Figure 1.

(A) Phylogenetic tree of the major events shaping the evolution of the DUF1220 domain family. Depicted are different mammalian lineages with their approximate divergence times at branch points in millions of years ago. Major events in DUF1220 evolution are identified, and approximate numbers of DUF1220 domains per genome are shown on the right. The dotted line of increasing density along the human divergence branch is indicative of the accumulation of the HLS DUF1220 triplet since the HLS pericentric inversion. (B) Expanded image of the human/chimp split in the evolutionary timeline of DUF1220 domains showing the different evolutionary fates of DUF1220 domains within each of the two lineages.