Quasispecies and recombination.

Recombination is introduced into Eigen's theory of quasispecies evolution. Comparing numerical simulations of the rate equations in the non-recombining and recombining cases show that recombination has a strong effect on the error threshold and, for a wide range of mutation rates, gives rise to two stable fixed points in the dynamics. This bi-stability results in the existence of two error thresholds. However, we prove that, for low mutation rates the bi-stability breaks down and the unique equilibrium distribution is concentrated around the sequence with highest fitness.