Tuesday, October 24, 2006
A new theory on just what causes Earth's worst mass extinctions may help settle the endless scientific dust-up on the matter. Whether you favor meteor impacts, volcanic eruptions, cosmic rays, epidemics, or some other cause for the worst mass extinction events in Earth's history, no single cause has ever satisfied all scientists all the time for any extinction event. That may be because big extinctions aren't simple events.
The new Press/Pulse theory gets around the controversy by rejecting the all-or-nothing approach to mass extinction, calling instead on a combination of deadly sudden catastrophes - 'pulses' - with longer, steadier pressures on species - 'presses.'
'What we wanted to do is move away from the idiosyncratic approach to extinction mechanisms and look for what these intervals had in common. If you have A and B you will get a mass extinction,' said Ian West, a 2006 graduate of Hobart and William Smith Colleges in Geneva, New York.
West and Hobart and William Colleges paleontology professor Nan Crystal Arens are scheduled to present their work on the Press/Pulse theory on Wednesday, 25 October, at the 118th annual meeting of the Geological Society of America held Oct. 22 to Oct. 25 in Philadelphia. [Evolution, Science, Palaeontology]
Continued at "New theory for mass extinctions"
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