Peter J. Richerson

Department of Environmental Science and Policy

University of California, Davis

Monique Borgerhoff Mulder

Department of Anthropology

University of California, Davis

Bryan J. Vila

Department of Sociology

University of Wyoming

The general format and content of this manual © 1991, 1993, 1995, 2001 by Peter J. Richerson

Stylistic modifications and enriched content © 1992, 1993 by Bryan J. Vila

and Monique Borgerhoff Mulder


Human Ecology is a nascent field for which there is no satisfactory textbook. We have essentially written our own by exanding our lecture notes during the past several years. The book has been evolving, mainly with the help of our students and teaching assistants at Irvine and Davis. We very much appreciate their patience with past imperfect versions and their generous help with constructive criticism.

The book is still imperfect. We beg your indulgence and invite your comments and critiques. We are especially interested in ferreting out presentations that are dull, incorrect, or confusing, expanding those features and sections that you find exciting and enlightening, and discoving major gap in our coverage. Let us know!

Jennifer Pollock, Elaine Fang, and Jane Foster helped immensely in scanning in figures, entering and proofing text, and in other chores which greatly improved the quality of the text.

Much of Chapters 11-14 and 23 derives from Richersonís collaborative work with Robert Boyd, without whose contribution they would not exist. One of the early intructors in this course, Davis anthropologist William G. Davis, helped establish the basic form of the course over about a decade of co-teaching it with Richerson. His stamp is still strong on Chapters 2-7. We especially thank them, but also absolve them from any resposiblity for the use to which their ideas have been put here.


Many colleagues over the years have improved our ideas about himan ecology in spritited discussions and helpful pointers to the literature. Most of them are recognized our citations to their work here.Barbara Sherry of Simon and Schuster Custom Publishing and her coworkers are responsible for the very professional appearance of this version of the material.


Peter Richerson, Monique Borgerhoff Mulder, and Bryan Vila


Give comments to any of the authors or send to:

Peter Richerson, Professor

Division of Environmental Studies

University of California Davis

Davis, CA 95616


Table of Contents

The chapters are in Adobe pdf format. Download Adobe PDF Reader free.

Chapter 1. What Is Human Ecology? Relationship between human ecology, biological ecology, and the social sciences. A synthetic or open discipline. Coping with complexity and diversity. Classical "discoveries," "concepts," and "models." Hypotheses and plausibility arguments. Virtues of general models.

Chapter 2. Environment, Technology, and Culture. Discovery of human diversity in time and space. Concepts of culture and the "culture core." The discovery of regularities in the relationship between technology, environment, and evolutionary level in human societies.

Part II. Human Natural History

Chapter 3. Hunting and Gathering Societies. Implications of dependence on wild plants and animals for demographic variables, settlement patterns, and social organization.

Chapter 4. Horticultural Societies. Implications of plant and animal domestication for demographic variables, settlement patterns, and social organization.

Chapter 5. Pastoral Societies. Implications of an emphasis on livestock herding on demographic variables, settlement patterns, and social organization.

Chapter 6. Agrarian Societies. Implications of advances in agricultural technology for demographic variables, settlement patterns and social organization.

Chapter 7. Commercial/Industrial Societies. Implications of an emphasis on trade and manufacturing for demographic variables, settlement patterns, and social organization.

Part III. Processes of Human Evolution

Chapter 8. Basic Demographic Concepts. Models of population growth and regulation. Concept of age structure. The population concept.

Chapter 9. Natural Selection and Biological Evolution. The discovery of biotic diversity and evolution. Basic models of biotic evolutionary processes.

Chapter 10. The Sociobiology Hypothesis. Relevance of natural selection to human behavior. Evolutionary theory of behavior. Some human examples.

Chapter 11. Mechanisms of Cultural Evolution. The population concept applied to culture. Basic models of the mechanisms of cultural change. The similarities and differences between organic and cultural evolution.

