[Increased recombination in a multi-locus system during environmental fluctuations].

The role of variability of environment as a factor of recombination evolution is studied. It was shown that selection in multilocus system under cyclic or random fluctuations of external conditions results in rapid increase in recombination frequency, even under free recombination between the rec-modificator and the selected system (SS). If so, pair-vise linkage disequilibrium coefficients have unchanged signs and are negative, and the advantage of rec+ alleles is provided by changes in signs of disequilibriums of higher order. The low frequency environmental fluctuations maintain recombination as it is, while high frequency ones induce the substitution of the low level by high. It was established that the recombination promoting mechanism of crossing-over maintenance, due to elimination of non-optimal allelic combinations of SS loci under temporal optimum variations, may be accomplished by smaller genetic load, than under elimination of deleterious mutations.