cross word

3. Any difference between individuals of the same species.
5. The gradual change in a species over time
6. System used to organize and classify all life on earth. Used to construct evolutionary trees. (biological classification)
11. Drift Theory- Idea that continents slowly shift their positions due to movement of the tectonic plates
12. Structures- A structure left over by evolution. Was once used, but we no longer use
13. Tree- A family tree that shows the evolutionary relationships thought to exist among groups of organisms
15. Variation- Differences among individuals in their genes or DNA segments.
17. Structures- Similar structure without having a common ancestor
18. Structures- Structures in different species that are similar because of common ancestry.

1. Tectonics- A theory stating that the earth's surface is broken into plates that move.
2. The amount of biological or living diversity.
4. An organism's genetic makeup, or allele combinations.
7. A trait that helps an organism survive and reproduce
8. An organism's physical appearance, or visible traits.
9. A random error in gene replication that leads to a change
10. Darwin- Proposed the idea of natural selection as primary means of species diversity.
14. Selection- Process by which individuals that are better suited to their environment survive and reproduce most successfully
16. Ancestor- The shared ancestor of new, different species