Stephen Jay Gould as a critic of orthodox neo-Darwinism
"I also developed immense sympathy for the beauty and raw intellectual power of various alternatives, even if I eventually found them wanting in empirical terms."
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The Structure of Evolutionary Theory
Stephen Jay Gould
The Belknap Press of Harvard University Press, 2002, 1433 pp
reviewed by Gert Korthof, 28 May 2004 (updated 7 Jun 2023). |
In developing his criticism of the neo-Darwinian theory of evolution, Stephen J. Gould created a very useful list
of the essential core constituents of neo-Darwinism.
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The Structure of Evolutionary Theory made me realise that Stephen Jay Gould has two seemingly incompatible sides. 'Gould-1' is the defender and populariser of evolution known from his popular books like Ever since Darwin, Hen's Teeth and Horse's Toes, Bully for Brontosaurus. 'Gould-2' is the critic of evolution who developed punctuated equilibrium and several other points
as criticisms of neo-Darwinian evolution. In this book he is not only a critic, but also reflects on his criticism. How much criticism is still compatible with being a Darwinist? This question leads him to a logical analysis of the core principles of Darwinism. Hence the name of the book. His analysis enables him to distinguish the core and the rest of Darwinism and consequently to distinguish between
criticism that is compatible or incompatible with the core of Darwinism.
The result is useful for classifying any criticism of evolution, including Gould's own criticism.
The main division of criticisms is "auxiliary to" (expand, improve) and "alternative to" (replace, substitute) natural selection. Alternatives are:
- Lamarckian inheritance of acquired characters = denial of undirected variation
- orthogenesis (there is a direction in evolution) = denial of undirected variation
- saltationism (big jumps in evolution) = denial of the claim that variation must be small in extent.
Alternatives to natural selection deny the creativity of natural selection and reduce it to a negative force. Lamarckism and orthogenesis deny undirected variation and saltationism refutes the claim that variation must be small in extent. These 3 non-Darwinian evolutionary theories completely replaced Darwinian evolution in the period called 'The Eclipse of Darwinism', 1875-1925. (8)
I perceived his Punctuated Equilibrium as a welcome addition to the theory of evolution. Welcome because it solved the apparent persistent lack of gradualism in the fossil record. According to Gould himself Punctuated Equilibrium is a critique of conventional Darwinism. Others, however, viewed Punctuated Equilibrium as an unwelcome and unnecessary criticism of orthodox Darwinism. Evolutionists Richard Dawkins, Daniel Dennett, and Michael Ruse were criticising and downplaying the Punctuated Equilibrium theory. For example, philosopher Michael Ruse (1) fiercely attacks Gould. This reaction has always puzzled me. Did those evolutionists dislike any criticism? Because neo-Darwinism is essentially complete? Did they dislike criticism from a palaeontologist? Did the data not justify criticism? Was there something wrong with palaentological data? Was Gould exaggerating? Was his criticism an attempt to get famous? Was it a hopeless attempt to improve Darwinism? Too many questions to answer here in this review. I restrict myself to Gould's view of what the core of Darwinism is, which is interesting and stimulating enough to justify our time. [Discovery Institute has its own method of measuring dissent: (6) ]
In this review I focus on the logic of Darwinism as presented by Gould. The logical structure of Darwinism elucidates empirical claims made by Darwinism and how they relate to each other. This logical structure should not be confused with the evidence that supports the claims.
The central Darwinian logic embodies three major claims, which are illustrated by Fig. 1. These claims are the minimal set of necessary theoretical claims (4). The central trunk of the Darwinian theory is natural selection.
The three branches of Darwinian theory are: agency, efficacy and scope.
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The structure of neo-Darwinism:
- agency: natural selection acts on individual organisms
- efficacy: natural selection as a creative force
- scope: extrapolation from micro to macro evolution
possible cuts:
- S : subsidiary cuts affect only subbranches.
- R : revision cuts replace branches, but leave the central branches intact.
- K : killing cuts destroy one of the three central Darwinian principles thereby destroying the whole theory.
Figure 1: The logic of Darwinian theory illustrated by a coral.
(I have added the labels agency, efficacy, scope for clarity)
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- agency: natural selection acts only on
individual organisms, not species.
