Fig. 4.

Disruption of gene flow and its consequences for trait matching in mutualistic networks. Trait matching decreases as gene flow is progressively lost in mutualistic networks but increases slightly with an extreme loss of gene flow. Initially, all species in the network have a high value of gene flow ($g_i=0.3\forall i$), and species randomly lose gene flow until all species lack gene flow ($g_i=0\forall i$). Each point is the mean equilibrium trait matching at site $A$ (${\overline{\tau }}_A*$) calculated with our analytical equilibrium expression using 10 different environmental optimum ($\mathit{\theta }$) samples in each of 10 distinct simulations. Lines connect points from the same network, and different colors indicate different types of mutualism. Sample distributions and values for simulation parameters: ${\phi }_{i,A}={\phi }_{i,B}=1$, ${\theta }_{i,A}\sim \mathcal{U}\left[\mathrm{0,10}\right]$, ${\theta }_{i,B}\sim \mathcal{U}\left[\mathrm{10,20}\right]$, $m_{i,A}=m_{i,B}=0.5$, and $\alpha =0.2$.