This chapter contains sections titled: Introduction Natural Selection Operates within Genomes without Regard for Phenotypic Effect Selective Forces, Heritable Variation, and the Definition of Function Natural Selection Can, and Does, Act on the Products of Individual Genes Natural Selection Can Act Directly on Genes Themselves What Are the Limitations on the Unit of Selection Being “the Gene”? The “Complexity” Argument: Do Complex Phenotypes Require Complex Explanations? Do “Epigenes/Epialleles” Provide a (...) “Non‐genetic” Source of Heritable Variation Upon Which Natural Selection May Act? Summary Points: The Usual Unit of Selection Is the Gene Postscript: Counterpoint Note References. (shrink)

Natural selection is an important force that shapes the evolution of all living things by determining which individuals contribute the most descendents to future generations. The biological unit upon which selection acts has been the subject of serious debate, with reasonable arguments made on behalf of populations, individuals, individual phenotypic characters and, finally, individual genes themselves. In this essay, I argue that the usual unit of selection is the gene. There are powerful logical arguments (...) in favor of this conclusion, as well as many real-world examples. I also explore the possibility that epigenetic differences between individuals may be heritable between generations. Although few such examples exist, epigenetic differences provide an exciting source of potentially heritable variation that may allow rapid evolutionary change to occur, perhaps in response to environmental influences. (shrink)

Natural selection is an important force that shapes the evolution of all living things by determining which individuals contribute the most descendents to future generations. The biological unit upon which selection acts has been the subject of serious debate, with reasonable arguments made on behalf of populations, individuals, individual phenotypic characters and, finally, individual genes themselves. In this essay, I argue that the usual unit of selection is the gene. There are powerful logical arguments (...) in favor of this conclusion, as well as many real-world examples. I also explore the possibility that epigenetic differences between individuals may be heritable between generations. Although few such examples exist, epigenetic differences provide an exciting source of potentially heritable variation that may allow rapid evolutionary change to occur, perhaps in response to environmental influences. (shrink)

It is tempting to invoke organismal selection as perpetually optimizing the function of any given gene. However, natural selection can drive genic functional change without improvement of biochemical activity, even to the extinction of gene activity. Detrimental mutations can creep in owing to linkage with other selectively favored loci. Selection can promote functional degradation, irrespective of genetic drift, when adaptation occurs by loss of gene function. Even stabilizing selection on a trait can lead to divergence (...) of the underlying molecular constituents. Selfish genetic elements can also proliferate independent of any functional benefits to the host genome. Here we review the logic and evidence for these diverse processes acting in genome evolution. This collection of distinct evolutionary phenomena – while operating through easily understandable mechanisms – all contribute to the seemingly counterintuitive notion that maintenance or improvement of a gene's biochemical function sometimes do not determine its evolutionary fate. (shrink)

This chapter offers a review of standard views about the requirements for natural selection to shape evolution and for the sorts of ‘units’ on which selection might operate. It then summarizes traditional arguments for genic selectionism, i.e., the view that selection operates primarily on genes (e.g., those of G. C. Williams, Richard Dawkins, and David Hull) and traditional counterarguments (e.g., those of William Wimsatt, Richard Lewontin, and Elliott Sober, and a diffuse group based on life (...) history strategies). It then offers a series of responses to the arguments, based on more contemporary considerations from molecular genetics, offered by Carmen Sapienza. A key issue raised by Sapienza concerns the degree to which a small number of genes might be able to control much of the variation relevant to selection operating on such selectively critical organs as hearts. The response to these arguments suggests that selection acts on many levels at once and that sporadic selection, acting with strong effects, can act successively on different key traits (and genes) while maintaining a balance among many potentially conflicting demands faced by organisms within an evolving lineage. (shrink)

In this paper, I discuss the concept of complexity. I show that the principle of natural selection as acting on complexity gives a solution to the problem of reconciling the seemingly contradictory notion of generally increasing complexity and the observation that most species don’t follow such a trend. I suggest the process of evolution to be illustrated by means of a schematic diagram of complexity versus time, interpreted as a form of the Tree of Life. The suggested (...) model implies that complexity is cumulatively increasing, giving evolution a direction, an arrow of time, thus also implying that the latest emerging species will be the one with the highest level of complexity. Since the human species is the last species evolved in the evolutionary process seen at large, this means that we are the species with the highest complexity. The model implies that the human species constitutes an integral part of organic evolution, yet rendering us the exclusive status as the species of the highest complexity. (shrink)

This chapter offers a review of standard views about the requirements for natural selection to shape evolution and for the sorts of ‘units’ on which selection might operate. It then summarizes traditional arguments for genic selectionism, i.e., the view that selection operates primarily on genes (e.g., those of G. C. Williams, Richard Dawkins, and David Hull) and traditional counterarguments (e.g., those of William Wimsatt, Richard Lewontin, and Elliott Sober, and a diffuse group based on life (...) history strategies). It then offers a series of responses to the arguments, based on more contemporary considerations from molecular genetics, offered by Carmen Sapienza. A key issue raised by Sapienza concerns the degree to which a small number of genes might be able to control much of the variation relevant to selection operating on such selectively critical organs as hearts. The response to these arguments suggests that selection acts on many levels at once and that sporadic selection, acting with strong effects, can act successively on different key traits (and genes) while maintaining a balance among many potentially conflicting demands faced by organisms within an evolving lineage. (shrink)

Does natural selection act primarily on individual organisms, on groups, on genes, or on whole species? The question of levels of selection - on which biologists and philosophers have long disagreed - is central to evolutionary theory and to the philosophy of biology. Samir Okasha's comprehensive analysis gives a clear account of the philosophical issues at stake in the current debate.

Evolutionary gradualism, the randomness of mutations, and the hypothesis that natural selection exerts a pervasive and substantial influence on evolutionary outcomes are pair-wise logically independent. Can the claims about selection and mutation be used to formulate an argument for gradualism? In his Genetical Theory of Natural Selection, R.A. Fisher made an important start at this project in his famous “geometric argument” by showing that a random mutation that has a smaller effect on two or more (...) phenotypes will have a higher average fitness than a random mutation that has a larger phenotypic effect. Motoo Kimura’s demonstration that a gene’s probability of fixation depends on both the selection coefficient and the effective population size shows that Fisher’s argument for gradualism was mistaken. Here we analyze Fisher’s argument and explain how Kimura’s theory leads to a conclusion that Fisher did not anticipate. We identify a fallacy that reasoning about fitness differences and their evolutionary consequences should avoid. We then distinguish forward-directed from backward-directed versions of gradualism. The backward-directed thesis about a single mutation may be correct, but the forward-directed thesis is not. After that we consider a sequence of random mutations that all affect the same cluster of phenotypes and Allen Orr’s idea that there is an optimal sequence of mutation sizes, moving from larger to smaller as the population approaches a fixed optimum. This provides a likelihood justification for a forward-directed version of gradualism when there is a fixed optimum, but it also provides an argument against forward-directed gradualism if the optimum shifts substantially as the population evolves. Finally, we consider whether genome-wide association studies (GWASs) can furnish empirical evidence that bears on the truth of gradualism. The version of gradualism that GWASs directly bear on concerns the phenotypic effect size of a gene after it arises by mutation and has reached an appreciable frequency, not the phenotypic size of the mutation event itself. (shrink)

This is the first of a two-part essay on the history of debates concerning the creativity of natural selection, from Darwin through the evolutionary synthesis and up to the present. Here I focus on the mid-late nineteenth century to the early twentieth, with special emphasis on early Darwinism and its critics, the self-styled “mutationists.” The second part focuses on the evolutionary synthesis and some of its critics, especially the “neutralists” and “neo-mutationists.” Like Stephen Gould, I consider the creativity (...) of natural selection to be a key component of what has traditionally counted as “Darwinism.” I argue that the creativity of natural selection is best understood in terms of selection initiating evolutionary change, and selection being responsible for the presence of the variation it acts upon, for example by directing the course of variation. I consider the respects in which both of these claims sound non-Darwinian, even though they have long been understood by supporters and critics alike to be virtually constitutive of Darwinism. (shrink)

