Archaeologists have found granaries that were used to store wild cereals near the Dead Sea in Jordan more than 11,000 years ago. The structures predate agriculture in the Middle East by at least a millennium, according to a report published by the scientists in the journal Proceedings of the National Academy of Sciences.
The findings suggest that it took awhile to establish domesticated farming. In other words, the agricultural revolution likely spanned an appreciable period of time, during which our ancestors switched from hunting and gathering to growing their own food. The earliest definitive traces of domesticated grains, wheat, barley, and oats have been found in the Near East and date back about 10,500 years. Yet much recent research suggests that plant domestication was preceded by a long period–perhaps thousands of years–during which prehistoric peoples cultivated wild plants without visibly changing their appearance or altering their genetic makeup [ScienceNOW]. In archaeological digs of early villages in Israel, Jordan, Syria, and Turkey researchers have found large quantities of wild barley and wild oats, now the new findings provide evidence that the gatherers carefully stored these wild cereals.
In the heat and humidity of the tropics you might expect that mammals take it slow and easy–but on the genetic level, they’re accelerating past their mammalian relations that live in more temperate zones. A new study has discovered that tropical mammals are accumulating mutations more quickly and are therefore evolving faster, in a finding that could help account for the phenomenal biodiversity of the rainforests. But the study’s unexpected results have posed a puzzle for biologists. “[It’s] an empirical pattern that is begging for an explanation” [The Scientist], says evolutionary ecologist James Brown, who was not involved in the current study.
Previous research had shown that plants and marine microorganisms evolve more quickly in the tropical zone near the equator, but scientists believed that pattern would hold true only for cold-blooded creatures, whose body temperatures and metabolisms are determined by the temperature of the surrounding environment. Scientists believe that this link between temperature and metabolic rate means that, in warmer climates, the germ cells that eventually develop into sperm and eggs divide more frequently. “An increase in cell division provides more opportunities for mutations in the population over a given time,” explained [lead researcher Len] Gillman. “This increases the probability of advantageous mutations that are selected for within the species” [BBC News]. But this mechanism wouldn’t work in warm-blooded mammals, whose body temperatures remain roughly constant regardless of environmental factors.
A noisy Italian disco may not seem like a conducive location for scientific experiments, but for a couple of researchers investigating hearing and language processing it was perfect. The undercover scientists studied clubbers who were trying to talk while the music was pumping, and found that they showed a decided preference for speaking into each other’s right ears. What’s more, when the researchers approached clubbers with a request for a cigarette, they found the unwitting test subjects were much more likely to comply if the petition was made in the right ear.
Previous lab studies have also suggested that humans tend to have a preference for listening to verbal input with their right ears and that given stimulus in both ears, they’ll privilege the syllables that went into the right ear. Brain scientists hypothesize that the right ear auditory stream receives precedence in the left hemisphere of the brain, where the bulk of linguistic processing is carried out [Wired.com]. Researchers say this bias holds true for both lefties and righties.
Sleek, streamlined wind turbines have become the icons of the green movement, but for all the growth in wind power — it accounted for 42% of all new electricity generation added to the U.S. grid last year — wind still makes up less than 3% of America’s total electricity generation [Time]. Its marginal role has led many to wonder whether the technology is worth investing in, and whether wind power is capable of supplying enough electricity to meet our needs. To answer those questions, researchers analyzed wind patterns around the world and found that wind power could theoretically supply the entire world with energy, and then some.
The study, published in the Proceedings of the National Academy of Sciences, isn’t being presented as a realistic plan to achieve a renewable energy nirvana; it’s simply an attempt to provide a sense of what’s possible [Ars Technica]. But the researchers’ reckoning of what’s possible is quite impressive: maxing out deployment of current-generation technology could produce five times the total energy used in the world today, and 40 times the electricity [Ars Technica].
The Department of Energy is handing out nearly $8 billion in loans today, and $465 million of the funds will go to Tesla Motors to produce its Model S electric sedan, the company’s first attempt at a mass-market car. The company already manufactures the Roadster, a high-performance electric sports car. Nissan and Ford Motor Company will receive the other loans; they’ll get $1.6 billion and $5.9 billion, respectively, to help produce fuel-efficient cars.
Nissan will use the funds updating a plant in Tennessee to produce the company’s upcoming electric sedan, and Ford’s loan will help expedite production of cars that go farther on less fuel. Tesla was perhaps the wild card in the funding equation because it is a small startup. The company has delivered slightly more than 500 Roadsters to customers, and the government loan will help pay for a Southern California manufacturing plant for the Model S sedan, due in 2011. A second plant in the Bay Area will make battery packs and electric drivetrains [The New York Times].
