Average population fitnesses after 8000 generations. Fitness values are plotted in relation to population size, type of selection against mutations and the male to female mutation rate ratio. Vertical axes show the relative model population fitnesses compared to a mutation free population. Horizontal axes show the male to female mutation rate ratios α. Large populations consist of 2000 individuals and small populations of 200 individuals. The legend shows the type of reproduction. The term hybrid refers to hybridogenetic reproduction and the term clonal refers to the fitness of a hypothetical population with a pair of chromosomes derived only from the clonal part of the hybridogenetic genomes. For easier comparison, the fitness under asexual reproduction at α = 1 is indicated by a dashed line extending over the whole range of α values. Data points in Figure 2 parts b1-b3 and c1-c3 show the average of 10 runs per parameter set. Standard deviations are indicated on the data points but are often smaller than the symbols.