive to a particular wavelength of light. Humans, for example, have three visual opsins sensitive to blue, green and red light. They absorb light at slightly different wavelengths, enabling us to see those three colors and others.

The scientists determined that the top part of Anableps' eyes, the set that sticks out of the water, possess opsins sensitive to green. The bottom half of the eyes, actually in the water, are sensitive to yellow. The entire eye has genes sensitive to ultraviolet, violet and blue light.

"This tells us that Anableps is more sensitive to yellow light from the water and green light from the air," Owens said. "We hypothesize that this functions to match their sensitivity with the light available. The water Anableps lives in is generally muddy (mangrove forests of northern South America) and in this muddy water yellow light transmits best."

The unique visual system allows the fish to avoid a problematic phenomenon Snell's Window," which occurs when you are underwater while looking up out of the water. Due to the refraction of light at the water's surface, after a certain angle you no longer see out of the water, and instead see a reflection on the water's surface. Thus, your field of vision is limited to about 96 degrees."

To compensate for this problem, certain other marine dwellers, such as archerfish, have to mentally calculate refraction to find the true position of objects they encounter. The "four eyed" Anableps instead sees a broader angle.

The vision system and associated over water and under water lifestyle comes at a price, though. As one might imagine, it's not hard for predators to miss a bug-eyed fish skimming along the surface. But Anableps is forever on the lookout, with large areas of its brain devoted to vision.

The researchers suspect that Anableps used to just have eyes suitable for the aerial environment. Over time, they think the fish lost green sensitivity in the lower eye halves, gaining yellow sensitivity there for better aquatic vision, particularly in muddy yellow water.

Read more at Discovery News

Report accidentally finds pirate movie website to be full of law abiding citizens

In June, police across several countries raided the operators of streaming video links portal Kino.to. This massive operation was one of the largest of its type and site admins and users alike were branded as enemies of the TV and movie business. However, it now appears that in respect of the latter group, the opposite was found to be true.

The June raids against Kino.to, which involved as many as 250 police and other authorities, dwarfed even the 2006 raids against The Pirate Bay.

Following the event the Kino.to site displayed notices which stated that the site had been “closed on suspicion of forming a criminal organization to commit professional copyright infringement.” While noting that several operators of the site had been arrested, it also criticized the site’s users.

“Internet users who illegally pirated or distributed copies of films may be subjected to a criminal prosecution,” read the warning.

But were the site’s users all criminals hell-bent on destroying the movie industry? According to a report from Telepolis, a recent study found the reverse was true. This, the survey claims, leads pirate site users to buy more DVDs, visit the cinema more often and on average spend more than their ‘honest’ counterparts at the box office.

“The users often buy a ticket to the expensive weekend-days,” the report notes.

In the past similar studies have revealed that the same is true for music. People who pirate a lot of music buy significantly more music than those who don’t.

Full report at Torrent Freak

Jul 19, 2011

Milky Way’s Core Hides Big Twisted Ribbon

A space telescope peering into the Milky Way galaxy’s dusty core has spied a colossal twisted ribbon of super-cooled material.

Until now astronomers had only seen bits and pieces of the ribbon’s 600-light-year-wide superstructure, which resembles the Latin symbol for infinity (∞).

“We have a new and exciting mystery on our hands, right at the center of our own galaxy,” said astronomer Sergio Molinari of the Institute of Space Physics in a press release. Molinari and others describe the strange ribbon in an upcoming Astrophysical Journal Letters study available on arXiv.org.

Astronomers previously studied gas-piercing infrared images of the Milky Way’s cloudy barred core, but they didn’t have photos with resolution high enough to discern the ribbon’s entire structure. Molinari and others found the ring by aiming the European Space Agency’s infrared Herschel Space Observatory toward galactic center.

The telescope’s images suggest the ring is a chilly 15 degrees Kelvin — warmer regions are blue while cooler regions are red — and has two segments that poke out of the galaxy’s pancake-like plain. Ground-based radio telescope data also hint that the ring is spinning around the core as one cohesive unit.

Read more at Wired Science

Experimental Archaeologists Test Past by Making It Real

Of all the scientific disciplines, archaeology lends itself most to the imagination. It's the scholarly embodiment of the impulse to imagine oneself as a Mongol raider or Roman slave, tracking gazelle across the Great Rift Valley or navigating by stars across the Pacific.

For a few lucky researchers, these dreams become hypotheses. Experimental archaeologists test ancient tools and techniques, determining how they worked and whether modern interpretations are correct. Sometimes the studies look more like play than research — but why shouldn't research be fun?

