Phylogenetic trees are fractal in the sense that the same ... tree with the root at the bottom and the tips at the top. The labels at the "tips" of a phylogeny can correspond to individual ...

The same number of species (three blue circles) can have a very different phylogenetic diversity (the sum of the red branches on the tree connecting them) depending on how closely they are related.

What do phylogenetic trees illustrate? These diagrams don't just organize knowledge of biodiversity - they also show us that living species are the summation of their evolutionary history.