Figure 4

Phylogenetic relationships of the major lineages of Cetaceans reconstructed using retroposon insertion data shown in Additional file 2. Closed vertical arrowheads denote insertions of retroposons into each lineage. All loci mapped onto the tree were newly isolated and characterized in the present study. Each clade is named alphabetically from A to J. Cetacean families are delimited by vertical lines to the right of the tree along with representative members.