1. 17.1

2. Fossils Paleontologists- study fossils Fossil Record evidence for hist. of life and how species have changed over time Extinct- some species have died out

3. Fossils Fossils Form buried in rock (sand/silt/clay) hardens around organism preserves an imprint of specimin

4. dating Relative dating age of a fossil is compared to other fossils in other layers of rocks Index fossils easily recognized organism that only existed for a short period of time

5. dating Radioactive dating C-14 dating fossils younger than 60,000 years Potassium-40 dating fossils billions of years old

6. Time Geological Time represents evolutionary time line of earth Time is divided into eras Eras is divided into periods