Evolution and Change. Chapter Thirteen: Evolution. 13.1 Evidence for Evolution 13.2 How Evolution Works 13.3 Natural Selection. Investigation 13A. Crazy Adaptations. How does the environment influence traits?. 13.2 Voyage of the Beagle.
1. Organisms change over time.
2. All organisms are descended from common ancestors by a process of branching.
3. Evolution is gradual, taking place over a long time.
4. The mechanism of evolution is natural selection.