1. Evolutionary Trees

2. An evolutionary tree represents the evolutionary relationships among a group of organisms. The pattern of branching reflects how different species evolved from a series of common ancestors.  

3. Evolutionary relationships among organisms are based on physical features and the DNA sequences of their genes.

4. Two species are more related if they have a more recent common ancestor and less related if they have a less recent common ancestor.

5. Which is more closely related?
A & B or
B & C

6. Which is more closely related?
B & D or
C & E

7. Which is more closely related?
B & D or
D & E

8. Which is more closely related?
Amphibian & Reptiles
Reptiles & Mammals

9. Which is more closely related?
Reptiles & Birds
Birds & Mammals

12. What traits do the salamander and hamster share?