Fixation times of de novo and standing beneficial variants in subdivided populations

Details

Serval ID
serval:BIB_3132BDAC5168
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Fixation times of de novo and standing beneficial variants in subdivided populations
Journal
Genetics
Author(s)
Sudbrack V., Mullon C.
ISSN
1943-2631 (Electronic)
ISSN-L
0016-6731
Publication state
In Press
Peer-reviewed
Oui
Language
english
Notes
Publication types: Journal Article
Publication Status: aheadofprint
Abstract
The rate at which beneficial alleles fix in a population depends on the probability of and time to fixation of such alleles. Both of these quantities can be significantly impacted by population subdivision and limited gene flow. Here, we investigate how limited dispersal influences the rate of fixation of beneficial de novo mutations, as well as fixation time from standing genetic variation. We investigate this for a population structured according to the island model of dispersal allowing us to use the diffusion approximation, which we complement with simulations. We find that fixation may take on average fewer generations under limited dispersal than under panmixia when selection is moderate. This is especially the case if adaptation occurs from de novo recessive mutations, and dispersal is not too limited (such that approximately FST < 0.2). The reason is that mildly limited dispersal leads to only a moderate increase in effective population size (which slows down fixation), but is sufficient to cause a relative excess of homozygosity due to inbreeding, thereby exposing rare recessive alleles to selection (which accelerates fixation). We also explore the effect of meta-population dynamics through local extinction followed by recolonization, finding that such dynamics always accelerate fixation from standing genetic variation, while de novo mutations show faster fixation interspersed with longer waiting times. Finally, we discuss the implications of our results for the detection of sweeps, suggesting that limited dispersal mitigates the expected differences between the genetic signatures of sweeps involving recessive and dominant alleles.
Keywords
Diffusion approximation, Fixation time, Inbreeding, Kin competition, Metapopulation, Selective sweeps
Pubmed
Create date
02/04/2024 9:33
Last modification date
05/04/2024 8:13
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