"The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme", also known as the "Spandrels paper", [1] is a paper by evolutionary biologists Stephen Jay Gould and Richard Lewontin, originally published in the Proceedings of the Royal Society B: Biological Sciences in 1979. [2] The paper criticizes the adaptationist school of thought that was prevalent in evolutionary biology at the time using two metaphors: that of the spandrels in St Mark's Basilica, a cathedral in Venice, Italy, and that of the fictional character "Pangloss" in Voltaire's novella Candide . The paper was the first to use the architectural term "spandrel" in a biological context; the term "spandrel" has since gained currency in biology to refer to byproducts of adaptation. [3]
"Spandrels" was originally written in 1978, and that year Gould delivered it as a talk to the Royal Society. [4] Gould had visited St. Mark's Cathedral shortly before he wrote the paper. [5] The published paper lists both Gould and Lewontin as authors. However, in a 2015 interview, Lewontin said that Gould wrote the majority of the paper, and that he himself had made only "a lesser contribution" to it. [6]
Gould himself has referred to the paper as an "opinion piece" because, unlike most scientific papers, it was not based on a literature review or empirical data. It was written in a provocative and literary style that was unusual even compared to that of most other opinion pieces. [7] David C. Queller described the paper as "an opinion piece, a polemic, a manifesto, and a rhetorical masterpiece". [8]
In the "Spandrels" paper, Gould and Lewontin argue that the mosaic design on the spandrels in St. Mark's Basilica is "so elaborate, harmonious, and purposeful that we are tempted to view it as the starting point of any analysis, as the cause in some sense of the surrounding architecture." They then claim that this would be inappropriate, because the spandrels themselves were an architectural constraint that "provide a space in which the mosaicists worked". The paper makes an analogy between these spandrels and the evolutionary constraints of living organisms, and the need to distinguish between the current use of a trait and the reason it evolved. [2] : 582 It also compares the adaptationist perspective to that of Dr. Pangloss, a character in Voltaire's Candide, who believed that the world he lived in was the best world possible. [9] This view is embodied in the statement by Pangloss that "Everything is made for the best purpose. Our noses were made to carry spectacles, so we have spectacles. Legs were clearly intended for breeches, and we wear them." [10] The "Spandrels" paper also criticizes adaptationists for not developing sufficiently rigorous methods to test their hypotheses. [11]
"Spandrels" has proven highly influential and controversial since it was first published. [8] Gerald Borgia of the University of Maryland described the paper as "among the best known and most factious papers in evolutionary biology in the past 50 years." [12] Similarly, David Sloan Wilson referred to it as "[o]ne of the most influential works in the field of evolutionary biology". [13] It is sometimes credited with beginning the debate about the validity of adaptationism in modern evolutionary biology, [14] though this claim is disputed by other scholars. [15] The paper also inspired a book, Understanding Scientific Prose, which was published in 1993. The book consists of fourteen reviews of the original 1979 paper by experts from various fields, followed by a chapter-length reply by Gould. [12] According to Massimo Pigliucci and Jonathan Kaplan, "After the ‘Spandrels paper’, evolutionists were more careful about producing just-so stories based on selection, and paid more attention to a panoply of other processes." [1] In 2009, Rasmus Nielsen wrote that the paper "fundamentally changed the discourse of evolutionary biology". [16]
Ernst Mayr argued that the criticisms made by Gould and Lewontin in "Spandrels" were valid, but that the problems they identified were the result of mistakes in the execution of the adaptationist program, such as excessively atomistic and deterministic perspectives, rather than flaws of the adaptationist program itself. [17] John Maynard Smith believed by and large "their paper had a healthy effect.… Their critique forced us to clean up our act and to provide evidence for our stories. But adaptationism remains the core of biological thinking." [18] In reviewing Understanding Scientific Prose, Tim Radford wrote that the "Spandrels" paper was "...unusual because a nonscientist can understand exactly what is being said, and read it all the way through without nodding off, while at the same time veteran and world-leading evolutionary theorists can read it and apparently have apoplexy." [5] Sandra Mitchell argues that the paper's arguments regarding adaptationism can be interpreted in three different ways: that adaptationist hypotheses need to be rigorously tested before they are accepted, that pluralistic explanations of biological phenomena should be widely accepted alongside adaptationist ones, or that non-adaptationist explanations are objectively preferable to adaptationist ones. [19]
Gould and Lewontin defined "spandrel" in biology as a constraint on an organism's evolution. However, Alasdair Houston subsequently suggested that another architectural term, "pendentive", might be a more accurate description of such constraints. [20] In his book Darwin's Dangerous Idea , Daniel Dennett also criticized Gould and Lewontin's "spandrels" metaphor for the same reason, adding, "the spandrels of San Marco aren't spandrels even in Gould's extended sense. They are adaptations chosen from a set of equipossible alternatives for largely aesthetic reasons..." This criticism was itself criticized by Robert Mark, who argued that "Gould and Lewontin's misapplication of the term spandrel for pendentive perhaps implies a wider latitude of design choice than they intended for their analogy. But Dennett's critique of the architectural basis of the analogy goes even further astray because he slights the technical rationale of the architectural elements in question." [21] Some defenders of the adaptationist perspective developed "explanatory adaptationism" as a response to some of the arguments made in the paper. Explanatory adaptationism argues that adaptation, though uncommon, is still uniquely important in the evolutionary process. [22]
