Gametic disequilibrium measures

proceed with caution.

P. W. Hedrick

Research output: Contribution to journalArticle

686 Citations (Scopus)

Abstract

Five different measures of gametic disequilibrium in current use and a new one based on R. C. Lewontin's D', are examined and compared. All of them, except the measure based on Lewontin's D', are highly dependent upon allelic frequencies, including four measures that are normalized in some manner. In addition, the measures suggested by A. H. D. Brown, M. F. Feldman and E. Nevo, and T. Ohta can have negative values when there is maximum disequilibrium and have rates of decay in infinite populations that are a function of the initial gametic array. The variances were large for all the measures in samples taken from populations at equilibrium under neutrality, with the measure based on D' having the lowest variance. In these samples, three of the measures were highly correlated, D2, D (equal to the correlation coefficient when there are two alleles at each locus) and the measure X(2) of Brown et al. Using frequency-dependent measures may result in mistaken conclusions, a fact illustrated by discussion of studies inferring recombinational hot spots and the effects of population bottlenecks from disequilibrium values.

Original languageEnglish (US)
Pages (from-to)331-341
Number of pages11
JournalGenetics
Volume117
Issue number2
StatePublished - Oct 1987
Externally publishedYes

Fingerprint

Population
Alleles

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)

Cite this

Hedrick, P. W. (1987). Gametic disequilibrium measures: proceed with caution. Genetics, 117(2), 331-341.

Gametic disequilibrium measures : proceed with caution. / Hedrick, P. W.

In: Genetics, Vol. 117, No. 2, 10.1987, p. 331-341.

Research output: Contribution to journalArticle

Hedrick, PW 1987, 'Gametic disequilibrium measures: proceed with caution.', Genetics, vol. 117, no. 2, pp. 331-341.
Hedrick, P. W. / Gametic disequilibrium measures : proceed with caution. In: Genetics. 1987 ; Vol. 117, No. 2. pp. 331-341.
@article{29e59782a7734bf5bf1d0a227374a13a,
title = "Gametic disequilibrium measures: proceed with caution.",
abstract = "Five different measures of gametic disequilibrium in current use and a new one based on R. C. Lewontin's D', are examined and compared. All of them, except the measure based on Lewontin's D', are highly dependent upon allelic frequencies, including four measures that are normalized in some manner. In addition, the measures suggested by A. H. D. Brown, M. F. Feldman and E. Nevo, and T. Ohta can have negative values when there is maximum disequilibrium and have rates of decay in infinite populations that are a function of the initial gametic array. The variances were large for all the measures in samples taken from populations at equilibrium under neutrality, with the measure based on D' having the lowest variance. In these samples, three of the measures were highly correlated, D2, D (equal to the correlation coefficient when there are two alleles at each locus) and the measure X(2) of Brown et al. Using frequency-dependent measures may result in mistaken conclusions, a fact illustrated by discussion of studies inferring recombinational hot spots and the effects of population bottlenecks from disequilibrium values.",
author = "Hedrick, {P. W.}",
year = "1987",
month = "10",
language = "English (US)",
volume = "117",
pages = "331--341",
journal = "Genetics",
issn = "0016-6731",
publisher = "Genetics Society of America",
number = "2",

}

TY - JOUR

T1 - Gametic disequilibrium measures

T2 - proceed with caution.

AU - Hedrick, P. W.

PY - 1987/10

Y1 - 1987/10

N2 - Five different measures of gametic disequilibrium in current use and a new one based on R. C. Lewontin's D', are examined and compared. All of them, except the measure based on Lewontin's D', are highly dependent upon allelic frequencies, including four measures that are normalized in some manner. In addition, the measures suggested by A. H. D. Brown, M. F. Feldman and E. Nevo, and T. Ohta can have negative values when there is maximum disequilibrium and have rates of decay in infinite populations that are a function of the initial gametic array. The variances were large for all the measures in samples taken from populations at equilibrium under neutrality, with the measure based on D' having the lowest variance. In these samples, three of the measures were highly correlated, D2, D (equal to the correlation coefficient when there are two alleles at each locus) and the measure X(2) of Brown et al. Using frequency-dependent measures may result in mistaken conclusions, a fact illustrated by discussion of studies inferring recombinational hot spots and the effects of population bottlenecks from disequilibrium values.

AB - Five different measures of gametic disequilibrium in current use and a new one based on R. C. Lewontin's D', are examined and compared. All of them, except the measure based on Lewontin's D', are highly dependent upon allelic frequencies, including four measures that are normalized in some manner. In addition, the measures suggested by A. H. D. Brown, M. F. Feldman and E. Nevo, and T. Ohta can have negative values when there is maximum disequilibrium and have rates of decay in infinite populations that are a function of the initial gametic array. The variances were large for all the measures in samples taken from populations at equilibrium under neutrality, with the measure based on D' having the lowest variance. In these samples, three of the measures were highly correlated, D2, D (equal to the correlation coefficient when there are two alleles at each locus) and the measure X(2) of Brown et al. Using frequency-dependent measures may result in mistaken conclusions, a fact illustrated by discussion of studies inferring recombinational hot spots and the effects of population bottlenecks from disequilibrium values.

UR - http://www.scopus.com/inward/record.url?scp=0023430504&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023430504&partnerID=8YFLogxK

M3 - Article

VL - 117

SP - 331

EP - 341

JO - Genetics

JF - Genetics

SN - 0016-6731

IS - 2

ER -