Unofficial SJG Archive

The Unofficial Stephen Jay Gould Archive

Unofficial SJG Archive


Quotations


  • Autobiographical
  • Cambrian Explosion
  • Natural Selection: Efficacy and Scope
  • Philosophy and History of Science
  • Progress vs. Historical Contingency
  • Punctuated Equilibrium
  • Race, IQ, and Human Evolution
  • Religion and Science
  • Unit of Selection

  •   Autobiographical

    “I was lucky to wander into evolutionary theory, one of the most exciting and important of all scientific fields. I had never heard of it when I started at a rather tender age; I was simply awed by dinosaurs. I thought paleontologists spent their lives digging up bones and putting them together, never venturing beyond the momentous issue of what connects to what. Then I discovered evolutionary theory. Ever since then, the duality of natural history—richness in particularities and potential union in underlying explanation—has propelled me.

    “I think that the fascination so many people feel for evolutionary theory resides in three of its properties. First, it is, in its current state of development, sufficiently firm to provide satisfaction and confidence, yet fruitfully undeveloped enough to provide a treasure trove of mysteries. Second, it stands in the middle in a continuum stretching from sciences that deal in timeless, quantitative generality to those that work directly with the singularities of history. Thus, it provides a home for all styles and propensities, from those who seek the purity of abstraction (the laws of population growth and the structure of DNA) to those who revel in the messiness of irreducible particularity (what, if anything, did Tyrannosaurus do with its puny front legs anyway?). Third, it touches all our lives; for how can we be indifferent to the great questions of genealogy: where did we come from and what does it all mean? and then, of course, there are all those organisms: more than a million described species, from bacterium to blue whale, with one hell of a lot of beetles in between—each with its own beauty, and each with a story to tell.”

    The Panda's Thumb, New York: W. W. Norton, 1980, pp. 11-12.


    “Evolutionists have generally depicted the second phase of the Synthesis as a gathering of traditional subdiciplines under the umbrella constructed during the first phase by fusing Mendel with Darwin. I learned something fundamental about this second phase as a participant at the conference, entitled Workshop on the Evolutionary Synthesis, that Ernst Mayr convened in Boston in 1974. This conference—an amazing experience for a young evolutionist at the beginning of a career—included every major living participant in the Synthesis except Bernhard Rensch, who was ill; G. G. Simpson, who was angry; and Sewall Wright, whom Mayr simply would not invite, despite pleas from yours truly and several others. I don't think I ever experienced a greater moment of pure "academic awe" than my first impression, when I looked across from "our" side of the table (where Mayr had placed the "young" historians and evolutionists) and saw Dobzhansky, Mayr, Stebbins, Ford, and Darlington all together on the other side.

    This marvelous conference was marred (in terms of its stated purpose) only by a severe difficulty in keeping these men to the intended subject of their reminiscences about past accomplishments. They all remained so passionately involved in modern research that, whenever the planned reminiscences began, someone would make a reference to the latest paper revising some view or another—and they would immediately begin a learned discussion about current events, fueled by delight at new findings that forced revisions of their old certainties! (A difficulty for the conference's stated aim perhaps, but personally one of the most memorable events that I have ever witnessed. If the best practitioners can maintain such openness and involvement to the end of their lives, then scholarship need not fear ossification. Such traits do not, however and alas, represent the norm in science—so I did come to understand the special excellence of these extraordinary men, and I did achieve some visceral grasp of why they, and not others, made the Synthesis.)”

    The Structure of Evolutionary Theory, Cambridge MA: Harvard University Press, 2002, p. 518-519.

    “The most beautiful things for me are better understandings of how evolution works. I am trying, as you know, to write a quite comprehensive book to be called The Structure of Evolutionary Theory. And to me that’s a personal definition. In a couple of years I will be able to gather in one volume my view of how evolution works. It is to me a great consolation because it represents the putting together of a lifetime of thinking into one source. That book will never be particularly widely read. It’s going to be far too long, and it’s only for a few thousand professionals—very different from my popular science writings—but it is of greater consolation to me because it is a chance to put into one place a whole way of thinking about evolution that I’ve struggled with all my life.”

    Beauty & Consolation: Stephen Jay Gould


      Cambrian Explosion

    Causes of Cambrian Diversity

    “We do not know why the Cambrian explosion could establish all major anatomical designs so quickly. An 'external' explanation based on ecology seems attractive: the Cambrian explosion represents an initial filling of the "ecological barrel" of niches for multicellular organisms, and any experiment found a space. The barrel has never emptied since; even the great mass extinctions left a few species in each principal role, and their occupation of ecological space forecloses opportunity for fundamental novelties. But an 'internal' explanation based on genetics and development also seems necessary as a complement: the earliest multicellular animals may have maintained a flexibility for genetic change and embryological transformation that became greatly reduced as organisms "locked in" to a set of stable and successful designs.”

    — "The Evolution of Life On Earth," Scientific American 271 (October 1994): 89.


    "As a framework for tackling the puzzle of why so much anatomical variety arose so rapidly at this unique time, I suggested that two basic approaches should be explored (with a full answer undoubtedly requiring a balance of both). An "external," or ecological, perspective would focus upon the uniquely "empty" ecological barrel of potential environments for mobile multicellular animals at the dawn of Cambrian time; almost any "experiment" might work for a while during an initial "filling"—at least until Darwinian forces sorted the workable from the suboptimal and placed a brake upon subsequent change of such magnitude. By contrast, an "internal" genetic or developmental perspective might view the Cambrian as a time of unique flexibility, before definite patterns of growth from egg to adult became so locked into the embryology of complex organisms that fundamental reconstructions became nearly impossible.

