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Teaching Timeline of evolution

Timeline of evolution

Life on Earth began about 3.5 to 4 billion years ago. The first life forms were single-celled organisms similar to bacteria. The first multicellular organisms did not appear until about 610 million years ago. Many different types of organisms evolved during the next ten million years, in an event called the Cambrian Explosion.

CK-12 (Middle School)


How long did it take for life to evolve from simple elements to millions of different complex life forms?
RST.1 - Analysis & Evidence, RST.2 - Main Ideas


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