Stephen Jay Gould was 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).

• * 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

In a brilliant move, Belknap Press has posthumously extracted a single chapter--number nine--from The Structure of Evolutionary Theory and published it as a stand-alone book, Punctuated Equilibrium. It's a testimony to the density of the work that a single chapter is sufficient to make a complete and thorough book on its own. The publisher has simply cut away the first 745 pages and the last 318 of the original. What's left is a text that is sharply focused on the theory for which Gould and his colleague Niles Eldredge are best known. It works beautifully...Gould documents the evidence for his controversial theory and its implications in impressive detail. The book is rich in data and dense in theory, representing a powerful summary of the arguments...Gould, in his typically immodest way, suggested that the theory of punctuated equilibrium could tell us about much more than the rate of evolution, and that it pointed to a whole new hierarchy of evolutionary phenomena. He proposed that the discipline of evolutionary biology should be expanded to accommodate new ideas that he, in part, had established. Inevitably that raised hackles. Yet critics and proponents must read his ideas. This sharp, detailed extract from his last great work offers an essential summary.