New research suggests that Earth’s greatest mass extinction was slow, not a sudden catastrophe

A team of researchers, including CIFAR’s Katherine Freeman, discover that the greatest mass extinction in Earth’s history was not sudden, but rather took place over tens or hundreds of thousands of years. The mass extinction, which scientists call “The Great Dying,” happened about 250 million years ago and wiped out 90% of marine life. Scientists previously believed that the extinction was a sudden event, caused by toxic gases and ash from the explosion of Siberian volcanoes. However, when this team of researchers studied ancient rock chemistry and fossils from Ellesmere Island, they discovered that the volcanic eruptions had a slow effect on the extinction of species. Their data show that the effect of the eruptions varied depending on how close an area was to an explosion, as well as the depth of ocean water.

The team’s findings challenge the view held previously by many scientists that the mass extinction was an abrupt catastrophe, suggesting an alternate history of Earth. Read more