---
_id: '3642'
abstract:
- lang: eng
text: We develop a general population genetic framework for analyzing selection
on many loci, and apply it to strong truncation and disruptive selection on an
additive polygenic trait. We first present statistical methods for analyzing the
infinitesimal model, in which offspring breeding values are normally distributed
around the mean of the parents, with fixed variance. These show that the usual
assumption of a Gaussian distribution of breeding values in the population gives
remarkably accurate predictions for the mean and the variance, even when disruptive
selection generates substantial deviations from normality. We then set out a general
genetic analysis of selection and recombination. The population is represented
by multilocus cumulants describing the distribution of haploid genotypes, and
selection is described by the relation between mean fitness and these cumulants.
We provide exact recursions in terms of generating functions for the effects of
selection on non-central moments. The effects of recombination are simply calculated
as a weighted sum over all the permutations produced by meiosis. Finally, the
new cumulants that describe the next generation are computed from the non-central
moments. Although this scheme is applied here in detail only to selection on an
additive trait, it is quite general. For arbitrary epistasis and linkage, we describe
a consistent infinitesimal limit in which the short-term selection response is
dominated by infinitesimal allele frequency changes and linkage disequilibria.
Numerical multilocus results show that the standard Gaussian approximation gives
accurate predictions for the dynamics of the mean and genetic variance in this
limit. Even with intense truncation selection, linkage disequilibria of order
three and higher never cause much deviation from normality. Thus, the empirical
deviations frequently found between predicted and observed responses to artificial
selection are not caused by linkage-disequilibrium-induced departures from normality.
Disruptive selection can generate substantial four-way disequilibria, and hence
kurtosis; but even then, the Gaussian assumption predicts the variance accurately.
In contrast to the apparent simplicity of the infinitesimal limit, data suggest
that changes in genetic variance after 10 or more generations of selection are
likely to be dominated by allele frequency dynamics that depend on genetic details.
article_processing_charge: No
article_type: original
author:
- first_name: Michael
full_name: Turelli, Michael
last_name: Turelli
- 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: 'Turelli M, Barton NH. Genetic and statistical analyses of strong selection
on polygenic traits: What, me normal? Genetics. 1994;138(3):913-941. doi:10.1093/genetics/138.3.913'
apa: 'Turelli, M., & Barton, N. H. (1994). Genetic and statistical analyses
of strong selection on polygenic traits: What, me normal? Genetics. Genetics
Society of America. https://doi.org/10.1093/genetics/138.3.913'
chicago: 'Turelli, Michael, and Nicholas H Barton. “Genetic and Statistical Analyses
of Strong Selection on Polygenic Traits: What, Me Normal?” Genetics. Genetics
Society of America, 1994. https://doi.org/10.1093/genetics/138.3.913.'
ieee: 'M. Turelli and N. H. Barton, “Genetic and statistical analyses of strong
selection on polygenic traits: What, me normal?,” Genetics, vol. 138, no.
3. Genetics Society of America, pp. 913–941, 1994.'
ista: 'Turelli M, Barton NH. 1994. Genetic and statistical analyses of strong selection
on polygenic traits: What, me normal? Genetics. 138(3), 913–941.'
mla: 'Turelli, Michael, and Nicholas H. Barton. “Genetic and Statistical Analyses
of Strong Selection on Polygenic Traits: What, Me Normal?” Genetics, vol.
138, no. 3, Genetics Society of America, 1994, pp. 913–41, doi:10.1093/genetics/138.3.913.'
short: M. Turelli, N.H. Barton, Genetics 138 (1994) 913–941.
date_created: 2018-12-11T12:04:24Z
date_published: 1994-11-01T00:00:00Z
date_updated: 2022-06-03T08:18:54Z
day: '01'
doi: 10.1093/genetics/138.3.913
extern: '1'
external_id:
pmid:
- '7851785'
intvolume: ' 138'
issue: '3'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://pubmed.ncbi.nlm.nih.gov/7851785/
month: '11'
oa: 1
oa_version: Published Version
page: 913 - 941
pmid: 1
publication: Genetics
publication_identifier:
issn:
- 0016-6731
publication_status: published
publisher: Genetics Society of America
publist_id: '2741'
quality_controlled: '1'
status: public
title: 'Genetic and statistical analyses of strong selection on polygenic traits:
What, me normal?'
type: journal_article
user_id: ea97e931-d5af-11eb-85d4-e6957dddbf17
volume: 138
year: '1994'
...