Humans may have a dormant ability to detect Earth's magnetic field, according to a new study in the journal Nature Communications. A variety of other animals are known to possess this ability, and scientists have long wondered if people could do it, too. If confirmed, this sixth sense might explain how ancient Polynesians navigated the Pacific under starless skies, the New York Times suggests, and raises the prospect of reviving the skill in modern humans.
The discovery comes courtesy of Steven Reppert, a University of Massachusetts neurobiologist who has been studying the navigation of monarch butterflies. The insects use light-sensitive proteins called "cryptochromes" to navigate by the sun, but since they don't get lost on cloudy days, scientists have concluded they must have a backup system. Reppert already solved that puzzle three years ago, showing that cryptochromes can also detect magnetic fields, but now he has taken it a step further. One of the monarch's two cryptochrome genes resembles the human version, inspiring Reppert to see if human cryptochromes could restore magnetic sensing in fruit flies after their own cryptochromes had been blocked. As reported Tuesday in Nature Communications, it turns out they can. "A reassessment of human magnetosensitivity may be in order," Reppert and his colleagues write.
The human cryptochrome gene is especially active in the eye, the Times reports, suggesting people — and other animals — might be able to "see" a magnetic field. Animals already could be using magnetic sensing for a variety of tasks, adds Virginia Tech neurobiologist John Phillips, such as a squirrel finding buried acorns or a fox calibrating a pounce. As for why such a useful ability would have gone dormant in humans, Phillips tells the Times it's possible we did it to ourselves. "It may be that our electromagnetic world is interfering with our ability to do this kind of stuff," he says.
Yet another swollen U.S. river is forcing its human neighbors to evacuate: Some 12,000 people have until 6 p.m. today to flee their homes in Minot, N.D., due to record flooding expected along the Souris River. The evacuation order covers a third of all residents in Minot, the fourth-largest city in North Dakota, and comes as forecasters predict the surging Souris will soon overwhelm local levees.
Much like the Mississippi and Missouri rivers before it — as well as many smaller waterways — the Souris has been overfed by a surplus of snowmelt from an unusually snowy winter. The U-shaped river only dips into part of north-central North Dakota before returning to Canada, but that bend bisects Minot, and authorities are warning it could soon flood beyond record levels. "It's really historic proportions of water," a spokeswoman for the North Dakota Department of Emergency Services tells CNN. "The river is rising faster than expectations, so [city officials] are kind of scrambling to shore up levees and do what they can."
Floodwaters are expected to climb over Minot's levees within the next 48 hours, the AP reports, and rise to nearly 1,563 feet above sea level this weekend — dwarfing the historic flood of 1969, when the Souris reached 1,554.5 feet. The river's record crest came in 1881, when it hit 1,558 feet above sea level.
Babies born near mountaintop-removal coal mines may be at a higher risk for birth defects, according to a new study in the journal Environmental Research. About 1 in 33 children nationwide are born with a birth defect, but the study's authors report that kids born in counties where mountaintop removal occurs face a 26 percent higher risk than children born elsewhere.
Mountaintop-removal mining involves blasting off mountain peaks to expose coal seams, and has been linked to both air and water pollution in nearby communities. To see how it might affect infant health, health economist Melissa Ahern and her colleagues looked at four states where the practice occurs: Kentucky, Tennessee, Virginia and West Virginia. Studying nearly 1.9 million births in those states from 1996 to 2003, they found that mountaintop-removal counties had higher birth-defect rates in six of seven categories, including heart, lung and gastrointestinal disorders. "Rates for any anomaly were approximately 235 per 10,000 live births in the mountaintop mining area versus 144 per 10,000 live births in the non-mining area," they report.
But since poverty has also been linked to birth defects, the researchers then controlled for poverty-related factors such as mother's education, smoking and drinking — and found that counties with mountaintop-removal mines still had a 26 percent higher risk. The birth-defect rate also seemed to increase over time and in areas with more mining activity, they report. "Circulatory and respiratory effects really stood out," Ahern tells USA Today. "These are costly to the health care system and involve a lot of human suffering. I would think public health officials would be interested."
It's not unusual for children's movies to feature morals, including lessons about environmental responsibility. But as the Huffington Post's Joanna Zelman reports, Pixar's upcoming "Cars 2" has angered some conservatives with its eco-friendly message. One blogger even accuses director John Lassester of "trying to indoctrinate our children with left wing propaganda."
"Cars 2" doesn't hit theaters till June 24, but Lasseter recently gave an interview to the Wall Street Journal in which he explained the film's storyline. "I kept thinking about, 'OK. A spy movie in the world where cars are alive. What would be a really good kind of über bad guy?' ... I kept going to big oil," he says, adding that the decision came before last year's Gulf oil spill. "The greatest bad guys, you understand where they're coming from. They believe they're doing the right thing. Sometimes it's for greed, sometimes it's for other reasons, but they are what they call the center of good. They always believe they're doing the right thing." As the film's trailer hints, "they're not only racing across the world; they're racing to save the world."
The idea of portraying oil companies as bad guys has already rubbed a few right-leaning bloggers the wrong way, Zelman reports. As the Lonely Conservative blog wrote Monday, "We conservatives and believers in free markets are accused of being paranoid when we say the Hollywood industry is trying to indoctrinate our children with left wing propaganda. But now movie directors and producers are coming out and admitting what they're doing." Another blogger accuses Lasseter of hypocrisy, since making and marketing "Cars 2" will inevitably burn energy, including oil. This isn't the first political spat for Pixar, though — Zelman points out that some conservative viewers were miffed at "WALL-E" for encouraging recycling.
Ohio's Cuyahoga River burns for the last time, world-record hail falls in Nebraska, and more.
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Photo (Magneto from "X-Men: First Class"): Paramount Pictures/ZUMA Press
Photo (Souris River): Marlene Welstad/U.S. Fish and Wildlife Service
Photo (mountaintop-removal coal mine): ZUMA Press
Image (Lightning McQueen in "Cars 2"): Walt Disnety Pictures/ZUMA Press