    "I suggested in Wonderful Life (and still maintain) that scientists should devote more attention to the unconventional internal arguments than to the more familiar ecological claims. I proposed no bizarre or novel evolutionary mechanisms but only emphasized a potentially greater efficacy for ordinary processes at a unique time of organic flexibility, before major developmental pathways became irrevocably set. I therefore feel that Conway Morris has misrepresented my views by vague allusion (for he can cite no true source for arguments I never made) when he states that I hint "at a special mechanism at work—some unusual genetic happenstance gone wild" or when he floats an even vaguer charge about unorthodox mechanisms that he 'believes' I have 'implied.'"

    — "Showdown on the Burgess Shale" Natural History, 107 (December 1998): 52-53.



      Natural Selection: Efficacy and Scope

    “Natural selection is not fully sufficient to explain evolutionary change for two major reasons. First, many other causes are powerful, particularly at levels of biological organization both above and below the traditional Darwinian focus on organisms and their struggles for reproductive success. At the lowest level of substitution in individual base pairs of DNA, change is often effectively neutral and therefore random. At higher levels, involving entire species or faunas, punctuated equilibrium can produce evolutionary trends by selection of species based on their rates of origin and extirpation, whereas mass extinctions wipe out substantial parts of biota's for reasons unrelated to adaptive struggles of constituent species in "normal" times between such events.

    — "The Evolution of Life On Earth," Scientific American 271 (October 1994): 85.


    “[S]ome evolutionists will protest that we are caricaturing their view of adaptation. After all, do they not admit genetic drift, allometry, and a variety of reasons for nonadaptive evolution? They do, to be sure, but we make a different point. In natural history, all possible things happen sometimes; you generally do not support your favored phenomenon by declaring rivals impossible in theory. Rather, you acknowledge the rival but circumscribe its domain of action so narrowly that it cannot have any importance in the affairs of nature. Then, you often congratulate yourself for being such an undogmatic and ecumenical chap. We maintain that alternatives to selection for best overall design have generally been relegated to unimportance by this mode of argument.”

    S. J. Gould and R. C. Lewontin, "The spandrels of San Marco and the Panglossian paradigm," Proc. R. Soc. Lond. B 205 (1161): 585.


    “Current critics of Darwinism and the modern synthesis are proposing a good deal more than a comfortable extension of the theory, but much less than a revolution. In my partisan view, neither of Darwinism's two central themes will survive in their strict formulation; in that sense, "the modern synthesis, as an exclusive proposition, has broken down on both of its fundamental claims." However, I believe that a restructured evolutionary theory will embody the essence of the Darwinian argument in a more abstract, and hierarchically extended form. The modern synthesis is incomplete, not incorrect.”

    — "Darwinism and the expansion of evolutionary theory," Science 216 (April): 380-387; Reprinted in Michael Ruse, ed., Philosophy of Biology, Amherst NY, Prometheus Books, 1998, p. 105.


    Development and Constraint

    “Developmental constraints, a subcategory of phyletic restrictions, may hold the most powerful rein of all over possible evolutionary pathways. In complex organisms, early stages of ontogeny are remarkably refractory to evolutionary change, presumably because the differentiation of organ systems and their integration into a functioning body is such a delicate process so easily derailed by early errors with accumulating effects. Von Baer's fundamental embryological laws (1828) represent little more than a recognition that early stages are both highly conservative and strongly restrictive of later development. Haeckel's biogenetic law, the primary subject of late nineteenth century evolutionary biology, rested upon a misreading of the same data (Gould, 1977). If development occurs in integrated packages and cannot be pulled apart piece by piece in evolution, then the adaptationist programme cannot explain the alteration of developmental programmes underlying nearly all changes of Bauplan.”

    S. J. Gould and R. C. Lewontin, "The spandrels of San Marco and the Panglossian paradigm," Proc. R. Soc. Lond. B 205 (1161): 594.


    “Darwin's vision [of natural selection] may prevail in the here and now of immediate adaptive struggles. But if we cannot extend the small changes thereby produced into the grandeur of geological time to yield the full tree of life, then Darwin's domain is a limited corner of evolutionary explanation. New documentation on the rapidity and intensity of mass extinction (including the event that wiped out dinosaurs) has provided the strongest argument for rejecting Darwinian extrapolation. Darwin clearly understood the threat, and he struggled against the implications of mass extinction in the Origin of Species by trying to deny both their extent and rapidity. He endeavored to spread them out in time and diminish their effects. He attempted to render them as an intensification of ordinary competition (inspired, perhaps, by an increase in rates of change for conventional processes like mountain-building and change in sea level). But if mass extinctions are true breaks in continuity, if the slow building of adaptation in normal times does not extend into predicted success across mass extinction boundaries, then extrapolationism fails and adaptationism succumbs.”

    — "The Confusion over Evolution," New York Review of Books, November 19, 1992, p. 53?.




      Philosophy and History of Science

    "Objectivity cannot be equated with mental blankness; rather, objectivity resides in recognizing your preferences and then subjecting them to especially harsh scrutiny—and also in a willingness to revise or abandon your theories when the tests fail (as they usually do)."

    — "Capturing the Center" Natural History 107 (December 1998): 18.


    “A theory often compels us to see the world in its light and support. Yet, we think we see objectively and therefore interpret each new datam as an independent confirmation of our theory. Although our theory may be wrong, we cannot confute it. To extract ourselves from this dilemma, we must bring a more adequate theory: it will not arise from facts collected in the old way. Paleontology supported creationism in continuing comfort, yet the imposition of Darwinism forced a new, and surely more adequate, interpretation upon old facts. Science progresses more by the introduction of new world-views or "pictures" than by the steady accumulation of information. . . . We have no desire to enter the tedious debate over what is, or what is not, a "model," "theory," or "paradigm" (Kuhnian, not Rudwickian). In using the neutral word "picture." we trust that readers will understand our concern with alternate ways of seeing the world that renders the same facts in different ways.”

