Figure 2

Mapping μ. Example of the mapping μ of nodes of the gene tree T to the species tree S. Speciation nodes in the gene tree (red circles) are mapped to nodes in the species tree, duplication nodes (blue squares) are mapped to edges in the species tree. σ is shown as dashed green arrows. For clarity of exposition, we have identified the leaves of the gene tree on the left with the species they reside in via the map σ.