From ancient noodle recipes to spear throwing, here are a few of our favorite studies.


In the annals of experimental archaeology, no experiment is more famous than a 4,300 mile trip taken by six men in a raft called the Kon-Tiki. Led by Norwegian adventurer Thor Heyerdahl, the voyage was supposed to show that pre-Columbian South Americans could have reached the South Pacific by floating across on rafts made of balsa wood.

Heyerdahl's journey was memorialized in a bestselling book and Academy Award-winning documentary, but the settlement hypothesis was discredited by further anthropological research. In June of this year, however, genetic tests of Polynesian islanders identified scattered DNA markers typically found among South Americans. Maybe a few ancient sailors indeed made the Kon-Tiki's epic voyage.

Read more at Wired Science

Giant Lost Island Found on Atlantic Seafloor

A 10,000 square kilometer (3,861 sq. mile) island sank beneath the waves long ago, in the frigid waters of the Atlantic north of Scotland.

No, it wasn't Atlantis.

The landmass sank beneath the waves of the North Atlantic long before humans arrived on the scene.

The island was created when the Icelandic Plume, a bubble of magma beneath the Earth’s surface, forced the crust up and out of the water. The land was forced up in a series of three steps, each one pushing the land 200-400 meters higher.

The island popped up out of the water for about a million years. Long enough for land plants to colonize it. But it sank back down and now resides almost 2 kilometers (1.2 miles) beneath the ocean.

Contractors using echo-sounding technology to search for deep-sea oil found the lost world beneath the sediments and debris that accumulated in the 56 million years since the island sank northeast of the Orkney-Shetland islands.

Echo-sounding involves the release of highly pressurized air beneath the water to create sound waves. The sound waves pass through sediments on the floor of the ocean. When the sound waves bounce back, a microphone records them. The data is then used to create a three dimensional map of what lies beneath the ocean.

Nicky White of the University of Cambridge and his team used those maps to observe the sunken island. They could even see what used to be rivers and mountains. Their findings were recently published in Nature Geoscience.

Read more at Discovery News

Jul 18, 2011

What Keeps Earth Cooking?

What spreads the sea floors and moves the continents? What melts iron in the outer core and enables Earth's magnetic field? Heat. Geologists have used temperature measurements from more than 20,000 boreholes around the world to estimate that some 44 terawatts (44 trillion watts) of heat continually flow from Earth's interior into space. Where does it come from?

Radioactive decay of uranium, thorium, and potassium in Earth's crust and mantle is a principal source, and in 2005 scientists in the KamLAND collaboration, based in Japan, first showed that there was a way to measure the contribution directly. The trick was to catch what KamLAND dubbed geoneutrinos -- more precisely, geo-antineutrinos -- emitted when radioactive isotopes decay. (KamLAND stands for Kamioka Liquid-scintillator Antineutrino Detector.)

"As a detector of geoneutrinos, KamLAND has distinct advantages," says Stuart Freedman of the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), which is a major contributor to KamLAND. Freedman, a member of Berkeley Lab's Nuclear Science Division and a professor in the Department of Physics at the University of California at Berkeley, leads U.S. participation. "KamLAND was specifically designed to study antineutrinos. We are able to discriminate them from background noise and detect them with very high sensitivity."

KamLAND scientists have now published new figures for heat energy from radioactive decay in the journal Nature Geoscience. Based on the improved sensitivity of the KamLAND detector, plus several years' worth of additional data, the new estimate is not merely "consistent" with the predictions of accepted geophysical models but is precise enough to aid in refining those models.

One thing that's at least 97-percent certain is that radioactive decay supplies only about half Earth's heat. Other sources -- primordial heat left over from the planet's formation, and possibly others as well -- must account for the rest.

Hunting for neutrinos from deep in the Earth

Antineutrinos are produced not only in the decay of uranium, thorium, and potassium isotopes but in a variety of others, including fission products in nuclear power reactors. In fact, reactor-produced antineutrinos were the first neutrinos to be directly detected (neutrinos and antineutrinos are distinguished from each other by the interactions in which they appear).

Because neutrinos interact only by way of the weak force -- and gravity, insignificant except on the scale of the cosmos -- they stream through Earth as if it were transparent. This makes them hard to spot, but on the very rare occasions when an antineutrino collides with a proton inside the KamLAND detector -- a sphere filled with a thousand metric tons of scintillating mineral oil -- it produces an unmistakable double signal.

