| A | B |
|---|
| Study of the Earth and its history | geology |
| Evidence of life in the past | fossils |
| Gradual change over time | evolution |
| Organisms that feed off others | heterotrophs |
| Darwin wrote this book | "Origin of the Species" |
| A cell without a nucleus | prokaryote |
| Darwin sailed on this ship | H.M.S. Beagle |
| Organisms that make their own food | autotrophs |
| All of the genes in a given population | gene pool |
| Shortest geological time frame | epoch |
| Longest geological time frame | era |
| Geological time frame that is longer than an epoch but shorter than an era | period |
| One of four chemical compounds thought to have helped form life on Earth | ammonia |
