Extended Data Fig. 2: Methods of adding a genome to a Progressive Cactus alignment.
From: Progressive Cactus is a multiple-genome aligner for the thousand-genome era

The top row shows the different ways of adding a new genome given its phylogenetic position, and the bottom row shows what subproblems would need to be computed for the new genome to be properly merged into the existing alignment. Green circles represent a new genome, and red circles represent newly reconstructed genomes.