Parasitism, mutation accumulation and the maintenance of sex

Nature 367, 554-557 (1994) DURING the production process, the contrast in shading in Figs 1 and 2 of this letter was lost; in addition, parts a and b of Fig. 3 were transposed. These figures should have appeared as they are shown here. The first sentence of each legend is given for guidance. FIG. 1 Results from computer simulations in which sexual populations were challenged by asexual lineages in the presence of coevolving parasites.