---
_id: '3675'
abstract:
- lang: eng
  text: "Sex and recombination have long been seen as adaptations that facilitate
    natural selection by generating favorable variations. If recombination is to aid
    selection, there must be negative linkage disequilibria—favorable alleles must
    be found together less often than expected by chance. These negative linkage disequilibria
    can be generated directly by selection, but this must involve negative epistasis
    of just the right strength, which is not expected, from either experiment or theory.
    Random drift provides a more general source of negative associations: Favorable
    mutations almost always arise on different genomes, and negative associations
    tend to persist, precisely because they shield variation from selection.\r\n\r\nWe
    can understand how recombination aids adaptation by determining the maximum possible
    rate of adaptation. With unlinked loci, this rate increases only logarithmically
    with the influx of favorable mutations. With a linear genome, a scaling argument
    shows that in a large population, the rate of adaptive substitution depends only
    on the expected rate in the absence of interference, divided by the total rate
    of recombination. A two-locus approximation predicts an upper bound on the rate
    of substitution, proportional to recombination rate.\r\n\r\nIf associations between
    linked loci do impede adaptation, there can be substantial selection for modifiers
    that increase recombination. Whether this can account for the maintenance of high
    rates of sex and recombination depends on the extent of selection. It is clear
    that the rate of species-wide substitutions is typically far too low to generate
    appreciable selection for recombination. However, local sweeps within a subdivided
    population may be effective."
acknowledgement: Royal Society and the Engineering and Physical Sciences for support
  (GR/ T11753/01)
article_processing_charge: No
author:
- first_name: Nicholas H
  full_name: Barton, Nicholas H
  id: 4880FE40-F248-11E8-B48F-1D18A9856A87
  last_name: Barton
  orcid: 0000-0002-8548-5240
citation:
  ama: 'Barton NH. Why sex and recombination? In: <i>Cold Spring Harbor Symposia on
    Quantitative Biology</i>. Vol 74. Cold Spring Harbor Laboratory Press; 2009:187-195.
    doi:<a href="https://doi.org/10.1101/sqb.2009.74.030">10.1101/sqb.2009.74.030</a>'
  apa: Barton, N. H. (2009). Why sex and recombination? In <i>Cold Spring Harbor Symposia
    on Quantitative Biology</i> (Vol. 74, pp. 187–195). Cold Spring Harbor Laboratory
    Press. <a href="https://doi.org/10.1101/sqb.2009.74.030">https://doi.org/10.1101/sqb.2009.74.030</a>
  chicago: Barton, Nicholas H. “Why Sex and Recombination?” In <i>Cold Spring Harbor
    Symposia on Quantitative Biology</i>, 74:187–95. Cold Spring Harbor Laboratory
    Press, 2009. <a href="https://doi.org/10.1101/sqb.2009.74.030">https://doi.org/10.1101/sqb.2009.74.030</a>.
  ieee: N. H. Barton, “Why sex and recombination?,” in <i>Cold Spring Harbor Symposia
    on Quantitative Biology</i>, vol. 74, Cold Spring Harbor Laboratory Press, 2009,
    pp. 187–195.
  ista: 'Barton NH. 2009.Why sex and recombination? In: Cold Spring Harbor Symposia
    on Quantitative Biology. vol. 74, 187–195.'
  mla: Barton, Nicholas H. “Why Sex and Recombination?” <i>Cold Spring Harbor Symposia
    on Quantitative Biology</i>, vol. 74, Cold Spring Harbor Laboratory Press, 2009,
    pp. 187–95, doi:<a href="https://doi.org/10.1101/sqb.2009.74.030">10.1101/sqb.2009.74.030</a>.
  short: N.H. Barton, in:, Cold Spring Harbor Symposia on Quantitative Biology, Cold
    Spring Harbor Laboratory Press, 2009, pp. 187–195.
corr_author: '1'
date_created: 2018-12-11T12:04:33Z
date_published: 2009-11-10T00:00:00Z
date_updated: 2025-09-30T09:56:29Z
day: '10'
department:
- _id: NiBa
doi: 10.1101/sqb.2009.74.030
external_id:
  isi:
  - '000578380600022'
intvolume: '        74'
isi: 1
language:
- iso: eng
month: '11'
oa_version: None
page: 187 - 195
publication: Cold Spring Harbor Symposia on Quantitative Biology
publication_status: published
publisher: Cold Spring Harbor Laboratory Press
publist_id: '2708'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Why sex and recombination?
type: book_chapter
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 74
year: '2009'
...