Across
- 2. difference between individuals
- 6. when no members of the species exist anymore
- 8. proposed all organisms are born with the desire to become better
- 9. the process of selecting a few organisms with desired traits to serve as parents for the next generation
- 10. his theory explains how modern organisms have evolved
- 12. the theory that species evolve during short periods of rapid change
- 13. preserved remains of a once living organism
Down
- 1. A diagram that shows how scientists think different organisms are related
- 3. A structure that is reduced in size
- 4. proccess by which individuals are better adapted to their environment are more likely to survive
- 5. body parts that are similar in related species that have a common ancestor
- 7. the idea that older more simple fossils are at the bottom and new complex are closer the top
- 9. theory tested concept that explains a wide range of observations
- 11. used to determine which of two fossils is older
