expected to be the most recent ancestor of the population with the same probability $\pi=1/N$ while the time to fixation is $T=2N$ [@kimura68; @kingman82; @donnelly95]. This prediction is confirmed in Figure \[figure:fig3\], where we see that for large $u$ both $T_{1}$ and $T_{2}$ are approximately equal to $2N$. Accordingly, in the interval $u_{1c} < u <
u_{2c}$, where $u_{ic}$ denotes the error-threshold for genotype of type $i$, we can describe the dynamics by ignoring the less beneficial mutant.

The explicit modeling of stochastic interference between beneficial mutation revealed an interesting observation concerning the mean number of fixation events and the expected fitness change. Naively one might surmise that, as the number of fixation events increases, so does the expected increase in fitness. Instead, we found the opposite dynamic: Fig. 6 clearly shows that if the mutant with the smaller selective advantage appears first, then we expect more fixation events because the second mutant then has a good chance to survive. Yet, this is not the best scenario if we are interested in maximizing fitness: In this case, it is better if the most beneficial mutant can establish itself first, even though this implies that there is little chance for another 