Figure 1
From: MHC allele frequency distributions under parasite-driven selection: A simulation model
Exemplary trajectories of P H statistic (top panel) and allele frequencies (middle and bottom panels) for host populations attacked by 25 pathogen species for simultaneous action of negative frequency-dependent selection and heterozygote advantage. The blue line in the top panel represents trajectory of PH statistic while the red dashed lines demarcate thresholds of PH = 0.025 and 0.975, above (or below) which allele frequencies are considered to significantly differ from neutrality. Allele trajectories, represented in the middle and bottom panels, were split into two groups: low frequency (< 0.15) (bottom panel) and high frequency (> 0.15) (middle panel) for clarity of presentation (note that the colours of trajectories in two frequency groups may overlap). Thick colour lines represent trajectories of alleles emerging or lost from a host population during the sampled period, all other ones are in grey.