Figure 1: An example for the interplay between host–parasite and host–supertype networks.
From: Host–parasite network structure is associated with community-level immunogenetic diversity
(a) On the left, host–parasite interactions between helminths and rodent species (ecological network). Arrow width is proportional to the prevalence of a given parasite on a host. On the right, the immunogenetic host-supertype network in which interactions represent the frequencies (indicated by line width) of supertypes harboured by individuals of a given host that are infected by each parasite (indicated by different colours). (b) A theoretical example showing how in a community-wide context, species and MHC supertypes affect each other indirectly with possible cascading indirect effects. Imagine that a mutation for resistance (depicted by a red star) occurs in an allele from supertype no. 3 in the population of host no. 1 (step 1), causing the prevalence of parasite no. 1 to decrease in that host (step 2). Parasite no. 1 now switches to host no. 2 (step 3), thus reducing the prevalence of parasite no. 2 in host no. 2 due to competition (step 4).
