FIG 1 .

The heritable portion of the bovine rumen microbiome is phylogenetically closely related. The mean pairwise similarity in the 16S rRNA gene sequence of randomly selected groups of rumen OTUs of the same size (n = 22) was compared to the mean pairwise similarity of the 22 heritable OTUs. The y axis represents the number of groups, and the x axis represents the sequence similarity. The group of heritable OTUs with a calculated mean similarity of 72% at the 16S rRNA gene sequence is depicted in pink. The distribution of randomly selected groups of rumen OTUs is depicted in blue. All random groups showed lower mean 16S rRNA gene similarity (P < 0.01).