May 28, 2012
End-Permian Crisis Recovery Took Earth 10 Million Years
It took the Earth 10 million years to recover from a cataclysmic event that wiped out 90% of plant and animal life some 250 million years ago, according to new evidence presented Sunday in the journal Nature Geoscience.
According to a press release detailing the research, Dr. Zhong-Qiang Chen of the China University of Geosciences in Wuhan and Professor Michael Benton from the University of Bristol discovered that biological recovery from what they dub "the greatest mass extinction of all time" took so long because of "the sheer intensity of the crisis" and "continuing grim conditions on Earth after the first wave of extinction."The event being described, the end-Permian crisis, followed a series of sudden, negative events that impacted the environment, including global warming, acid rain, and oceanic acidification. Those and other factors wiped out all but 10% of both terrestrial and aquatic life on Earth.
“It is hard to imagine how so much of life could have been killed, but there is no doubt from some of the fantastic rock sections in China and elsewhere round the world that this was the biggest crisis ever faced by life," Dr. Chen said.
Research shows that these conditions, including global warming and carbon-related problems, continued in on-and-off bursts over the next five to six million years following the initial catastrophe. Due to these factors, those animals which did manage to recover quickly and start rebuilding their ecosystems "suffered further setbacks."
“Life seemed to be getting back to normal when another crisis hit and set it back again. The carbon crises were repeated many times, and then finally conditions became normal again after five million years or so," explained Benton, a Professor of Vertebrate Paleontology at the University of Bristol.
"We often see mass extinctions as entirely negative but in this most devastating case, life did recover, after many millions of years, and new groups emerged," he added. "The event had re-set evolution. However, the causes of the killing - global warming, acid rain, ocean acidification - sound eerily familiar to us today. Perhaps we can learn something from these ancient events."