    N. Eldredge and S. J. Gould, "Punctuated equilibria: an alternative to phyletic gradualism," In T. J. M. Schopf, ed., Models in Paleobiology, San Francisco: Freeman, Cooper and Company, 1972, pp. 86.


    "As a romantic teen-ager, I believed that my future life as a scientist would be justified if I could discover a single new fact, add a single brick to the bright temple of human knowledge. The conviction was noble enough; the metaphor was simply silly. Yet that metaphor still influences the attitude of many scientists towards their subject. In the conventional model of scientific progress, we begin in superstitious ignorance and move towards final truth by the successive accumulation of facts. In this arrogant perspective, the history of science is of little more than anecdotal interest—for it can only chronicle errors of the past and credit the bricklayers for discerning glimpses of final truth. Historians of science have utterly discredited this model during the past decade. Science is not a heartless pursuit of objective information. It is a creative human activity, its geniuses acting more as artists than as information processors. Changes in theory are not the derivative results of new discoveries but the work of creative imagination influenced by contemporary social and political forces.”

    — "On heroes and fools in science" Natural History 83 (August-Sept. 1974): 30.


    “As many scholars have pointed out (including yours truly in his very first published paper of 1965) uniformitarianism is a complex term with multiple meanings, some legitimate, but some potentially false and surely constraining. If we simply mean that we will regard nature's laws as invariant in space and time, then we merely state a general assumption and rule of reasoning in science. But if we falsely extend such a claim to current phenomena (rather than universal law)—and argue, for example, that continents must always be separated because oceans now divide our major land masses, or that mass extinction by meteritic bombardment cannot occur because we have never witnessed such an event during the short span of recorded human history—then we surely go too far. History does include aspects of directionality, and the present range of causes and phenomena does not exhaust the realm of past possibilities.”

    — "Unusual Unity," Natural History, 106 (April 1997): 71.


    “Skepticism or debunking often receives the bad rap reserved for activities—like garbage disposal—that absolutely must be done for a safe and sane life, but seem either unglamorous or unworthy of overt celebration. Yet the activity has a noble tradition, from the Greek coinage of ‘skeptic’ (a word meaning ‘thoughtful’) to Carl Sagan's last book, The Demon-Haunted World. […] Skepticism is the agent of reason against organized irrationalism—and is therefore one of the keys to human social and civic decency. […] Skepticism's bad rap arises from the impression that, however necessary the activity, it can only be regarded as a negative removal of false claims. Not so […]. Proper debunking is done in the interest of an alternate model of explanation, not as a nihilistic exercise. The alternate model is rationality itself, tied to moral decency—the most powerful joint instrument for good that our planet has ever known.”

    — "Forward," In Michael Shermer, Why People Believe Weird Things, NY: Freeman & Company, 1997, pp. ix-xii.




      Progress vs. Contingency

    “Sigmund Freud often remarked that great revolutions in the history of science have but one common, and ironic, feature: they knock human arrogance off one pedestal after another of our previous conviction about our own self-importance. In Freud's three examples, Copernicus moved our home from center to periphery, Darwin then relegated us to ‘descent from an animal world’; and, finally (in one of the least modest statements of intellectual history), Freud himself discovered the unconscious and exploded the myth of a fully rational mind. In this wise and crucial sense, the Darwinian revolution remains woefully incomplete because, even though thinking humanity accepts the fact of evolution, most of us are still unwilling to abandon the comforting view that evolution means (or at least embodies a central principle of) progress defined to render the appearance of something like human consciousness either virtually inevitable or at least predictable. The pedestal is not smashed until we abandon progress or complexification as a central principle and come to entertain the strong possibility that H. sapiens is but a tiny, late-arising twig on life's enormously arborescent bush—a small bud that would almost surely not appear a second time if we could replant the bush from seed and let it grow again.”

    — "The Evolution of Life On Earth," Scientific American 271 (October 1994): 91.


    “We talk about the ‘march from monad to man’ (old-style language again) as though evolution followed continuous pathways of progress along unbroken lineages. Nothing could be further from reality. I do not deny that, through time, the most ‘advanced’ organism has tended to increase in complexity. But the sequence from protozoan to jellyfish to trilobite to nautiloid to armored fish to dinosaur to monkey to human is no lineage at all, but a chronological set of termini on unrelated evolutionary trunks. Moreover life shows no trend to complexity in the usual sense—only an asymmetrical expansion of diversity around a starting point constrained to be simple.”

    — "Tires to Sandals," Eight Little Piggies, New York: W. W. Norton, 1993, p. 322.


    “History includes too much chaos, or extremely sensitive dependence on minute and unmeasurable differences in initial conditions, leading to massively divergent outcomes based on tiny and unknowable disparities in starting points. And history includes too much contingency, or shaping of present results by long chains of unpredictable antecedent states, rather than immediate determination by timeless laws of nature. Homo sapiens did not appear on the earth, just a geologic second ago, because evolutionary theory predicts such an outcome based on themes of progress and increasing neural complexity. Humans arose, rather, as a fortuitous and contingent outcome of thousands of linked events, any one of which could have occurred differently and sent history on an alternative pathway that would not have led to consciousness.”

    — "The Evolution of Life On Earth," Scientific American, 271 (October 1994): 85-86.


    “It seems the height of antiquated hubris to claim that the universe carried on as it did for billions of years in order to form a comfortable abode for us. Chance and historical contingency give the world of life most of its glory and fascination. I sit here happy to be alive and sure that some reason must exist for ‘why me?’ Or the earth might have been totally covered with water, and an octopus might now be telling its children why the eight-legged God of all things had made such a perfect world for cephalopods. Sure we fit. We wouldn't be here if we didn't. But the world wasn't made for us and it will endure without us.”

