Tuesday, November 28, 2006

The Sky Was Not Falling

Andrew Revkin, a science reporter at the New York Times, writes about a new analysis of the recovery of ocean life following the Permo-Triassic extinction 251 million years ago. This extinction is often called the “Great Dying” because more species winked out then than in any of the other great extinctions that have walloped life on Earth. As Revkin writes in his lede:

At least five mass extinctions, most presumably caused by asteroids that struck the earth, have transformed global ecology in the half-billion years since the emergence of multicelled life, lopping entire branches from the evolutionary tree and causing others to flourish.
The problem is, apart from the end-Cretaceous extinction that killed the dinosaurs, no mass extinction has lots of evidence to support an impact-killer theory. In fact, in the case of the Great Dying, the impact theory is more of a minority opinion, albeit one with some very vocal supporters. I’m surprised that a reporter like Revkin would gloss over this. I have NEVER seen it suggested anywhere nor talked to any evolutionary biologist or geologist that felt most mass extinctions were related to asteroids. Many are willing to entertain the hypothesis, but acknowledge that the data don’t support it.

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