Across
- 2. A group of organisms that can mate with one another to produce fertile offspring.
- 4. Dating: Any method of determining whether an event or object is older or younger than other events or objects.
- 6. Dating: Any method of measuring the age of an object of even in years.
- 8. Era: The geologic era that follow Precambrian time and that lasted from 542 million to 251 million years ago.
- 9. Time: the period in the geologic time Scale from the formation of the earth to the beginning of the Paleozoic era from about 4.6 billion to 542 million years ago.
- 14. Era: The most recent geologic era beginning 65 million years ago; also called the age of mammals.
- 15. Selection: The process by which individuals that are better adapted to their environment survive and reproduce more successfully than less adapted individuals do; a theory to explain the mechanism of evolution.
Down
- 1. Tectonics: The theory that explains how large prices of the Earth's outermost layers called tectonic plates move and change shape.
- 3. Describes a species that has died out completely.
- 5. Breeding: The human practice of breeding animals or plants that have certain desired traits
- 7. A characteristic that helps an organism survive and reproduce in its environment.
- 10. The process in which inherited characteristics within a population change over generations such that new species sometimes arise
- 11. The trace or remains of an organism that live long ago, most commonly preserved in sedimentary rock.
- 12. Time Scale: The standard method used to divide the Earth's long natural history into manageable parts.
- 13. Era: the geologic era that lasted from 251 million to 65.5 million years ago; also called the age of reptiles.
- 16. A genetically determined characteristic.
