Fossils and Evolution

Evidence for Evolution B2 Topic 3 

HideShow resource information
  • Created by: Revise15
  • Created on: 18-05-16 17:46
View mindmap
  • Evidence for Evolution
    • Fossils are the "remains" of organisms from many years ago, found in rocks
    • Hard parts of animals that do not decay easily
    • Simplest organisms are found in the oldest rocks, and fossils of more complex organisms in the newest
      • supports the theory of evolution- Charles Darwin
    • Why is the Fossil record incomplete?
      • Soft tissues decay and do not form fossils
      • Organisms die without the necessary conditions for fossilisation
      • may not have been discovered yet
      • Organisms remains may have been separated by natural disasters
    • How do Fossils Form?
      • Sea creatures are alive swimming and feeding
        • Sea creatures die and sink to the bottom of the sea bed
          • Soft parts rot away leaving the hard shell
            • Creatures hard remains get covered by sedimet
              • Layers of sediment are compressed over time forming sedimentary rock
                • Hard shells get replaced by minerals forming rock
                  • Rock is worn away over time perhaps exposed above sea level- the fossil can be discovered
    • What can fossils tell us about..
      • How long ago they existed
        • Simplest organisms are found in the oldest rocks, and fossils of more complex organisms in the newest
          • supports the theory of evolution- Charles Darwin
    • Preserved traces of organisms e.g footprints
    • The pentadactyl limb (5 digits) is seen in many species. In each species the limb  has a similar bone structure.
      • The similarity in bone structure provides evidence that species with a pentadactyl limb have all evolved from a common ancestor.

Comments

No comments have yet been made

Similar Science resources:

See all Science resources »See all Evolution resources »