Figure 1.

(A) Number of genes that are found (by having the same consensus gene name, see Methods) in at least two-thirds of prokaryotic genomes, and that are found in a random sample of x = 1 through x = 147 of these genomes. The point at x = 0 of y = 474 represents the number of genes found in at least 97 prokaryotes. For x > 0, means are reported for 10,000 random selections of x genomes. Small genomes were progressively deleted from the analysis in order to produce the series of curves shown. (B) As in A, but for selected clades of prokaryotes.