Earth experiences a biodiversity explosion every 36 million years

It indirectly triggers biodiversity increases in 36-million-year cycles by forcing sea levels to rise and fall, a new study finds.

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Researchers, including geoscientists, think that these cycles of changes in sea levels, driven by geological changes, have had a significant impact on marine species for at least 250 million years.

As water levels rise and fall, different habitats on the continental shelves and shallow seas expand and contract, paving the way for life to flourish or disappear. Examining the fossil record, scientists showed that these changes led to the rapid emergence of new life forms.

The study, spearheaded by Assistant Professor Slah Boulila at the Sorbonne University in Paris, has been published in the Proceedings of the National Academy of Sciences.

As written in Popular Science Turkish, article co-author Professor Dietmar Müller, working at the Faculty of Earth Sciences at Sydney University, quotes: “In the context of tectonic movements, this 36-million-year cycle causes the sea floor to spread sometimes faster and sometimes slowly, causing deep and cyclical changes in the ocean basins and the Earth. It causes tectonic water transfer to the depths of .

As a result, fluctuations occur between continents' flooding and drought events. Periods with wide shallow seas feed biodiversity.”

The research team bases their findings on strikingly similar cycles in sea level changes, Earth's internal mechanisms, and the marine fossil record.

Scientists have compelling evidence that Earth dynamics-driven tectonic cycles and global sea-level changes have played a crucial role in shaping the biodiversity of marine life for millions of years.

“This research challenges previous ideas about why species change over long periods of time,” says Professor Müller.

"These cycles are 36 million years long because the regular patterns of tectonic plates mixing and recycling into the heat-carrying mantle layer, the moving part of Earth's depths, is like a hot, thick soup slowly moving in a pot."

Professor Müller says the Cretaceous-era Winton Formation in Queensland, Australia, is a good example of how changes in sea level have shaped and affected ecosystems in Australia.

Known for hosting various dinosaur fossils and precious opal stones, this formation serves as an important window into the times when much of the Australian continent was submerged.

As sea levels rise and fall, the submersion of the continent has created ecological coves that expand and contract in shallow seas, providing unique habitats for a wide range of species.

“Depicting a time in Australia when the landscape was transformed and fascinating creatures roamed the land, the Cretaceous Winton Formation is emblematic of the profound impact of these sea-level changes,” says Professor Müller.