Clustering tree of 461 species based on amino acid frequency differences. The inner circle is the phylogenetic tree of 461 species from Archaea, Bacteria, and Eukaryota. The tree was inferred from a Euclidean distance matrix of amino acid frequency with a neighbor-joining method using the Mega 5.05 software and edited on iTOL. Ancestral branches with children that had identical colors were assigned the same color as the children. The outer circle displays the corresponding species, which are covered by different colors to show the taxonomic group as the legend indicated. Each taxon is linked to the corresponding branch by a dotted line.
Chen et al. BMC Evolutionary Biology 2013 13:219 doi:10.1186/1471-2148-13-219