    — "Pleasant Dreams," An Urchin in the Storm, New York: W. W. Norton, 1987, p. 206.


    “Scientists long ago abandoned the concept of necessary links between evolution and progress as the worst kind of anthropocentric bias. Yet most laymen still equate evolution with progress and define human evolution not simply as change, but as increasing intelligence, increasing height, or some other measure of assumed improvement.”

    — "Darwin's Dilemma," Natural History 83 (June/July 1974): 29


    “I have consciously permitted a professional's bias to permeate this essay so far. I have been equating 'success' with numbers of branches on the bush—for paleontologists tend to view large-scale evolution as the differential birth and death of species, and we slip to easily into an equation of success with exuberance of branching. But, of course, we must also consider the quality of twigs, not merely their number.”

    — "The declining empire of apes," Eight Little Piggies, New York: W. W. Norton, 1993, p. 294.




      Punctuated Equilibrium

    “The modern theory of evolution does not require gradual change. It in fact, the operation of Darwinian processes should yield exactly what we see in the fossil record. It is gradualism that we must reject, not Darwinism. […] Eldredge and I believe that speciation is responsible for almost all evolutionary change. Moreover, the way in which it occurs virtually guarantees that sudden appearance and stasis shall dominate the fossil record. All major theories of speciation maintain that splitting takes place rapidly in very small populations. The theory of geographic, or allopatric, speciation is preferred by most evolutionists for most situations (allopatric means ‘in another place’). A new species can arise when a small segment of the ancestral population is isolated at the periphery of the ancestral range. Large, stable central populations exert a strong homogenizing influence. New and favorable mutations are diluted by the sheer bulk of the population through which they must spread. They may build slowly in frequency, but changing environments usually cancel their selective value long before they reach fixation. Thus, phyletic transformation in large populations should be very rare—as the fossil record proclaims. But small, peripherally isolated groups are cut off from their parental stock. They live as tiny populations in geographic corners of the ancestral range. Selective pressures are usually intense because peripheries mark the edge of ecological tolerance for ancestral forms. Favorable variations spread quickly. Small peripheral isolates are a laboratory of evolutionary change.

    “What should the fossil record include if most evolution occurs by speciation in peripheral isolates? Species should be static through their range because our fossils are the remains of large central populations. In any local area inhabited by ancestors, a descendant species should appear suddenly by migration from the peripheral region in which it evolved. In the peripheral region itself, we might find direct evidence of speciation, but such good fortune would be rare indeed because the event occurs so rapidly in such a small population. Thus, the fossil record is a faithful rendering of what evolutionary theory predicts, not a pitiful vestige of a once bountiful tale.”

    — "The Episodic Nature of Evolutionary Change," The Panda's Thumb, New York: W. W. Norton, 1980, pp. 182-184.


    “Charles Darwin viewed the fossil record more as an embarrassment than as an aid to his theory. Why, he asked (1859, p. 310), do we not find the ‘infinitely numeral transitional links’ that would illustrate the slow and steady operation of natural selection? ‘Why then is not every geological formation and every stratum full of such intermediate links? Geology assuredly does not reveal any such finely graduated organic chain; and this, perhaps is the gravest objection which can be urged against my theory’ (1859, p. 280). Darwin resolved this dilemma by invoking the great inadequacy of surviving evidence (1859, p. 342): ‘The geological record is extremely imperfect and this fact will to a large extent explain why we do not find interminable varieties, connecting together all the extinct and existing forms of life by the finest graduated steps. He who rejects these views on the nature of the geological record, will rightly reject my whole theory.' Thus Darwin set the path for the new science of evolutionary paleontology: to demonstrate evolution, search the fossil record and extract the rare exemplars of Darwinian process—insensibly graded fossil series, spared somehow from the ravages of decomposition, non-deposition, metamorphism, and tectonism.”

    N. Eldredge and S. J. Gould, "Punctuated equilibria: an alternative to phyletic gradualism," In T. J. M. Schopf, ed., Models in Paleobiology, San Francisco: Freeman, Cooper and Company, 1972, p. 87.


    “Traditional explanations for stasis and abrupt appearance had paid an awful price in sacrificing the possibility of empirics for the satisfaction of harmony. Eventually we (primarily Niles) recognized that the standard theory of speciation—Ernst Mayr's allopatric or peripatric scheme—would not, in fact, yield insensibly graded fossil sequences when extrapolated into geological time, but would produce just what we see: geologically unresolvable appearance followed by stasis. For if species almost always arise in small populations isolated at the periphery of parental ranges, and in a period of time slow by the scale of our lives but effectively instantaneous in the geological world of millions, then the workings of speciation should be recorded in the fossil record as stasis and abrupt appearance. The literal record was not a hopelessly and imperfect fraction of truly insensible gradation within large populations but an accurate reflection of the actual process identified by evolutionists as the chief motor of biological change. The theory of punctuated equilibrium was, in its initial formulation, little more than this insight adumbrated.”

    — "Punctuated Equilibrium in Fact and Theory," In Albert Somit and Steven Peterson The Dynamics of Evolution. New York: Cornell University Press, 1992, pp. 56-57.


    “I want to argue that the ‘sudden’ appearance of species in the fossil record and our failure to note subsequent evolutionary change within them is the proper prediction of evolutionary theory as we understand it. Evolution usually proceeds by ‘speciation’—the splitting of one lineage from a parental stock—not by the slow and steady transformation of these large parental stocks. Repeated episodes of speciation produce a bush. How does speciation occur? This is a perennial hot topic in evolutionary theory, but most biologist would subscribe to the ‘allopatric theory’ (the debate centers on the admissibility of other modes; nearly everyone agrees that allopatric speciation is the most common mode). Allopatric means ‘in another place.’ In the allopatric theory, popularized by Ernst Mayr, new species arise in very small populations that become isolated from their parental group at the periphery of the ancestral range. Speciation in these small isolates is very rapid by evolutionary standards—hundreds or thousands of years (a geological microsecond).

