from Science News
Earth's first living organisms didn't leave behind footprints or bite marks or bones. These single cells thrived quietly in a tiny pocket somewhere on the planet. For centuries, scientists trying to describe this earliest life have relied on evidence provided by biology, studying what features modern life-forms have in common to deduce the most primitive components of cells.
By working backward, biologists have developed proposals describing when and where such simple forms of life could have arisen. But the ideas so far are guesses at best, impossible to prove.
Researchers from a different field--geology--have more recently joined in the effort. With guidance from biologists, geologists are looking to Earth's oldest rocks to uncover traces of life left behind by the very first cells. Geologists are also pointing biologists toward unusual environments where early cells might have gained a foothold. Where the two fields intersect, more concrete scenarios regarding life's formative years are now taking shape.
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from the San Francisco Chronicle
Drilling deeply into ancient sediments beneath Clear Lake, UC Berkeley scientists are seeking vital clues to the future of plant and animal life by investigating how changing climates have altered life in the distant past.
The drilling will end next week, and then the 17 scientists on the project will begin analyzing thousands of tiny pollen grains brought up in drill cores from far beneath the lakebed to learn how plant species large and small met the challenge of survival during past periods of climate change.
Significant episodes of global warming--and cold waves, too--hit the Earth many thousands of years ago, leaving records of the past. Those records, in microscopic bits of plant matter, make up the evidence the researchers will study.
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from Nature News
Humans walk on two feet and (mostly) lack hair-covered bodies, but the feature that sets us furthest apart from other apes is a brain capable of language, art, science, and other trappings of civilisation.
Now, two studies published online today in Cell suggest that DNA duplication errors that happened millions of years ago might have had a pivotal role in the evolution of the complexity of the human brain. The duplications--which created new versions of a gene active in the brains of other mammals--may have endowed humans with brains that could create more neuronal connections, perhaps leading to greater computational power.
The enzymes that copy DNA sometimes slip extra copies of a gene into a chromosome, and scientists estimate that such genetic replicas make up about 5% of the human genome. However, gene duplications are notoriously difficult to study because the new genes differ little from their forebears, and tend to be overlooked.
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from ScienceNOW Daily News
Yawn next to your dog, and she may do the same. Though it seems simple, this contagious behavior is actually quite remarkable: Only a few animals do it, and only dogs cross the species barrier. Now a new study finds that dogs yawn even when they only hear the sound of us yawning, the strongest evidence yet that canines may be able to empathize with us.
Besides people and dogs, contagious yawning has been observed in gelada baboons, stump-tail macaques, and chimpanzees. Humans tend to yawn more with friends and acquaintances, suggesting that "catching" someone's yawn may be tied to feelings of empathy. Similarly, some studies have found that dogs tend to yawn more after watching familiar people yawning. But it is unclear whether the canine behavior is linked to empathy as it is in people. One clue might be if even the mere sound of a human yawn elicited yawning in dogs.
To that end, scientists at the University of Porto in Portugal recruited 29 dogs, all of whom had lived for at least 6 months with their owners. To reduce anxiety, the study was performed in familiar rooms in the dogs' homes and in the presence of a known person but with no visual contact with their owners.
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from the New York Times (Registration Required)
He threw away tax documents, got a ticket for trying to pass an ambulance and bought stock in companies that were obviously in trouble. Once a good cook, he burned every pot in the house. He became withdrawn and silent, and no longer spoke to his wife over dinner. That same failure to communicate got him fired from his job at a consulting firm.
By 2006, Michael French--a smart, good-natured, hardworking man--had become someone his wife, Ruth, felt she hardly knew. Infuriated, she considered divorce.
But in 2007, she found out what was wrong.... Mr. French, now 71, has frontotemporal dementia--a little-known, poorly understood and frequently misdiagnosed group of brain diseases that eat away at personality and language. Although it was first recognized more than 100 years ago, there is still no cure or treatment, and patients survive an average of only eight years after the diagnosis.
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from Nature News
The world's largest particle accelerator is roaring along at an unprecedented pace, delivering torrents of data to its physicist handlers. But the hundreds of millions of collisions happening inside the machine every second are now growing into a thick fog that, paradoxically, threatens to obscure a fabled quarry: the Higgs boson.
The problem is known as pile-up, and it promises to be one of the greatest challenges this year for scientists working on the Large Hadron Collider (LHC) at CERN, Europe's main high-energy physics laboratory near Geneva, Switzerland.
Huge amounts of computing power, cunning software and technical tricks are helping scientists to stay ahead of the problem. But researchers may still need to scale back the collisions to find the long-sought Higgs, the manifestation of a field that is believed to confer mass on other particles.
