| A | B |
|---|
| Species | A group of similar organisms that can mate with each other and produce fertile offspring |
| Fossil | The preserved remains or traces of organisms that lived in the past |
| Adaptation | A trait that helps an organism survive and reproduce |
| Evolution | The gradual change of a species over time |
| Scientific Theory | A well-tested concept that explains a wide range of observations |
| Natural Selection | The process by which individuals that are better adapted to their environment are more likely to survive and reproduce |
| Variation | Differences between members of the same species |
| Overproduction | The term referring to a species creating more offspring than can possibly survive |
| Competition | Struggle for an organism to get what it needs to survive |
| Homologous Structures | A term that refers to similar structures that related species have inherited from a common ancestor |
| Branching Tree | A diagram showing how scientists think different groups of organisms are related |