Steven Pinker criticized Gould and Lewontin for reusing an argument by George C. Williams in favor of the importance of nonadaptive features without attributing it to him. Gould responded that Pinker's accusation was "serious, and false", writing, "I love Williams’s book and cite it frequently—but not in our spandrels paper because neither he, nor I, nor anyone else in our century invented the idea. The concept has always been part of evolutionary theory." [23] Gerald Borgia criticized the paper, arguing that "...its unforgiving tone and use of hyperbole is designed to incite emotion rather than encourage reasoned debate." [12] According to Tim Lewens, "...one of the most significant lessons that the Spandrels paper teaches is about the importance for evolutionary biology of an empirically grounded account of what is, and what is not, a trait." [24]
Darwin's Dangerous Idea: Evolution and the Meanings of Life is a 1995 book by the philosopher Daniel Dennett, in which the author looks at some of the repercussions of Darwinian theory. The crux of the argument is that, whether or not Darwin's theories are overturned, there is no going back from the dangerous idea that design might not need a designer. Dennett makes this case on the basis that natural selection is a blind process, which is nevertheless sufficiently powerful to explain the evolution of life. Darwin's discovery was that the generation of life worked algorithmically, that processes behind it work in such a way that given these processes the results that they tend toward must be so.
Stephen Jay Gould was an American paleontologist, evolutionary biologist, and historian of science. He was one of the most influential and widely read authors of popular science of his generation. Gould spent most of his career teaching at Harvard University and working at the American Museum of Natural History in New York. In 1996, Gould was hired as the Vincent Astor Visiting Research Professor of Biology at New York University, after which he divided his time teaching between there and Harvard.
The Mismeasure of Man is a 1981 book by paleontologist Stephen Jay Gould. The book is both a history and critique of the statistical methods and cultural motivations underlying biological determinism, the belief that "the social and economic differences between human groups—primarily races, classes, and sexes—arise from inherited, inborn distinctions and that society, in this sense, is an accurate reflection of biology".
The neutral theory of molecular evolution holds that most evolutionary changes occur at the molecular level, and most of the variation within and between species are due to random genetic drift of mutant alleles that are selectively neutral. The theory applies only for evolution at the molecular level, and is compatible with phenotypic evolution being shaped by natural selection as postulated by Charles Darwin. The neutral theory allows for the possibility that most mutations are deleterious, but holds that because these are rapidly removed by natural selection, they do not make significant contributions to variation within and between species at the molecular level. A neutral mutation is one that does not affect an organism's ability to survive and reproduce. The neutral theory assumes that most mutations that are not deleterious are neutral rather than beneficial. Because only a fraction of gametes are sampled in each generation of a species, the neutral theory suggests that a mutant allele can arise within a population and reach fixation by chance, rather than by selective advantage.
Richard Charles Lewontin was an American evolutionary biologist, mathematician, geneticist, and social commentator. A leader in developing the mathematical basis of population genetics and evolutionary theory, he pioneered the application of techniques from molecular biology, such as gel electrophoresis, to questions of genetic variation and evolution.
Adaptationism is the Darwinian view that many physical and psychological traits of organisms are evolved adaptations. Pan-adaptationism is the strong form of this, deriving from the early 20th century modern synthesis, that all traits are adaptations, a view now shared by only a few biologists.
"Human Genetic Diversity: Lewontin's Fallacy" is a 2003 paper by A. W. F. Edwards. He criticises an argument first made in Richard Lewontin's 1972 article "The Apportionment of Human Diversity", that the practice of dividing humanity into races is taxonomically invalid because any given individual will often have more in common genetically with members of other population groups than with members of their own. Edwards argued that this does not refute the biological reality of race since genetic analysis can usually make correct inferences about the perceived race of a person from whom a sample is taken, and that the rate of success increases when more genetic loci are examined.
In science and philosophy, a just-so story is an untestable narrative explanation for a cultural practice, a biological trait, or behavior of humans or other animals. The pejorative nature of the expression is an implicit criticism that reminds the listener of the essentially fictional and unprovable nature of such an explanation. Such tales are common in folklore genres like mythology. A less pejorative term is a pourquoi story, which has been used to describe usually more mythological or otherwise traditional examples of this genre, aimed at children.
Elliott R. Sober is Hans Reichenbach Professor and William F. Vilas Research Professor in the Department of Philosophy at University of Wisconsin–Madison. Sober is noted for his work in philosophy of biology and general philosophy of science.