All higher order effects are explainable as the result of organisms acting for their own personal advantages.
The biotic struggle in a crowded world.
- efficacy: natural selection is a creative force
('the creativity of natural selection') (2). Natural selection creates the fit; it is a positive force.
It is not only eliminating the unfit, it is not only a negative force. The creativity of natural selection makes adaptation central, undirected variation necessary, and gradualism pervasive. The external environment (biotic + abiotic factors) has the causal and controlling role in the direction of evolutionary change.
- variations are copious, small, nondirected:
- copious: Without variation selection can do nothing. Variation proposes, but only natural selection can dispose. If every individual of a species would be identical, there is nothing to select. Today this topic is discussed under the heading mutations. Deviations from these conditions create alternative theories. Every organ and property of an organism must vary. A well known criticism of Fleeming Jenkin's (repeated by creationists and other cirtics today) is: if there are limits to variation then natural selection will stop working. New mutations restore variation used up by selection.
- small: if mutations would be large (saltation, hopeful monster),
variation itself would be the creative force in evolution and selection could only be negative.
- undirected (non-adaptive, random). Darwinians have never argued for "random" mutation in the restricted sense and technical sense of "equally likely in all directions", as in tossing a die (7).
Correct is: variation must be unrelated to the direction of evolutionary change and undirected towards adaptation. With directed variation natural selection can be bypassed entirely. Please note that Gould does not mention the positive, negative or neutral character of mutations, neither the relative frequencies of those categories. A view that holds that there are no positive, beneficial mutations destroys the
efficacy of natural selection and is in fact non-Darwinian.
- gradualism is a consequence of natural selection as creative mechanism.
Selection becomes creative only if it can impart direction to evolution by superintending the slow and steady accumulation of variation. (labels gradualism-1,-2,-3 are mine):
- 'gradualism-1' At the broadest level gradualism merely asserts unbroken historical connectedness between putative ancestor and descendant. If new species originate as creations ex nihilo by a divine power, then connectivity fails. Gradualism-1 does not assert anything about how evolution occurred, but merely that evolution occurred. Gould does not mention here common descent of all life, but I assume it is what he means.
- 'gradualism-2': In going from ancestor A to descendant B, A and B must be linked by a series of changes, each within the range of what natural selection might construct from ordinary variability. Otherwise, large steps would constitute the creative force of the evolutionary process, instead of natural selection. Therefore, variation necessarily occurs in small steps and the creativity of natural selection resides in the summation of those tiny inconsequential steps, which creates substantial modifications. Nature does not proceed by leaps. Macromutations normally do not contribute to evolution. Darwin: "If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely breakdown".
- 'gradualism-3': evolutionary change occurs slowly and smoothly and with a constant rate on a geological time scale (thousands of generations). Missing intermediates are caused by the imperfection of the geological record. The Cambrian 'explosion' is an artifact.
Gould's and Eldredge's theory of punctuated equilibrium opposes gradualism-3, not gradualism-1 and gradualism-2. From the perspective of thousands of generations, changes can be abrupt (discontinuous, punctuated), while still being gradual from the perspective of generations of organisms.
The change of conditions on earth is not catastrophic (change is not too much and not to fast); mass extinctions are not dominant in the history of life, they do not overrule natural selection as an explanation of adaptation. Catastrophic mass extinctions are unrelated to the fitness of the individual.
- adaptionism Adaptation is the primary outcome of natural selection as creative force.
The explanation of adaptation is the chief requirement of any evolutionary theory.
The creativity of natural selection makes adaptation central, isotropy of variation necessary, and gradualism pervasive. Perfection is not required, only better adapted than others. Imperfections are signs of history. Natural selection is the main cause of adaptation. Variation only provides the raw material. For Darwin Lamarckian inheritance of acquired characters was a secondary cause.
- scope Extrapolationism: natural selection is sufficient to explain all the diversity of life and adaptation. No other causes are needed (uniformitarism). There is no large-scale force.
Extrapolation from micro evolutionary to macro evolutionary processes.