Chapter 12. Natural Selection on Cultural Variation. Discovery that human decision-making powers are weak. Model of the consequences of selection on cultural variation. Costly information hypothesis; an amended proposal for the relationship between genes and culture.

Chapter 13.Evolution of Social Organization. The evolutionistís concept of altruism (or the economistís of public goods). Models of kin and group selection. Discovery that cooperation rare in nature. A model of the adaptive advantages of conformist transmission. A model of group selection on cultural variation, a hypothesis to explain the large scale of human cooperation.

Chapter 14. Evolution of Symbolic Traits. Concept of symbols. Discovery of human symbolic diversity. A model of the indirect bias mechanism. The runaway process, a hypothetical mechanism to underpin group-functional and functional theories of symbolic diversity.

Links here to html versions of the PowerPoint Presentations of the cultural evolution material:

Presentation 1

Presentation 2

Part IV. Systemic Interactions

1. Demographic Processes

Chapter 15. Population Regulation in Human Societies. Fundamental importance of demography to understanding human behavior. Demographic diversity in time and space. Malthusian, Ricardian, and Boserupian models. The European demographic transition.

Chapter 16.Crime and Criminology. Concepts of crime versus criminality. Ecological, micro-level and macro-level factors. Causes and correlates of crime.

2. Society/Society Interactions

Chapter 17. Commerce and Trade. The concept of division of labor. The "Law of comparative advantage" model of the benefits of the international division of labor. Monopoly and other coercive models of trade. Trade as a stimulus to technical evolution.

Chapter 18. Warfare and Population Displacement. A game-theoretic model of violent conflict. Varieties of warfare. Demographic effects. Role in technical progress. Other forms of inter-societal competition.

Chapter 19. Diffusion of Innovations. Patterns in the spread of ideas within and between societies. Empirical evidence for direct and indirect bias mechanisms. Hypothesis that diffusion of innovations between societies is responsible for rapid evolution.

Chapter 20. Disease Exchanges. Discovery of role of disease in human population interactions. Concept of endemic versus epidemic diseases. Epidemiological models. Disease patterns as a function of level of technical development. The evolution and exchange of new diseases.

3. Technology/Environment Interactions.

Chapter 21. Technology and Environmental Deterioration: Preindustrial Societies. Concepts of environmental deterioration and coevolution. Examples of positive and negative feedbacks of environmental alterations by preindustrial people. Overkill hypothesis for Terminal Pleistocene extinctions. Role of environmental "deterioration" in cultural evolution.

Chapter 22. Technology and Environmental Deterioration: Industrial Societies. Argument that industrial societies have as strong interactions with their environment as preindustrial ones. Concept of public choice. Concepts of risk and uncertainty. Role of value conflicts and limited information in limiting adaptive responses to environmental degradation. Voting paradox model.

Part V. Evolutionary Transformations of Human Ecological Patterns.

Chapter 23. Macroevolution: Microevolutionary Processes and the History of the Human Species. Concept of micro versus macroevolution (time scales). Concept of uniformitarianism. Punctuational versus gradual models. Externalist and internalist models of historical process.

Chapter 24. Origin of the Human Adaptive Pattern. The discoveries of the Pleistocene climatic pattern and of the mosaic pattern of hominid evolution. Externalist and internalist hypotheses of hominid evolution.

Chapter 25. The Origin of Plant and Animal Domestication. The discovery of the Neolithic. Externalist and Internalist hypotheses to explain the origins of agriculture.

Chapter 26. The Origin of States and Stratification. Historiansí and archaeologistsí discoveries regarding the development of complex societies. Functional (voluntaristic) versus coercive hypotheses for the origin of states.

Chapter 27. The Development of Commercial and Industrial Societies. The concept of modernity. Hypotheses regarding the failure of agrarian states to routinely modernize. Hypotheses to explain why the key breakthrough to modernity occurred in Europe.

Chapter 28. Summary and Review. A summary of the ecological perspective on human behavior.