Scientists Solve Mystery of Earth's Largest Mass Extinction

Scientists have pinpointed the cause of the "Great Dying," a catastrophic natural event that occurred 252 million years ago and led to the extinction of more than half of the planet's living species. This discovery sheds light on how marine species adapted to drastic environmental shifts, mirroring patterns seen millions of years ago.

The extinction event, which took place at the boundary between the Permian and Triassic periods, saw 96% of marine species and 70% of terrestrial animals perish. While initially perceived as a total catastrophe, some evolutionary branches survived, allowing life to continue once the climate stabilized. A study published in the Proceedings of the National Academy of Sciences revealed that prolonged volcanic eruptions released vast quantities of carbon dioxide and methane into the atmosphere. This process gradually displaced oxygen, leading to the demise of most brachiopods, which were once dominant in ocean floors.

This extinction was not an overnight event but a gradual process that began around 300 million years ago. Ocean waters slowly warmed, reaching temperatures between 8 and 12 degrees Celsius, conditions lethal to many species. "Our findings show that, across different groups of organisms, extinctions occurred at much higher rates for those most vulnerable to increases in water temperature and decreases in oxygen availability," stated Erik Anders Sperling, one of the scientists involved.

Researchers analyzed marine organisms, some extracted from the seabed, to understand how certain sea creatures survived the ocean warming millions of years ago and how they behave today amidst rising global temperatures. Experiments on brachiopods in the San Juan Islands, Washington, indicated their tolerance for low oxygen levels, but their metabolic demand increased significantly when water temperatures rose above normal levels.

“

Our findings show that, in different groups of organisms, the extinctions occurred at much higher rates for those most vulnerable to increases in temperature of the water and decreases in the availability of oxygen.