1. Change Over Time

2. remains of ancient plants and animals
fossil
remains of ancient plants and animals

3. natural selection
slow process of organisms that are best suited in their environment survive and reproduce

4. adaptation
a structure or behavior that helps an organism survive in its environment

5. common ancestor
the shared ancestor of new, different species that came from one population

6. the dying out of a whole species
extinction
the dying out of a whole species

7. a large-scale dying out of many species in a short period of time
mass extinction
a large-scale dying out of many species in a short period of time

8. a group of organisms that look alike and can reproduce offspring
species
a group of organisms that look alike and can reproduce offspring

9. geologic time scale
a chart that shows earth’s history and divides it into eras and periods

10. mold fossil
a fossil made when an organism decays inside a rock and leaves it’s shape in the rock

11. tree sap that hardens, often with an insect inside
amber
tree sap that hardens, often with an insect inside

12. cast fossil
a fossil made when minerals fill a hole left when an organism decayed; a cast fossil is a model of the organism.

13. petrification
Fossil made when minerals replace the bones or organic matter left by an organism; internal bone structure can be seen