The fourth edition of this classic text continues its tradition of providing the basis for understanding the genetic principles behind quantitative differences in phenotypes and how they apply to animal and plant improvement, and evolution. Features Coverage of new theory and technique in quantitative genetic, addressing potential applications in animal and plant breeding and human disease. Exposition of concepts necessary to understand and use computer programs for analysis of quantitative traits. Increased coverage of evolutionary quantitative genetics. Use of molecular markers to identify the genes that cause genetic variation in quantitative traits. Contents Genetic Constitution of a Population Changes of Gene Frequency Small Populations: I. Changes of Gene Frequency Under Simplified Conditions Small Populations: II. Less Simplified Conditions Small Populations: III. Pedigreed Populations and Close Inbreeding Continuous Variation Values and Means Variance Resemblance Between Relatives Heritability Selection: I. The Response And Its Prediction Selection: II. The Results Of Experiments Selection: III. Information from Relatives Inbreeding and Crossbreeding: I. Changes of Mean Value Inbreeding and Crossbreeding: II. Changes of Variance Inbreeding and Crossbreeding: III. Applications Scale Threshold Characters Metric Characters Under Natural Selection Quantitative Trait Loci Appendix Tables Glossary of Symbols Solutions of Problems References & Index About the Authors D.S. Falconer was formerly Professor of Genetics at the University of Edinburgh, UK, and Director of the ARC Unit of Animal Genetics Trudy F.C. Mackay is currently Professor in the Department of Genetics at the North Carolina State University, USA.