Unofficial SJG Archive

The Unofficial Stephen Jay Gould Archive

Unofficial SJG Archive


Quotations


"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.


“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 darwiniana 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.


“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.


“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.


“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.


“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, peripherially 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.


“In other words, morphological change correlates so strongly with speciation not because cladogenesis accelerates evolutionary rates, but rather because such changes, which can occur at any time in the life of a local population, cannot be retained (and sufficiently stabilized to participate in selection) without the protection provided by individuation—and speciation, via reproductive isolation, represents nature's preeminent mechanism for generating macroevolutionary individuals. Speciation does not necessarily promote evolutionary change; rather, speciation 'gathers in' and guards evolutionary change by locking and stabilization for sufficient geological time within a Darwinian individual of the appropriate scale. If a change in a local population does not gain such protection, it becomes—to borrow Dawkins's metaphor at a macroevolutionary scale—a transient duststorm in the desert of time, a passing cloud without borders, integrity, or even the capacity to act as a unit of selection, in the panorama of life's phylogeny.”

The Structure of Evolutionary Theory, Cambridge MA: Harvard University Press, 2002, p. 801.


“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 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.


“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.


“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.


“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.


“‘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, 1988, 12 (2): 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 (creation 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.…They then pointed out, as Hutton had, that questions of ultimate origins are not resolvable by science. 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," Natural History 96 (October 1987): 18.


“Two organisms may maintain the same feature because both inherited it from a common ancestor. These are homologous similarities, and they indicate ‘propinquity of descent,’ 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 disparate 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.


“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.


“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.


“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.


“If we must deal in metaphors [to characterize the Cambrian Explosion and trends in the evolution of complexity], I prefer a very broad, low and uniform slope. Water drops randomly at the top and usually dries before flowing anywhere. Occasionally, it works its way downslope and carves a valley to channel future flows. The myriad valleys could have arisen anywhere on the landscape. The current positions are quite accidental. If we could repeat the experiment, we might obtain no valleys at all, or a completely different system. Yet we now stand at the shore line contemplating the fine spacing of valleys and their even contact with the sea. How easy it is to be misled and to assume that no other landscape could possibly have arisen.”

— "In the Midst of Life…," The Panda's Thumb, New York: W. W. Norton, 1980, p. 140.


“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.


“[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.”

The Spandrels of San Marco and the Panglossian Paradigm, Proc. R. Soc. Lond. B 205 (1161): 585.


“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.”

The Spandrels of San Marco and the Panglossian Paradigm, Proc. R. Soc. Lond. B 205 (1161): 594.


“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.


“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.”

— "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.



Home Page  |  Further Reading  |  Site Map  |  Send Feedback