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from the New York Times (Registration Required)
JACI PARANÁ, Brazil - The revolt here on the banks of the Madeira River, the Amazon's largest tributary, flared after sunset. At the simmering end of a 26-day strike by 17,000 workers last month, a faction of laborers who were furious over wages and living conditions began setting fire to the construction site at the Jirau Dam.
Throughout the night, they burned more than 30 structures to the ground and looted company stores, capturing the mayhem on their own cellphone cameras, before firefighters extinguished the blazes. The authorities in Brasília flew in hundreds of troops from an elite force to quell the unrest.
Men in camouflage fatigues still patrol the sprawling work site, reflecting a dilemma for Brazil's leaders. Even as they move to tap one of the world's last great reserves of hydroelectric power, the Amazon basin, strikes and worker uprisings at the biggest projects are producing delays and cost overruns.
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from ScienceNOW Daily News
Shards of pottery with traces of mare's milk, mass gravesites for horses, and drawings of horses with plows and chariots: These are some of the signs left by ancient people hinting at the importance of horses to their lives. But putting a place and date on the domestication of horses has been a challenge for archaeologists. Now, a team of geneticists studying modern breeds of the animal has assembled an evolutionary picture of its storied past. Horses, the scientists conclude, were first domesticated 6000 years ago in the western part of the Eurasian Steppe, modern-day Ukraine and West Kazakhstan. And as the animals were domesticated, they were regularly interbred with wild horses, the researchers say.
"This is a very good paper," says biologist Michael Hofreiter of the University of York in the United Kingdom. "Nobody has applied this method of population modeling to horses before."
Throughout their history, horses have been interbred, traded between populations of people, and moved across continents. All of this makes their genetic history hard to follow. Moreover, the wild ancestor of horses, Equus ferus, is extinct, complicating researchers' efforts to compare the genetics of domestic animals with wild ones. Previous research nailed down a broad area--the Eurasian Steppe, which stretches from Hungary and Romania through Mongolia--as the region where horses originated and were domesticated. But earlier genetic studies relied mostly on mitochondrial DNA, which is inherited only from a mother, to try to understand horses' evolutionary history.
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from NPR
Fossil-hunting scientists are coming to grips with a new discovery that could change forever how we think of dinosaurs. What they've found is that dinosaurs may well have been tortured by large, flealike bloodsucking insects.
Yes, it appears that the greatest predators that ever roamed Earth suffered just as we mammals did--and as we still do. Fleas were thought to have evolved along with mammals--they like our soft skins and a diet of warm blood. But now scientists in China have discovered Pseudopulex jurassicus and its equally tyrannical cousin, Pseudopulex magnus--magnus as in "great."
Indeed, they were big--several times as big as current fleas-and equipped to feed. "They have this large beak," says zoologist George Poinar Jr. "Oh, it looks horrible. It looks like a syringe when you go to the doctor to get a shot or something."
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from the Christian Science Monitor
California's Salton Sea hasn't been looking too good for some time, and now environmentalists are concerned that conditions at this salty inland "sea" are about to get much worse.
Their big worry: that the body of water, created during a huge flood in 1905 in which distant Colorado River water coursed into a desert basin, will shrink much faster in coming years than it has been. As the shallow lake dries out, contaminants from decades of agricultural runoff--such as selenium and arsenic--will be exposed and, whipped by high winds, carried far afield, threatening the health of people and wildlife. Several species of migratory birds along the Pacific Flyway will also be threatened, environmentalists warn.
Why are they expecting this accelerated shriveling of the Salton Sea? A big water diversion system is slated to transfer water now used locally for farming to the south, in San Diego County, for use by city-dwellers.
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from the Baltimore Sun
LONDON (Reuters) - Scientists who scanned the brains of men convicted of murder, rape and violent assaults have found the strongest evidence yet that psychopaths have structural abnormalities in their brains.
The researchers, based at King's College London's Institute of Psychiatry, said the differences in psychopaths' brains mark them out even from other violent criminals with anti-social personality disorders (ASPD), and from healthy non-offenders.
Nigel Blackwood, who led the study, said the ability to use brain scans to identify and diagnose this sub-group of violent criminals has important implications for treatment. The study showed that psychopaths, who are characterized by a lack of empathy, had less grey matter in the areas of the brain important for understanding other peoples' emotions.
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Controversial research on a hybrid strain of bird flu that could potentially spread between humans was published last week in Nature after security restrictions on the work were lifted. Publication was delayed after the U.S. government's biosecurity advisers said key sections of the paper should be struck out to prevent the details being exploited by bioterrorists.