    “Pressures of natural selection tend to be intense in geographically marginal areas where the species barely maintains a foothold. Favorable genetic variation can quickly spread through these reduced populations. In large central populations, on the other hand, favorable variations spread very slowly, and most change is steadfastly resisted by the well-adapted population. Small changes occur to meet the requirements of slowly altering climates, but major genetic reorganizations almost always take place in the small, peripherally isolated populations that form new species.

    “If evolution almost always occurs by rapid speciation in small, peripheral isolates, then what should the fossil record look like? We are not likely to detect the event of speciation itself. It happens too fast, in too small a group, isolated too far from the ancestral range. Only after its successful origin will we first meet the new species as a fossil—when it reinvades the ancestral range and becomes a large central population in its own right. During its recorded history in the fossil record, we should expect no major change. We know it only as a successful central population. It will participate in the process of organic change only when some of its peripheral isolates species to become new branches on the evolutionary bush. But it, itself, will appear ‘suddenly’ in the fossil record and become extinct later with equal speed and little perceptible change in form.”

    — "Ladders, Bushes, and Human Evolution" Natural History 85 (April 1976): 30-31.


    “The simple claim that species arise by splitting, and not by transformation of entire ancestral populations, does not guarantee punctuated equilibrium. Suppose that most splitting events divide large populations into two units of roughly equal size, which then change at the conventional gradualistic rate. Splitting events, in this scenario, would yield two examples of gradualism—and the case for punctuated equilibrium would be compromised, not strengthened. Punctuated equilibrium gains its rationale from the ideal also a standard component of the allopatric speciation theory, that most peripherally isolated populations are relatively small and undergo their characteristic changes at a rate that translates into geological time as an instant.”

    — "Opus 200" Natural History 100 (August 1991): 14.


    “[B]ecause species often maintain stability through such intense climatic change as glacial cycling, stasis must be viewed as an active phenomenon, not a passive response to unaltered environments. Many leading evolutionary theorists, while not accepting our preference for viewing stasis in the context or habitat tracking or developmental constraint have been persuaded by punctuated equilibrium that maintenance of stability within species must be considered as a major evolutionary problem.”

    — "Punctuated equilibrium comes of age" Nature 366 (November 18, 1993): 223-24


    “I emphatically do not assert the general ‘truth’ of this philosophy of punctuational change. Any attempt to support the exclusive validity of such a grandiose notion would border on the nonsensical. […] Nonetheless, I will confess to a personal belief that a punctuational view may prove to map tempos of biological and geographic change more accurately and more often than any of its competitors—if only because complex systems in steady state are both common and highly resistant to change. As my colleague British geologist Derek V. Ager writes in supporting a punctuational view of geologic change: ‘The history of any one part of the earth, like the life of a soldier, consists of long periods of boredom and short periods of terror.’”

    — "The Episodic Nature of Evolutionary Change," The Panda's Thumb, New York: W. W. Norton, 1980, p. 185.


    “Since we proposed punctuated equilibria to explain trends, it is infuriating to be quoted again and again by creationists—whether through design or stupidity, I do not know—as admitting that the fossil record includes no transitional forms. Transitional forms are generally lacking at the species level, but they are abundant between larger groups.”

    — "Evolution as Fact and Theory," Hen's Teeth and Horse's Toes, New York: W. W. Norton, 1994, p. 260.


    “[M]echanisms of speciation can be studied directly only with experimental and field techniques applied to living organisms. No theory of evolutionary mechanisms can be generated directly from paleontological data. Instead, theories developed by students of the modern biota generate predictions about the course of evolution in time. With these predictions, the paleontologist can approach the fossil record and ask the following question: Are observed patterns of geographic and stratographic distribution, and apparent rates and directions of morphological change, consistent with the consequences of a particular theory of speciation? We can apply and test, but we cannot generate new mechanisms. If discrepancies are found between paleontological data and the expected patterns, we may be able to identify those aspects of a general theory that need improvement. But we cannot formulate these improvements ourselves.”

    N. Eldredge and S. J. Gould, "Punctuated equilibria: an alternative to phyletic gradualism," In T. J. M. Schopf, ed., Models in Paleobiology, San Francisco: Freeman, Cooper and Company, 1972, pp. 93-94.


    “Eldredge and I argue that most species are stable for most of their geological lifetimes, often lasting many millions of years—the equilibrium—and that change does not usually occur by imperceptibility gradual alteration of entire species but rather by isolation of small populations and their geologically instantaneous transformation to new species—the punctuation. Our theory entails no new or violent mechanism, but only represents the proper scaling of ordinary events into the vastness of geological time. An isolated population may take a thousand years to speciate, and its transformation would therefore appear glacially slow if measured by the irrelevant scale of our personal lives. But a thousand years, appropriately recorded in geological time, is only an unresolvable moment, usually preserved on a single bedding plane, in the lifetime of species that often live for several million years in stasis.”

    — "Life in a Punctuation," Natural History 101 (October 1992): 12-14.


    “In this crucial sense, the theory of punctuated equilibrium adopts a very conservative position. The theory asserts no novel claim about modes or mechanisms of speciation; punctuated equilibrium merely takes a standard microevolutionary model and elucidates its expected expression when properly scaled into geological time.”

    The Structure of Evolutionary Theory, Cambridge MA: Harvard University Press, 2002, p. 778.


    “Ordinary speciation remains fully adequate to explain the causes and phenomenology of punctuation.”

