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Changes Over Time
| Term | Definition |
|---|---|
| Absolute Dating | The technique that allows scientists to determine the actual age of a fossil. |
| Adaptation | Any trait that helps an organism survive and reproduce. |
| Geographic Isolation | When species are separated for a long time, a new species may form. |
| Species | A group of similar organisms that can mate and produce fertile offspring. |
| Branching Tree | A diagram that shows how different groups of organisms are related. |
| Variation | Any difference between individuals of the same species. |
| Mold | An empty space that forms when an organism buried in sediment dissolves. |
| Homologous Structure | Similar structures that related species have inherited from a common ancestor. |
| Fossils | The preserved remains or traces of organisms that lived in the past. |
| Relative Dating | A technique used to determine which of two fossils is younger and which is older. |
| Evolution | The gradual change in a species over time. |
| Natural Selection | The process by which individuals that are better adapted to their environment are more likely to survive and reproduce. |
| Overproduction | When a species creates more offspring than can possibly survive. |
| Petrified Fossil | When minerals replace all or part of an organism. |