WHY SEX AND RECOMBINATION

Most higher organisms reproduce sexually, despite the automatic reprod uctive advantage experienced by asexual variants. This implies the ope ration of selective forces that confer an advantage to sexuality and g enetic recombination, at either the population or individual level. Th e effect of sex and recombination in breaking down negative correlatio ns between favorable variants at different genetic loci, which increas es the efficiency of natural selection, is likely to be a major factor favoring their evolution and maintenance. Various processes that can cause such an effect have been studied theoretically. It has, however, so far proved hard to discriminate among them empirically.