Fossils

Cards (12)

  • Give three reasons why the fossil record is not clear for older species+ INCOMPLETE
    • more likely to be destroyed by geological activity / earthquakes
    • fossils buried deeper so harder to find
    • fossils smaller so harder to find
  • Is the fossil record complete?
    • No
  • Fossils
    • Remains of animals from many (million) years ago
    • Found in rocks
  • OLDEST Soft-bodied organisms
    • Oldest organisms were soft-bodied
    • Decay away completely (without forming fossils)
    • Very few fossils
  • Why can't scientists be certain about how life began on Earth?

    • traces mainly destroyed by geological activity.
    • oldest organisms were soft bodied so most of the tissue decayed.
    • fossils buried deeper so harder to find
  • Why is the fossil record not complete, in terms of soft bodied?
    • Oldest organisms are soft-bodied so there were very few fossils
  • Fossils formed by being replaced by minerals
    • Parts of organism will not decay easily e.g bones, shells, teeth
    • Replaced by minerals
    • Form rocks with the same original shape
    • Surrounding sediments turn to rock but the fossil will be distinct
  • Fossils form from when the conditions?
    • Parts of organisms has not decayed because one or more conditions needed for decay not present e.g ice, peatbogs, amber, tar pits
    • Organism is conserved
  • Traces of organisms Fossils
    • Soft material e.g clay can harden around whole organisms, traces of organisms such as footprints, burrows, and rootlet traces
    • This forms a cast
  • How does the fossil record prove Darwin's theory?
    • Fossils found deeper in the soil are generally from more simple organisms.
    • organisms evolved from these simple life forms
  • Observe changes in different organisms over time in life as developed on earth
    • Fossils
  • Importance of fossils
    • fossils show evidence of extinction
    • fossils show change over time