Natural Selection

3. / the preserved trace, imprint, or remains of a plant or animal
6. isolation / separation of populations as a result of geographic change or migration to geographically isolated places
7. / the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth
9. / disappearance of a species from all parts of its geographical range
11. / any genetic variation that makes an organism better suited to its environment

1. / group of similar organisms that can breed and produce fertile offspring
2. structure / remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species
4. / any difference between individuals of the same species
5. / a group of organisms of the same species populating a given area
8. Darwin / English natural scientist who formulated a theory of evolution by natural selection (1809-1882)
10. selection / the process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species