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arXiv · 1012.1808

Rare events in population genetics: Stochastic tunneling in a two-locus model with recombination

Alexander Altland·Andrej Fischer·Joachim Krug·Ivan G. Szendro
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Abstract

We study the evolution of a population in a two-locus genotype space, in which the negative effects of two single mutations are overcompensated in a high fitness double mutant. We discuss how the interplay of finite population size, $N$, and sexual recombination at rate $r$ affects the escape times $t_\mathrm{esc}$ to the double mutant. For small populations demographic noise generates massive fluctuations in $t_\mathrm{esc}$. The mean escape time varies non-monotonically with $r$, and grows exponentially as $\ln t_{\mathrm{esc}} \sim N(r - r^\ast)^{3/2}$ beyond a critical value $r^\ast$.

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Alexander Altland, Andrej Fischer, Joachim Krug, Ivan G. Szendro. 2011-02-22. Rare events in population genetics: Stochastic tunneling in a two-locus model with recombination. https://doi.org/10.1103/physrevlett.106.088101

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