Scientists propose a new mechanism by which oxygen may have first built up in the atmosphere - Phys.org

For the first 2 billion years of Earth's history, there was barely any oxygen in the air. While some microbes were photosynthesizing by the latter part of this period, oxygen had not yet accumulated at levels that would impact the global biosphere.

For the first 2 billion years of Earth's history, there was barely any oxygen in the air. While some microbes were photosynthesizing by the latter part of this period, oxygen had not yet accumulated … [+5982 chars]

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