Tag Archives: southern hemisphere

Ancient snakes — a new hiss-tory

The ancestral snakes in the grass actually lived in the forest, according to the most detailed look yet at the iconic reptiles.

A comprehensive analysis by Yale University paleontologists reveals new insights into the origin and early history of snakes. For one thing, they kept late hours; for another, they also kept their hind legs. (more…)

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Brain of World’s First Known Predators Discovered

Scientists have found the fossilized remains of the brain of the world’s earliest known predators, from a time when life teemed in the oceans but had not yet colonized the land.

An international team of paleontologists has identified the exquisitely preserved brain in the fossil of one of the world’s first known predators that lived in the Lower Cambrian, about 520 million years ago. The discovery revealed a brain that is surprisingly simple and less complex than those known from fossils of some of the animal’s prey. (more…)

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UCLA life scientists, colleagues differentiate microbial good and evil

To safely use bacteria in agriculture to help fertilize crops, it is vital to understand the difference between harmful and healthy strains. The bacterial genus Burkholderia, for example, includes dangerous disease-causing pathogens — one species has even been listed as a potential bioterrorist agent — but also many species that are safe and important for plant development.

Can the microbial good and evil be told apart? Yes, UCLA life scientists and an international team of researchers report Jan. 8 in the online journal PLOS ONE. (more…)

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Stronger winds explain puzzling growth of sea ice in Antarctica

Much attention is paid to melting sea ice in the Arctic. But less clear is the situation on the other side of the planet. Despite warmer air and oceans, there’s more sea ice in Antarctica now than in the 1970s – a fact often pounced on by global warming skeptics. The latest numbers suggest the Antarctic sea ice may be heading toward a record high this year.

While changes in weather may play a big role in short-term changes in sea ice seen in the past couple of months, changes in winds have apparently led to the more general upward sea ice trend during the past few decades, according to University of Washington research. A new modeling study to be published in the Journal of Climate shows that stronger polar winds lead to an increase in Antarctic sea ice, even in a warming climate. (more…)

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Earth orbit changes were key to Antarctic warming that ended last ice age

For more than a century scientists have known that Earth’s ice ages are caused by the wobbling of the planet’s orbit, which changes its orientation to the sun and affects the amount of sunlight reaching higher latitudes, particularly the polar regions.

The Northern Hemisphere’s last ice age ended about 20,000 years ago, and most evidence has indicated that the ice age in the Southern Hemisphere ended about 2,000 years later, suggesting that the south was responding to warming in the north.

But new research published online Aug. 14 in Nature shows that Antarctic warming began at least two, and perhaps four, millennia earlier than previously thought. (more…)

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Invasive Crazy Ants Are Displacing Fire Ants, Researchers Find

AUSTIN, Texas — Invasive “crazy ants” are displacing fire ants in areas across the southeastern United States, according to researchers at The University of Texas at Austin. It’s the latest in a history of ant invasions from the southern hemisphere and may prove to have dramatic effects on the ecosystem of the region.

The “ecologically dominant” crazy ants are reducing diversity and abundance across a range of ant and arthropod species — but their spread can be limited if people are careful not to transport them inadvertently, according to Ed LeBrun, a research associate with the Texas invasive species research program at the Brackenridge Field Laboratory in the College of Natural Sciences (more…)

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Remote Clouds Responsible for Climate Models’ Glitch in Tropical Rainfall

It seems counterintuitive that clouds over the Southern Ocean, which circles Antarctica, would cause rain in Zambia or the tropical island of Java. But new research finds that one of the most persistent biases in global climate models – a phantom band of rainfall just south of the equator that does not occur in reality – is caused by poor simulation of the cloud cover thousands of miles farther to the south.

University of Washington atmospheric scientists hope their results help explain why global climate models mistakenly duplicate the inter-tropical convergence zone, a band of heavy rainfall in the northern tropics, on the other side of the equator. The study appears this week in the Proceedings of the National Academy of Sciences. (more…)

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Cassini Suggests Icing on a Lake

It’s not exactly icing on a cake, but it could be icing on a lake. A new paper by scientists on NASA’s Cassini mission finds that blocks of hydrocarbon ice might decorate the surface of existing lakes and seas of liquid hydrocarbon on Saturn’s moon Titan. The presence of ice floes might explain some of the mixed readings Cassini has seen in the reflectivity of the surfaces of lakes on Titan.

“One of the most intriguing questions about these lakes and seas is whether they might host an exotic form of life,” said Jonathan Lunine, a paper co-author and Cassini interdisciplinary Titan scientist at Cornell University, Ithaca, N.Y. “And the formation of floating hydrocarbon ice will provide an opportunity for interesting chemistry along the boundary between liquid and solid, a boundary that may have been important in the origin of terrestrial life.” (more…)

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