Biological or process structuralism is a school of biological thought that objects to an exclusively Darwinian or adaptationist explanation of natural selection such as is described in the 20th century's modern synthesis. It proposes instead that evolution is guided differently, basically by more or less physical forces which shape the development of an animal's body, and sometimes implies that these forces supersede selection altogether.
In evolutionary biology, a spandrel is a phenotypic trait that is a byproduct of the evolution of some other characteristic, rather than a direct product of adaptive selection. Stephen Jay Gould and Richard Lewontin brought the term into biology in their 1979 paper "The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme". Adaptationism is a point of view that sees most organismal traits as adaptive products of natural selection. Gould and Lewontin sought to temper what they saw as adaptationist bias by promoting a more structuralist view of evolution.
Ontogeny and Phylogeny is a 1977 book on evolution by Stephen Jay Gould, in which the author explores the relationship between embryonic development (ontogeny) and biological evolution (phylogeny). Unlike his many popular books of essays, it was a technical book, and over the following decades it was influential in stimulating research into heterochrony, which had been neglected since Ernst Haeckel's theory that ontogeny recapitulates phylogeny had been largely discredited. This helped to create the field of evolutionary developmental biology.
Evolutionary psychology seeks to identify and understand human psychological traits that have evolved in much the same way as biological traits, through adaptation to environmental cues. Furthermore, it tends toward viewing the vast majority of psychological traits, certainly the most important ones, as the result of past adaptions, which has generated significant controversy and criticism from competing fields. These criticisms include disputes about the testability of evolutionary hypotheses, cognitive assumptions such as massive modularity, vagueness stemming from assumptions about the environment that leads to evolutionary adaptation, the importance of non-genetic and non-adaptive explanations, as well as political and ethical issues in the field itself.
Marion J. Lamb was Senior Lecturer at Birkbeck, University of London, before her retirement. She studied the effect of environmental conditions such as heat, radiation and pollution on metabolic activity and genetic mutability in the fruit fly Drosophila. From the late 1980s, Lamb collaborated with Eva Jablonka, researching and writing on the inheritance of epigenetic variations, and in 2005 they co-authored the book Evolution in Four Dimensions, considered by some to be in the vanguard of an ongoing revolution within evolutionary biology.
The beneficial acclimation hypothesis (BAH) is the physiological hypothesis that acclimating to a particular environment provides an organism with advantages in that environment. First formally tested by Armand Marie Leroi, Albert Bennett, and Richard Lenski in 1994, it has however been a central assumption in historical physiological work that acclimation is adaptive. Further refined by Raymond B. Huey and David Berrigan under the strong inference approach, the hypothesis has been falsified as a general rule by a series of multiple hypotheses experiments.
Phylogenetic inertia or phylogenetic constraint refers to the limitations on the future evolutionary pathways that have been imposed by previous adaptations.
Teleology in biology is the use of the language of goal-directedness in accounts of evolutionary adaptation, which some biologists and philosophers of science find problematic. The term teleonomy has also been proposed. Before Darwin, organisms were seen as existing because God had designed and created them; their features such as eyes were taken by natural theology to have been made to enable them to carry out their functions, such as seeing. Evolutionary biologists often use similar teleological formulations that invoke purpose, but these imply natural selection rather than actual goals, whether conscious or not. Dissenting biologists and religious thinkers held that evolution itself was somehow goal-directed (orthogenesis), and in vitalist versions, driven by a purposeful life force. Since such views are now discredited, with evolution working by natural selection acting on inherited variation, the use of teleology in biology has attracted criticism, and attempts have been made to teach students to avoid teleological language.
Human evolutionary developmental biology or informally human evo-devo is the human-specific subset of evolutionary developmental biology. Evolutionary developmental biology is the study of the evolution of developmental processes across different organisms. It is utilized within multiple disciplines, primarily evolutionary biology and anthropology. Groundwork for the theory that "evolutionary modifications in primate development might have led to … modern humans" was laid by Geoffroy Saint-Hilaire, Ernst Haeckel, Louis Bolk, and Adolph Schultz. Evolutionary developmental biology is primarily concerned with the ways in which evolution affects development, and seeks to unravel the causes of evolutionary innovations.
In evolutionary biology, developmental bias refers to the production against or towards certain ontogenetic trajectories which ultimately influence the direction and outcome of evolutionary change by affecting the rates, magnitudes, directions and limits of trait evolution. Historically, the term was synonymous with developmental constraint, however, the latter has been more recently interpreted as referring solely to the negative role of development in evolution.
Constructive neutral evolution(CNE) is a theory that seeks to explain how complex systems can evolve through neutral transitions and spread through a population by chance fixation. Constructive neutral evolution is a competitor for both adaptationist explanations for the emergence of complex traits and hypotheses positing that a complex trait emerged as a response to a deleterious development in an organism. Constructive neutral evolution often leads to irreversible or "irremediable" complexity and produces systems which, instead of being finely adapted for performing a task, represent an excess complexity that has been described with terms such as "runaway bureaucracy" or even a "Rube Goldberg machine".