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Approximately 4.5 billion years ago the Earth formed. The way scientists found this out was by studying the primary record for the history of life, fossils. Some of these fossils found are deep in rocks under the Earth surface, relative dating doesn’t tell you how older the rock but the lower you go the older the rock, so say rock ABCD are all lined up A being the oldest rock if a scientists found a fossil of fish in rock layer B and jellyfish is rock ...
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Keywords
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