This is the second of a two-part essay on the history of debates concerning the creativity of natural selection, from Darwin through the evolutionary synthesis and up to the present. In the first part, I focussed on the mid-late nineteenth century to the early twentieth, with special emphasis on early Darwinism and its critics, the self-styled “mutationists.” The second part focuses on the evolutionary synthesis and some of its critics, especially the “neutralists” and “neo-mutationists.” Like Stephen Gould, I (...) consider the creativity of natural selection to be a key component of what has traditionally counted as “Darwinism.” I argue that the creativity of natural selection is best understood in terms of selection initiating evolutionary change, and selection directing evolutionary change, for example by creating the variation that it subsequently acts upon. I consider the respects in which both of these claims sound non-Darwinian, even though they have long been understood by supporters and critics alike to be virtually constitutive of Darwinism. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Mimesis: Culture, Art, SocietyGene FendtMimesis: Culture, Art, Society, by Gunter Gebauer and Christoph Wulf; translated by Don Reneau; 400 pp. Berkeley: University of California Press, 1995, $45.00 cloth, $18.00 paper.The purpose of this book is to develop “a historical reconstruction of important phases in the development of mimesis” (p. 1) from a brief discussion of its pre-Platonic Greek significance through contemporary thinkers. It is, then, not strictly a (...) philosophical text, as are most of the texts and authors the book takes up. It is, however, a significant effort in the history of ideas, and as such it is shot through with traces of the traditional tropes, shaping power, ideology, and even social relations of that discipline, particularly as it is practiced in the venerable school of German scholarship. That is, the structure, tone, and argument of the book are shaped mimetically. This book’s problematic is, then, not simply historical, as Republic’s problem with the poets is not simply philosophical. Rather, both books partake of mimesis, even while each one aims to criticize or set forth the concept’s historical development.Let this stand as notice of a deep philosophical problem with the method of historical criticism. In fairness we should note that the authors are not unconscious of their difficulty here: “The fact that mimesis cannot be represented without the use of mimetic processes poses the fundamental problem of theory formation in reference to our object. What is the relation between the representational and the represented world? Is the representation of representation structurally equivalent to simple representation?” (p. 21). The authors hope to moot the power of those questions, if not the questions themselves, by attending “first of all to representations of mimesis found in texts best selected for that purpose and only afterward begin to offer considerations of a more generalizing nature” (p. 21). Their reasoning and choice of texts here is the traditional trope of the discipline: a mimema. Among other things, this methodos requires that the authors treat Girard as developing a “literary critical examination of [mimesis in] nineteenth and twentieth century novels” (p. 359n1) and a “new ordering of nineteenth century social relations” (p. 235), rather than, as he claims, a comprehensive anthropological thesis. At least, this method requires treating the former as essential, and the latter as less justifiable, for if Girard’s anthropological thesis about mimesis were justifiable a history of the idea of mimesis would be merely a heresiology. This problem can be restated mutatis mutandis for such thinkers as Plato and Augustine, whose theses—if they have theses—about mimesis are deeply anthropological.Two further questions arise early on and remain at the end. If, as the authors hold (and show), “the concept of mimesis necessarily loses its intellectual centrality with the rise of rational thought,” so much so that “the field of art, which comes to be regarded in the process as autonomous, undergoes a complete and fundamental restructuring” (p. 3), must we not begin to [End Page 199] suspect—as recent philosophers like Derrida attempt to show—that there is a dialectical relationship between the intentional, truth-functional relations of modern rational thought and the mimetic, unformalizable and “ambivalent” (pp. 2–3) processes of mimesis? Rather than conclude that “the question what is mimesis? is one which demonstratively leads to error” (p. 309), does it not begin to seem that intentional representation, as most visible in science, and mimetic assimilations, as most obviously effective in art, are together the necessary dialectical elements of culture, art and science? While it seems that the rise of rational scientific thought pushes mimesis to the social fringes of the arts, isn’t scientific activity and writing still just as much subject, and just as much a product, of the power of mimesis as art? Similarly art is just as bound as science to “probability” or “the convincing impossibility,” to recall Aristotle. This idea is not entirely foreign to the book; it appears subliminally as a plausible explication of the work of theorists like Benjamin and Adorno (pp. 267–93).The third difficulty is a question about selection. As in Auerbach’s renowned precursor, Wulf... (shrink)

This book is a manifesto for what John Alcock calls “orthodox sociobiology,” the systematic study of the biological basis of all social behavior following the premise that behaviors and their mechanisms evolve under the primary influence of natural selection acting on individual differences in genetic success. Sociobiology focuses narrowly on finding adaptive explanations for social behaviors while attempting a grand synthesis of biological and social sciences. Alcock's book is largely defensive, aimed at refuting criticisms and a perception (...) that, twenty‐five years after its proclamation, sociobiology is moribund. Alcock's defense relies not on an extensive review of relevant literature but on the persuasiveness of arguments illustrated with favored examples. He emphasizes sociobiology of human cultures and prescribes practical applications for restructuring societal institutions.The major argument against orthodox sociobiology is summarized in Edward O. Wilson's book Consilience : “We know that virtually all of human behavior is transmitted by culture. We also know that biology has an important effect on the origin of culture and its transmission. … Culture allows a rapid adjustment to changes in the environment through finely tuned adaptations invented and transmitted without correspondingly precise genetic prescription. In this respect human beings differ fundamentally from all other animal species” . This argument denies that human social behaviors are best understood as biologically evolved adaptations and places them outside the domain of the genetical theory of natural selection.Alcock's major claim for sociobiology's triumph is its use of comparative methodology to identify ultimate causes of social behaviors. Over the past twenty‐five years, evolutionary biologists have developed rigorous systematic methodologies for making comparative inferences in evolutionary research. Such explicitly phylogenetic approaches provide more powerful tests of ultimate causality in evolution than the comparative methods available when sociobiology was first proposed. Although the success of sociobiology would seem to lie in its ability to use the strongest comparative methods to test its major claims, Alcock's examples rely entirely on archaic methodology that no contemporary evolutionist should accept.The hypothesis of adaptation predicts that a character enhances its possessor's ability to utilize resources for survival or reproduction relative to alternatives against which it has been tested evolutionarily. Phylogenetic analysis of species possessing the character and their closest relatives identifies the comparisons appropriate for testing this hypothesis. Hypothetical adaptations are mapped onto phylogenies to identify their origins, antecedent conditions, associated characters, environmental contexts, and selective regimes. Alcock forfeits the power of evolutionary study by arguing that sociobiologists “can only use data from unrelated species known to experience similar selection pressures” in the “independent convergence test” of adaptation. No animal species are completely unrelated, nor are their behaviors adaptive in an absolute sense. Even comparisons of analogous characters across species must consider phylogeny because homologous genes and developmental programs can be utilized for analogous roles in different species. Without a firm grounding in phylogenetic principles, Alcock's methods cannot effectively test hypotheses of evolutionary causality.Alcock spends much effort defending sociobiology against the criticism that its major claims constitute untestable adaptationist stories. David Barash's sociobiological interpretations of mating behavior in bluebirds receive particular attention because Stephen Jay Gould criticized them as untestable. Alcock shows that Barash and others have empirically rejected some explanations in favor of better ones, although the hypotheses tested and the knowledge gained reside entirely in proximate mechanisms, not the ultimate causes that constitute sociobiology's main challenge. Gould's criticism therefore withstands Alcock's counterarguments.Readers unfamiliar with evolution should consult recent books such as Brian Hall's Evolutionary Developmental Biology , Jeffrey Levinton's Genetics, Paleontology, and Macroevolution , and John Avise's Phylogeography to see evolutionary disciplines that have triumphed over the past twenty‐five years. These disciplines contrast with sociobiology in their methodological rigor and profound reformulation of major theories. By contrast, Alcock's sociobiology seems essentially unchanged from the 1970s. If twenty‐five years of sociobiological study have produced only a repetition of its initial conjectures, their effectiveness as testable hypotheses seems doubtful.Alcock acknowledges “human evolutionary psychology” as a new subdiscipline of sociobiology. Indeed, orthodox sociobiology seems to be relocating from biology to psychology departments. My interpretation of this move is that sociobiology has not kept pace with evolutionary biology and therefore has sought refuge in a traditionally nonevolutionary discipline that has not yet incorporated the current critical standards of comparative evolutionary research.Sociobiology has served evolutionary biology mainly by revealing the limits of reductionist selective arguments, thereby directing us to move beyond them. (shrink)

