PT  - JOURNAL ARTICLE
AU  - Philip J Gerrish
AU  - Fernando Cordero
AU  - Benjamin Galeota-Sprung
AU  - Alexandre Colato
AU  - Varun Vejalla
AU  - Paul Sniegowski
TI  - Natural selection promotes the evolution of recombination 2: during the selective process
AID  - 10.1101/2021.06.07.447324
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.06.07.447324
4099  - http://biorxiv.org/content/early/2021/06/07/2021.06.07.447324.short
4100  - http://biorxiv.org/content/early/2021/06/07/2021.06.07.447324.full
AB  - The ubiquity of genetic mixing in nature has eluded unified explanation since the time of Darwin. Conditions that promote the evolution of genetic mixing (recombination) are fairly well understood: it is favored when genomes tend to contain more selectively mismatched combinations of alleles than can be explained by chance alone. Yet, while a variety of theoretical approaches have been put forth to explain why such conditions would have an overarching tendency to prevail in natural populations, each has turned out to be of limited scope and applicability. In our two-part study, we show that, simply and surprisingly, the action of natural selection acting on standing heritable variation creates conditions favoring the evolution of recombination. In this paper, we focus on the mean selective advantage created by recombination between individuals from the same population. We find that the mean selective advantages of recombinants and recombination are non-negative, in expectation, independently of how genic fitnesses in the standing variation are distributed. We further find that the expected asymptotic frequency of a recombination-competent modifier is effectively equal to the probability that the fittest possible genotype is a virtual recombinant; remarkably, expected asymptotic modifier frequency is independent of the strength of selection. Taken together, our findings indicate that the evolution of recombination should be promoted in expectation wherever natural selection is operating.Competing Interest StatementThe authors have declared no competing interest.