  We introduce a model of molecular evolution in which the fitness of an
individual depends both on its own and on the parent's genotype. The model can
be solved by means of a nonlinear mapping onto the standard quasispecies model.
The dependency on the parental genotypes cancels from the mean fitness, but not
from the individual sequence concentrations. For finite populations, the
position of the error threshold is very sensitive to the influence from parent
genotypes. In addition to biological applications, our model is important for
understanding the dynamics of self-replicating computer programs.