This anthology collects some of the most important papers on what is believed to be the major force in evolution, natural selection. An issue of great consequence in the philosophy of biology concerns the levels at which, and the units upon which selection acts. In recent years, biologists and philosophers have published a large number of papers bearing on this subject. The papers selected for inclusion in this book are divided into three main sections covering the history (...) of the subject, explaining its conceptual foundations, and focusing on kin and group selection and higher levels of selection.One of the book's interesting features is that it draws together material from the biological and philosophical literatures. The philosophical literature, having thoroughly absorbed the biological material, now offers conceptual tools suitable for the reworking of the biological arguments. Although a full symbiosis has yet to develop, this anthology offers a unique resource for students in both biology and philosophy.Robert N. Brandon is Professor in the Philosophy Department, Duke University. Richard M. Burian is Professor of Philosophy and Department Chairman, Virginia Polytechnic Institute and State University.A Bradford Book. (shrink)

Brandon ([1982] 1984, 1990) has argued that Salmon's (1971) concept of screening-off can be used to characterize (i) the idea that natural selection acts directly on an organism's phenotype, only indirectly on its genotype, and (ii) the biological problem of the levels of selection. Brandon also suggests (iii) that screening-off events in a causal chain are better explanations than the events they screen off. This paper critically evaluates Brandon's proposals.

De Vries' mutation theory has not stood the test of time. The supposed mutations of Oenothera were in reality complex recombination phenomena, ultimately explicable in Mendelian terms, while instances of large-scale mutations were found wanting in other species. By 1915 the mutation theory had begun to lose its grip on the biological community; by de Vries' death in 1935 it was almost completely abandoned. Yet, as we have seen, during the first decade of the present century it achieved an enormous (...) popularity. As this paper has tried to suggest, one of the principal reasons for this was that de Vries' theory served as a banner around which a whole crowd of disaffected Darwinians or anti-Darwinians could rally. However, not all of those who favored de Vries did so for quite the same reasons. Underlying the multitude of views ran several common threads: a dissatisfaction with current Darwinian theory born out of misunderstanding natural selection, a general misunderstanding of the nature of species, and a prejudice against speculative, nontestable theories in biology.Supporters of de Vries were not the only opponents of Darwinism, nor was the mutation theory the only alternative to natural selection. In the early twentieth century a number of theories had been proposed to explain away the problems which Darwin had left unsolved. There was the idea of orthogenesis, championed by the American paleontologists Cope, Osborn and others; organic selection (or orthoplasy) was championed by M. M. Baldwin and C. Lloyd Morgan; there were the concepts of convergent evolution proposed by Hermann Friedmann, the theory of physiological selection by John George Romanes, and the concepts of reproductive divergence by H. M. Vernon. Virtually none of these men either accepted or were strong supporters of the de Vriesian theory, for each had his own particular ‘ism” to advocate as the major factor in evolution. The existence of a large number of such theories, each purporting to be the explanation, was characteristic of evolutionary theory at the turn of the century. It is to a large extent the emphasis on such fragmentary concepts that retarded development of the comprehensive theory of evolution which emerged in the 1920's and 1930's. For the historian, however, a study of these alternative theories is instructive in trying to understand the inherent difficulties which Dawwinian theory posed to biologists at the time. De Vries' mutation theory serves historically as a mirror to reflect the critical mood of a generation hostile to the theory of natural selection.It has often been claimed that it was impossible to understand the mechanism of natural selection until it could be placed in genetic and mathematical terms. It is certainly true that great strides have been made in population genetics and the treatment of evolutionary concepts with mathematical tools in the last forty years. But the very people who developed the genetical and mathematical approach to evolution were already convinced of the essential correctness of Darwinian theory before they started. Advances in an understanding of Mendelian heredity aided greatly in solving one important issue for evolutionists: the origin of variations. And the rigor with which selection acted could best be studied by observing changes in gene frequencies (calculated mathematically) over a number of generations. But as this paper has shown, two of the basic problems which biologists faced in evaluating Darwinian theory at the turn of the century-the nature of species, and the criteria of what constituted an acceptable explanation in biological science-could not be answered directly by mathematics. What mathematical and genetical theory did do was to help convince the skeptics of the validity of the Darwinian proposition.The change in explanatory criteria which many hailed as de Vries' most important contribution to evolutionary theory seems to have been part of a general emergence of twentieth-century biology from the domination of theorizers in the nineteenth. It also marked the emergence of America from the domination of biological, and particularly evolutionary, influence of Europeans. The change occurred in three areas: in the kinds of questions asked: testable versus non-testable; in the kind of data sought: quantitative versus qualitative; and in the kinds of theories proposed: analytical and reductive—the attempt to see complex processes in terms of simpler components-as opposed to synthetic and speculative. Although ultimately wrong in his idea, de Vries and his theories rode high on the wave of “experimentalism” which was the harbinger of a new era in evolutionary theory. (shrink)

As a species, we are on the cusp of being able to alter that which makes us uniquely human, our genome. Two new genetic technologies, embryo selection and germline engineering, are either in use today or may be developed in the future. Embryo selection acts to alter the human gene pool, reducing genetic diversity, while germline engineering will have the ability to alter directly the genomes of engineered individuals. Our genome has come to be what it is (...) through an evolutionary process extending over millions of years, a process that has involved exceedingly complex and unpredictable interactions between ourselves or our ancestors and myriad other life forms within Earth's biosphere. In this paper, the ecological imperative, which states that we must not alter the human genome or the collective human genetic inheritance, will be introduced. It will be argued based on ecological principles that embryo selection and germline engineering are unethical and unwise because they will diminish our survivability as a species, will disrupt our relationship with the natural world, and will destroy the very basis of that which makes us human. (shrink)