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The core of neo-Darwinism
"All evolution is due to the accumulation of small genetic changes, guided by natural selection [the first two themes of agency and efficacy], and that transspecific evolution [the third theme of scope, or uniformitarian extension] is nothing but an extrapolation and magnification of the events that take place within populations and species". Quoted by SJG on p.160 from Ernst Mayr (1963) Animal species and evolution, p. 586. Note: transspecific = macro-evolution. In black are SJG's inserts.
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The useful effect of summarising Darwin's theory in this way is that it becomes immediately clear where criticism enters. Gould's three main criticisms are:
core element | Subsidiary-, Revision-, Killing cuts of the branches of Neo-Darwinism: R1, R2, R3: Gould's revisions |
1 agency |
S1 | subsidiary cuts in agency |
R1 | Selection works simultaneously at 3 levels: genes, organisms, species (not only at the level of the organism). This is called the 'hierarchical theory of selection'. Gould wants to expand the theory of evolution to include higher-level process of species selection, which drives large-scale evolutionary processes and is irreducible to natural selection on organisms. |
K1 | killing cuts of agency |
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2 efficacy |
S2 | subsidiary cuts in efficacy |
R2 |
internal constraints (developmental constraints, channeling). (3)
challenge the notion that mutations occur in all directions.
Internal factors restrict the freedom of natural selection to establish and control the direction
of evolutionary change
Orthodox Darwinians have not balked at negative meanings of constraint as limits
to the power of natural selection in certain definable situations. But they have been far less willing to embrace positive meanings of constraints
as promotors, suppliers, and causes of evolutionary direction and change. |
K2 |
Natural selection is not a creative force and can only eliminate the unfit. This kills neo-Darwinism. Also: if the inheritance of acquired characteristics (Lamarckism) were the dominant mechanism of change then it would kill neo-Darwinism. |
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3 scope |
S3 | subsidiary cuts in scope |
R3 |
Catastrophic mass extinction challenge Darwin's notion that biotic struggle between individuals is the most important cause. [chapter 12]
Catastrophic mass extinctions contradict Darwinian gradualism and uniformitarianism. Darwinian gradualism is based on competition between individuals, therefore the best individuals survive and this results in a general improvement of species during the geological time.
Physical causes that indiscriminately destroy thousands of species cannot improve species. Natural selection is overruled during periods of mass extinction because even the fittest and well-adapted individuals die. Physicist Luis Alvarez's theory of an extraterrestrial impact as the cause of the Cretaceous-Tertiary (K-T boundary) mass extinction was fiercely opposed by Darwinian orthodoxy, while Gould was in favour of the hypothesis. Alvarez extraterrestrial impact as an explanation for extinction runs contrary to gradualism!
The hypothesis was later confirmed by iridium measurements. Mass extinctions are more frequent, more rapid, more intense, and more different in their effects than paleontologists had suspected, and that Lyellian geology and Darwinian biology could permit.
Macroevolutionary processes must be added to microevolutionary. |
K3 | the extrapolation from micro to macro is unjustified, but natural selection can be creative in microevolution. This kills neo-Darwinism. |
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Gould as an orthodox evolutionist
"I argue, as the major thesis of this book, that modern debates have developed important and coherent auxiliary critiques on all three branches of essential Darwinian logic, and that these debates may lead to a fundamentally revised evolutionary theory with a retained Darwinian core." (p. 61)
It is important to note that Gould retained a Darwinian core, and in that sense he is an orthodox evolutionist. His revisions expand or add to the core commitments of Darwinism. He proposed revisions to agency, efficacy and scope, but no 'killing cuts' of the branches of Neo-Darwinism (see table above). Gould did not doubt evolution. Furthermore, his revisions do not introduce supernatural causes. For example, Gould's and Eldredge's theory of punctuated equilibrium opposes gradualism-3, not gradualism-1 and gradualism-2 (see gradualism). Gradualism-1 asserts unbroken historical connectedness between ancestor and descendant. If new species originate as creations ex nihilo by a divine power, then connectivity fails.
Gould as an unorthodox evolutionist
Gould illustrates his revisions with the following triangular diagram. Three causes interact in a varying degree to form the phenotype:
Figure 10-10 page 1052
Chapter 10: Historical constraints and the evolution of development.
