Considering that our planet may be on the precipice of experiencing its sixth mass extinction event, this makes for pretty disturbing reading. According to researchers from the University of Bristol, it took the planet an incredible 10 million years to recover from the greatest extinction event in history, which took place some 250 million years ago.
During this time, the Permian-Triassic extinction event, also known as “The Great Dying,” wiped out 90 percent of animals and plants on the planet (not to be confused with the asteroid that killed the dinosaurs a mere 65 million years ago). The Bristol-based team is studying how life recovered from this event and the impact of the devastation.
In the latest issue of Nature Geoscience, Professor Michael Benton, working with Dr Zhong-Qiang Chen from the University of Geosciences in Wuhan, reports that life may have taken up to 10 million years to recover due to “the sheer intensity of the crisis” and “continuing grim conditions on Earth after the first wave of extinction”.
The Great Dying is believed to have been caused by a number of physical environmental shocks — global warming, acid rain, ocean acidification and ocean anoxia. All of these effects led to 90 percent of the planet’s species dying. While some species did recover quickly, they were hampered by more ‘events’ every five to six million years after the initial crisis. Repeated carbon and oxygen crises, warming and other ill effects led to ecosystems failing to properly develop.
“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,” said Dr Chen in a press release.
Professor Benton, Professor of Vertebrate Palaeontology at the University of Bristol, said: “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.”
The team believes it took 10 million years for the crises to end, allowing complex ecosystems to form and creatures such as crabs and lobsters to form the basis of future modern-style ecosystems.
Professor Benton added: “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. 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.”
Here’s hoping we don’t see something similar for a long, long time.
via Discovery News