Movements in Earth’s tectonic plates indirectly trigger explosions in biodiversity on 36-million-year cycles by forcing sea levels to rise and fall, new research shows.
Researchers, including geoscientists from the University of Sydney, believe these geological cycles of sea level change have had a significant impact on marine species diversity, dating back at least 250 million years.
As water levels rise and fall, various habitats on continental shelves and in shallow seas expand and contract, giving organisms the opportunity to thrive or die. By examining the fossil record, scientists have shown that these changes trigger the emergence of new life.
The research was published in the journal Actes de l’Académie Nationale des Sciences, led by Associate Professor Slah Boulila from Sorbonne University in Paris.
Study co-author Professor Dietmar Müller of the University of Sydney School of Geosciences said: “In terms of tectonics, the 36-million-year cycle marks changes between faster and slower spreading from the seafloor, leading to cyclical Changes in depth leads.” the ocean. basins and in the tectonic transfer of water deep within the earth.
“This in turn has led to fluctuations in the inundation and drying out of continents, with periods of extensive shallow seas promoting biodiversity.”
“This work was made possible by the plate tectonics software GPlates developed by the EarthByte group at the University of Sydney and supported by the Australian Collaborative Research Infrastructure Strategy (NCRIS) via AuScope.”
The team based their findings on the discovery of strikingly similar cycles in sea-level fluctuations, the Earth’s inner workings and the marine fossil record.
Scientists now have overwhelming evidence that tectonic cycles driven by Earth dynamics and global sea level changes have played critical roles in shaping the biodiversity of marine life over millions of years.
“This research challenges previous ideas about why species have changed over long periods of time,” said Prof. Müller.
“Cycles last 36 million years due to regular patterns in how tectonic plates circulate through the convective mantle, the moving part of the deep Earth, like thick hot soup in a pot, moving slowly.”
Professor Müller said the Cretaceous Winton Formation in Queensland is a prime example of how sea level changes have shaped ecosystems and impacted biodiversity in Australia.
Known for its collection of dinosaur fossils and valuable opal, the formation offers a valuable insight into a time when much of the Australian continent was inundated.
As sea levels rose and fell, continental flooding created expanding and shrinking ecological voids in shallow seas that provided unique habitats for a wide variety of species.
“The Winton Cretaceous Formation testifies to the profound effects of these sea level changes and captures a snapshot of a time when the Australian landscape changed and fascinating creatures roamed the land,” said Prof. Müller.