Effect of Hilla-Robertsona

The effect of Hill-Robertson - a phenomenon observed in population genetics, first described by Bill Hill and Alan Robertson in 1966. It is about the superiority of evolutionary genetic recombination.

In the case of finite populations that are subject to natural selection, random imbalances will occur. They can trigger genetic drift or mutation. They will work towards delaying the evolution process. The easiest way to explain this is to consider a case of imbalance caused by a mutation: Consider a population of individuals whose genomes consist of only two genes, and b. If a mutation is present and a beneficial allele A is produced, then the genes of this individual by natural selection will over time become more frequent in the population. . If, however, before the persistence of this frequency a non-A gene is also present, another B-mutant of the b-gene, then the individuals having B will compete with the A-holders. If recombinant, then individuals carrying both A and B alleles genotype AB). Assuming no negative effect on the presence of both AB alleles, the individual with this genotype will have a greater selective advantage than the aB or Ab carriers, and the AB genotype will be fixed. However, if there is no recombination, AB individuals may only appear if the subsequent mutation B occurs in an individual with the genotype Ab. The chance of such an event depends on the frequency of new mutations and the size of the population, but this is generally unlikely before A is established. Predicting the time between the emergence of A and the fixation of AB show that it would be much longer in the absence of recombination. Wobe's presence makes it possible to speed up the evolution.

Joe Felsenstein (1974) showed the similarity of this effect from a mathematical point of view with the Fisher-Muller model proposed by R.A. Fisher (1930) and H.J. Muller (1932), although its verbal description is significantly different.

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