The implication is that analogous proteins followed evolutionary pathways from different origins to converge upon the same activity. Thus, analogous genes or proteins are considered a product of convergent evolution. A foreign macromolecule that does not belong to the host organism and that elicits an immune response. This method uses a heuristic algorithm which seeks local as opposed to global alignments and can therefore identify isolated regions of similarity. The points of branching within a cladogram are called nodes.
All taxa occur at the endpoints of the cladogram.
The tree is determined from the scores of pairwise alignments of the sequences. Contrast with homology. COGs - Clusters of orthologous groups. See the COGs web site for more details. All the taxa descended from a major cladogenesis event, recognized by possessing the clade's synapomorphy.