"Our approach shows how plate tectonics has helped shape the habitability of the Earth," lead author Professor Dietmar Muller said. "It provides a new way to think about how tectonics, climate and life co-evolved through deep time."
Published in Earth and Planetary Science Letters, the research dispels the "Boring Billion" myth and demonstrates that tectonic activity was actively reshaping the planet. These changes led to stable oxygen-rich oceans that supported the appearance of eukaryotes-the ancestors of all complex life including plants, animals, and fungi.
"Our work reveals that deep Earth processes, specifically the breakup of the ancient supercontinent Nuna, set off a chain of events that reduced volcanic carbon dioxide emissions and expanded the shallow marine habitats where early eukaryotes evolved," said Professor Dietmar Muller from the EarthByte Group at the University of Sydney.
The researchers constructed a plate tectonic model covering 1.8 billion years and tracked shifts in plate boundaries and continental margins. Once Nuna fragmented 1.46 billion years ago, shallow continental shelves more than doubled in extent, supporting extensive temperate oxygenated seas which promoted complex life.
Volcanic outgassing waned while carbon storage in ocean crust increased, further cooling the climate and adjusting ocean chemistry for the rise of more complex lifeforms, noted co-author Associate Professor Adriana Dutkiewicz from the School of Geosciences at the University of Sydney.
The first fossil eukaryotes appeared about 1.05 billion years ago, timed with continental dispersal and the expansion of shallow seas. "We think these vast continental shelves and shallow seas were crucial ecological incubators," said Associate Professor Juraj Farkas from the University of Adelaide. "They provided tectonically and geochemically stable marine environments with presumably elevated levels of nutrients and oxygen, which in turn were critical for more complex lifeforms to evolve and diversify on our planet."
This research presents the first quantitative linkage of deep-time plate tectonic reconstructions with carbon outgassing and biological milestones. Authors used computational models and thermodynamic simulations to link tectonic activity with carbon cycles and the evolution of complex life.
Research Report:Mid-proterozoic expansion of passive margins and reduction in volcanic outgassing supported marine oxygenation and eukraryogenisis
Related Links
University of Sydney
Tectonic Science and News
| Subscribe Free To Our Daily Newsletters |
| Subscribe Free To Our Daily Newsletters |