Discussions of altruism occur in three importantly different contexts. During the past four decades, evolutionary theory has been concerned with the possibility that forms of behaviour labelled as altruistic could emerge and could be maintained under natural selection. In these discussions, an agent A is said to act altruistically towards a beneficiary B when A's action promotes the expected reproductive success of B at expected reproductive cost to A. This sort of altruism, biological altruism, is quite different from (...) the kind of behaviour important to debates about ethical and social issues. There the focus is on psychological altruism, a notion that is concerned with the intentions of the agent and that need have no connection with the spread of anyone's genes. Psychological altruists are people with other-directed desires, emotions or intentions (this is a rough preliminary characterization, to be refined below). Finally, in certain kinds of social scientific research, the important concept is that of behavioural altruism. From the outside, behavioural altruists look like psychological altruists, although their motives and preferences may be very different. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:The Peculiarly Favored Condition of GeneticsJames J. Lee, PhD (bio) and Damien Morris, MSc (bio)Turkheimer and Greer (2024) (henceforth “T&G”) make some fair points about problems in the scientific profession, including the regrettable tendency to promise practical applications of research that then never materialize. However, T&G’s sustained critique of a body of work associated with one particular researcher to make these general points struck us as uncharitable. More pressingly, (...) we feel that the far-reaching conclusions that T&G attempt to draw from the results they review from the Spit for Science (S4S) cohort are unjustified and risk misleading readers that psychiatric and behavioral genetics is in a parlous state.T&G state that S4S “produced a clear answer to the question it was designed to address,” namely, that its results “unambiguously contradict the hypothesis that alcohol-related behaviors have a meaningful genetic basis.” But S4S cannot possibly have provided affirmative evidence for the null hypothesis, because as a single cohort it lacked the statistical power to do so. Elsewhere T&G acknowledge that the sample size of S4S does not suffice for many purposes; they cannot have it both ways. When GCTA has been applied to samples of greater size, it has unambiguously supported the hypothesis that alcohol-related behaviors have a meaningful genetic basis. The UK Biobank yielded estimates exceeding 0.10 for the contribution of single nucleotide polymorphisms (SNPs) with minor allele frequency of greater than 0.05 to the heritability of drinks per week, estimates more than ten times their standard errors (Liu et al., 2019).This heritability contributed by common variants is sometimes called “SNP heritability,” and T&G disparage it for the alleged “disadvantage of being substantially smaller” than “twin and family heritabilities.” Nowhere do T&G consider what the precise numbers actually mean—an approach that can be hazardous to your scientific health, as the late John Loehlin might have said. Let us, then, consider these numbers. Under a model of pure neutrality, SNP and pedigree narrow-sense heritabilities should be fairly close, essentially as a result of factors p(1 − p) canceling in the multiplication of the numbers of SNPs to be found at a given allele frequency by the average heritability contributed per SNP (Hill, 2010). If SNP and pedigree heritabilities are not close, then natural selection must have been acting on [End Page 441] the trait, preventing new mutations of large effect from becoming common and thereby concentrating heritability at allele frequencies lower than those typically studied in genome-wide association studies (GWAS). This deduction has been abundantly confirmed: the tendency of GWAS SNPs to reside in evolutionarily conserved regions (Finucane et al., 2015; Kim et al., 2019), the younger age of GWAS SNPs when compared to control SNPs of comparable frequencies (Gazal et al., 2017), the discovery of several rare variants with larger effects than those observed in typical GWAS (Barton et al., 2021; Chen et al., 2023; Marouli et al., 2017), the directly measured deleterious fitness effects of mutations in evolutionarily constrained genes (Gardner et al., 2022), and the substantial additional genetic variance accumulated when rare variants are included in GCTA-type studies, sometimes enough to close the gap between SNP and pedigree heritabilities (Evans et al., 2018; Jang et al., 2022; Pathan et al., 2024; Wainschtein et al., 2022).The genetic architecture of a typical quantitative trait consists of many sites across the genome that can mutate to affect it, numbering potentially in the millions (Agarwala et al., 2013; Zeng et al., 2021), of which those that are common SNPs have very small effects as a result of selection. This is the message, but T&G seem to find fault with the messenger, painting “tiny” effect sizes as an embarrassment to the field of behavioral genetics as a whole. We prefer to view the finding of high polygenicity as a revelation about nature, rather than as a debating point. What is this finding telling us? If one takes the action of stabilizing selection as the initial assumption (Uyeda et al., 2011), then the extreme polygenicity revealed by GWAS becomes part of the answer to the question regarding how traits can... (shrink)

Hierarchical expansions of the theory of natural selection exist in two distinct bodies of thought in evolutionary biology, the group selection and the species selection traditions. Both traditions share the point of view that the principles of natural selection apply at levels of biological organization above the level of the individual organism. This leads them both to considermultilevel selection situations, where selection is occurring simultaneously at more than one level. Impeding unification of (...) the theoretical approaches of the multilevel selection traditions are the different goals of investigators in the different subdisciplines and the different types of data potentially available for analysis. We identify two alternative approaches to multilevel situations, which we termmultilevel selection [1] andmultilevel selection [2]. Of interest in the former case are the effects of group membership onindividual fitnesses, and in the latter the tendencies for the groups themselves to go extinct or to found new groups (i.e., group fitnesses). We argue that: neither represents the entire multilevel selection process; both are aspects of any multilevel selection situation; and both are legitimate approaches, suitable for answering different questions. Using this formalism, we show that: multilevel selection [2] does not require emergent group properties in order to provide an explanatory mechanism of evolutionary change; multilevel selection [1] is usually more appropriate for neontological group selection studies; and species selection is most fruitfully considered from the point of view of multilevel selection [2]. Finally we argue that the effect hypothesis of macroevolution, requiring, in selection among species, both the absence of group effects on organismic fitness (multilevel selection [1]), and the direct determination of species fitnesses by those of organisms, is untestable with paleontological data. Furthermore, the conditions for the effect hypothesis to hold are extremely restrictive and unlikely to apply to the vast majority of situations encountered in nature. (shrink)

In his theory of evolution, Darwin recognized that the conditions of life play a role in the generation of hereditary variations, as well as in their selection. However, as evolutionary theory was developed further, heredity became identified with genetics, and variation was seen in terms of combinations of randomly generated gene mutations. We argue that this view is now changing, because it is clear that a notion of hereditary variation that is based solely on randomly varying genes that (...) are unaffected by developmental conditions is an inadequate basis for evolutionary theories. Such a view not only fails to provide satisfying explanations of many evolutionary phenomena, it also makes assumptions that are not consistent with the data that are emerging from disciplines ranging from molecular biology to cultural studies. These data show that the genome is far more responsive to the environment than previously thought, and that not all transmissible variation is underlain by genetic differences. In Evolution in Four Dimensions (2005) we identify four types of inheritance (genetic, epigenetic, behavioral, and symbol-based), each of which can provide variations on which natural selection will act. Some of these variations arise in response to developmental conditions, so there are Lamarckian aspects to evolution. We argue that a better insight into evolutionary processes will result from recognizing that transmitted variations that are not based on DNA differences have played a role. This is particularly true for understanding the evolution of human behavior, where all four dimensions of heredity have been important. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Changing Human Nature: Ecology, Ethics, Genes, and God by James C. PetersonDolores L. ChristieChanging Human Nature: Ecology, Ethics, Genes, and God James C. Peterson Grand Rapids, Mich.: Eerdmans, 2010. 259 pp. $18.00Grounding himself in the Christian tradition, James Peterson argues for the moral efficacy of human genetic manipulation. Interpreting intentional intervention as part of human stewardship rather than as a wrongful interference with some divine plan, (...) he takes on the sticky questions, making critical distinctions, for example, between cure and enhancement or welcoming children as they come and making them “better.” Not neglecting future implications of current tinkering with human biology, even in such taboo areas as gamete selection, he contends that engineering a baby free of harmful genes (for example, Tay-Sachs or Down syndrome) not only makes that person better, but it also eliminates an ongoing burden to family, to society, and perhaps to future generations. Treading gingerly among the sacred cows of some Christian ethicists, he advocates the implanting of selected embryos free of unwanted genes; in his view, embryos are not yet persons.Peterson considers serious concerns such as eugenics projects and racial bias but offers standards to address them. He contends that intentionally increasing choices for our children is not only acceptable but also praiseworthy. What parents would not optimize the educational and social opportunities for their child, even without the child’s consent? Interventions should be safe, offer genuine improvement, increase the recipient’s capacity, and make the best use of limited resources. Peterson is not so naive that he does not recognize that technology does not always make us better. He recognizes, too, that his standards do not eliminate risk.Fair enough, but the issue of what “improvement” may mean to the individual as well as to the greater community remains somewhat ambiguous. Peterson suggests that broadening the decision making among a variety of professional and individual cohorts would help, but his argument is not totally persuasive. In sum, Peterson’s treatment falls short of offering a totally satisfying standard for determining which characteristics should be manipulated and which should be accepted. Nor does he demonstrate definitively how a [End Page 187] Christian perspective would contribute to sorting out possible choices. Does the deaf parents’ desire for their child to be deaf like them constitute an instance where intervention should not be attempted? Can the disparate cohorts he suggests as arbiters rise above their own biases? Does Christianity and its belief system offer answers? Readers—even readers who call themselves Christian—will likely be persuaded that genetic intervention is a good, and even compatible with their religious perspective. Nonetheless, they will harbor lingering doubts about how the questions can best be solved, who should solve them, and how Christian belief helps sort among the possibilities. In his closing comments Peterson appears to agree.The book is rich in research and in provocative ideas. It is an exciting book. It is a readable and enlightened contribution to the professional conversation on gene therapy. Peterson’s research is extensive, his argumentation balanced. His attempt to locate the question within the Christian tradition is laudable. Happily, Peterson eschews a creationist approach to world and human origins. Unhappily, his approach to the scriptural text is not always nuanced. His assertion that Jesus himself was different biologically from other human beings (132) seems a stretch. If one takes the passages of Jesus’s biological origins literally, as apparently does the author, what happens to the assertion that Jesus is like other human beings “in all things but sin”? And where did Jesus get the Y chromosomes? While he persuades the reader that genetic intervention is compatible with a Christian worldview, Peterson does not offer—at least in this reviewer’s view—an adequate criterion for navigating this new world of the possible.Dolores L. ChristieJohn Carroll UniversityCopyright © 2013 Society of Christian Ethics... (shrink)

