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q |
Photosynthesis was the
primary
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|
process to increase the amount of
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|
oxygen in the atmosphere.
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|
è |
Primitive forms of life in oceans
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began to produce oxygen through
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photosynthesis probably 2.5 billion
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|
years ago.
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|
è |
With the concurrent decline of CO2,
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oxygen became the second most
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|
abundant atmospheric as after
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nitrogen.
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