INTRODUCTION 1. SELECTION FILTER: THE GOOD LEGACY 2. SELECTION FILTER? A NOT-SO-GOOD LEGACY 3. HEREDITY: THE GOOD LEGACY 4. HEREDITY? A NOT-SO-GOOD LEGACY 5. REDUCTIONISM: THE GOOD LEGACY 6. REDUCTIONISM? A NOT-SO-GOOD LEGACY 7. A UNIFIED THEORY: THE GOOD LEGACY 8. A UNIFIED THEORY? A NOT-SO-GOOD LEGACY 9. RANDOMNESS: THE GOOD LEGACY 10. RANDOMNESS? A NOT-SO-GOOD LEGACY 11. NO PURPOSE: THE GOOD LEGACY 12. NO PURPOSE? A NOT-SO-GOOD LEGACY 13. NO DESIGNER: THE GOOD LEGACY 14. NO DESIGNER? A NOT-SO-GOOD LEGACY 15. GRADUALISM: THE GOOD LEGACY 16. GRADUALISM? A NOT-SO-GOOD LEGACY 17. NO THRESHOLDS: THE GOOD LEGACY 18. NO THRESHOLDS? A NOT-SO-GOOD LEGACY 19. SUGGESTIONS FOR FURTHER READING 20. INDEX