    The Structure of Evolutionary Theory, Cambridge MA: Harvard University Press, 2002, p. 1001.


    “I did speak extensively—often quite critically—about the reviled work of Richard Goldschmidt, particularly about aspects of his thought that might merit a rehearing. This material has often been confused with punctuated equlibrium by people who miss the crucial issue of scaling, and therefore regard all statements about rapidity at any level as necessarily unitary, and necessarily flowing from punctuated equilibrium. In fact, as the long treatment in Chapter 5 of this book should make clear, my interest in Goldschmidt resides in issues bearing little relationship with punctuated equilibrium, but invested instead in developmental questions that prompted my first book, Ontogeny and Phylogeny. The two subjects, after all, are quite separate, and rooted in different scales of rapidity—hopeful monsters in genuine saltation, and punctuated equilibrium in macroevolutionary puntuation (produced by ordinary allopatric speciation).”

    The Structure of Evolutionary Theory, Cambridge MA: Harvard University Press, 2002, p. 1005.


    “Finally, the claim that we equated punctuated equilibrium with saltation makes no sense within the logical structure of our theory—so, unless we are fools, how could we ever have asserted such a proposition? Our theory holds, as a defining statement, that ordinary allopatric speciation, unfolding gradually at microevolutionary scales, translates to punctuation in geological time.”

    The Structure of Evolutionary Theory, Cambridge MA: Harvard University Press, 2002, p. 1009.


    “Punctuated equilibrium is not a theory of macromutation…it is not a theory of any genetic process…It is a theory about larger-scale patterns—the geometry of speciation in geological time. As with ecologically rapid modes of speciation, punctuated equilibrium welcomes macromutation as a source for the initiation of species: the faster the better. But punctuated equilibrium clearly does not require or imply macromutation, since it was formulated as the expected geological consequence of Mayrian allopatry.”

    — "The meaning of punctuated equilibrium and its role in validating a hierarchical approach to macroevolution." In R. Milkman, ed., Perspectives on Evolution, Sunderland MA: Sinauer Associates, 1982, p. 83.


    “For all the hubbub it engendered, the model of punctuated equilibria is scarcely a revolutionary proposal. As Simpson (1976, p. 5), with his unfailing insight, recognized in three lines (where others have misunderstood in entire papers) our model tries to 'clarify and emphasize ideas nascent in previous studies of the synthetic theory.' We merely urged our colleagues to consider seriously the implications for the fossil record of a theory of speciation upheld by nearly all of us and to recognize that the search for phyletic gradualism as a bad historical habit not consistent with modern evolutionary ideas.”

    — "Punctuated equilibria: the tempo and mode of evolution reconsidered." Paleobiology 3 (Spring 1977): 117.


    “Punctuated equilibrium is a specific claim about speciation and its deployment in geological time; it should not be used as a synonym for any theory of rapid evolutionary change at any scale....Punctuated equilibrium holds that accumulated speciation is the root of most major evolutionary change, and that what we have called anagenesis is usually no more than repeated cladogenesis (branching) filtered through the net of differential success at the species level.”

    — "The meaning of punctuated equilibrium and its role in validating a hierarchical approach to macroevolution." In R. Milkman, ed., Perspectives on Evolution, Sunderland MA: Sinauer Associates, 1982, pp. 84-85.


    “First, simple misunderstanding of basic content was distressingly common, even among professional evolutionists. Many colleagues thought that we had raised the old anti-Darwinian specter of macromutationism, or truly sudden speciation in a single generation by a large and incredibly lucky mutation. I do not know why this happened; I think that all our articles and public statements were clear in separating human from geological rapidity.”

    — "Opus 200" Natural History 100 (August 1991): 16.


    “Punctuated equilibrium was not a grandiose theory of the nature of change, a Marxist plot, a cladistical cabal, an attempt to sneak the hopeful monster back into evolution, or a tortuous assault on the concept of adaptation. It was at first, and has always been: (1) A well-defined, testable theory about the origin of species and their geological deployment (not a general rubric for any old idea about rapidity at any scale, and specifically not a notion about saltation, the origin of new Baupläne, or mass extinction). (2) A theory based on the recognition that events judged as glacially slow in ecological time might appear instantaneous in geological resolution (the conversion of the peripheral isolate into species, in particular). Some neontologists, misconstruing punctuated equilibrium as a theory of saltation, have charged that we made a disabling error in not recognizing the difference in scale between ecology and geology and in thinking that geological abruptness demanded some notion of true discontinuity. Quite the reverse: Punctuated equilibrium is not a theory of saltation, and its anchor lies in this appreciation of scaling—particularly, in recognizing how an ecological "slow" event like allopatric speciation must translate into the geological record.”

    — "Punctuated equilibrium in fact and theory." In Albert Somit and Steven Peterson, The Dynamics of Evolution, New York: Cornell University Press, p. 57.


    Others Voice In

    “The tale of punctuated equilibria is an odd one. Its factual basis, commonly reported by paleontologists, is that lineages often change very little for millions of years, and then change rather rapidly. When the idea was first put forward by Gould and Niles Eldredge, it was presented as just what one would expect to see if the orthodox view, that species often arise by rapid evolution in small peripheral populations, is indeed accurate. If only they had left the argument there! Their paper would then have been seen as a useful extension of the picture given in Tempo and Mode in Evolution by George Gaylord Simpson, which was the Darwinian orthodoxy when I was a student. Sometimes, however, Gould appears to be saying that the changes, when they occurred, were not the result of natural selection, but of some other process—genetic revolutions, 'hopeful monsters' (large mutational changes), or what you will. Since "sudden" in the fossil record means thousands of generations, there is no reason whatever for supposing any such thing.”

