Overview of core gene set size and function for clades including at least 30 organisms.

We list for each clade, the α-diversity [37], the number of genomes, the number of core gene families, and the sizes of COG categories within these cores: S, unknown function; housekeeping, comprising J (translation, ribosomal structure, biogenesis), K (transcription), and L (replication, recombination, repair); and O, posttranslational modification, protein turnover, and chaperones. COG percentages refer to the fraction of orthologous core genes in the given functional category; statistically significant enrichments are computed using hypergeometric test with p