Standard triangular diagram for depicting basic causes of form as functional (immediate adaptation to current circumstances), historical (inherited by homology, whatever the basis of ancestral origin), and structural, or arising either as physical consequence of other features or directly from the nature of physical forces acting on biological materials. All vertices may yield aptve straits of great utility to the organism.
Mainline Darwinism is a functionalist theory of "trail-and-error externalism"; the organism proposes, and the environment (interacting with the organism) disposes; variation provides potential, but not direction is the fundamental postulate of Darwinism. Natural selection carries full responsibility for the direction. If variation is undirected, then natural selection fully determines all evolutionary change.
However, constraints, that is internal factors restrict the freedom of natural selection to establish and control direction of evolutionary change. That is the unorthodox part.
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Darwin's Origin of Species is a response to Paley
Darwin knew every word of Paley's Natural Theology (1802). Darwin's The Origin of Species is one long argument against Paley's Natural Theology and for evolution. The Origin is a refutation of Natural Theology. Darwin inherited the concept of adaptation from Paley, and explained it by natural selection, whereas Paley interpreted adaptation as direct proof of the creator. Gould was struck by the correspondence between Paley's and Darwin's structure of argument and Darwin used many examples from Paley.
"The explanation of adaptation therefore stands forth as the primary problem of evolution". This is not reflected in the title of Darwin's book. But it is clear that if Darwin is to succeed he needs to explain adaptation. Gould's observations are absolutely magnificent: Darwin accepts Paley's primary observation: adaptation is pervasive in nature. He could have refuted it by pointing to imperfection [he did elsewhere], but turns Paley's explanation on its head.
"But the unkindest cut of all then holds that this order, the very basis of Paley's inference about the nature of God, arises not directly
from omnipotent benevolence, but only as a side-consequence of a causal principle of entirely opposite import - namely, as the incidental
effect of organisms struggling for their own benefit, expressed as reproductive success". [121]
"The very observation that Paley had revered as the most glorious handiwork of God, the unquestionable proof of his benevolent concern,
"just happen" as a consequence of causes operating at a lower level among struggling individuals". [124]
Gould believes that we achieve insight into the essential claims of Darwinism and natural selection by interpreting Darwin's radical theory as a response to Paley.
"Selection works directly for the benefit of organisms only, and not for any larger harmony that might embody God's benevolent intent" [127]
It follows from the above that Darwin's theory is a scientific answer to a theological doctrine ('natural theology') and that the substitution of Natural Theology by the science of evolution is the core of Darwinism (5).
Surely, Gould is a critic of orthodox Darwinism, but nowhere in his book Gould rejects this central claim of Darwinism. One cannot turn Gould into a creationist!
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Gould as an anti-creationist
Two quotes will suffice to illustrate Gould's opinion about creationists:
"We should not simply count Darwin's errors, but rather assess their importance relative to his essential postulates. (Consider, for example, the standard rhetorical, and deeply anti-intellectual, ploy of politically motivated and destructive critics, American creationists in particular. They just list the mistakes, envelop each in a cloud of verbal mockery, and pretend that the whole system has drowned in this tiny puddle of inconsequential error.)" [p. 166]
and creationism:
"Creation marks the surrender of any attempt to understand connections and patterns. We express no causal insight whatever when we say that taxonomic order reflects the plan of a creator – for unless we can know the will of God, such a statement only stands as a redundant description of the order itself." [p. 100]
Gould about junk DNA
Postscript 7 Jun 2023
Gould was a paleontologist but was interested in molecular biology too:
"Gene duplication, and other modes of origin of repeated elements that constitute such a high percentage of the genomes of complex organisms (and have been so puzzling under Darwinian assumptions about organisms as "lean and mean" machines honed to optimality by the relentless power of natural selection), ...
We can resolve this problem by recognizing augmented copies as nonadaptive spandrels at the time of their initial expression at the organismic level....
But he [Brenner] also finds a resolution to the conceptual puzzles surrounding junk DNA in recognizing that such amplified sequences, when they arise causally at the gene level and then get propagated as effects to the organismal level are nonadaptive spandrels with great potential for later exaptation to utility. Therefore, their designation as junk –that is, as currently useless, but harmless (as opposed to garbage), and replete with potential future value–seems entirely appropriate, ...
page 1268-1270.
