evolution

2. The theory that species evolve during short periods of rapid change
3. The millions of fossils that scientists have collected. Newer fossils are closer to the surface and older ones are in lower layers.
5. The theory that evolution occurs slowly but steadily
6. A diagram that shows how scientists think different groups of organisms are related.
7. A difference between individuals of the same species
11. the gradual change in a species overtime
12. A structure that is reduced in size and has little or no function.
13. Body parts that are structurally similar in related species and that provide evidence for a common ancestor.
14. The process of selecting a few organism with desired traits to serve as parents of the next generation.
15. trait or novel process that helps an organism survive and reproduce.

1. his theory explains how modern organisms evolved over millions of years. Refer to the attached reading for more information.
4. similarities in structure
8. how well an organism can survive and reproduce in its environment
9. Idea that over time older species evolved into new species.
10. The last shared common ancestor on the branching tree of evolution.