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).
The Lying Stones of Marrakech, New York: Harmony Books, 2000, pp. 104-105.
We talk about the ‘march from monad to man’ (old-style language again) as though evolution followed continuous pathways to 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 [allocated in most texts] from 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.
Eight Little Piggies: Reflections in Natural History, New York: W. W. Norton, 1993, p. 322.
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, 1994, 271 (4): 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: Reflections in Natural History, New York: W. W. Norton & Company, 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 stocknot by the slow and steady transformation of these large parental stocks. Repeated episodes of speciation produce a bush. Evolutionary ‘sequences’ are not rungs on a ladder, but our retrospective reconstruction of a circuitous path running like a labyrinth, branch to branch, from the base of the bush to a lineage now surviving at its top. 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 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 standardshundreds or thousands of years (a geological microsecond). Major evolutionary change may occur in these small isolated populations. Favorable genetic variation can quickly spread through them. Moreover, natural selection tends to be intense in geographically marginal areas where the species barely maintains a foothold. 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 isolatesrather than by slow change in large central populationsthen 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. We will 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; for 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.
"Bushes and Ladders," Ever Since Darwin: Reflections in Natural History, New York: W. W. Norton & Company, 1977, pp. 61-62.
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 speciationErnst Mayr's allopatric or peripatric schemewould 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," Skeptic, 1 (3): 49.
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: Reflections in Natural History, New York: W. W. Norton & Company, 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 of the blame for this utterly false impression about evolution's invisibility in the here and now of everyday human life. Darwin himself thought 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, through out 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 though 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 completely opposite situation actually 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," The Lying Stones of Marrakech, New York: Harmony Books, 2000, pp. 334-335.
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: Further Reflections in Natural History, New York: W. W. Norton & Company, 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: Reflections in Natural History, 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.
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: Reflections in Natural History, 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: Further Reflections in Natural History, New York: W. W. Norton & Company, 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 AmericaBiblical literalism.
"Creationism: Out of the Mainstream," The Scientist, 1986, 1 (Nov. 17): 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: Reflections in Natural History, New York: W. W. Norton & Company, 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: More Reflections in Natural History, New York: W. W. Norton & Company, 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-riged 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 & Co., 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 decencythe most powerful joint instrument for good that our planet has ever known.
Why People Believe Weird Things, New York: 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 & Co., 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, 1994, 271 (4): 85-86.
If we must deal in metaphors [to characterize the Cambrian Explosion as well as 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 & Co., 1980, p. 140.
There is no progress in evolution. The fact of evolutionary change through time doesn't represent progress as we know it. Progress is not inevitable. Much of evolution is downward in terms of morphological complexity, rather than upward. We're not marching toward some greater thing. The actual history of life is awfully damn curious in the light of our usual expectation that there's some predictable drive toward a generally increasing complexity in time. If that's so, life certainly took its time about it: five-sixths of the history of life is the story of single-celled creatures only.
"The Pattern of Life's History," The Third Culture, New York: Simon & Shuster, 1995, p. 52.
Natural selection can only produce adaptation to immediately surrounding (and changing) environments. No feature of such local adaptation should yield any expectation of general progress (however such a vague term be defined). Local adaptation may as well lead to anatomical simplification as to greater complexity. As an adult, the famous parasite Sacculina, a barnacle by ancestry, looks like a formless bag of reproductive tissue attached to the underbelly of its crab host (with ‘roots’ of equally formless tissue anchored within the body of the crab itself)a devilish device to be sure (at least by our aesthetic standards), but surely less anatomically complex than a barnacle on the bottom of your boat, waving its legs through the water in search of food.
"The Bare Bones of Natural Selection," Full House: The Spread of Excellence from Plato to Darwin, New York: Harmony Books, 1996, p. 139.
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: More Reflections in Natural History, New York: W. W. Norton & Company, 1980, pp. 89-90.
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 in 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 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 & Company, 1980, pp. 11-12.
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