Data for: Coevolution fails to maintain genetic variation in a host-parasite model with constant finite population size

By comparing host heterozygosity to the expectation in a single-species model of neutral genetic drift we find that while this is also largely true in finite populations two additional phenomena arise. First, reciprocal natural selection acting on stochastic perturbations in host and pathogen allele frequencies results in a slight increase or decrease in genetic variation depending on the parameter conditions. Second, following the fixation of an allele in the parasite, selection in the MAM becomes directional, which then rapidly erodes genetic variation in the host.

Hence, rather than maintain it, we find that, on average, matching-alleles coevolution depletes genetic variation.

Methods

Mathematica notebooks for model analysis and individual-based simulations run in C++.