    John Maynard-Smith "Genes, Memes, & Minds," New York Review of Books 42 (November 30, 1995): ??



      Race, IQ, and Human Evolution

    “I do not claim that intelligence, however defined, has no genetic basis—I regard it as trivially true, uninteresting, and unimportant that it does. The expression of any trait represents a complex interaction of heredity and environment. Our job is simply to provide the best environmental situation for the realization of valued potential in all individuals. I merely point out that a specific claim purporting to demonstrate a mean genetic deficiency in the intelligence of American blacks rests upon no new facts whatever and can cite no valid data in its support. It is just as likely that blacks have a genetic advantage over whites. And, either way, it doesn't matter a damn. An individual can't be judged by his group mean.”

    "Racist Arguments and I.Q." Natural History 83 (May 1974): 29

      Religion and Science

    “The anatomical transition from reptiles to mammals is particularly well documented in the key anatomical change of jaw articulation to hearing bones. Only one bone, called the dentary, builds the mammalian jaw, while reptiles retain several small bones in the rear portion of the jaw. We can trace, through a lovely sequence of intermediates, the reduction of these small reptilian bones, and their eventual disappearance or exclusion from the jaw, including the remarkable passage of the reptilian articulation bones into the mammalian middle ear (where they became our malleus and incus, or hammer and anvil). We have even found the transitional form that creationists often proclaim inconceivable in theory—for how can jawbones become ear bones if intermediaries must live with an unhinged jaw before the new joint forms? The transitional species maintains a double jaw joint, with both the old articulation of reptiles (quadrate to articular bones) and the new connection of mammals (squamosal to dentary) already in place! Thus, one joint could be lost, with passage of its bones into the ear, while the other articulation continued to guarantee a properly hinged jaw. Still, our creationist incubi, who would never let facts spoil a favorite argument, refuse to yield, and continue to assert the absence of all transitional forms by ignoring those that have been found, and continuing to taunt us with admittedly frequent examples of absence.”

    — "Hooking Leviathan by Its Past," Dinosaur in a Haystack, New York: Crown Trade Paperbacks, 1997, pp. 360-361.


    “Scientific claims must be testable; we must, in principal, be able to envision a set of observations that would render them false. Miracles cannot be judged by this criterion, as Whitcomb and Morris have admitted. But is all creationists writing merely about untestable singularities? Are arguments never made in proper scientific form? Creationists do offer some testable statements, and these are amenable to scientific analysis. Why, then, do I continue to claim that creationism isn't science? Simply because these relatively few statements have been tested and conclusively refuted.”

    — "Genesis vs. Geology," In Ashley Montagu, ed., Science and Creationism, New York: Oxford University Press, 1984, pp. 130-131.


    “Our creationist detractors charge that evolution is an unproved and unprovable charade—a secular religion masquerading as science. They claim, above all, that evolution generates no predictions, never exposes itself to test, and therefore stands as dogma rather than disprovable science. This claim is nonsense. We make and test risky predictions all the time; our success is not dogma, but a highly probable indication of evolution's basic truth.”

    — "Magnolias from Moscow," Dinosaur in a Haystack, New York: Crown Trade Paperbacks, 1997, p. 409.


    “Well evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts do not go away when scientists debate rival theories to explain them. Einstein's theory of gravitation replaced Newton's, but apples did not suspend themselves in mid-air, pending the outcome. And humans evolved from apelike ancestors whether they did so by Darwin's proposed mechanism or by some other yet to be discovered.”

    — "Evolution as Fact and Theory," Hen's Teeth and Horse's Toes, New York: W. W. Norton, 1994, p. 254.


    “In my field of evolutionary biology, the most prominent urban legend—another ‘truth’ known by ‘everyone’—holds that evolution may well be the way of the world, but one has to accept the idea with a dose of faith because the process occurs far too slowly to yield any observable result in a human life-time. Thus, we can document evolution from the fossil record and infer the process from the taxonomic relationships of living species, but we cannot see evolution on human timescales ‘in the wild.’ In fairness, we professionals must shoulder some blame for this utterly false impression about evolution's invisibility in the here and now of everyday human life. Darwin himself—although he knew and emphasized many cases of substantial changes in human time (including the development of breeds in his beloved pigeons—tended to wax eloquent about the inexorable and stately slowness of natural evolution. In a famous passage from the Origin of Species, he even devised a striking metaphor about clocks to underscore the usual invisibility:

    It may be said that natural selection is daily and hourly scrutinizing, throughout the world, every variation, even the slightest; rejecting that which is bad, preserving and adding up all that is good; silently and invisibly working. . . . We see nothing of theses slow changes in progress until the hand of time has marked the long lapse of ages.

    “Nonetheless, the claim that evolution must be too slow to see can only rank as an urban legend—although not a completely harmless tale in this case, for our creationists incubi can then use the fallacy as an argument against evolution at any scale, and many folks take them seriously because they just ‘know’ that evolution can never be seen in the immediate here and now. In fact, a precisely opposite situation prevails: biologists have documented a veritable glut of cases for rapid and eminently measurable evolution on timescales of years and decades.”

    — "The Paradox of the Visibly Irrelevant," Natural History 106 (December 2000): 12.


    “‘Creation science’ has not entered the curriculum for a reason so simple and so basic that we often forget to mention it: because it is false, and because good teachers understand exactly why it is false. What could be more destructive of that most fragile yet most precious commodity in our entire intellectual heritage — good teaching—than a bill forcing honorable teachers to sully their sacred trust by granting equal treatment to a doctrine not only known to be false, but calculated to undermine any general understanding of science as an enterprise?”

    — "Verdict on Creationism," The Skeptical Inquirer 12 (no. 2 1988): 186.