In other biomedical news, a groundbreaking trial involved 43 patients who got immune cells designed to attack and kill cells infected with HIV. Scientists reported that as much as 16 years later, these genetically engineered T cells are still circulating in their bloodstreams. And there's been no sign the gene therapy caused any cancers, or is likely to.
Scientists have detected tiny amounts of a strangely shaped protein -- a relative of a well-known suspect in Alzheimer's disease -- spreading destruction throughout the brains of mice. If a similar process happens in the human brain, it could help explain how Alzheimer's starts, and even suggest new ways to stop the molecule's spread.
Researchers are hopeful that a genetic test could help predict breast cancer many years before the disease is diagnosed. Ultimately the findings, in the journal Cancer Research, could lead to a simple blood test to screen women, they say.
And the Los Angeles Times was among media outlets to report on a pair of studies that may offer some clarity on mammograms. Researchers found that women who have a mother or sister diagnosed with breast cancer, or those who have unusually dense breast tissue, should have their first test at age 40 and repeat the exam at least once every other year.
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Last week the New York Times featured the work of a paleontologist who has discovered some intriguing specimens in a Brazilian rock quarry.
In other news of the ancient past, researchers studying Oetzi, a 5,300-year-old body discovered frozen in the Italian Alps, have found red blood cells around his wounds, representing the oldest red blood cells ever observed.
A study of people from the Solomon Islands in Melanesia suggests that they evolved their striking blonde hair independently of people in Europe. This refutes the possibility that blonde hair was introduced by colonial Europeans, says Carlos Bustamante, a Stanford University geneticist.
A collection of ochre-tinted human bones in the Oxford University Museum of Natural History, known as the Red Lady of Paviland, is older than previously thought, according to a new analysis. At 33,000 years old, the bones represent one of the earliest examples of ceremonial burial in Western Europe.
In a southern Illinois coal mine, the largest fossil forest ever discovered may shed new light on climate change today.
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The European Space Agency has set its sights on Jupiter and its icy moons. A probe, called Juice, was approved at a meeting of member state delegations in Paris. It would be built in time for a launch in 2022.
In other space news, when Hal Levison presented what he called a "slightly radical" mechanism for building the solar system's giant planets, he received a pastry in the face for his trouble. Luckily, he was wearing a catcher's mask.
Astronomers have observed a star in another galaxy plunging toward a giant black hole and being ripped to shreds, sparking a flare so brilliant that observers detected it from a distance of 2.1 billion light-years.
Meanwhile, here on Earth, in the week since a fireball shot across the sky and exploded, scattering a rare type of meteorite over California's Gold Country, the hills have drawn a new rush of treasure seekers.
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from the Economist
SPACE flight defies mere reason. From its beginning in the 1950s until the present day, it has teetered along the line that divides science from science fiction. The rocketeers who took America into orbit were, many of them, space cadets drawn to the field by the shiny spaceships and bug-eyed monsters of the pulp fiction of their boyhoods--and the same was probably true of their Soviet counterparts. What they produced, too, was only quasi-real. The Apollo programme, to land a man on the Moon and return him safely to Earth, in the words of John Kennedy, America's president at the time, was a deadly serious engineering and diplomatic project. It aimed to show the world that American know-how was better than the Russian variety. But it was also an idealised fantasy of American power. ("We came in peace, for all mankind.") The flag Neil Armstrong planted in the Sea of Tranquility staked a claim to what many hoped would be a new frontier.
In the case of Apollo, reality--in the form of government budget cuts--triumphed over the plans for a permanent moon base. But 40 years later the tension between fantasy and reality in space remains, as two new projects show.
The first, announced in April, seems closer to the dreamy end of the spectrum. A group of rich Americans, among them James Cameron, a film director with a penchant for science fiction, announced that they planned to boldly go into the void to mine asteroids for precious metals. This modern version of a good, old-fashioned gold rush could be a classic sci-fi tale, with the accent on the fi: it will probably cost a fortune (some think $2.5 billion just to drag a 500-tonne asteroid to the Moon), and, even if the investors' plans really do come true, the platinum, iridium and other precious metals would arrive in such quantity that they would rapidly become a lot less precious.
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from the New Yorker (Registration Required)
Late in the afternoon on April 2, 1991, Mt. Pinatubo, a volcano on the Philippine island of Luzon, began to rumble with a series of the powerful steam explosions that typically precede an eruption. Pinatubo had been dormant for more than four centuries, and in the volcanological world the mountain had become little more than a footnote. The tremors continued in a steady crescendo for the next two months, until June 15th, when the mountain exploded with enough force to expel molten lava at the speed of six hundred miles an hour. The lava flooded a two-hundred-and-fifty-square-mile area, requiring the evacuation of two hundred thousand people.
