Natural Selection

4. Form A bridge fossil showing a species in the middle of changing into a new type
5. A measure of how well an organism survives and passes traits to the next generation
7. Structure A “leftover” body part that was useful to an ancestor but is not useless.
9. When a species completely dies out and no longer exists.
10. An ancient relative that two or more modern species evolved from
12. Natural differences between individuals of the same species.
13. Body parts with the same bone map but different uses
15. Sand, mud, or dirt that buries a dead organism and turns it into rock

1. A random change or “typo” in DNA that creates a new trait.
2. A challenge (like a predator or drought) that makes it hard to survive.
3. The preserved remains or traces of an organism from long ago.
6. Selection The process where organisms with the “best” traits survive and reproduce more than others.
8. A specific trait that helps an organism survive in its environment
11. Record All fossils ever found, acting like a “history book” of life on Earth.
14. of Superposition The rule that older fossils are in bottom layers and younger fossils are in top layers.