    “As a methodology for research, science adopts as its cardinal postulate (proved fruitful by its enormous success since the time of Galileo, Newton and Descartes) the commitment to explain empirical phenomena by reference to invariant laws of nature and to avoid appeals to the miraculous, defined as a suspension of those laws for particular events. The notion of ‘abrupt appearance,’ the origin of complex somethings from previous nothings, resides in this domain of miracle and is not part of science.

    “Punctuated equilibrium, catastrophic theories of mass extinction, hopeful monsters, and a variety of hypotheses about rapid rates of change in continuous sequences, not about unintelligible abrupt appearances, are part of scientific debate and bear no relationship to the nonscientific notion of abrupt appearance, despite pernicious and willful attempts by many creationists to distort such claims by misquote and halfquote to their alien purposes. Punctuated equilibrium, in particular, is a claim that evolutionary trends have a geometry that resembles a climb up a staircase rather than a slide up an inclined plane. It is, in other words, an alternate theory about the nature of intermediate stages in evolutionary trends not, as creationists have claimed, a denial of these stages. As a term, ‘creation science’ is an oxymoron, a self-contradictory and meaningless phrase, a whitewash for a specific, particular, and minority religious view in America—Biblical literalism.”

    — "Creationism: Out of the Mainstream," The Scientist 1 (November 17, 1986): 10.


    “In their recently aborted struggle to inject Genesis literalism into science classrooms, fundamentalist groups followed their usual opportunistic strategy of arguing two contradictory sides of a question when a supposed rhetorical advantage could be extracted from each. Their main pseudoargument held that Genesis literalism is not religion at all, but really an alternative form of science not acknowledged by professional biologists too hidebound and dogmatic to appreciate the cutting edge of their own discipline. When we successfully pointed out that ‘creation science’—as an untestable set of dogmatic proposals—could not qualify as science by any standard definition, they turned around and shamelessly argued the other side. […] (They actually pulled off the neater trick of holding both positions simultaneously.) Now they argued that, yes indeed, creation science is religion, but evolution is equally religious. Thus, they claimed, creation science and evolution science are symmetrical—that is, equally religious. Creation science isn't science because it rests upon the untestable fashioning of life ex nihilo by God. Evolution science isn't science because it tries, as its major aim, to resolve the unresolvable and ultimate origin of life. But we do no such thing. We understand Hutton's wisdom—‘he has nowhere treated of the first origin …of any substance… but only of the transformations which bodies have undergone…’”

    — "Justice Scalia's Misunderstanding," Bully for Brontosaurus, New York: W. W. Norton, 1991, pp. 455-456.


    “Two organisms may maintain the same feature because both inherited it from a common ancestor. These are homologous similarities, and they indicate ‘propinquity of dissent,’ to use Darwin's words. Forelimbs of people, porpoises, bats and horses provide the classic example of homology in most textbooks. They look different, and do different things, but are built of the same bones. No engineer, starting from scratch each time, would have built such desperate structures from the same parts. Therefore, the parts existed before the particular set of structures now housing them: they were, in short, inherited from a common ancestor.”

    — "Inside a Sponge's Cell," The Panda's Thumb, New York: W. W. Norton, 1980, p. 248.


    “Orchids manufacture their intricate devices from the common components of ordinary flowers, parts usually fitted for very different functions. If God had designed a beautiful machine to reflect his wisdom and power, surely he would not have used a collection of parts generally fashioned for other purposes. Orchids were not made by an ideal engineer; they are jury-rigged from a limited set of available components. Thus, they must have evolved from ordinary flowers.”

    — "The Panda's Thumb," The Panda's Thumb, New York: W. W. Norton, 1980, p. 20.




      Unit of Selection

    “Yet, just as individual selection emerged relatively unscarred after its battle with group selection from above, other evolutionists launched an attack from below. Genes, they argue, not individuals are the units of selection. They begin by recasting Butler's famous aphorism that a hen is merely the egg's way of making another egg. An animal, they argue, is only DNA's way of making more DNA. Richard Dawkins has put the case most forcefully in his recent book The Selfish Gene. ‘A body,’ he writes, ‘is the gene's way of preserving the gene unaltered.’ For Dawkins, evolution is a battle among genes, each seeking to make more copies of itself. Bodies are merely the places where genes aggregate for a time. Bodies are temporary receptacles, survival machines manipulated by genes and tossed away on the geological scrap heap once genes have replicated and slaked their insatiable thirst for more copies of themselves in bodies of the next generation. He writes:

    We are survival machines—robot vehicles blindly programmed to preserve the selfish molecules known as genes. . . . They swarm in huge colonies, safe inside gigantic lumbering robots . . . they are in you and me; they created us, body and mind; and their preservation is the ultimate rationale for our existence.

    “Dawkins explicitly abandons the Darwinian concept of individuals as the units of selection: ‘I shall argue that the fundamental unit of selection, and therefore of self-interest, is not the species, nor the group, nor even, strictly, the individual. It is the gene, the unit of heredity,’ Thus, we should not talk about kin selection and apparent altruism. Bodies are not the appropriate units. Genes merely try to recognize copies of themselves wherever they occur. They act only to preserve copies and make more of them. They couldn't care less which body happens to be their temporary home. […] Still, I find a fatal flaw in Dawkins' attack from below. No matter how much power Dawkins wishes to assign to genes, there is one thing he cannot give them—discrete visibility to natural selection. Selection simply cannot see genes and pick among them directly. It must use bodies as an intermediary. A gene is a bit of DNA hidden within a cell. Selection views bodies. It favors some bodies because they are stronger, better insulated, earlier in their sexual maturation, fiercer in combat, or more beautiful to behold.”

    — "Caring Groups and Selfish Genes," The Panda's Thumb, New York: W. W. Norton, 1980, pp. 89-90.



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