Positive Feedback in Natural Systems

1. Front Matter

   Pages I-XII

   PDF

2. Introduction

   • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

   Pages 1-14

3. The Mathematics of Positive Feedback

   • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

   Pages 15-25

4. Physical Systems

   • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

   Pages 27-37

5. Evolutionary Processes

   • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

   Pages 39-49

6. Organism Physiology and Behavior

   • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

   Pages 51-59

7. Resource Utilization by Organisms

   • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

   Pages 61-73

8. Social Behavior

   • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

   Pages 75-98

9. Mutualistic and Competitive Systems

   • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

   Pages 99-126

10. Age-Structured Populations

    • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

    Pages 127-155

11. Spatially Heterogeneous Systems: Islands and Patchy Regions

    • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

    Pages 157-186

12. Spatially Heterogeneous Ecosystems: Pattern Formation

    • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

    Pages 187-200

13. Disease and Pest Outbreaks

    • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

    Pages 201-219

14. The Ecosystem and Succession

    • Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

    Pages 221-245

15. Back Matter

    Pages 247-292

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Cybernetics, a science concerned with understanding how systems are regulated, has reflected the preoccupations of the century in which it was born. Regulation is important in twentieth century society, where both machines and social organizations are complex. Cybernetics focused on and became primarily associated with the homeostasis or stability of system behavior and with the negative feedbacks that stabilize systems. It paid less attention to the processes opposite to negative feedback, the positive feedback processes that act to change systems. We attempt to redress the balance here by illustrating the enormous importance of positive feedbacks in natural systems. In an article in the American Scientist in 1963, Maruyama called for increased attention to this topic, noting that processes of change could occur when a "deviation in anyone component of the system caused deviations in other components that acted back on the first component to reinforce of amplify the initial deviation." The deviation amplification is the result of positive feedback among system components. Maruyama demonstrated by numerous examples that the neglect of such processes was unjustified and suggested that a new branch of cybernetics, "the second cybernetics," be devoted to their study.

• Markov chain
• Mathematica
• Systems
• behavior
• complex system
• cybernetics
• dynamics
• homeostasis
• mathematics
• matrices
• modeling
• regulation
• society
• stability
• system

• Oak Ridge National Laboratory, Oak Ridge, USA

  Donald L. DeAngelis, Wilfred M. Post, Curtis C. Travis

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