Punctuated Equilibrium

Stephen Jay Gould

    Introduction

    1. What Every Paleontologist Knows

    An Introductory Example

    Testimonials to Common Knowledge

    Darwinian Solutions and Paradoxes

    The Paradox of Insulation from Disproof

    The Paradox of Stymied Practice

    2. The Primary Claims of Punctuated Equilibrium

    Data and Definitions

    Microevolutionary Links

    Macroevolutionary Implications

    Tempo and the Significance of Stasis

    Mode and the Speciational Foundation of Macroevolution

    3. The Scientific Debate on Punctuated Equilibrium: Critiques and Responses

    Critiques Based on the Definability of Paleontological Species

    Empirical Affirmation

    Reasons for a Potential Systematic Underestimation of Biospecies by Paleospecies

    Reasons for a Potential Systematic Overestimation of Biospecies by Paleospecies

    Reasons Why an Observed Punctuational Pattern Might Not Represent Speciation

    Critiques Based on Denying Events of Speciation as the Primary Locus of Change

    Critiques Based on Supposed Failures of Empirical Results to Affirm Predictions of Punctuated Equilibrium

    Claims for Empirical Refutation by Cases

    Phenotypes

    Genotypes

    Empirical Tests of Conformity with Models

    4. Sources of Data for Testing Punctuated Equilibrium

    Preamble

    The Equilibrium in Punctuated Equilibrium: Quantitatively Documented Patterns of Stasis in Unbranched Segments of Lineages

    The Punctuations of Punctuated Equilibrium: Tempo and Mode in the Origin of Paleospecies

    The Inference of Cladogenesis by the Criterion of Ancestral Survival

    The "Dissection" of Punctuations to Infer Both Existence and Modality

    Time

    Geography

    Morphometric Mode

    Proper and Adequate Tests of Relative Frequencies: The Strong Empirical Validation of Punctuated Equilibrium

    The Indispensability of Data on Relative Frequencies

    Relative Frequencies for Higher Taxa in Entire Biotas

    Relative Frequencies for Entire Clades

    Causal Clues from Differential Patterns of Relative Frequencies

    5. The Broader Implications of Punctuated Equilibrium for Evolutionary Theory and General Notions of Change

    What Changes May Punctuated Equilibrium Instigate in Our Views about Evolutionary Mechanisms and the History of Life?

    The Explanation and Broader Meaning of Stasis

    Frequency

    Generality

    Causality

    Punctuation, the Origin of New Macroevolutionary Individuals, and Resulting Implications for Evolutionary Theory

    Trends

    The Speciational Reformulation of Macroevolution

    Ecological and Higher-Level Extensions

    Punctuation All the Way Up and Down? The Generalization and Broader Utility of Punctuated Equilibrium (in More Than a Metaphorical Sense) at Other Levels of Evolution, and for Other Disciplines In and Outside the Natural Sciences

    General Models for Punctuated Equilibrium

    Punctuational Change at Other Levels and Scales of Evolution

    A Preliminary Note on Homology and Analogy in the Conceptual Realm

    Punctuation Below the Species Level

    Punctuation Above the Species Level

    Punctuational Models in Other Disciplines: Towards a General Theory of Change

    Principles for a Choice of Examples

    Examples from the History of Human Artifacts and Cultures

    Examples from Human Institutions and Theories about the Natural World

    Two Concluding Examples, a General Statement, and a Coda

    Appendix: A Largely Sociological (and Fully Partisan) History of the Impact and Critique of Punctuated Equilibrium

    The Entrance of Punctuated Equilibrium into Common Language and General Culture

    An Episodic History of Punctuated Equilibrium

    Early Stages and Future Contexts

    Creationist Misappropriation of Punctuated Equilibrium

    Punctuated Equilibrium in Journalism and Textbooks

    The Personal Aspect of Professional Reaction

    The Case Ad Hominem against Punctuated Equilibrium

    An Interlude on Sources of Error

    The Wages of Jealousy

    The Descent to Nastiness

    The Most Unkindest Cut of All

    The Wisdom of Agassiz's and von Baer's Threefold History of Scientific Ideas

    A Coda on the Kindness and Generosity of Most Colleagues

    Notes

    Bibliography

    Illustration Credits

    Index

  • Cover: Punctuated Equilibrium
  • A photo of the author

Stephen Jay Gould was the Alexander Agassiz Professor of Zoology at Harvard University and Vincent Astor Visiting Professor of Biology at New York University. A MacArthur Prize Fellow, he received innumerable honors and awards and wrote many books, including Ontogeny and Phylogeny and Time's Arrow, Time's Cycle (both from Harvard).