1. The Fossil Record

2. Fossils Preserved remains or traces of ancient organisms
Ex. Shells, teeth, imprints, bone
Items are found in sedimentary rock and amber.
Paleontologists study fossils to learn about:
Structure of ancient organisms, their environment and the ways in which they lived

3. How do we date fossils?
Relative dating: allows paleontologist to determine whether a fossil is older or younger than other fossils.
Index fossils – distinctive fossils used to establish and compare the relative ages of rock layers and their fossils.

4. Dating fossils
Radiometric Dating – using radioactive isotopes, which decay into stable isotopes at a steady rate ex. – potassium-40, carbon-14
Half life – time required for half of the radioactive atoms in a sample to decay.

5. Geological Time Scale Time line of Earth’s History
Based on relative and absolute dating.
Broken into eons, eras, and periods.

6. Life on a changing planet
Physical forces – climate and geological forces
Building mountains, opening coastlines, changing climates and geological forces have altered habitats of living organisms repeatedly throughout Earth’s history.
Continental Drift/plate tectonics – Panagea
Biological forces – the actions of living organisms over time have changed conditions in the land, water and atmosphere of planet earth.