<p>Mean pairwise nucleotide diversity of the V1V2 sequences for each animal at each time point, calculated using the Tamura-Nei model of nucleotide substitution in MEGA 2.1 [<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.0010003#ppat-0010003-b52" target="_blank">52</a>]. The diversity of the SI is indicated on the y-axis. Trend lines are drawn for RMs (red) and SMs (blue).</p
