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Evidence:
In order to reconstruct the story of the origin of life we study the geological records
of Earth. However, no rocks from the first half billion years after earth’s formation
have survived. What we know comes from limited geological clues and laboratory
experiments.
Three lines of fossil evidence suggest that life arose quite early on earth, earlier
than 3.5 billion years back.
1.
Stromatolites – These are rocks which have a distinct structured layer. They
are formed in shallow waters by the trapping and binding of sedimentary grains
by mats of microorganisms. The oldest stromatolites which imply fossil remnants
of early life are about 3.5 billion years old. However, this line of evidence has been
under some controversy as geological processes of sedimentation can also mimic
their layering.
Source: http://simple.wikipedia.org/wiki/Origin_of_life
ICY SCIENCE | QTR 1 2014