The first signal comes when the antineutrino converts the proton to a neutron plus a positron (an anti-electron), which quickly annihilates when it hits an ordinary electron -- a process called inverse beta decay. The faint flash of light from the ionizing positron and the annihilation process is picked up by the more than 1,800 photomultiplier tubes within the KamLAND vessel. A couple of hundred millionths of a second later the neutron from the decay is captured by a proton in the hydrogen-rich fluid and emits a gamma ray, the second signal. This "delayed coincidence" allows antineutrino interactions to be distinguished from background events such as hits from cosmic rays penetrating the kilometer of rock that overlies the detector.

Says Freedman, "It's like looking for a spy in a crowd of people on the street. You can't pick out one spy, but if there's a second spy following the first one around, the signal is still small but it's easy to spot."

KamLAND was originally designed to detect antineutrinos from more than 50 reactors in Japan, some close and some far away, in order to study the phenomenon of neutrino oscillation. Reactors produce electron neutrinos, but as they travel they oscillate into muon neutrinos and tau neutrinos; the three "flavors" are associated with the electron and its heavier cousins.

Being surrounded by nuclear reactors means KamLAND's background events from reactor antineutrinos must also be accounted for in identifying geoneutrino events. This is done by identifying the nuclear-plant antineutrinos by their characteristic energies and other factors, such as their varying rates of production versus the steady arrival of geoneutrinos. Reactor antineutrinos are calculated and subtracted from the total. What's left are the geoneutrinos.

Read more at Science Daily

Grappling hooks help bacteria slingshot forward

Like tiny mountaineers, bacteria use grappling hooks to pull themselves across a surface – and can get an extra boost by releasing one of the taut lines to slingshot themselves forward. Thwarting them could help combat the biofilms behind hospital infections.

Fan Jin and Gerard Wong of the University of California, Los Angeles, filmed the bacterium Pseudomonas aeruginosa crawling through a viscous medium on a glass surface. They then analysed how it moved using an algorithm. This confirmed what biologists had long suspected: many bacteria use hair-like appendages called pili as grappling hooks to pull themselves along a surface.

But the algorithms also picked up on something else: sometimes a bacterium's rear end performed a jittery but purposeful little dance. Instead of merely contracting their pili, the bacteria released one taut pilus from the surface altogether, sending their behinds skittering across the surface. This fired the cell forwards 20 times faster than contracting pili.

"The paper is interesting and suggests aspects of pilus-based cell movement that I had not considered," says Mark McBride of the University of Wisconsin-Milwaukee, who also studies bacterial movement but was not involved in the study.

Read more at New Scientist

All Non-Africans Part Neanderthal, Genetics Confirm

If your heritage is non-African, you are part Neanderthal, according to a new study in the July issue of Molecular Biology and Evolution. Discovery News has been reporting on human/Neanderthal interbreeding for some time now, so this latest research confirms earlier findings.

Damian Labuda of the University of Montreal's Department of Pediatrics and the CHU Sainte-Justine Research Center conducted the study with his colleagues. They determined some of the human X chromosome originates from Neanderthals, but only in people of non-African heritage.

"This confirms recent findings suggesting that the two populations interbred," Labuda was quoted as saying in a press release. His team believes most, if not all, of the interbreeding took place in the Middle East, while modern humans were migrating out of Africa and spreading to other regions.

The ancestors of Neanderthals left Africa about 400,000 to 800,000 years ago. They evolved over the millennia mostly in what are now France, Spain, Germany and Russia. They went extinct, or were simply absorbed into the modern human population, about 30,000 years ago.

Neanderthals possessed the gene for language and had sophisticated music, art and tool craftsmanship skills, so they must have not been all that unattractive to modern humans at the time.

"In addition, because our methods were totally independent of Neanderthal material, we can also conclude that previous results were not influenced by contaminating artifacts," Labuda said.

This work goes back to nearly a decade ago, when Labuda and his colleagues identified a piece of DNA, called a haplotype, in the human X chromosome that seemed different. They questioned its origins.

Fast forward to 2010, when the Neanderthal genome was sequenced. The researchers could then compare the haplotype to the Neanderthal genome as well as to the DNA of existing humans. The scientists found that the sequence was present in people across all continents, except for sub-Saharan Africa, and including Australia.

"There is little doubt that this haplotype is present because of mating with our ancestors and Neanderthals," said Nick Patterson of the Broad Institute of MIT and Harvard University. Patterson did not participate in the latest research. He added, "This is a very nice result, and further analysis may help determine more details."