Natural selection is the main mechanism that drives the evolution of species, including human societies. Under natural selection, human species responds through genetic and cultural adaptations to internal and external selection pressures for survival and reproductive success. However, this theory is ineffective in explaining human societal evolution in the Holocene and a cultural selection argument has been made to remedy the theory. The present article provides a critique of the cultural selection argument and (...) proposes an alternative conception that treats human self-selection as an emergent mechanism of human societal evolution characterized by a new type of selection pressure and a separate fitness criterion. Specifically, the evolution of human societies is divided into two major periods, each driven by a different mode of selection: natural selection acting on genes and cultures for survival and reproductive success prior to the Neolithic Revolution, and human self-selection acting on cultures – and potentially genes as well – for thrival and prosperous living after the Neolithic Revolution. The conditions for the transition from the first mode of selection to the second and the implications of this transition for social research are also discussed. (shrink)

The idea that natural selection acts on many levels—and not only at the level of organisms or individual genes—is increasingly accepted among biologists. However, it is not easy to reconcile this idea with the strictly “individualistic” conception of the evolutionary process that has always characterized Darwinian thought. Moreover, the individuality of some forms of life is a vague concept and therefore controversial. This is the case of Candidatus Magnetoglobus multicellularis, whose discovery immediately inspired the following question: Does (...) the concept of individuality have degrees? Alternatively, how far is this structure of prokaryotic cells from deserving to be called an organism? In this article, we propose a new conceptual scheme based on an idea of individuality that is not limited to organisms and that makes sense in terms of Darwinian evolution. In this conceptual scheme, selection at levels above that of the individual organism is interpreted as the evolutionary emergence of higher-level individuality. This proposal may serve as a basis on which to construct a promising hierarchical evolutionary theory. (shrink)

It was C.H. Waddington's contention that the Neo-Darwinian Theory of Evolution ought to be amended by imbedding it in a broader theoretical framework which takes the role of the phenotype into account. Waddington's theory alleges the existence of two interlocking feedback circuits between environment and phenotype on the one hand and genotype and phenotype on the other. The resulting dynamical model of evolutionary change gives new meaning to the notion of progress in evolution. In this model natural selection (...) acts directly on the phenotype, thereby influencing the feedback relationships. Better tuning of the feedback relations, however, leads to progress in adaptability which in Waddington's theory replaces the cumbersome concept of progress in adaptation.This paper expounds Waddington's theory and places it into a broader philosophical perspective. (shrink)

According to the received view of evolution, only genes are inherited. From this view it follows that only genetically-caused phenotypic variation is selectable and, thereby, that all selection is at bottom genetic selection. This paper argues that the received view is wrong. In many species, there are intergenerationally-stable phenotypic differences due to environmental differences. Natural selection can act on these nongenetically-caused phenotypic differences in the same way it acts on genetically-caused phenotypic differences. Some selection (...) is at bottom nongenetic selection. The argument against the received view involves a reformulation of the concepts of inheritance and heritability. Inherited factors are all those developmental factors responsible for parent–offspring similarity; some inherited factors are genetic and some are not. Heritable variation is intergenerationally-stable phenotypic variation; some such variation is genetically-caused and some is not. The received view and its critics The possibility of nongenetic selection (the lucky butterfly) The reality of nongenetic selection 3.1 Imprinting mechanisms 3.2 Other learning mechanisms 3.3 Other nongenetic mechanisms Genetic and nongenetic inheritance mechanisms Genetic and nongenetic inherited factors Genetic and nongenetic heritability Conclusions + Current address: Dr Matteo Mameli, Research Fellow, King's College, Cambridge, CB2 1ST, United Kingdom, matteo.mameli{at}kings.cam.ac.uk' + u + '@' + d + ''//-->. (shrink)

Much of the recent work on oncogenes has been interpreted as signifying that the cancerous phenotype is caused by the direct expression of ‘dominantly‐acting’ oncogenes. On the other hand, numerous somatic cell hybridization experiments suggest that there are potent tumour‐suppressor genes in the genome. The conflict between the observations and the possible nature of the relationships between oncogenes and tumour‐suppressor are discussed.

In lieu of an abstract, here is a brief excerpt of the content:Kennedy Institute of Ethics Journal 10.3 (2000) 265-281 [Access article in PDF] Scope Note 39 Genes, Patents, and Bioethics-Will History Repeat Itself? Susan Cartier Poland Gene patenting--the very notion sounds absurd! How can anyone claim to have invented the genes with which one is born? To make matters worse, genetic makeup precedes birth, meaning the existence of the invention predates the existence of the inventor. So, do (...) we really own our genes, or do they belong to our parents, or our governments, or a Supreme Being? Ownership is only one bioethical issue involved in gene patenting. But before looking at the issues, some essential and basic terms must be understood, namely genes and patents. Genes In his book On the Origin of Species, published in 1859, the biologist Charles Darwin proposed a theory called "natural selection," whereby living things changed over time or evolved through generations due to competition and variation. By experimenting with the garden pea in the 1860s, Gregor Mendel, a monk and accomplished horticulturalist, provided the mechanism of inheritance supporting the natural selection theory of his contemporary Darwin. That mechanism is the gene, or, as Mendel described it, a discrete "factor." The gene has also been defined as "the fundamental unit of heredity" (United States 1987, p. 157). Each individual has two copies of a gene, one from each parent, but that individual passes down to offspring only one of the two copies. Because of Mendel, the gene has become a scientific concept and the basis of a new scientific field: genetics.David C. Page (2000) of the Whitehead Institute for Biomedical Research at the Massachusetts Institute of Technology explained today's terms for genetics structures using an analogy taken from the home. In his view, the cell is a kitchen, the genome is a shelf in the kitchen, the chromosome is a cookbook on the shelf, the gene is a recipe in the cookbook, and a base-pair (either adenine with thymine or guanine with cytosine) is a single letter in the recipe. A protein, the [End Page 265] working molecule blueprinted by a gene, is a dish ready to eat, and an ingredient in the dish is an amino acid, which is a building block of the protein as specified by a string of base-pairs.Colin Tudge (1993), a British science journalist, would disagree with Page's description of the gene as a recipe. A recipe is like a blueprint: both are directions that precede the work. But a gene is not passive according to Tudge; it actively administers the cell's work, and it also responds to cellular events (Aldridge 1996).The current focus of scientific research and funding is on the gene and the completion of the sequencing of all the genes that comprise the human genome, portrayed in the press as a race between the U.S. government's Human Genome Project and the private corporation Celera Genomics. The real action, however, is at the protein level. The gene only holds the information to produce a protein; it is the three-dimensional shaped protein that does the work. In order to produce energy, eliminate waste, and perform other functions specific to a cell or tissue, proteins must bind, thus creating "biological pathways." Proteins bind (or not) and detach as a function of their shapes, which are determined by their precise chemical composition as spelled out in their genetic code. IBM will spend the next five years making one computer, Blue Gene, that will then take an entire year to come up with the chemical map for only one protein (Gillis 2000). It is estimated that there are about 40,000 proteins in the human body.Despite these overwhelming numbers, modern biology has been able to achieve significant results within the Human Genome Project's 15-year time frame, from 1990 to 2005. The genetic map was completed in 1993; the physical map was completed in 1995; and the genetic sequence is expected to be completed in 2002, with 97 to 99 percent completed as of 26 June 2000. This... (shrink)

