New Oxygen research; volcanos helped early oxygen (Introduction)

by David Turell , Thursday, August 26, 2021, 19:17 (976 days ago) @ David Turell

From a study in Australian rocks:

https://www.sciencedaily.com/releases/2021/08/210826111724.htm

"A new analysis of 2.5-billion-year-old rocks from Australia finds that volcanic eruptions may have stimulated population surges of marine microorganisms, creating the first puffs of oxygen into the atmosphere. This would change existing stories of Earth's early atmosphere, which assumed that most changes in the early atmosphere were controlled by geologic or chemical processes.

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"In its earliest days, Earth had no oxygen in its atmosphere and few, if any, oxygen-breathing lifeforms. Earth's atmosphere became permanently oxygen-rich about 2.4 billion years ago, likely after an explosion of lifeforms that photosynthesize, transforming carbon dioxide and water into oxygen.

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"Where there were volcanic emissions, the authors reason, there must have been lava and volcanic ash fields. And those nutrient-rich rocks would have weathered in the wind and rain, releasing phosphorus into rivers that could fertilize nearby coastal areas, allowing oxygen-producing cyanobacteria and other single-celled lifeforms to flourish.

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"'There are other nutrients that modulate biological activity on short timescales, but phosphorus is the one that is most important on long timescales," Meixnerová said.

"Today, phosphorus is plentiful in biological material and in agricultural fertilizer. But in very ancient times, weathering of volcanic rocks would have been the main source for this scarce resource.

"'During weathering under the Archaean atmosphere, the fresh basaltic rock would have slowly dissolved, releasing the essential macro-nutrient phosphorus into the rivers. That would have fed microbes that were living in the shallow coastal zones and triggered increased biological productivity that would have created, as a byproduct, an oxygen spike," Meixnerová said.

"The precise location of those volcanoes and lava fields is unknown, but large lava fields of about the right age exist in modern-day India, Canada and elsewhere, Buick said.

"'Our study suggests that for these transient whiffs of oxygen, the immediate trigger was an increase in oxygen production, rather than a decrease in oxygen consumption by rocks or other nonliving processes," Buick said. "It's important because the presence of oxygen in the atmosphere is fundamental -- it's the biggest driver for the evolution of large, complex life.'" (my bold)

Comment: Note my bold. I don't think oxygen as a driver of evolution. Lots of oxygen allows evolution to advance but the driver is up for debate here. Again this shows how our planet evolved to support life, but remember the origin of life predates oxygen by its appearance with other metabolisms at about 3.5 billion years ago, all previously presented here.