Biology

2. A well tested concept that explains a wide range of observations.
4. The process of selecting a few organisms with desired traits to serve as parents.
6. A structure that is reduced in size and has no funtion.
7. When no members of a species are alive.
9. The diagram that shows how scientist think different groups of organisms are related.
12. Body parts that are structurally similar in related species.
13. The theory that species evolve in short periods.
14. A trait or a novel processes that helps an organism survive and reproduce.
15. The theory that evolution occurs slowly.

1. Idea that over time older species evolved into new species.
3. The millions of fossils that scientists have collected.
5. He proposed that all organisms are born with a desire to become better.
8. His theory explained how modern organisms evolved over time.
10. A technique used to determine which fossil is older based on its layer its found in.
11. The gradual change in a species over time.