Figure 2
From: Origin and evolution of gene families in Bacteria and Archaea
a) Mean family size 
against genome size (N
genes
) for genomes of 92 Bacteria (â– ) and 79 Archaea (â—¦), both clustered at E
cut
= 1e-20 and f
min
= 0.7. Analysis of variance showed a significant effect of N
genes
on 
(F(1, 167) = 421.54, p ≪ 0.001) and a significant interaction between N
genes
and taxa group (F(1, 167) = 28.27, p ≪ 0.001), indicating that the slopes for Bacteria and Archaea were significantly different. Least-squared linear regressions are thus shown separately for Bacteria (dashed line, 
) and Archaea (solid line, 
). (b) Total number of families (F
tot
) against N
genes
for Bacteria and Archaea, clustered as above. Lines are the regressions from (a), defined by the relation 
.