So Gould viewed junk DNA as nonadaptive but potentially useful on the long term for an organism. Indeed, several publications claim that there is evidence that some junk DNA has acquired useful functions (9, 10, 11, 12).
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Notes
- In his The Evolution Wars, he devoted chapter 9 ('Challenges to orthodoxy').
- That selection operated in nature was accepted before The Origin, Darwin added the creative effect of natural selection. This has not been clearly explained in the Evolution textbooks! Because I did not know this, Phillip Johnson could have such a big effect on me, initially. Charles Lyell never accepted the creative force of natural selection.
- Wallace Arthur (2004) claims in his new Biased Embryos and Evolution that the direction of evolution is partly determined by 'developmental bias'.
- I miss a very important core constituent of Darwinism: the tree of life (alternatively called: 'branching evolution', or 'descent with modification', or 'speciation' or 'biodiversity' or 'multiplication of species'). Gould listed it under 'gradualism' (my gradualism-1), but it is far more important and different from gradualism. A branching tree (contrary to 'fusion') says something about the structure of the tree, not about the tempo of evolutionary change. See also the 5 theories view of Ernst Mayr. Mayr would disagree with Gould's classification.
- Ernst Mayr (1991) also states "There is indeed one belief that all true original Darwinians held in common, and that was their rejection of special creation." (One Long Argument, page 99).
- "We are skeptical of claims for the ability of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged."
My objections are: (1) this definition is too broad, (2) it is irrelevant for IDT, (3) it is too narrow. It is too broad, because it is open to the supernatural, yet framed in terms of purely scientific dissent. The questionnaire omits a crucial question: "do you accept the supernatural as valid science?". The only dissent relevant for Intelligent Design Theory is dissent from natural science. DI's questionnaire is irrelevant for IDT. My third objection is that the definition is too narrow. At least Common Descent should be included: "Do you accept that all species on earth descended from one or a few organisms?" (this conflicts with special creation!). [16 May 2005]
- Arlin Stoltzfus comments: "Neo-Darwinians quite often say that mutation is "random" and imply that it is uniform, with no preferences. Sometimes this is made explicit, as when Ridley (1985, The Problems of Evolution. Oxford University Press, Oxford) says the following:
"Because evolutionary innovations result from mutation and recombination, we should rephrase the question to ask whether mutation and recombination produce directed or undirected change. The answer is that, like pure Mendelian inheritance, they too are undirected. They do not consistently produce changes in any particular direction. Mutations affecting size are just as likely to produce
taller organisms as shorter ones. " (p. 25)
In fact, this is not the case. The effects of spontaneous mutations may tend to increase or decrease size. Recent mutation-accumulation experiments in C. elegans by Azevedo, et al. showed precisely this kind of effect:
Azevedo, R. B., P. D. Keightley, C. Lauren-Maatta, L. L. Vassilieva, M. Lynch, and A. M. Leroi. 2002. Spontaneous mutational variation for body size in Caenorhabditis elegans, Genetics 162:755-765.
This kind of effect is not adaptive for C. elegans, but that is not the point. It is non-uniform. When neo- Darwinists say "random", they often imply "uniform", but every geneticist who has ever studied mutation knows that such a claim would be incorrect. Different types of mutational effects occur at different rates. This is true if one is describing the effects in genotypic dimensions such as nucleotides, or in phenotypic ones. The reason this confusion is never resolved is that neo-Darwinists just don't care. If you are caught up in their way of thinking, quibbling about whether mutation is "random" in one way or another is irrelevant to the evolutionist: what matters is selection. In the neo-Darwinian context, the claim that mutation is "random" turns out to be, not a claim about statistics, or causation, or metaphysics, but just another way of saying that mutation is unimportant and can be ignored."
- chapter 7 in Peter Bowler (2003) Evolution The History of an Idea
- Kitta MacPherson (2009) Research team finds important role for junk DNA, Princeton University.
- Scientists discover a role for 'junk' DNA.
- So-called 'junk' DNA plays a key role in speciation.
- J Brosius, S. J. Gould (1992) On "genomenclature": a comprehensive (and respectful) taxonomy for pseudogenes and other "junk DNA".
