Its duration is 36 million years.. The geological cycle that drives biodiversity on Earth | Science

As water levels rise and fall, different habitats on the continental shelf and in shallow oceans expand and contract, providing opportunities for organisms to thrive or die.

Prevailing geoscientific theory states that the Earth’s lithosphere consists of several tectonic plates, where there are 7 or 8 large plates in addition to several smaller plates that moved slowly 3.4 billion years ago.

Earthquakes and volcanoes occur, and mountains and ocean trenches form at the boundaries of tectonic plates, which are separated into oceanic lithosphere and thick continental lithosphere, both of which are topped by a special crust.

Geological cycle

At convergent boundaries of tectonic plates, the plates sink into the Earth’s crust and replace the lost material by forming new oceanic crust at divergent boundaries as a result of sea floor extension, and in this way the total surface area of ​​the globe remains constant.

By studying tectonic plate movements, scientists found that plate movement indirectly leads to biodiversity fluctuations in 36-million-year cycles, forcing sea levels to rise and fall.

And inside search In a new paper published in the Proceedings of the National Academy of Sciences (PNAS), researchers led by Associate Professor Sala Bolilla of the Sorbonne University in Paris say that as water levels rise and fall, different habitats exist on continental shelves and in shallow oceans. Expansion and contraction provide opportunities for organisms to flourish or die, and by examining the fossil record, scientists have shown that these changes lead to bursts of new life.

Biodiversity driven by plate motion

Study co-author Professor Dietmar Müller, from the University of Sydney’s School of Geosciences, says: Report In terms of tectonic movement, the 36-million-year cycle represents transitions between fast and slow seafloor subsidence, leading to cyclical changes in the depth of ocean basins and tectonic transport to Earth’s depths, leading to fluctuations. Periods of flooding and drying on continents and vast shallow seas promote biodiversity.

It refers to the site report Scientific alert Scientifically, a closer look at the fossil record shows that biological diversity is not small and stable, but rather fluctuates greatly on scales of tens of thousands of years, punctuated by extinction events and the appearance of new species, but the purpose of these changes is not clear, and whether each event is unique in se or an underlying mechanism connecting these changes. Is there

To unravel this mystery, Professor Poulila and his team painstakingly analyzed multiple geological data sets of the past 250 million years combined with computer simulations and modelling.

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“This work was made possible by the GPlates – plate tectonics software developed by the Earthbite team at the University of Sydney, with support from the Australian National Collaborative Research Infrastructure Strategy (NCRIS) via AuScope,” Professor Muller notes.

The team based their findings on finding similar cycles in sea-level changes, Earth’s internal mechanisms and the marine fossil record, and scientists now have conclusive evidence that tectonic cycles driven by Earth dynamics and global sea-level change played a role. Biodiversity of marine life over millions of years.

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

Tectonic plate rotation and other drivers

“Like a warm, thick soup in a slow-moving bowl, the cycles are 36 million years long because of the regular patterns of how tectonic plates, the moving part of the Earth’s core, recycle through the crust,” Professor Müller explains.

Muller says the Cretaceous Winton Formation in Queensland is an example of how changes in sea level affect ecosystems and affect biodiversity in Australia.

Renowned for its collection of fossils, the formation provides a priceless window into a period when much of the Australian continent was submerged. As sea levels rose and fell, the continent’s flooding expanded and contracted ecological niches in the shallow seas. Unique habitats for a variety of species.

“The Cretaceous Winton Formation is evidence of the profound impact of these changes in sea level, providing a snapshot of a time when Australia’s landscape changed and amazing creatures roamed the land,” Professor Muller said.

Scientists say there are other triggers that could have driven biodiversity throughout Earth’s history. For example, the team found evidence of a 62-million-year biodiversity cycle, which the researchers say could be driven by changes in carbon dioxide levels, but this hypothesis needs to be verified. Further investigation.