Bacteria and the development of an oxygen rich atmosphere

Professor Brian Cox explains how the Earth developed an oxygen rich atmosphere. The secret lies with an ancient group of organisms called cyanobacteria. Around 2.4 billion years ago, these bacteria evolved an incredible ability to produce their own food using photosynthetic pigments. A by-product of this process was oxygen, and the success of these pioneering organisms filled the atmosphere with oxygen. This transformed our planet and allowed the development of more complex life, like plants and animals.

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