Practice question

The second edition of Bergey's Manual of Systematic Bacteriology expanded to five volumes published between 2001 and 2012 to accommodate explosive growth of 16S rRNA phylogeny and genomic taxonomy. Volume 1 covers introductory essays on systematics, Volume 2 Proteobacteria, Volume 3 Firmicutes, Volume 4 Bacteroidetes, Spirochaetes, Tenericutes and allied phyla, Volume 5 Actinobacteria and Archaea. This reorganization shifted from phenotype-based clustering to molecular phylogenetic framework, reflecting deeper understanding of monophyletic groups and necessitating additional volume beyond original four-volume first edition for comprehensive coverage.