Metabolism vulnerability drove Earth's greatest mass extinction survivors

The Permian-Triassic extinction event, known as the "Great Dying," remains the most catastrophic mass extinction in Earth's history, wiping out 96% of marine species and 70% of land animals around 252 million years ago. Recent research from multiple institutions has pinpointed a critical factor in determining which species survived: metabolic vulnerability. By integrating geological, climatological, and physiological data, scientists have uncovered how the interplay of volcanic activity, oceanic changes, and biological adaptations shaped the survival of life during this crisis.

A Stanford-led study published in the *Proceedings of the National Academy of Sciences* revealed that marine animals with slower metabolisms, such as brachiopods and sea lilies, were disproportionately affected by the extreme environmental shifts. These organisms, which thrived in cool, oxygen-rich waters, struggled to cope with the warming and oxygen-depleted conditions that followed massive volcanic eruptions in the Siberian Traps. The eruptions released vast amounts of carbon dioxide and methane, triggering global warming and ocean acidification. "Warming and oxygen loss are the key drivers," said Erik Anders Sperling, a Stanford researcher. "Species with higher metabolic demands, like modern bivalves and fish, were better equipped to adapt to these changes."

However, the extinction was not solely a result of volcanic activity. A study from the University of Bristol and China University of Geosciences highlighted the role of prolonged El Niño-like weather patterns, which amplified climate instability. These mega-El Niños, fueled by a supercontinent configuration and volcanic-induced warming, created extreme temperature swings and droughts that devastated terrestrial ecosystems. "Climate warming alone cannot drive such devastating extinctions," said Dr. Alexander Farnsworth. "The variability and intensity of these events made it nearly impossible for species to adapt."

Geochemical analyses from the CORDIS-funded BASE-LiNE Earth project further linked the extinction to ocean acidification and deoxygenation. By studying brachiopod fossils, researchers reconstructed a sharp decline in seawater pH, indicating severe acidification. This, combined with volcanic carbon emissions, disrupted marine ecosystems and triggered a cascade of environmental failures. "The domino-like collapse of interconnected life-sustaining cycles ultimately led to the observed catastrophic extent of mass extinction," said Dr. Hana Jurikova.

The metabolic resilience of surviving species played a pivotal role in shaping post-extinction ecosystems. Modern marine groups such as mollusks, fish, and echinoderms, which required faster metabolisms for mobility and predation, outcompeted their slower counterparts. This shift mirrored the aftermath of the dinosaur extinction, where mammals rose to dominance. "Brachiopods have almost no meat," said Sperling. "That's why we eat clam chowder and not brachiopod chowder."

These findings carry stark warnings for today's climate crisis. As modern oceans warm and lose oxygen, the same metabolic vulnerabilities could determine which species endure. "We’re still at the point where we can change things," Sperling said. Yet the parallels between the Permian-Triassic crisis and current trends underscore the urgency of mitigating human-driven climate change. The interplay of volcanic activity, climate variability, and biological adaptation during the Great Dying offers a cautionary tale: the survival of life hinges on its ability to withstand environmental extremes, a test modern ecosystems may soon face.