History of Life on Earth
Across
- 4. the process of determining the approximate age of a rock, fossil, or event
- 7. date, or information, that either supports or counters a scientific theory or idea
- 8. the variety of species on Earth
- 9. the process of determining whether one rock, fossil, or event is older or younger than another
- 12. the requirements that must be met for an engineering solution to be considered successful
- 13. a description of a natural phenomenon that has been repeatedly tested and appears to be without exception
- 14. a representation of an object or process that makes important aspects easier to observe
Down
- 1. the preserved remains or traces of a once-living organism
- 2. an event in the history of life on Earth in which a large number of species go extinct over a relatively short time period
- 3. a well-tested explanation of scientific observations and experiments that is supported by a large amount of evidence
- 5. the history of life on Earth as documented by the fossils collected so far
- 6. when all members of a species die and the species no longer exists
- 10. a model used to study the history of Earth that divides this history into blocks of time such as geologic eras and geologic periods
- 11. the limitations on an engineering solution