Skip to main content
Fig. 3 | BMC Evolutionary Biology

Fig. 3

From: The evolutionary and coevolutionary consequences of defensive microbes for host-parasite interactions

Fig. 3

Host fitness as a function of defensive microbe density. Fitness under (i) costs only and (ii) costs and benefits of harbouring defensive microbes. Host fitness decreases as microbe density increases but is lower when benefits of protection from infection accrue. At low microbe density the fitness of the host is of the order \(\lambda \int _{0}^{\infty } \psi (x) P(x) dx\) but the fitness difference between costs only and costs-benefits increases (at \(\approx (2\lambda \int _{0}^{\infty } \psi (x) P(x) dx)(1+D_{m})^{-3}\)). (Parameter values: r−μ=2.0, λ=0.1)

Back to article page