Relationship between sampling depth of congeners and pangenome size. (a) Percent increase in pan-genome size (number of proteins assigned to previously unobserved homologous sets vs. total number of proteins) as the number of sequenced members of a genus increases from x(current # of organisms) to x + 1. Markers indicate average values for each x over ten randomized replicate sets for six selected genera, while lines without markers show results for another fifteen genera. (b) Percent increase for 21 genera as the number of sequenced representatives increases from nine to ten. Gray bars indicate average values over ten replicates, while error bars indicate the standard deviation.