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Reviews of The Structure of Evolutionary Theory
- 12 reviews of 'The Structure' on the 'Unofficial Stephen Jay Gould Archive" web site.
- Douglas Futuyma (2002) Stephen Jay Gould à la recheche du temps perdu.
- David Wake A few words about evoluton. Nature, 416, 787-788, 25 April 2002.
- Douglas Futuyma in Science, 296, 5568, 661-663, 26 Apr 2002.
- Mark Ridley: 'The Evolution Revolution', NewYorkTimes Mar 17, 2002. Recommended: very clearly written.
- David Jablonski in the American Scientist July-August 2002.
- H. Allen Orr THE DESCENT OF GOULD. How a paleontologist sought to revolutionize evolution, The New Yorker, Issue of 2002-09-30 Posted 2002-09-23.
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Further Reading
- suggested reading: Chapter 2: Darwin as a Philosophical Revolutionary (116-169), and the classification of challenges (166).
- suggested reading for creationists: paragraph Creationist misappropriation of punctuated equilibrium (pp.986-990) and Two Ways to Glorify God in Nature (260-281) about theists Paley and Agassiz.
- A review of Niles Eldredge (1995) Reinventing Darwin.
- A review of "Unifying Biology. The Evolutionary Synthesis and Evolutionary Biology." by Vassiliki Betty Smocovitis.
- Stephen Jay Gould (1991) Male Nipples and Clitoral Ripples is chapter 8 in: Bully for Brontosaurus. Gould uses the non-adaptive byproduct hypothesis to explain the fact that 25% of women have always, 75% have sometimes and 25% have rarely or never orgasm during intercourse (review of Elisabeth Lloyd's book).
- Computational and Analytical Molecular Evolution Lab, CAMEL, Arlin Stoltzfus. See also: "Mutationism and the Dual Causation of Evolutionary Change". (pdf)
- Who is afraid of a reductionist? is a review of Niles Eldredge's "Reinventing Darwin. The Great Evolutionary Debate."
- Warren D. Allmon, Patricia H. Kelley, and Robert M. Ross, Eds. (2008) Stephen Jay Gould. Reflections on His View of Life, Oxford University Press, New York, 2008. OUP: "This book serves as a "reader's guide" to Gould's thinking and writing, especially to his largely unreadable master work Structure of Evolutionary Theory."
Reviewed in: Nature (18 Dec 2008): "The great biologist John Maynard Smith wrote that most evolutionists saw Gould as "a man whose ideas are so confused as to be hardly worth bothering with, but as one who should not be publicly criticized because at least he is on our side against the creationists". Gould was hurt by that acidulous statement, which was without doubt unfair".
Review in American Scientist by
Kim Sterelny: "Gould's ambivalence regarding, or perhaps even hostility toward, core growth points in biology: cladistics, population genetics, ecology". "Gould showed very little interest in the evolving state of population genetics".
"Gould showed extraordinarily little interest in ecology and the processes that link population-level events to patterns in the history of life."
- David F. Prindle (2009) Stephen Jay Gould and the Politics of Evolution, Prometheus, Amherst, NY, 2009. reviewed in Science 6 November 2009 by Vassiliki Betty Smocovitis.
- Stephen Jay Gould (2007) Punctuated Equilibrium. Belknap Press of Harvard University Press, 396 pages. 'Punctuated Equilibrium' is an edited reprint of Chapter 9 from Gould's The Structure of Evolutionary Theory.
Review: Trends in Ecology & Evolution Volume 23, Issue 3, March 2008, Pages 121-122.
- Richard York and Brett Clark (2011) The Science and Humanism of Stephen Jay Gould, Monthly Review Press, New York, 2011 Paperback: 223 pp. $16.95. ISBN 9781583672167.
- Nature Editorial: Mismeasure for mismeasure, Nature 23 Jun 2011. "A critique of the work of Stephen Jay Gould should serve as encouragement to scrutinize the celebrated while they are still alive." "This month sees the latest episode: an assault on the work of US evolutionary biologist and celebrated author Stephen Jay Gould, who died in 2002. Although the critique leaves the majority of Gould's work unscathed, it carries a special sting because it deconstructs a posthumous attack that Gould launched on nineteenth-century physician Samuel Morton."
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