History of life

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    Earliest Evidence of Life (3.8 billions years years ago):

    The first microscopic life forms, likely single-celled prokaryotes, appeared.
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    Formation of Earth’s Crust hand Ocean (4.5 billions years ago):

    Description:The earth cooled forming a solid crust and liquid water, creating the first oceans.
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    Proliferation of Cyanobacteria (3.5 billions years years ago):

    Cyanobacteria, or blue green algae, began producing oxygen via photosynthesis.
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    First Fossil Evidence (3.5 billions years ago)

    Stromatolites p, layered structures formed by Cyanobacteria, are the earliest fossil evidence of life.
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    Evolution of Eukaryotic Cells (2.1 billion years ago)

    More complex cells with a nucleus and organelles evolved.
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    Evolution of Prokaryotic Cells (2.1 billions years ago)

    Prokaryotes, simple single celled organisms, dominated early earth.
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    Evolution of Multicellular Organism (1 billion years ago)

    Description: Cells began working together, forming multicellular organisms.
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    Dinosaurs (230 to -66 million years ago)

    Description: Dinosaurs dominated Earth for over 160 million years before their extinction.
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    Cambrian Explosion (540 million years ago)

    Description: A rapid increase in the diversity of life forms occurred, including the first hard-bodied animals.
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    First Land Plants (470 million years ago)

    Description: Plants adapted to survive on land, paving the way for terrestrial ecosystems.