Natural Selection

1. the mating and production of offspring by animals
4. the surroundings or conditions in which a person, animal, or plant lives
5. a change by which an organism or species becomes better suited to its environment.
7. a distinguishing quality or characteristic
8. make partial or minor changes to something
10. relating to genes or heredity
13. a seed-eating songbird that typically has a stout bill and colorful plumage
14. able to be maintained at a certain rate or level
15. a self-replicating material that is present in nearly all living organisms
16. the remains or impression of a prehistoric organism preserved in petrified form
17. relating to biology or living organisms
18. a scientist who specializes in the study of life forms that existed in previous geologic periods

2. the process by which different kinds of living organisms are thought to have developed
3. the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations
6. all the inhabitants of a particular town, area, or country
9. an individual animal, plant, or single-celled life form
11. the production of offspring by a sexual or asexual process
12. a change or difference in condition, amount, or level, typically with certain limits