| A | B |
|---|
| fossil | the preserved remains of a once living organism |
| evolution | the gradual development from a simple organism to a more complex one |
| radiometric dating | a method for determining the age of rocks and fossils using a ratio of radioactive isotopes |
| organism | an individual animal, plant or single celled organism |
| superposition | the law that states the older rocks will be found on the bottom layer of an undisturbed formation |
| geologic time scale | a chronological method of dating the Earth's history |
| relative age | determining age by comparing one thing to another, chronological not exact, a qualitative method |
| absolute age | a rock or fossils true age, more exact, determined by several methods one of which is radiometric dating. |
| extinct | no longer in existence |
| trait | a distinguishing characteristic or quality |
| petrified fossil | remains that have turned to stone |
| mold fossil | an organisms remains decay until just the shape remains |
| trace fossil | an imprint or mark left by an organism |
| carbon film | when an organisms remains decay until all that is left is a film of carbon |
| preserved remains | remains of an organism usually encased in tar, amber or ice. |
| geologist | an expert who study's the Earth, it's rocks and fossils |
| paleontologist | a scientist who studies fossils |
| diversity | having a variety of organism |
| notochord | in an embryo it is a small flexible rod, it is the beginnings of a backbone. |
| DNA | a substance that carries genetic information |