Few people enjoy being poked and prodded at the doctor’s office, but we usually assume that those unpleasantries are worth detecting a disease or disorder early on. Unfortunately, though, we might never hear about worrisome test results, according to a new study published in the journal Archives of Internal Medicine. Researchers found that about 7 percent of clinically significant test results are never reported to the patient or that the notification of patients is not documented, largely a result of medical information slipping through the cracks.
The researchers examined the records of 5,434 patients between the ages of 50 and 69 at 19 community-based primary care practices and an additional four academic medical care facilities. The patients were old enough to likely be developing conditions that warranted testing (such as for high cholesterol, impaired blood-sugar control, prostate cancer or waning liver function), but not so old as to be ill enough to make certain of these findings relatively unimportant. Patients’ records were reviewed for any of 10 types of blood tests and for three types of screening exams — mammography, Pap smears and occult blood assays of possible colon cancer. During a yearlong period, the participating practices had prescribed several thousand such tests [Science News]. The researchers found that physicians did not inform patients about abnormal test results about one out of 14 times, or around 7 percent of the time.
Five days after their launch, NASA‘s two new lunar probes have successfully rendezvoused with their target. The Lunar Reconnaissance Orbiter fired its thrusters this morning to settle into orbit around the moon, while the Lunar Crater Observation and Sensing Satellite (LCROSS) swung past the moon, streaming live video all the while. (NASA promises to put the video playback online soon.)
The paired satellites will spend the next year mapping the moon and searching for traces of water ice, culminating in a dramatic crash when LCROSS plunges into a crater. But for now, NASA is busy celebrating the successful first steps. The $504 million LRO is the first NASA vessel to orbit the moon since 1998. “LRO has returned NASA to the moon,” a flight controller said as NASA’s LRO mission control center erupted in applause. The probe’s lunar arrival comes just under one month ahead of the 40th anniversary of NASA’s first moon landing by Apollo 11 astronauts on July 20, 1969 [SPACE.com].
When a person pick up a rake or a croquet mallet or any other tool, their mental image of their body expands subtly, according to a new study. To move our bodies around in space, the brain builds what’s called a “body schema,” a representation of all our various parts. And this so-called schema is frequently updated to keep up with our ever-changing bodies [Scientific American]. This new study, published in Current Biology, found that using a tool for even a brief amount of time caused volunteers to update their body schema, and to consider the tool a part of their bodies.
Lead researcher Alessandro Farnè first asked volunteers to point at and grab wooden blocks with their hands, then had them perform the same motions with a grabber tool, and finally returned to the hands-only gestures. The researchers recorded all of these tasks using a high-resolution three-dimensional motion-tracking system, so that they could compare in detail the movements performed in each task. They found that after using the grabber, the volunteers approached the blocks with slightly lower acceleration and velocity, although their accuracy was not affected. “They behave like their arm is longer,” says Farnè. “They aren’t clumsy, but they are slower and more determined” [Nature News].
The giant, prehistoric kangaroo that once hopped over the Australian landscape may have been wiped out by the first human settlers on that continent, a new study argues. In making this claim, the researchers are entering into a long-running debate over whether Australia’s “megafauna,” which also included marsupial lions and hippo-sized wombats, were driven extinct by the changing climate or by overzealous hunting. And while the new study, which will be published in the Proceedings of the National Academy of Sciences, makes an interesting case for the latter hypothesis, some researchers are not convinced.
Researchers analyzed the teeth of the nearly seven-foot-tall kangaroo, known as Procoptodon goliah, to determine what it ate and drank. Different sources of water and food leave trace amounts of particular types, or isotopes, of hydrogen and carbon atoms, which are deposited in the teeth like a recorded diet. Additionally, tiny patterns of wear give clues about the type of food a given creature chewed. The team concluded that the giant kangaroos fed mainly on saltbush shrubs [BBC News]. These hardy bushes thrive in arid conditions, which makes it less likely that the kangaroos ran out of food as the continent’s climate got hotter and drier.
Cleveland’s Cuyahoga River caught on fire 40 years ago June 22 when oily garbage floating in it was ignited, probably by sparks from a passing train. In turn, the fire sparked the creation of environmental agencies such as the Environmental Protection Agency, along with passage of 1972’s Clean Water Act. And the river, once a dumping ground for industrial waste and an icon for environmental disrepair, today supports more than 60 species of fish along with beavers and various bird species, and serves as an example of environmental restoration.
The river’s recovery is an inspirational account of how even the most putrid bodies of water could be cleaned up. Indeed, the first time [Cleveland resident] Gene Roberts fell into the Cuyahoga River, he worried he might die. The year was 1963, and the river was still an open sewer for industrial waste. Walking home, Mr. Roberts smelled so bad that his friends ran to stay upwind of him. Recently, Mr. Roberts returned to the river carrying his fly-fishing rod. In 20 minutes, he caught six smallmouth bass. “It’s a miracle,” said Mr. Roberts, 58. “The river has come back to life” [The New York Times].