Figure 1.
The relationship between the master matrix and the four auxiliary matrices.
Table 1.
Parameters of the model.
Figure 2.
Distribution of host-parasite and symbiont-parasite specificities in the two sets of master matrices analysed in this study (red and green).
A set of 4000 master matrices generated by independent sampling of entries from an uniform distribution on [0,1] is provided for comparison (blue).
Figure 3.
Impact of specificity and symbiont inheritance rate on the survival and frequency dynamics of host-symbiont associations.
In both graphs, as well as in Figures 4 and 6, the master matrices are divided into 11 bins according to their appropriate specificity. The first bin holds exclusively the non-specific matrices, and the remaining 10 are equally spaced across [0,1]. All bins hold similar numbers of matrices (see Figure 2).
Figure 4.
Specificity and maintenance of allelic diversity.
Note that the model is constructed is such a way that both symbiont alleles but no more than one host and one parasite allele can be lost.
Figure 5.
Symbionts may take part in Red Queen dynamics.
Top: “classical” RQ dynamics, with frequencies of host and parasite alleles oscillating due to antagonistic coevolution between the two species (symbiont allele frequencies remain stable). Middle: symbiont and parasite alleles oscillate, and the host background is stable. Bottom: host background is stable, one symbiont allele is lost, and the frequency of the other oscillates with the frequencies of the two parasite alleles. All simulations performed with random initial frequencies, and for parameters values shown in bold in Table 1, except .
Figure 6.
The influence of host-parasite and symbiont-parasite specificities on host and parasite population fitness, and its interaction with the fidelity of symbiont inheritance.
The results are presented for the values of parameters roughly corresponding to the aphid-wasp system [14], [37], but qualitatively similar patterns were observed for most of the other parameter combinations.