Many biologists assume, as Darwin did, that natural selection acts mainly on late embryonic or postnatal development. This view is consistent with von Baer's observations of morphological divergence at late stages. It is also suggested by the conserved morphology and common molecular genetic mechanisms of pattern formation seen in embryos. I argue here, however, that differences in adult morphology may be generated at a variety of stages. Natural selection may have a major action on developmental mechanisms (...) during the organogenetic period, because this is when many adult traits are specified. Evolutionary changes in these early developmental mechanisms probably include subtle shifts in the timing of gene expression. Changes of this kind have little or no gross effect on the anatomy of the embryo; they are only phenotypically expressed, or readily detected, when amplified at later stages. The phylotypic stage, the developmental hourglass, modularity, and von Baerian divergence are reassessed in terms of these arguments. BioEssays 21:604–613, 1999. © 1999 John Wiley & Sons, Inc. (shrink)

The notion that natural selection is a process of fitness maximization gets a bad press in population genetics, yet in other areas of biology the view that organisms behave as if attempting to maximize their fitness remains widespread. Here I critically appraise the prospects for reconciliation. I first distinguish four varieties of fitness maximization. I then examine two recent developments that may appear to vindicate at least one of these varieties. The first is the ‘new’ interpretation of Fisher's (...) fundamental theorem of natural selection, on which the theorem is exactly true for any evolving population that satisfies some minimal assumptions. The second is the Formal Darwinism project, which forges links between gene frequency change and optimal strategy choice. In both cases, I argue that the results fail to establish a biologically significant maximization principle. I conclude that it may be a mistake to look for universal maximization principles justified by theory alone. A more promising approach may be to find maximization principles that apply conditionally and to show that the conditions were satisfied in the evolution of particular traits. (shrink)

For a number of years, the debate in evolutionary biology over the ’levels of selection’ has attracted intense interest from philosophers of science. The main question concerns the level of the biological hierarchy at which natural selection occurs. Does selection act on organisms, genes, groups, colonies, demes, species, or some combination of these? According to traditional Darwinian theory the answer is the organism -- it is the differential survival and reproduction of individual organisms that drives (...) the evolutionary process. But there are alternative views too, including pluralist views which say that the choice between different levels of selection is often a matter of perspective, not empirical fact. (shrink)

. On June 13, 2013, the Supreme Court issued a unanimous decision in Association for Molecular Pathology v. Myriad Genetics, holding that a naturally occurring DNA segment that has merely been “isolated” is not patent eligible, and effectively overturning a longstanding policy that had allowed for patents to be issued on thousands of human genes. Drawing largely on the expert testimony and arguments presented during the court proceedings, this paper provides an overview of the discovery and patenting of the (...) BRCA1 and BRCA2 genes at issue in the case, the impacts of gene patents on biomedical research and innovation and clinical practice, and the legal analysis presented by the plaintiffs throughout the case for how patents issued on genes violate the Patent Act and the U.S. Constitution. Finally, it discusses how the Court’s decision in this case marked an extraordinary victory not only for the plaintiffs directly involved, but more generally for women, patients, researchers, civil liberties, and the future of medicine. (shrink)

This paper elaborates the hypothesis that the unique demography and sociology of Ashkenazim in medieval Europe selected for intelligence. Ashkenazi literacy, economic specialization, and closure to inward gene flow led to a social environment in which there was high fitness payoff to intelligence, specifically verbal and mathematical intelligence but not spatial ability. As with any regime of strong directional selection on a quantitative trait, genetic variants that were otherwise fitness reducing rose in frequency. In particular we propose that the (...) well-known clusters of Ashkenazi genetic diseases, the sphingolipid cluster and the DNA repair cluster in particular, increase intelligence in heterozygotes. Other Ashkenazi disorders are known to increase intelligence. Although these disorders have been attributed to a bottleneck in Ashkenazi history and consequent genetic drift, there is no evidence of any bottleneck. Gene frequencies at a large number of autosomal loci show that if there was a bottleneck then subsequent gene flow from Europeans must have been very large, obliterating the effects of any bottleneck. The clustering of the disorders in only a few pathways and the presence at elevated frequency of more than one deleterious allele at many of them could not have been produced by drift. Instead these are signatures of strong and recent natural selection. (shrink)

Sexual selection processes have received much attention in recent years, attention reflected in interest in human mate preferences. Among these mate preferences are preferences for physical attractiveness. Preferences in and of themselves, however, do not fully explain the nature of the relationships that individuals attain. A tacit negotiation process underlies relationship formation and maintenance. The notion that preferences for physical attractiveness evolved under parasite-driven “good genes” sexual selection leads to predictions about the nature of trade-offs that (...) individuals make between mates’ physical attractiveness and investment potential. These predictions and relevant data are explored, with a primary emphasis on women’s preferences for men’s qualities. In addition, further implications of trade-offs are examined, most notably (a) the impact of environmental variations on the nature of mating and (b) some effects of trade-offs on infidelity and male attempts to control women. (shrink)

Modern biology has been heavily influenced by the gene‐centric concept. Paradoxically, this very concept – on which bioresearch is based – is challenged by the success of gene‐based research in terms of explaining evolutionary theory. To overcome this major roadblock, it is essential to establish new theories, to not only solve the key puzzles presented by the gene‐centric concept, but also to provide a conceptual framework that allows the field to grow. This paper discusses a number of paradoxes and illustrates (...) how they can be addressed by the genome‐centric concept in order to further resynthesize evolutionary theory. In particular, methodological breakthroughs that analyze genome evolution are discussed. The multiple interactions among different levels of a complex system provide the key to understanding the relationship between self‐organization and natural selection. Darwinian natural selection applies to the biological level due to its unique genetic and heterogeneous features, but does not simply or directly apply to either the lower non‐living level or higher intellectual society level. At the complex bio‐system level, the genome context (the entire package of genes and their genomic physical relationship or genomic topology), not the individual genes, defines the system and serves as the principle selection platform for evolution. (shrink)

Bence Nanay has argued that we must abandon the etiological theory of teleological function because this theory explains functions and functional categories in a circular manner. Paul Griffiths argued earlier that we should retain the etiological theory and instead prevent the circularity by making etiologies independent of functional categories. Karen Neander and Alex Rosenberg reply to Nanay similarly, and argue that we should analyze functions in terms of natural selection acting not on functional categories, but merely on (...) lineages. Nanay replies that these lineages cannot be individuated except by reference to functional categories. Worryingly, Neander and Rosenberg themselves have previously argued persuasively that homology often depends on function. This article addresses their arguments and shows how to escape them: Regardless whether the arguments are right about long-term homological categories, they do not apply to generation-to-generation homology. The latter, moreover, is sufficient for individuating the lineages needed to explain teleological functions. (shrink)

Two major clarifications have greatly abetted the understanding and fruitful expansion of the theory of natural selection in recent years: the acknowledgment that interactors, not replicators, constitute the causal unit of selection; and the recognition that interactors are Darwinian individuals, and that such individuals exist with potency at several levels of organization (genes, organisms, demes, and species in particular), thus engendering a rich hierarchical theory of selection in contrast with Darwin’s own emphasis on the organismic (...) level. But a piece of the argument has been missing, and individuals at levels distinct from organisms have been denied potency (although granted existence within the undeniable logic of the theory), because they do not achieve individuality with the same devices used by organisms and therefore seem weak by comparison. We show here that different features define Darwinian individuality across scales of size and time. In particular, species-individuals may develop few emergent features as direct adaptations. The interactor approach works with emergent fitnesses, not with emergent features; and species, as a consequence of their different mechanism for achieving individuality (reproductive exclusivity among subparts, that is, among organisms), express many effects from other levels. Organisms, by contrast, suppress upwardly cascading effects, because the organismic style of individuality (by functional integration of subparts) does not permit much competition or differential reproduction of parts from within. Species do not suppress the operation of lower levels; such effects therefore become available as exaptations conferring emergent fitness—a primary source of the different strength that species achieve as effective Darwinian individuals in evolution. (shrink)

