Cyanobacteria's photosynthesis with carbon dioxide helped oxygenate Earth's early atmosphere.
Cyanobacteria, such as green and purple bacteria, played a vital role in transforming Earth's early conditions by photosynthesizing using carbon dioxide as a source of carbon and releasing oxygen as a byproduct. This process led to the oxygenation of the atmosphere, creating an environment favorable for the evolution of various life forms.
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