The ancestors of bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago.[23] For about 3 billion years, most organisms were microscopic, and bacteria and archaea were the dominant forms of life.
The earliest trees evolved around 400 million years ago.
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The ancestors of bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago.[23] For about 3 billion years, most organisms were microscopic, and bacteria and archaea were the dominant forms of life.
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