Evolutionary History

4. a body structure in two or more species that features the same parts (for example, the same bones)
7. when something stays mostly the same over time
8. a more recent species that evolved from an ancestor population
11. a group of individuals born and living at about the same time
12. the process by which one population evolves into two or more different species
13. the process by which species adapt to environmental changes over a very long time
14. an older population from which two or more newer species descended

1. sharing a common ancestor population
2. having died out completely and no longer alive anywhere on Earth
3. a random change to a gene that sometimes results in a new trait
4. a group of organisms of the same kind (in one or more populations) that do not reproduce with organisms from any other group
5. everything (living and nonliving) that surrounds an organism
6. a scientist who studies fossils in order to understand the ancient history of life on Earth
9. a related organism from a previous generation
10. an organism's arm, leg, or wing