Fig. 3.

Red Queen coevolution more common in pairwise host-parasite interactions. We tested for Red Queen dynamics by regressing the change in host allele frequency from day 5 to day 10 (y-axis) with observed frequency on day 5 (x-axis). We found evidence for negative frequency dependent selection on host alleles under low (black) and medium (blue) parasite diversity, but not at high parasite diversity (yellow). The string of points forming a straight downward slope from zero in all three panels are alleles observed on day 5 that had subsequently decreased in frequency to below our ability to detect them at day 10.