The Earth Spinning Closely to Its Own Extinction (2449 words, 9 pages)
About 3.8 billion years ago the first signs of life appeared on earth taking the form of very simple, small, single celled microorganisms. 1.8 billion Years after this, these cells became more and more complex, with the formation of internal structures called organelles, such as mitochondria. Moving 2 billion years ...
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