B2- old and new species
- Created by: safia rassool
- Created on: 06-06-16 15:58
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the origins of life on earth
- earth began 4500million years ago and life on earth began 3500million years ago
- we can date rocks by the fossils found in them
- fossils can be formed by: hard parts of body not decaying
- conditions for decay being absent
- parts of organism being replaced by other materials eg minerals
- preserved traces of animals in mug
- many early life forms had soft bodies so they decayed
- traces are likely to be destroyed by geologically catastrophes
fossil evidence
- extinction means that a species that once existsted…
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