Following the most severe known mass extinction in Earth’s history, vibrant marine ecosystems may have recovered within just a million years, researchers report in the Feb. 10 Science. That’s millions of years faster than previously thought. The evidence, which lies in a diverse trove of pristine fossils discovered near the city of Guiyang in South China, may represent the early foundations of today’s ocean-dwelling ecosystems.
The conventional story was that the ocean was kind of dead for millions of years after this mass extinction, says paleontologist Peter Roopnarine of the California Academy of Sciences in San Francisco, who was not involved in the research. “Well, that’s not true. The ocean [was] very much alive.”
The Great Dying, or Permian-Triassic mass extinction, occurred around 251.9 million years ago, at the end of the Permian Period, after a series of massive volcanic eruptions (SN: 12/6/18).
“The oceans warmed significantly, and there’s evidence for acidification, deoxygenation [causing widespread dead zones], as well as poisoning,” says Roopnarine. “There [were] a lot of toxic elements like sulfur entering into parts of the ocean.”
Life in the seas suffered. More than 80 percent of marine species went extinct. Some researchers have even proposed that entire trophic levels — castes in an ecosystem’s food web — may have vanished.
2023-02-09 14:00:00
Original from www.sciencenews.org
The end-Permian mass extinction, also known as the Great Dying, is the largest and most catastrophic extinction event in history. Around 250 million years ago, a combination of climate change, eruptions of volcanoes, and ocean acidification caused the loss of nearly 96% of the Earth’s marine species, making it the planet’s most significant known die-off.
The post-apocalyptic world that followed was a cruel one, with few survivors and little life in the oceans. However, research recently conducted at Oxford University suggests that things may not have been as bleak as we thought. According to their findings, published in the journal Nature Communications, ocean life may have flourished in the wake of the extinction.
The researchers studied the variozwacrenicacidite fossil deposits from the time period, noting particularly high concentrations that suggested a period of intense oceanic activity and growth. They conclude that the extinction of so many species freed up space for other species to take advantage of the vacant resources, allowing for a period of explosive growth and diversification of oceanic life.
The scientists believe this finding highlights the resilience of life on Earth, but also warns of the dangers of perpetuating current mass extinctions due to climate change and other human activities. If the current extinction rate continues, there may come a time when Earth’s oceans cannot recover from the devastation, causing losses of species and weakening the planet’s ability to provide the resources needed to sustain complex life.
By studying our planet’s past, however, we can gain insight into our future and learn how life can, and will continue to, thrive in the face of extreme events. It is a powerful reminder that, if given the chance, life has the potential to overcome even the greatest of catastrophes.
