Spatial connectedness imposes local- and metapopulation-level selection on life history through feedbacks on demography

Dispersal evolution impacts the fluxes of individuals and hence, connectivity in metapopulations. Connectivity is therefore decoupled from the structural connectedness of the patches within the spatial network. Because of demographic feedbacks, local selection also drives the evolution of other life history traits.

We investigated how different levels of connectedness affect trait evolution in experimental metapopulations of the two-spotted spider mite. We separated local- and metapopulation-level selection and linked trait divergence to population dynamics.

Methods
Metapopulations of T. urticae were established on a 3-by-3 grid of patches connected with bridges of different length and let to evolve for ~12 generations. A subset of the replicates were weekly randomized to remove local kin and kind structure. Local population densities were recorded once a week.

After the experimental evolution period, different evolved traits were tested: starvation resistence, individual growth rate and dispersal propensity.