Median-joining network of the human-specific AluYb elements. The network of the AluYb lineage was reconstructed using the 36 non-Yb7/8/9 elements and the consensus sequences of the Yb7, Yb8, and Yb9 subfamilies as representatives of these three subfamilies. Black circles denote sequence types. Reconstructed nodes are identified as empty circles. The size of circles indicates the number of Alu loci with this sequence type, while arbitrary sizes were chosen for the Yb7/8/9 nodes to represent the relative sizes of the three subfamilies. Lines denote substitution steps, with a one-step distance being indicated in the bottom–right corner. Broken lines indicate that the length of the branch is not drawn to scale.