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mary caperton morton

Bigger is better in the sea

Since first appearing in the fossil record more than 550 million years ago, complex animals have steadily grown in average size, from millimeters to meters to many meters in length. This tendency of species to evolve toward larger sizes over time — known as Cope’s rule — has been studied before in individual species, such as horses and clams, but a new dataset of thousands of marine animals is giving scientists their first large-scale look at how Cope’s rule applies to whole ecosystems over hundreds of millions of years.
 
28 Jun 2015

Banana-preserving bacterium shows promise against bat-killing fungus

Since White Nose Syndrome began decimating bat colonies in New England in 2006, most of the news hasn’t been good, and to date, as many as 6 million bats in 26 states have died as a result of infection. But a new trial pitting a particular soil bacterium against White Nose is providing a glimmer of hope in the fight to slow its devastating march across the country.

18 Jun 2015

Exploding source of lithium

Trace amounts of lithium are found in all living organisms, and the soft metal is widely used in cellphones and batteries, and as a mood-stabilizing medication. But the galactic source of the element has been unclear.

10 Jun 2015

Oldest climbing and burrowing mammals discovered in China

During the Mesozoic, mammals were small and inconspicuous, remaining hidden in the shadows of their larger reptilian neighbors and only diversifying into the many ecological niches they now occupy after the dinosaurs went extinct. Or so scientists thought. Now, two new shrew-sized fossils, each dating to about 160 million years ago, lend support to the alternative idea that mammals were ecologically diverse long before the dinosaurs left the scene.

09 Jun 2015

Getting to the bottom of a tectonic plate

Earth’s rigid, brittle lithosphere is broken into seven major plates, as well as many minor plates, which ride along atop a ductile layer of the upper mantle called the asthenosphere. For all we know about Earth’s cracked outer shell, however, a clear picture of the lithosphere-asthenosphere boundary at the bottom of the plates has proved elusive. Now, new research using explosives to image the oceanic plate dipping beneath New Zealand’s North Island is helping to blast away some of the uncertainty about this boundary by giving scientists a sharper look at a piece of the planet’s tectonic underbelly.

08 Jun 2015

Monkeys in the New World earlier than thought

Monkeys originated in Africa, but how and when they first appeared in Central and South America has long been something of a mystery. Now, a new set of fossilized teeth places monkeys in South America about 10 million years earlier than previously thought.

 
07 Jun 2015

Did volcanism drive Earth into global glaciation?

Between about 720 million and 635 million years ago, Earth suffered two big chills. During these “Snowball Earth” episodes, geologists think the world’s oceans froze over and glaciers spilled from tropical coastlines. Scientists have previously suggested that intense volcanism, unleashed by the disintegration of the supercontinent Rodinia, plunged Earth into these global glaciations. New research now lends support to this so-called fire-and-ice hypothesis.
05 Jun 2015

Earth's most abundant mineral finally gets a name

An elusive, high-density form of magnesium iron silicate, long known colloquially as “silicate perovskite,” now officially bears the name “bridgmanite,” after the father of high-pressure experiments, Nobel laureate Percy W. Bridgman.

 
03 Jun 2015

Mapping solar winds

Two types of solar winds emanate from the sun: fast winds that travel at more than 700 kilometers per second, and slow winds that move at a mere 400 kilometers per second. As they pass by Earth on their way to the outer reaches of the heliosphere, these winds — composed of charged particles called plasma — can interact with the geomagnetic field and set off spectacular auroras. Now, a newly constructed solar map, published in a study in Nature Communications, has illuminated the sources and directions of the sun’s solar winds in greater detail than ever before.

 
02 Jun 2015

Pre-settlement erosion rates illuminated

Humans are one of the most powerful erosive agents on Earth, moving copious amounts of sediment to and fro, mainly through agriculture and development. But quantifying how much we actually move — often a necessary step for developing sustainable land management practices — hinges on determining erosion rates in an area before humans intervened. A new study using surface exposure dating to estimate pre-colonial erosion rates in the southeastern U.S. has now clarified the natural background rate in more detail than ever before, revealing the dramatic human impact on the regional landscape.

 
31 May 2015

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