The properties of continuous variation are basic to the theory of evolution and to the practice of plant and animal improvement. Yet the genetical study of continuous variation has lagged far behind that of discontinuous variation. The reason for this situation is basically methodological. Mendel gave us not merely his principles of heredity, but also a method of experiment by which these principles could be tested over a wider range ofliving species, and extended into the elaborate genetical theory of today. The power of this tool is well attested by the speed with which genetics has grown. In less than fifty years, it has not only developed a theoretical structure which is unique in the biological sciences, but has established a union with nuclear cytology so close that the two have become virtually a single science offering us a new approach to problems so diverse as those of evolution, development, disease, cellular chemistry and human welfare. Much of this progress would have been impossible and all would have been slower without the Mendelian method of recognizing and using unit differences in the genetic materials. These great achievements should not, however, blind us to the limitations inherent in the method itself. It depends for its success on the ability to assign the individuals to classes whose clear phenotypic distinctions reveal the underlying genetic differences.
|Edition description:||3rd ed. 1982. Softcover reprint of the original 3rd ed. 1982|
|Product dimensions:||6.10(w) x 9.25(h) x 0.03(d)|
Table of Contents1. The Genetical Foundation.- 2. Characters.- 3. Sources of Variation: Scales.- 4. Components of Means: Additive and Dominance Effects.- 5. Components of Means: Interaction and Heterosis.- 6. Components of Variation.- 7. Interaction and Linkage.- 8. Randomly Breeding Populations.- 9. Diallels.- 10. Departures from Simple Disomic Inheritance.- 11. Genes, Effective Factors and Progress under Selection.- 12. Experiments and Concepts.- References.