Mar. 5th, 2014

brdgt: (Science Works by iconomicon)


When Trilobites Ruled the World
By Natalie Angier, March 3, 2014, The New York Times

WASHINGTON — Trilobites may be the archetypal fossils, symbols of an archaic world long swept beneath the ruthless road grader of time. But we should all look so jaunty after half a billion years.

At the Smithsonian’s National Museum of Natural History, Brian T. Huber, chairman of paleobiology, points to a flawless specimen of Walliserops, a five-inch trilobite that swam the Devonian seas around what is now Morocco some 150 million years before the first dinosaurs hatched. With its elongated, triple-tined head horn and a bristle brush of spines encircling its lower body, the trilobite could be a kitchen utensil for Salvador Dalí. Nearby is the even older Boedaspis ensifer, its festive nimbus of spiny streamers pointing every which way like the ribbons of a Chinese dancer.

In a back room of the museum, Dr. Huber opens a drawer to reveal a dark, mouse-size and meticulously armored trilobite that has yet to be identified and that strains up from its sedimentary bed as though determined to break free.

“A lot of people, when they see these fossils, don’t believe they’re real,” said Dr. Huber, who is 54, fit from years of fieldwork, and proud that the state fossil of his native Ohio is a trilobite. “They think they must be artists’ models.”

The fossils are real, and so, too, is scientists’ unshakable passion for trilobites (TRY-luh-bites), a diverse and illuminating group of marine animals, distantly related to the horseshoe crab, that once dominated their environment as much as dinosaurs and humans would later dominate theirs — and that still have a few surprises up their jointed sleeves.

Read more... )





The Mammoth Cometh
By Nathaniel Rich, February 27, 2014, The New York Times

The first time Ben Novak saw a passenger pigeon, he fell to his knees and remained in that position, speechless, for 20 minutes. He was 16. At 13, Novak vowed to devote his life to resurrecting extinct animals. At 14, he saw a photograph of a passenger pigeon in an Audubon Society book and “fell in love.” But he didn’t know that the Science Museum of Minnesota, which he was then visiting with a summer program for North Dakotan high-school students, had them in their collection, so he was shocked when he came across a cabinet containing two stuffed pigeons, a male and a female, mounted in lifelike poses. He was overcome by awe, sadness and the birds’ physical beauty: their bright auburn breasts, slate-gray backs and the dusting of iridescence around their napes that, depending on the light and angle, appeared purple, fuchsia or green. Before his chaperones dragged him out of the room, Novak snapped a photograph with his disposable camera. The flash was too strong, however, and when the film was processed several weeks later, he was haunted to discover that the photograph hadn’t developed. It was blank, just a flash of white light.

In the decade since, Novak has visited 339 passenger pigeons — at the Burke Museum in Seattle, the Carnegie Museum of Natural History in Pittsburgh, the American Museum of Natural History in New York and Harvard’s Ornithology Department, which has 145 specimens, including eight pigeon corpses preserved in jars of ethanol, 31 eggs and a partly albino pigeon. There are 1,532 passenger-pigeon specimens left on Earth. On Sept. 1, 1914, Martha, the last captive passenger pigeon, died at the Cincinnati Zoo. She outlasted George, the penultimate survivor of her species and her only companion, by four years. As news spread of her species’ imminent extinction, Martha became a minor tourist attraction. In her final years, whether depressed or just old, she barely moved. Underwhelmed zoo visitors threw fistfuls of sand at her to elicit a reaction. When she finally died, her body was taken to the Cincinnati Ice Company, frozen in a 300-pound ice cube and shipped by train to the Smithsonian Institution, where she was stuffed and mounted and visited, 99 years later, by Ben Novak.

The fact that we can pinpoint the death of the last known passenger pigeon is one of many peculiarities that distinguish the species. Many thousands of species go extinct every year, but we tend to be unaware of their passing, because we’re unaware of the existence of most species.Read more... )





Out of Siberian Ice, A Virus Revived
By Carl Zimmer, March 3, 2014, The New York Times

Siberia fills the heads of scientists with dreams of resurrection. For millions of years, its tundra has gradually turned to permafrost, entombing animals and other organisms in ice. Some of their remains are exquisitely well preserved — so well, in fact, that some scientists have nibbled on the meat of woolly mammoths.

Some researchers even hope to find viable mammoth cells that they can use to clone the animals back from extinction. And in 2012, Russian scientists reported coaxing a seed buried in the permafrost for 32,000 years to sprout into a flower.

Now a team of French and Russian researchers has performed a resurrection of a more sinister nature. From Siberian permafrost more than 30,000 years old, they have revived a virus that’s new to science.

Read more... )



Is Breast-Feeding Really Better?
By Nicholas Bakalar, March 4, 2014, The New York Times

Many women who are unable to breast-feed feel guilty about it and worry they may be depriving their children of a range of benefits. Groups like the American Academy of Pediatrics and the World Health Organization recommend six months of exclusive breast-feeding for all infants, citing studies that show breast milk is easily digestible and has nutrients that are superior to or absent from infant formulas, including immunological substances that reduce rates of infection and fatty acids important in brain development.

But now a new study suggests that many of the long-term benefits attributed to breast-feeding may be an effect not of breast-feeding or breast milk itself but of the general good health and prosperity of women who choose to breast-feed.

Read more... )

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