| A | B |
|---|
| evolution | change in a species over time; process of biological change by which descendants come to differ from their ancestors |
| species | group of organisms so similar to one another that they can breed and produce fertile offspring |
| fossil | trace of an organism from the past |
| catastrophism | theory that states that natural disasters such as floods and volcanic eruptions shaped Earth's landforms and caused extinction of some species |
| gradualism | principle that states that the changes in landforms result from slow changes over a long period of time |
| uniformitarianism | theory that states that the geologic processes that shape Earth are uniform through time |
