Across
- 2. scientist who first presented the theory of natural selection and evolution
- 4. structure that remains from an ancestor that is no longer useful
- 7. structure that is similar between unrelated organisms due to a shared function
- 8. common _________; an organism from which different species are descended
- 9. structure that is similar among organisms due to a common ancestor
Down
- 1. a trait that makes an organisms better able to survive and reproduce
- 3. natural _______ favors organisms with advantageous traits
- 5. natural differences between members of a species
- 6. organisms must _______ for resources such as food and territory