Caste and Ecology in the Social Insects

Description

In this pathbreaking and far-reaching work George Oster and Edward Wilson provide the first fully developed theory of caste evolution among the social insects. Furthermore, in studying the effects of natural selection in generally increasing the insects' ergonomic efficiency, they go beyond the concentration of previous researchers on the physiological mechanisms of the insects and turn our attention instead to the scale and efficiency of the insects' division of labor. Recognizing that the efficiency of the insect colony is based on a complex fitting of the division of labor to many simultaneous needs, including those imposed by the distribution of resources and enemies around the nest, Professors Oster and Wilson are able to construct a series of mathematical models to characterize the agents of natural selection that promote particular caste systems. The social insects play a key role in the subject of sociobiology because their social organization is so rigid and can be related to genetic evolution. Because of this important consideration, the authors' work has consequences not only for entomology but also for general evolutionary theory. Cover Page Half-title Page Title Page Copyright Page Dedication Preface Contents 1. Why Is Caste Important? 1.1. The Simplification of Individual Behavior 1.2. The Lack of Great Behavioral Novelty 1.3. Concurrent Operations as the Key Advance 1.4. The Eusociality Threshold 1.5. Caste and Roles 1.6. The Superorganism and Factory-Fortress Summary 2. Colony Life Cycles 2.1. The Stages of Colony Growth 2.2. The Founding Stage 2.3. The Ergonomic Stage: Queen/Worker Ratios 2.4. The Ergonomic Stage: The First Brood 2.5. The Ergonomic Stage: Later Colony Growth 2.6. The Reproductive Stage 2.7. Growth Versus Consolidation Summary Appendix 2.1 3. The Genetic Preconditions for Caste Evolution 3.1. The Haplodiploid System in Hymenoptera 3.2. The Inclusive Fitness of the Queen and Workers 3.3. Reproductive Success Depends on the Composition of the Community 3.4. The Conflict Between the Queen and Her Daughters 3.5. The Optimum Investment of Colony Resources 3.6. What Are the Optimum Investment Ratios? 3.7. What Are the Limitations of the Kin-Selection Model? 3.8. How Can the Intermediate Case 0 < p < 1 Be Consistent with the Kin-Selection Model? 3.9. The Relation Between Reproductive Fitness, Ergonomic Efficiency, and Caste Evolution 3.10. Individual-Level Selection Versus Caste Multiplication Summary Appendix 3.1 Appendix 3.2 Appendix 3.3 4. The Biological Characteristics of Caste Systems 4.1. Behavioral Acts, Roles, and Castes 4.2. The Nature of Physical Castes 4.3. The Evolution of Physical Castes in Ants 4.4. Developmental Shaping of the Caste Size-Distribution 4.5. The Nature of Temporal Castes 4.6. The Nonexistence of Teams 4.7. Within-Caste Elitism, Specialization, and Idiosyncrasy Summary 5. Caste Structure and Ergonomic Optimization 5.1. The Caste Distribution Function 5.2. Adaptive Demography 5.3. Castes and Tasks: Allometric Space and the Ergonomic Scale 5.4. The Resource Distribution Function and Foraging Efficiency 5.5. Energy as a Measure of Utility 5.6. Defensive Contingencies: Risk Versus Return Summary Appendix 5.1 Appendix 5.2 6. Optimum Caste Ratios 6.1. How Many Castes? 6.2. Forces Affecting Caste Specialization 6.3. The Correlates of Caste Proliferation 6.4. Optimum Size-Frequency Distributions 6.5. The Effect of Uncertain Environments on Caste Specialization 6.6. Specialists and Generalists 6.7. Defense of the Colony: Workers Versus Soldiers Summary Appendix 6.1 Appendix 6.2 Appendix 6.3 7. Caste in the Service of Foraging Strategy 7.1. Foraging Techniques Used by Social Insects 7.2. Caste and the Evolution of Foraging Behavior 7.3. Calculating the Task Efficiency 7.4. Modeling the Foraging Process 7.5. Recruiting and Optimal Foraging 7.6. Tempo and Efficiency Summary Appendix 7.1 8. A Critique of Optimization Theory in Evolutionary Biology 8.1. The Structure of Optimization Models 8.2. What Is the Proper Role for Optimization Models in Evolutionary Biology? Summary 9. Unsolved Problems 9.1. Basic Evolutionary Problems 9.2. Caste Diversification 9.3. Ecology and Demography 9.4. Comparative Studies Glossary Bibliography Index