Tag Archives: mammals

Asteroid that Killed the Dinosaurs also Wiped out the ‘Obamadon’

The asteroid collision widely thought to have killed the dinosaurs also led to extreme devastation among snake and lizard species, according to new research — including the extinction of a newly identified lizard Yale and Harvard scientists have named Obamadon gracilis.

“The asteroid event is typically thought of as affecting the dinosaurs primarily,” said Nicholas R. Longrich, a postdoctoral associate with Yale’s Department of Geology and Geophysics and lead author of the study. “But it basically cut this broad swath across the entire ecosystem, taking out everything. Snakes and lizards were hit extremely hard.” (more…)

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Yale Study Reveals New Family Tree for Ray-Finned Fish

The most common lineages of fish found today in oceans, lakes, and rivers evolved about the same time as mammals and birds, a new Yale University-led study shows.

The comparative genetic analysis of more than 200 fish species, reported the week of Aug. 6 in the Proceedings of the National Academy of Sciences, gave an earlier than expected evolutionary birthday to well-known teleost — or ray-finned — fish such as salmon, bass, or tuna.

The analysis also shows that the very earliest lineages of living teleost fish were eels and bonefishes, not tropical freshwater bonytongue fish as some scientists had proposed. (more…)

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Ribbeting Research

Studies of frogs may lead to better hearing aids

When Mark Bee talks to his 106-year-old grandmother alone, her two enormous hearing aids enable her to understand him well.

“But at a table at Thanksgiving, with everybody talking, the devices don’t do well,” says Bee, an associate professor of ecology, evolution and behavior at the University of Minnesota.

Her difficulty in a noisy situation is called the cocktail party problem, after the background babble that stymies many hearing-impaired people trying to pick out individual voices at a party. But in ponds all over the world, frogs handle a similar problem, and Bee hopes to learn enough about how they do it to put the principles to work helping people like his grandmother. (more…)

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Pregnant Primates Miscarry When New Male Enters Group

ANN ARBOR, Mich.— Pregnant female geladas show an unusually high rate of miscarriage the day after the dominant male in their group is replaced by a new male, a new University of Michigan study indicates.

The “Bruce effect” – in which pregnant females spontaneously miscarry after being exposed to an unfamiliar male – has been found repeatedly in laboratory rodents. However, no conclusive evidence for this effect had ever been demonstrated in a wild population prior to this study. Geladas are Old World monkeys that are close relatives of baboons. (more…)

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Severe Declines in Everglades Mammals Linked to Pythons

HOMESTEAD, Fla. — Precipitous declines in formerly common mammals in Everglades National Park have been linked to the presence of invasive Burmese pythons, according to a study published on Jan. 30, 2012, in the Proceedings of the National Academy of Sciences.

The study, the first to document the ecological impacts of this invasive species, strongly supports that animal communities in this 1.5-million-acre park have been markedly altered by the introduction of pythons within 11 years of their establishment as an invasive species.  Mid-sized mammals are the most dramatically affected. (more…)

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Oil Exploration Would Endanger The Most Biodiverse Region in The Western Hemisphere, Say Scientists

AUSTIN, Texas — An international team of scientists that includes two University of Texas at Austin researchers has found that Ecuador’s Yasuní National Park, which sits on top of massive reserves of oil, is in the single most biodiverse region in the Western Hemisphere.

The announcement is part of a final push for the Yasuní-ITT Initiative at the United Nations General Assembly. The initiative proposes that Ecuador receive compensation for half of the revenues the nation would lose by protecting the estimated 846 million barrels of oil that lie beneath the forest. (more…)

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It Takes a Community of Soil Microbes to Protect Plants From Disease

*Berkeley Lab scientists decipher immune system for plants beneath our feet*

Those vegetables you had for dinner may have once been protected by an immune system akin to the one that helps you fight disease. Scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the Netherland’s Wageningen University found that plants rely on a complex community of soil microbes to defend themselves against pathogens, much the way mammals harbor a raft of microbes to avoid infections.

The scientists deciphered, for the first time, the group of microbes that enables a patch of soil to suppress a plant-killing pathogen. Previous research on the phenomenon of disease-suppressive soil had identified one or two pathogen-fighting microbes at work. (more…)

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