1. SSA Review 4 – Earth’s History

2. Fossils
How do scientists know what changes occurred long ago inside and on the Earth's surface?

3. Fossils
Fossil – the preserved remains or traces of living things

4. Fossils
*most fossils form when living things die and are buried by sediment.
*the sediment slowly hardens into rock and preserves the shape of the organism.

5. Fossils *What fossils show us (the fossil record):
1 – shows evidence about past life and environments on Earth

6. Fossils *What fossils show us (the fossil record):
2- shows how different groups of organisms have changed over time

7. Human Impact on Earth’s Landforms
*Agriculture
*Mining
*Deforestation
*Desertification
*Urbanization

8. Agriculture
* farming
* raising livestock (animals)

9. Mining
- The removal of non-renewable resources from the land
*rocks, minerals, metals

10. 3. Development/Urbanization
*towns and cities
*buildings, houses, roads, etc.

11. Desertification – Fertile land becoming barren
Caused by:
*Drought
*Overgrazing by livestock
*Cutting down trees for lumber

12. Advantages ? Disadvantages ?
Deforestation – Cutting down forests for wood products or to make way for developments
Advantages ?
Disadvantages ?