Fig. 4. Parasite diversity leads to more Arms Race coevolutionary dynamics.

(A) To test for Arms Race Dynamics, we calculated FST for all host SNPs across the P. aeruginosa genome across the high (yellow), medium (blue) and low (black) parasite diversity treatments and the parasite free control (grey). Each plotted point in the panel represents a single SNP and host genes that are known parasite targets are shown in italics, including genes involved in LPS biosynthesis, Type IV pili biosynthesis, and the Ton-B dependent receptor. (B) We used a conservative FST cutoff to identify selective sweeps of SNPs per host population (+/- standard error), and we found that increasing parasite diversity increased the rate of fixation of SNPs (X²= 20, df = 3, P <0.001).