Evidence for Evolution-Fossils

• Definition of fossils

  Remains or organisms from millions of years ago which are found in rocks
• What's the first way fossils can form

  When part of an organism has not decayed meaning the conditions needed for this aren't present like not enough water oxygen or a low temperature
• What's the second way fossils can form

  If parts of an organism decay it can slowly be replaced by minerals
• What's the third way fossils can form

  A preserved trace of an organism like a footprint
• Why aren't we certain on how life on earth began

  Most of the organisms in early life were soft bodied meaning they have no shell or skeleton. This means they rarely formed fossils or they were destroyed by changes to rocks in the earths crust
• How can species become extinct

  Catastrophic event

  Environment change

  New disease or predator

  A new more successful species evolves and competes with it