The idea that natural selection acts on many levels—and not only at the level of organisms or individual genes—is increasingly accepted among biologists. However, it is not easy to reconcile this idea with the strictly “individualistic” conception of the evolutionary process that has always characterized Darwinian thought. Moreover, the individuality of some forms of life is a vague concept and therefore controversial. This is the case of Candidatus Magnetoglobus multicellularis, whose discovery immediately inspired the following question: Does (...) the concept of individuality have degrees? Alternatively, how far is this structure of prokaryotic cells from deserving to be called an organism? In this article, we propose a new conceptual scheme based on an idea of individuality that is not limited to organisms and that makes sense in terms of Darwinian evolution. In this conceptual scheme, selection at levels above that of the individual organism is interpreted as the evolutionary emergence of higher-level individuality. This proposal may serve as a basis on which to construct a promising hierarchical evolutionary theory. (shrink)

My general aim is to clarify the foundational difference between Stephen Jay Gould and Richard Dawkins concerning what biological entities are the units of selection in the process of evolution by natural selection. First, I recapitulate Gould’s central objection to Dawkins’s view that genes are the exclusive units of selection. According to Gould, it is absurd for Dawkins to think that genes are the exclusive units of selection when, after all, genes are (...) not the exclusive interactors: those agents directly engaged with, directly impacted by, environmental pressures. Second, I argue that Gould’s objection still goes through even when we take into consideration Sterelny and Kitcher’s defense of gene selectionism in their admirable paper “The Return of the Gene.” Third, I propose a strategy for defending Dawkins that I believe obviates Gould’s objection. Drawing upon Elisabeth Lloyd’s careful taxonomy of the various understandings of the unit of selection at play in the philosophy of biology literature, my proposal involves realizing that Dawkins endorses a different understanding of the unit of selection than Gould holds him to, an understanding that does not require genes to be the exclusive interactors. (shrink)

“Evolvability,” writes Evelyn Fox Keller, “refers to the capacity to generate any kind of heritable phenotypic variation upon which selection can act” . Whether one considers genes or organisms, the potential to adapt and evolve, to respond flexibly to a changing environment, is now recognized by many biologists as itself a trait actively favored by natural selection. Keller correctly presents this idea as an antidote to an old notion of genetic stability. She seems not to appreciate (...) how well it applies to her own subject.The Century of the Gene is Keller's latest collection of linked essays, six tidy, intelligent shovelfuls from her ongoing effort to undermine the claims of mainstream molecular biology and to substitute from the scientific margins an alternative interpretation. This project stems from her philosophical biography of the geneticist Barbara McClintock, published in 1983. In her Nobel speech, also from 1983, McClintock wrote of the genome as a dynamic “sensitive organ of the cell,” responsive, flexible, and interacting with the environment. For half a century, McClintock had railed at biologists that genes must be studied not as autonomous, independently acting units but rather as parts of an exquisite whole, acting in concert. Keller celebrated this in McClintock's work, though many have read Keller as applying to this view of nature a gloss of feminism that McClintock rejected. More recently, among other projects, Keller has criticized the “master molecule” concept in biology, examined the use of metaphor in science, and celebrated Christiane Nüsslein‐Vollhard's studies in developmental biology. Through it all, she maintains a fascination with gender and with language as shapers of scientific thought.Here Keller explores what she sees as the divergent histories of studies of genes and use of the term “gene.” While scientists continue to talk of genes much as they have done for a century now—as stable, discrete units directing the activities of the cell and the development of the organism—the molecular biology of the last forty years has seen a breaking down of the boundaries of the gene, physically, chemically, and physiologically. Keller begins by attacking the notion of genetic stability—whence the introductory quotation about evolvability. Next she explores the idea of genetic regulation, the fact that genes do not make anything, nor do they literally control anything. The molecular biologist's version of the chicken‐and‐egg problem is: Which comes first—proteins or genes? Proteins read the DNA that provides the instructions to make more proteins. Keller argues for chickens.The most important idea in the book is Keller's distinction between a developmental program and a genetic program. The former is a sequence of ontological steps in the life of an organism; it does not presuppose that all steps in the program are encoded in genes or that all steps are determined prior to the beginning of development. Developmental programs may be derived empirically, independently of genetic analysis. In contrast, the genetic program is a more recent idea that does locate the program instructions in the nucleus in the fertilized egg. For Keller, genetic programs carry implications of determinism, a restriction of vision in our attempts to understand nature.The term “gene,” Keller concludes, has outlived its utility. Molecular biologists no longer work with anything so discrete as genes. Their own data, she argues, show that genes and genomes are flexible, modular, and interactive. Keller wishes for, but does not offer, a new term or set of terms that would better reflect current understanding of genetics and development.If biologists have shown that the gene concept is outmoded, why don't they know it? Keller's answer is that the biologists have not yet recognized the implications of their own results; their language lags behind their knowledge. Eventually, she believes, either they will drop the term “gene” or biology must suffocate in its shell. Yet the changes she describes have been under way for decades and biology shows no signs of slowing. Keller recognizes this, and in the conclusion she briefly acknowledges the obvious solution to the conundrum: that biology continues to grow because of, not despite, this linguistic flexibility. This important idea deserves fuller treatment.As with the gene in nature, so with the word “gene” in the scientific lexicon: its very evolvability is selected for, a crucial trait that ensures its survival. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Selected Letters by William, Henry JamesWilliam James EarleWilliam and Henry James. Selected Letters. Edited by Ignas K. Skrupskelis and Elizabeth M. Berkeley. Introduction by John J. McDermott. Charlottesville VA: University Press of Virginia, 1997. Pp. xxxi + 570. $ 39.95.Almost fifty years of letters to and from the very diversely brilliant James brothers: in this volume a generous, and probably ample, selection of 216 from a total (...) of 740 surviving letters or postcards, from an original total, according to the present editors, of twice as many. This volume of correspondence reflects the deep, unquestioned, unshakable familial (and virtually statutory) closeness of William and Henry who happened, as adults, to be seldom in the same place. There is, it must be said, very little explicit philosophy, narrowly or broadly defined, in these letters, but the philosophical reader will—or ought to—find much raw material for philosophical reflection. For example, a reasonable historicist thesis of how brotherhood, or family connection generally, plays itself out is supported by these documents. The nineteenth century is not the same as the twentieth. For example, here is William’s comment on the will of his sister, Alice, who left more to her companion and care-giver, Katherine Loring, a [End Page 479] women of extraordinary virtue and burden, than to her brother Robertson: “I can well sympathize with Alice’s desire to leave her something handsome; but I must say that her own consent (being apparently privy to the will) strikes me as tant soit peu lacking in delicacy. Surely no one of us would like to be in such a position in her family or any other” (271). This would be, in 1998, a rather unenlightened and ungenerous attitude, but is natural enough in 1892, even if not quite inevitable, not being shared by Alice herself. There is, incidentally, much discussion of wills and bequests, for the Jameses were of the genteel class, people with small family money and modest private incomes for whom the wherewithal to maintain homes with servants and to provide themselves with country houses and recuperative European vacations was always a faintly embarrassing, and occasionally a pressing, problem.It is probably also true that the much-discussed question of Henry’s homosexuality has, somehow, to be recast in historically relative terms. Here is an early report—1869—of Henry’s from Oxford: “As I walked along the river I saw hundreds of the mighty lads of England, clad in white flannel & blue, immense, fair-haired, magnificent in their youth, lounging down the stream in their punts or pulling in straining crews & rejoicing in their godlike strength” (41). This could not, the point is, be said by anyone, gay or straight, in 1998. Yet Henry is neither generally naive nor uncritically anglophile. He says of the Warwickshire scenery, which in a way he likes, that it is “too monotonously sweet & smooth—too comfortable, too ovine, too bovine, too English in a word.” And he adds, a little surprisingly: “It seems like a vast show region kept up at the expense of the poor” (41). This is only one of many appealing comments not sparsely scattered, but unpredictably, in letters of more ordinary news. Here’s one I liked occasioned by seeing theater in Paris: “We talk about it & write about it & criticize & dogmatize & analyse to the end of time: but those brave players stand forth & exemplify it & act—create—produce!” (66).Of course the “wit and wisdom” are not the monopoly of Henry. Here is William being wise: “We all learn sooner or later that we must gather ourselves up and more or less arbitrarily concentrate our interests, throw much overboard to save any” (55–56). Again: “It is a sweet world, in the interstices of its bedevilment & brutality” (321). And William being funny: “Boils are surely the most slowly evolving things in nature—Christian doctrine is nothing to them” (393). He is talking about his own boils and was subject, at every period, to ailments and infirmities: “Since writing to you, I have been swimming in deep seas of influenza, gout and Erysipelas of the face” (443). Or as he, in 1900, sums it up: “My... (shrink)