Within hours, the plume of gas and ash had penetrated the stratosphere, eventually reaching an altitude of twenty-one miles. Three weeks later, an aerosol cloud had encircled the earth, and it remained for nearly two years. Twenty million metric tons of sulfur dioxide mixed with droplets of water, creating a kind of gaseous mirror, which reflected solar rays back into the sky. Throughout 1992 and 1993, the amount of sunlight that reached the surface of the earth was reduced by more than ten per cent.
The heavy industrial activity of the previous hundred years had caused the earth's climate to warm by roughly three-quarters of a degree Celsius, helping to make the twentieth century the hottest in at least a thousand years. The eruption of Mt. Pinatubo, however, reduced global temperatures by nearly that much in a single year. It also disrupted patterns of precipitation throughout the planet. It is believed to have influenced events as varied as floods along the Mississippi River in 1993 and, later that year, the drought that devastated the African Sahel. Most people considered the eruption a calamity.
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from NewScientist
LAST year was a particularly deadly year for tornadoes in the US, with the second highest death toll in 137 years. Already this year, major outbreaks have killed 63 people. All eyes are now on May, when the season usually peaks, amid talk in some quarters of another year of extremes.
The result is that discussion about human influences on severe thunderstorms and tornadoes has been reignited. Such discussion is not new. It seems that, following every major tornado event in the last decade, the influence of rising levels of atmospheric carbon dioxide has been questioned. Human impacts have been talked about for much longer than that, however. Three tornadoes that killed at least 90 people in 1953 led to speculation that atmospheric tests of nuclear weapons caused them.
But the speculation has been one-sided, with talk of human influences on tornadoes following disasters, but little about whether human influences have acted as a brake on their numbers after anomalously low activity.
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from Science News
Feeling peppy may lead older adults to settle for less. In a new study, seniors in a good mood compared fewer options and made worse choices than did those in a bad mood or younger participants.
"Positive emotions may have costs for older adults' decision making," says study coauthor Bettina von Helversen, a psychologist at the University of Basel in Switzerland.
A bright mood makes it harder to select a quality option from a series of choices, such as finding a bargain on a new computer offered at different prices by various online sites, say von Helversen and University of Basel colleague Rui Mata.
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from Science News
Casino bosses, take note: Physicists have described a way to guarantee complete randomness in a flow of information, such as the numbers generated by a roulette wheel.
The work could allow a person to transform a stream of not-quite-random information into a totally random one. "Even if you don't have perfect randomness, you can make perfect randomness," says Roger Colbeck, a theoretical physicist at ETH Zurich in Switzerland. "This is sort of a guarantee given to you by the laws of physics."
Colbeck and ETH Zurich colleague Renato Renner describe the finding online May 6 in Nature Physics.
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from BBC News Online
Japan is switching off its last working nuclear reactor, as part of the safety drive since the March 2011 tsunami triggered a meltdown at the Fukushima plant.
The third reactor at the Tomari plant, in Hokkaido prefecture, is shutting down for routine maintenance. It leaves Japan without energy from atomic power for the first time for more than 40 years.
Until last year, Japan got 30% of its power from nuclear energy. Hundreds of people marched through Tokyo, waving banners to celebrate what they hope will be the end of nuclear power in Japan.
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from BBC News Online
A team from the UK's University of Leeds and Japan's Tokyo University of Agriculture and Technology have used microbes that eat iron.
As they ingest the iron, the microbes create tiny magnets inside themselves, similar to those in PC hard drives. The research may lead to the creation of much faster hard drives, the team of scientists say.
As technology progresses and computer components get smaller and smaller, it becomes harder to produce electronics on a nano-scale. So researchers are now turning to nature--and get microbes involved.
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from BBC News Online
British scientists have calculated the methane output of sauropods, including the species known as Brontosaurus.
By scaling up the digestive wind of cows, they estimate that the population of dinosaurs--as a whole--produced 520 million tonnes of gas annually. They suggest the gas could have been a key factor in the warm climate 150 million years ago.
David Wilkinson from Liverpool John Moore's University and colleagues from the University of London and the University of Glasgow published their results in the journal Current Biology.
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from the New York Times (Registration Required)
MOJAVE, Calif. -- The sign into town, slightly weathered, says "Gateway to Space!"