David Reich, a Harvard Medical School geneticist, added, "Dr. Labuda and his colleagues were the first to identify a genetic variation in non-Africans that was likely to have come from an archaic population. This was done entirely without the Neanderthal genome sequence, but in light of the Neanderthal sequence, it is now clear that they were absolutely right!"

Read more at Discovery News

Jul 17, 2011

Fossil Forensics Reveals How Wasps Populated Rotting Dinosaur Eggs

Exceptionally preserved fossils of insect cocoons have allowed researchers in Argentina to describe how wasps played an important role in food webs devoted to consuming rotting dinosaur eggs. The research is published in the scientific journal Palaeontology.

The approximately 70 million year old eggs, from gigantic titanosaur sauropod dinosaurs were discovered in 1989 in the Patagonia region of Argentina, well known for yielding fossils of sauropod dinosaur eggs and even embryonic dinosaurs. Only recently it was discovered that one of the broken eggs contained tiny sausage-shaped structures, 2-3cm long and 1cm wide. The structures closely resembled fossilised insect cocoons, and were most similar in size and shape to the cocoons of some species of modern wasp.

There are many records of fossilised dinosaur eggs, and even several records of fossil cocoons, but, as author Dr Jorge Genise of the Museo Argentino de Ciencias Naturales states "this is the first time that these cocoons are found closely associated with an egg." Such a study of organismal behaviour (e.g. burrows, footprints) is known as ichnology.

The results indicate "that wasps probably participated in the food web, mostly composed of scavenging insects, which developed on the rotten egg." The make-up of carrion communities -- spiders, beetles and other creatures populating rotting organic matter -- is more familiar to us from the screens of crime scene investigation documentaries.

The numbers and different types of creatures indicate the length of deposition and the time since death. In this particular CSI, it appears that the dinosaur egg was broken by force, and subsequent fractures in the egg shell allowed scavenging creatures to feed upon the contents. At egg sizes of around 20cm, this represents a sizable amount of yolk! Other creatures later appeared to feed not upon the egg contents, but on the initial scavengers themselves. The wasps represent the top of the food web, and could have been feeding on insects or spiders gorging on rotting egg contents.

Read more at Science Daily

Homo Sapiens, Meet Your New Astounding Family

A single, unforgettable image comes to mind when we ponder human origins: a crouching ape slowly standing and morphing into a tall, erect human male poised to conquer every bit of habitable land on this planet. We walk this earth—we, this unparalleled experiment in evolution—reflexively assuming we are the crown of creation. Certainly we are rare and strange: As biological anthropologist Owen Lovejoy of Kent State University says, “The chances that a creature like us will ever happen again are so small that I can’t even measure them.”

But that ascent-of-man picture is looking as dated as the flat earth. A series of scientific and technological breakthroughs have altered much of our fundamental understanding of human evolution. In the new view, the path to Homo sapiens was amazingly dilatory and indirect. Along the way, our planet witnessed many variations on the human form, multiple migrations out of Africa, interspecies trysts, and extinctions that ultimately wiped out all hominid species except one (pdf). “Human evolution used to seem simple and linear,” says paleoanthropologist William Jungers of the State University of New York at Stony Brook. “Now, you look at almost any time slice and you see diversity. We may be special and we may be lucky, but we’re far from the only human experiment.”

Unexpected fossil finds keep showing us an ever-expanding variety of human and prehuman species. Probably the most stunning of these recent discoveries is Ardipithecus ramidus, an ancestor who displayed a fantastical mosaic of ape and human traits. 
A. ramidus apparently climbed trees but also walked upright some 4.4 million years ago—more than half a million years before the long-accepted origin of bipedalism.

More at Discover

70 year old woman sued for “porn piracy”

For those who believe that using the BitTorrent protocol for piracy is a young person’s game, you might want to know about a San Francisco woman risking a potential $150,000 fine for torrenting porn. She’s 70 years old, you see.

Of course, she claims to not even know what BitTorrent is, but who can believe the word of a thief? Well, as you might expect, the case isn’t exactly a slam dunk. The anonymous 70-year-old was named as part of a lawsuit against multiple users for illegally downloading adult material, but she believes that someone else was using her unsecured Wi-Fi to do so.

Refusing to pay the $3,400 settlement requested by the lawsuit, the woman plans to go to court and explain to the judge what’s what.

Full article at Techland