These kinds of diagrams are called cladograms.
We can use them to trace lineages back to find a point of common ancestry.
Let's see how this works.
Look at the lineages of the three animals that are highlighted.
As you can see, caimans and parrots share a more recent common ancestor, so they are more closely related.
Because all life is related to some degree, all three of these animals also shared a common ancestor, just an earlier one.
Can you find the common ancestor for all of them?
Click on the green dot that represents the common ancestor to all three animals.
You are beginning to understand what cladograms can tell us.
Just like tables or graphs, cladograms help us organize information.
But why did we draw the cladogram this way?
Ooops. Trace the caiman and parrot lineages to see if they are more closely related. Try again!
Ooops. Look for the place where the lineages of all three animals intersect. Try again!