Beyond it lies the Mojave Air and Space Port, once a Marine auxiliary air station during World War II, now an incubator for the tinkerers and dreamers in the New Space movement. Adherents believe that the next phase of space exploration will be led by nimble, ambitious entrepreneurs--a new generation of people like Bill Hewlett and Dave Packard, who helped create the electronics industry in a garage--and that this is their moment to come together and make it happen.
"It's very similar to the Silicon Valley effect," said Stuart O. Witt, the chief executive of the space port for the past decade, explaining how half a dozen outer space start-ups came to cluster at Mojave, a small desert town about 90 miles north of Los Angeles.
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from the New York Times (Registration Required)
MOJAVE, Calif. -- The sign into town, slightly weathered, says "Gateway to Space!"
Beyond it lies the Mojave Air and Space Port, once a Marine auxiliary air station during World War II, now an incubator for the tinkerers and dreamers in the New Space movement. Adherents believe that the next phase of space exploration will be led by nimble, ambitious entrepreneurs--a new generation of people like Bill Hewlett and Dave Packard, who helped create the electronics industry in a garage--and that this is their moment to come together and make it happen.
"It's very similar to the Silicon Valley effect," said Stuart O. Witt, the chief executive of the space port for the past decade, explaining how half a dozen outer space start-ups came to cluster at Mojave, a small desert town about 90 miles north of Los Angeles.
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from the New York Times (Registration Required)
Today we worked in the Teresina area for the first time this year. We decided we would return to the quarry outside the town of Timon, where we found a very interesting fish skull last year. We're just starting to prepare that specimen, so I can't offer many details about it at this point, but it certainly seems to have a lot of potential. Based on that specimen, our expectations were high, and the quarry did not disappoint.
Not long after arriving today, Martha Richter literally stumbled across a partial skeleton of a terrestrial vertebrate, or tetrapod, preserved in a few pieces of rock in one of the quarry spoil piles. The main layer of the quarry that is used for paving material is the hard red siltstone that forms much of the vertical walls. However, at the base of the wall and exposed in some other areas, there is a softer sandstone that is too friable to use for paving, which is why pieces of it are mostly discarded.
It's not an exaggeration to say that this specimen is the most exciting that we've found in our two years of fieldwork in the Parnaíba Basin. It appears to represent a type of amphibian and has a fairly short, broad skull that lacks the very elongated snout of the Prionosuchus. Therefore it is definitely something new to the basin. The size and shape are a bit reminiscent of the little jaw fragment that Domingas found a few days ago, so it might represent that animal. More preparation of both specimens will be necessary to say definitively whether that's the case.
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from BBC News Online
The European Space Agency (Esa) is to mount a billion-euro mission to Jupiter and its icy moons. The probe, called Juice, has just been approved at a meeting of member state delegations in Paris.
It would be built in time for a launch in 2022, although it would be a further eight years before it reached the Jovian system. The mission has emerged from a five-year-long competition to find the next "large class" space venture in Europe.
Juice stands for JUpiter ICy moon Explorer. The concept proposes an instrument-packed, nearly five-tonne satellite to be sent out to the Solar System's biggest planet, to make a careful investigation of three of its biggest moons. The spacecraft would use the gravity of Jupiter to initiate a series of close fly-bys around Callisto and Europa, and then finally to put itself in a settled orbit around Ganymede.
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from Time
The theory of dark matter took decades to take hold in astronomy, and no wonder. It's pretty tough to wrap your mind around the notion that some mysterious, invisible substance pervades the cosmos -- and even tougher to accept that it outweighs ordinary matter by a factor of 6 to 1, at least. Evidence eventually trumped incredulity, though, and by the 1980s, the vast majority of scientists were on board with the idea, nutty though it might seem, and there they've remained ever since.
But a new study out of the European Southern Observatory claims that this now established theory could be in trouble. Chilean astronomers took a look at the motion of 400-plus stars in the broadly defined neighborhood of the sun and concluded that the way they're all moving is inconsistent with conventional ideas about dark matter. "Our calculations show that [evidence of dark matter] should have shown up very clearly in our measurements," said Christian Moni-Bidin, of the University of Concepción, in a press release. "But it was just not there!"
This could indeed be a blow to dark matter -- in principle, anyway. Looking at the motion of visible matter to deduce the presence of dark matter is, in fact, the way the shadowy stuff was first detected. It was back in the 1930s that Caltech astronomer Fritz Zwicky initially noted something very odd. He could tell that the individual galaxies in galactic clusters were orbiting around each other like swarming bees. But they were moving too fast -- at a speed that, by rights, they should have flown away from one another. His crazy-sounding explanation: the extra gravity of dark matter (he called it "missing mass") was binding them together.
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