Biologists at Indiana University have significantly advanced understanding of the genetic pathways that control the appearance of different physical traits in the same species depending on nutritional conditions experienced during development.
In many animals, nutrition -- not genetic differences -- controls the appearance of certain physical traits. Ants and bees, for example, grow into workers or queens based upon the food eaten as larvae.
The idea that the young Earth had a thicker atmosphere turns out to be wrong. New research from the University of Washington uses bubbles trapped in 2.7 billion-year-old rocks to show that air at that time exerted at most half the pressure of today’s atmosphere.
Air pollution legislation to control fossil fuel emissions and the associated acid rain has worked – perhaps leading to the need for sulfur fertilizers for crop production. A University of Illinois study drawing from over 20 years of data shows that sulfur levels in Midwest watersheds and rivers have steadily declined, so much so that farmers may need to consider applying sulfur in the not too distant future.
“We don’t think there are actual sulfur deficiencies yet, but clearly more sulfur is coming out of the soil and water than what is going in,” says U of I biogeochemist Mark David. “As the Clean Air Act and amendments have taken effect there has been a reduction in sulfur emissions from coal combustion, so that the amount of atmospheric sulfur deposited each year is only 25 percent of what it used to be. At some point, farmers are going to have to fertilize with sulfur.”
A recent study released by the National Aeronautics and Space Administration (NASA) concludes that the current drought that began in 1998 in the eastern Mediterranean Levant – which includes Cyprus, Israel, Jordan, Lebanon, Palestine, Syria, and Turkey – is the region’s worst dry spell since 1100 C.E.
NASA scientists reconstructed our regional drought history by studying records of tree rings, from dead and live specimens, across several Mediterranean countries to determine patterns of dry and wet years over a 900-year time span. Tree rings are good indicators of precipitation since dry years cause thin rings while thick rings show when water was plentiful. They concluded that the years between 1998 and 2012 were drier than any other period, and that the drought was likely caused by humans.
Ben Cook, lead author and climate scientist at NASA’s Goddard Institute for Space Studies and the Lamont Doherty Earth Observatory at Columbia University in New York City, said the range of regional weather events has varied widely over the last millennium, but the past twenty years stand out as extreme, falling outside the range of natural variability.
Canada is no stranger to wildfires, but this week’s ferocious blaze in Fort McMurray is extreme — even by Canadian standards. 80,000 people have fled from the heart of tar sands country in an unprecedented evacuation effort.
As people consign their homes and belongings to the flames and firefighters struggle to contain the blaze, there’s an inevitable question: Do we have climate change to thank for the intensity of this fire?
This issue is emerging all over the world as shifts in the climate drive environmental imbalances that promote the spread of fire. Droughts turn the landscape into tinder, and tree die-offs create ample fuel for fast-moving, incredibly hot fires that can whip through the landscape at terrifying speeds.
Scientists have had a literal breakthrough off the coast of Mexico.
After weeks of drilling from an offshore platform in the Gulf of Mexico, they have reached rocks left over from the day the Earth was hit by a killer asteroid.
The cataclysm is believed to have wiped out the dinosaurs. "This was probably the most important event in the last 100 million years," says Joanna Morgan, a geophysicist at Imperial College in London and a leader of the expedition.
Since the 1980s, researchers have known about the impact site, located near the present-day Yucatan Peninsula. Known as Chicxulub, the crater is approximately 125 miles across. It was created when an asteroid the size of Staten Island, N.Y., struck the Earth around 66 million years ago. The initial explosion from the impact would have made a nuclear bomb look like a firecracker. The searing heat started wildfires many hundreds of miles away.
Scientists studying data from the top of the Greenland ice sheet have discovered that during winter in the center of the world's largest island, temperature inversions and other low-level atmospheric phenomena effectively isolate the ice surface from the atmosphere -- recycling water vapor and halting the loss or gain of ice.
A team of climate scientists made the surprising discovery from three years of data collected at Summit Camp, an arid, glaciated landscape 10,500 feet above sea level in the middle of the Greenland ice sheet.
"This is a place, unlike the rest of the ice sheet, where ice is accumulating," says Max Berkelhammer, assistant professor of earth and environmental sciences at the University of Illinois at Chicago. Berkelhammer is first author on the study, reported in Science Advances, an open-access online publication of the journal Science.
Coastal wading birds shape their lives around the tides, and new research in The Auk: Ornithological Advances shows that different species respond differently to shifting patterns of high and low water according to their size and daily schedules, even following prey cycles tied to the phases of the moon.
Many birds rely on the shallow water of the intertidal zone for foraging, but this habitat appears and disappears as the tide ebbs and flows, with patterns that go through monthly cycles of strong "spring" and weak "neap" tides. Leonardo Calle of Montana State University (formerly Florida Atlantic University) and his colleagues wanted to assess how wading birds respond to these changes, because different species face different constraints--longer-legged birds can forage in deeper water than those with shorter legs, and birds that are only active during the day have different needs than those that will forage day or night.
Most of us think of that sweet smell after a storm as the aftereffect of rain that has rinsed the air of pollutants and dust. But it turns out that rain also triggers the release of a mist of particles from wet soils into the air, a finding with consequences of its own for how scientists model our planet's climate and future.
The evidence comes in the form of tiny glassy spheres, less than one-hundredth the width of a human hair, discovered at the Great Plains of Oklahoma after a rainstorm and put under scrutiny by scientists at several U.S. Department of Energy facilities. The study appears May 2 in Nature Geoscience.
According to the authors, scientists have largely assumed that organic particles from the soil enter the air through erosion by wind or through agricultural work. The effects of rain splash haven't been part of the discussion.
But the team's field observations indicate that up to 60 percent of particles that are airborne after a rainstorm in certain areas, such as grasslands and tilled fields, come from the soil. These organic particles are carbon-based and come from decaying vegetation and organisms. The tiny bits of organic matter can hold tremendous sway over our climate, playing a role in the fate of sunlight as it hits Earth.
Authors of the study are from two DOE Office of Science user facilities — EMSL, the Environmental Molecular Sciences Laboratory at the Pacific Northwest National Laboratory, and the Advanced Light Source at Lawrence Berkeley National Laboratory — as well as the Berkeley Lab and the University of Massachusetts at Amherst.
Chemist Alexander Laskin led the team at PNNL and chemical scientist Mary Gilles led the group at the Berkeley Lab.
A small mammal has sabotaged the world's most powerful scientific instrument.
The Large Hadron Collider, a 17-mile superconducting machine designed to smash protons together at close to the speed of light, went offline overnight. Engineers investigating the mishap found the charred remains of a furry creature near a gnawed-through power cable.
"We had electrical problems, and we are pretty sure this was caused by a small animal," says Arnaud Marsollier, head of press for CERN, the organization that runs the $7 billion particle collider in Switzerland. Although they had not conducted a thorough analysis of the remains, Marsollier says they believe the creature was "a weasel, probably." (Update: An official briefing document from CERN indicates the creature may have been a marten.)
The shutdown comes as the LHC was preparing to collect new data on the Higgs Boson, a fundamental particle it discovered in 2012. The Higgs is believed to endow other particles with mass, and it is considered to be a cornerstone of the modern theory of particle physics.
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