Introduction to Quantitative Genetics

Fourth Edition

D. S. Falconer

Trudy F. C. Mackay

PREFACE TO THE THIRD EDITION

ixPREFACE TO THE FOURTH EDITION

xACKNOWLEDGEMENTS

xiINTRODUCTION

xiii

f GENETIC CONSTITUTION OF A POPULATION

1Frequencies of genes and genotypes

1Mendelian variation in natural populations Causes of chang e

Hardy-Weinberg equilibrium

5The Hardy-Weinberg law Applications of the Hardy-Weinberg la wMating frequencies and another proof of the Hardy-Weinberg la wMultiple alleles Sex-linked genes More than one locu s

Non-random mating

1 9Assortative mating

Problems

20

2 CHANGES OF GENE FREQUENCY

23Migration

23Mutation

24Non-recurrent mutation Recurrent mutatio n

Selection

25Change of gene frequency under selection Effectiveness of selectionNumber of generations required Average fitness and loa d

Equilibria

34Balance between mutation and selection Changes of equilibriu mSelection favouring heterozygotes

Polymorphism

42Problems

45

3 SMALL POPULATIONS: I. CHANGES OF GENEFREQUENCY UNDER SIMPLIFIED CONDITIONS

48The idealized population

49Sampling

5 1Variance of gene frequency Fixation Genotype frequencie s

Inbreeding

5 7Inbreeding in the idealized population Variance of gene frequencyGenotypefrequencies

Problems

63

4 SMALL POPULATIONS : II. LESS SIMPLIFIE D

CONDITIONS

65Effective population size

6 5Exclusion ofclosely related matings Different numbers ofmales andfemales Unequal numbers in successive generations Non-randomdistribution offamily size Minimal inbreeding Overlapping generations

Mutation, migration, and selection

7 2Non-recurrent neutral mutation Recurrent mutation and migratio nSelection

Random drift in natural populations

76Polymorphism

78Neutral theory

Problems

8 1

5 SMALL POPULATIONS : III . PEDIGREEDPOPULATIONS AND CLOSE INBREEDING

82Pedigreed populations

$ 2The inbreeding coefficient ofan individual Coancestry or kinship

Regular systems of inbreeding

$ 8Close inbreeding Fixation Repeated backcrosses Crosses andsubsequent generations Mixed inbreeding and crossing Change ofbase : structured population Mutation Selection favourin gheterozygotes

Problems

-

98

6 CONTINUOUS VARIATION

100Metric characters

102Properties of metric characters

104Problems

106

7 VALUES AND MEANS

10 8Population mean

10 9Average effect

11 2Breeding value

114Dominance deviation

116Interaction deviation

119Problems

120

8 VARIANCE

122Components of variance '

122Components as proportions of the total Estimation of the degree ofgenetic determination, VG/Vp

Genetic components of varianc eAdditive and dominance variance Total genetic variance Interactio nvariance Variance due to disequilibriu m

Correlation and interaction between genotype and environment

13 1Correlation Interaction

Environmental variance

134Multiple measurements: repeatability

Summary of variance partitioning

14 3Problems

14 3

9 RESEMBLANCE BETWEEN RELATIVES

14 5Genetic covariance

14 6Offspring and one parent Offspring and mid-parent Half sibs Full sib sTwins General Epistatic interactio n

Environmental covariance

15 5Phenotypic resemblance

157Problems

15 8

10 HERITABILITY

160Estimation of heritability

16 3Offspring parent regression Sib analysis Intra-sire regression ofoffspring on dam Combined estimate s

Twins and human data

17 1Assortative mating

174Precision of estimates and design of experiments

177Offspring parent regression Sib analyses Selection ofparents

Problems

18 1

11 SELECTION : I . THE RESPONSE AND ITS PREDICTION

184Response to selection

18 5Prediction of response Selection differential and intensity ofselectionImprovement of response

Measurement of response

194Variability ofgeneration means Weighting the selection differentia lRealized heritability Maternal effects

Change of gene frequency under artificial selection

199Effects of selection on variance

20 1Problems

204

12 SELECTION: II . THE RESULTS OF EXPERIMENTS

208Short-term results

208Repeatability of response Sampling variance Asymmetry of response

Long-term results

21 5Selection limits Mutation Causes of selection limitsNumber of loci (effective factors) and standardized effect s

Problem

226

13 SELECTION: III. INFORMATION FROM RELATIVES

228Criteria for selection

229Simple methods Prediction of response Combined selectio nRelative merits of the methods

Index selection

240Construction of an index Accuracy Response to selectio nActual achievements

Problems

245

14 INBREEDING AND CROSSBREEDING : I . CHANGESOF MEAN VALUE

247Inbreeding depression

247The effect of selection

Heterosis

253Single crosse s

Problems

26 1

15 INBREEDING AND CROSSBREEDING : II. CHANGE SOF VARIANCE

263Inbreeding

264Redistribution of genetic variance Environmental variance Uniformityof inbred strains

Mutation

269Subline divergenc e

Crossing

272Variance between crosses Combining ability

Problems

279

16 INBREEDING AND CROSSBREEDING : III. APPLICATIONS

281Selection for combining ability Three-way and four-way crosses ;backcrosses Reciprocal recurrent selection Overdominanc eNaturally self-fertilizing plants

Problems

28 8

17 SCALE

290Distribution and variance Interactions Conclusions

Problems

297

18 THRESHOLD CHARACTERS

29 9Liability and threshold Two classes, one threshold Adequacy of th eliability model Scale relationships Three classes, two threshold sSelection for threshold characters

Problems

310

19 CORRELATED CHARACTERS

312Genetic and environmental correlations

312Estimation of the genetic correlatio n

Correlated response to selection

31 7Indirect selection

Genotype-environment interaction

321

Index selection

32 5Construction of the index Response Effect of selection on geneti ccorrelations

Problems

33 2

20 METRIC CHARACTERS UNDER NATURAL SELECTION

33 5Natural selection

33 5Fitness and its components

Relationships between metric characters and fitness

33 7`Fitness profiles '

Responses to natural selection

33 9Fitness Correlated responses Strength of selectio n

Equilibrium populations

34 2Fitness Major components Characters with intermediate optim aCharacters with minimum fitness of intermediates Neutral characters

Origin of variation by mutation

34 8Mutational variance

Maintenance of genetic variation

35 1Balance between neutral mutation and random driftMutation-selection balanc e

Problems

354

21 QUANTITATIVE TRAIT LOCI

356Major genes

356Methods of detection

Methods for mapping QTLs

359Marker loci QTL genotypes Single marker analysis Interva lmapping analysis

Genetical and statistical considerations

366Experimental design Multiple tests Maximum likelihoodestimation Multiple QTLs

Experimental results

370Number of loci Gene effects Consistenc y

From QTL to gene

37 5Problem

37 7

APPENDIX TABLES

379GLOSSARY OF SYMBOLS

38 1Equivalence of symbols used by Mather and Jinks

38 3SOLUTIONS OF PROBLEMS

38 5REFERENCES

437INDEX

459