Thursday, April 13, 2006

Climate blamed for mass extinctions

A palaeontologist claims climate change rather than asteroid impacts caused most mass extinctions - and the same could be happening today

MOST mass extinctions were caused by gradual climate change rather than catastrophic asteroid impacts. That's the controversial view of one palaeontologist, who says it could mean we are in the midst of a mass extinction now.

Other palaeontologists disagree, and the dispute is turning into a full-scale academic brawl. "It's a shoot-out at the OK Corral," says Peter Ward of the University of Washington in Seattle, who aired his climate change theory at NASA's Astrobiology Science Conference (AbSciCon) in Washington DC last week.

Five major extinctions have occurred in the past 500 million years: the Ordovician, the Devonian, the Permian, the Triassic and the Cretaceous.

There is widespread agreement that the Cretaceous extinction, which wiped out the dinosaurs 65 million years ago, was triggered by an asteroid impact.

"It's such a simple idea that for 20 years we just assumed the same was true for all extinctions," says Ward.



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AGRI-INFO/APRIL 13, 2006


TITLE: CLIMATE BLAMED FOR MASS EXTINCTIONS

ALAM BA NINYO NA HINDI ANG ASTEROIDS KUNDI ANG KLIMA SA PLANETANG ITO ANG POSIBLENG DAHILAN KUNG BAKIT NANGAWALANG PARANG BULA ANG IBAT-IBANG SPECIES?

ITO ANG LUMABAS SA PAG-AARAL NG ISANG PALEONTOLOGIST NA KINILALANG SI PETER WARD NG UNIVERSITY OF WASHINGTON AT KANYANG PORMAL NA INIHAYAG ANG CLIMATE CHANGE THEORY SA NASA ASTROBIOLOGY SCIENCE CONFERENCE SA WASHINGTON DC.

LIMANG MAJOR EXTINCTIONS ANG NANGYARI SA NAKALIPAS NA 500 MILYUNG TAON SA PLANETENG EARTH.

ANG MGA ITO AY TINAGURIANG ORDOVICIAN EXTINCTION, DEVONIAN, PERMIAN, TRIASSIC AT CRETACEOUS EXTINCTIONS.

TALIWAS SA TEORYA NI WARD, MARAMING SIYENTISTA ANG NANINIWALA NA ANG CRETACEOUS EXTINCTION KUNG SAAN NAWALANG PARANG BULA ANG MGA DINOSAUR 65 MILYUNG TAON ANG LUMIPAS AY SANHI NG BUMAGSAK NA MALAKING ASTEROID.

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