Summarize the theories on how life on earth began

Life on Earth began more than 3 billion years ago, evolving from the most basic of microbes into a dazzling array of complexity over time.  One theory involved a "shocking" start. Another idea is utterly chilling. And one theory is out of this world! Inside you'll learn just how mysterious this all is, as we reveal the different scientific theories on the origins of life on Earth.

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