Biologists and philosophers differ on whether selection should be analyzed at the level of the gene or of the individual. In Peter Godfrey-Smith’s book, Darwinian Populations and Natural Selection, he argues that individuals can be good members of Darwinian populations, whereas genes rarely can. I take issue with parts of this view, and suggest that Godfrey-Smith’s scheme for thinking about Darwinian populations is also applicable to populations of genes.

Foot defends her proposal to meet Hume's practicality requirement with a cognitivist ethical theory. The central feature of Foot's theory is that she places the evaluation of human action in the wider contexts not only of the evaluation of other features of human life, but also of evaluative judgements of the characteristics and operations of other living things. She focuses on the description of natural goodness in plant and animal life, and argues that such judgements of goodness and badness (...) are normative and indeed evaluative. Thus, Foot shows that these norms can be explained in terms of facts about natural things, i.e. without recourse to speech acts or the expression of psychological states. Natural goodness, Foot argues, is attributable only to living things themselves and their parts, characteristics, and operations; it is an intrinsic or autonomous goodness that depends directly on the relation of an individual to the life form of its species. (shrink)

Darwin's theory of evolution by natural selection provided the first, and only, causal-mechanistic account of the existence of adaptations in nature. As such, it provided the first, and only, scientific alternative to the “argument from design”. That alone would account for its philosophical significance. But the theory also raises other philosophical questions not encountered in the study of the theories of physics. Unfortunately the concept of natural selection is intimately intertwined with the other basic concepts of (...) evolutionary theory—such as the concepts of fitness and adaptation —that are themselves philosophically controversial. Fortunately we can make considerable headway in getting clear on natural selection without solving all of those outstanding problems. (shrink)

In the recent philosophical literature, two questions have arisen concerning the status of natural selection: (1) Is it a population-level phenomenon, or is it an organism-level phenomenon? (2) Is it a causal process, or is it a purely statistical summary of lower-level processes? In an earlier work (Millstein, Br J Philos Sci, 57(4):627–653, 2006), I argue that natural selection should be understood as a population-level causal process, rather than a purely statistical population-level summation of lower-level processes (...) or as an organism-level causal process. In a 2009 essay entitled “Productivity, relevance, and natural selection,” Stuart Glennan argues in reply that natural selection is produced by causal pro- cesses operating at the level of individual organisms, but he maintains that there is no causal productivity at the population level. However, there are, he claims, many population-level properties that are causally relevant to the dynamics of evolution- ary processes. Glennan’s claims rely on a causal pluralism that holds that there are two types of causes: causal production and causal relevance. Without calling into question Glennan’s causal pluralism or his claims concerning the causal relevance of natural selection, I argue that natural selection does in fact exhibit causal production at the population level. It is true that natural selection does not fit with accounts of mechanisms that involve decomposition of wholes into parts, such as Glennan’s own. However, it does fit with causal production accounts that do not require decomposition, such as Salmon’s Mark Transmission account, given the extent to which populations act as interacting “objects” in the process of natural selection. (shrink)

Change is the fundamental idea of evolution. Explaining the extraordinary biological change we see written in the history of genomes and fossil beds is the primary occupation of the evolutionary biologist. Yet it is a surprising fact that for the majority of evolutionary research, we have rarely studied how evolution typically unfolds in nature, in changing ecological environments, over space and time. While ecology played a major role in the eventual acceptance of the population genetic viewpoint of evolution in the (...) synthetic era (circa 1918-1956), it held a lesser role in the development of evolutionary theory until the 1980s, when we began to systematically study the evolutionary dynamics of natural populations in space and time. As a result, early evolutionary theory was initially constructed in an abstract vacuum that was unrepresentative of evolution in nature. The subtle synthesis between ecology with evolutionary biology (eco-evo synthesis) over the past 40 years has progressed our knowledge of natural selection dynamics as they are found in nature, thus revealing how natural selection varies in strength, direction, form, and, more surprisingly, level of biological organization. Natural selection can no longer be reduced to lower levels of biological organization (i.e., individuals, selfish genes) over shorter timescales but should be expanded to include adaptation at higher levels and over longer timescales. Long-term and/or emergent evolutionary phenomena, such as multilevel selection or evolvability, have thus become tenable concepts within an evolutionary biology that embraces ecology and spatiotemporal change. Evolutionary biology is currently suspended at an intermediate stage of scientific progress that calls for the organization of all the recent knowledge revealed by the eco-evo synthesis into a coherent and unified theoretical framework. This is where philosophers of biology can be of particular use, acting as a bridge between the subdisciplines of biology and inventing new theoretical strategies to organize and accommodate the recent knowledge. Philosophers have recommended transitioning away from outdated philosophies that were originally derived from physics within the philosophical zeitgeist of logical positivism (i.e., monism, reductionism, and monocausation) and toward a distinct philosophy of biology that can capture the natural complexity of multifaceted biological systems within diverse ecosystems—one that embraces the emerging philosophies of pluralism, emergence, and multicausality. Therefore, I see recent advances in ecology, evolutionary biology, and the philosophy of biology as laying the groundwork for another major biological synthesis, what I refer to as the Second Synthesis because, in many respects, it is analogous to the aims and outcomes of the first major biological synthesis (but is notably distinct from the inorganic and contrived progressive movement known as the extended evolutionary synthesis). With the general development of a distinctive philosophy of science, biology has rightfully emerged as an autonomous science. Thus, while the first synthesis legitimized biology, the Second Synthesis autonomized biology and afforded biology its own philosophy, allowing biology to finally realize its full scientific potential. (shrink)

Although natural selection might be expected to reduce the incidence and severity of disease, disease persists. Natural selection leads to increases in the mean fitness of populations and so will reduce the frequency of disease-associated alleles, but other evolutionary processes, such as mutation and gene flow, may introduce or increase the frequency of these deleterious alleles. The pleiotropic actions of genes and the epistatic interactions between them complicate the relationship between genotype and phenotype, and may (...) result in the preservation of disease-associated alleles. Deleterious alleles may also be maintained because of linkage to beneficial alleles. The inability of natural selection to eliminate diseases of aging is a reminder that fitness – success in producing progeny, or in contributing genes to the population gene pool – is not equivalent to the absence of disease. Nutritional or psychosocial cues may lead to life history strategies that maximize survival to reproductive maturity at the expense of disease later in life. Natural selection acts on genes, cells, and groups, as well as on organisms; the outcome of evolution reflects selection at different levels of biological organization. Finally, the human environment is constantly changing, largely because of the evolution of our parasites and because of changes in cultural beliefs and practices; genetic evolution is comparatively slow and lags behind environmental change. An evolutionary nosology complements traditional medical nosologies and enhances our understanding of the persistence of disease and the meaning of human variation. (shrink)

Even today, a century after the publication of the “Origin of Species”, current zoological literature often reveals an insufficient grasp of the implications of the now generally accepted view that it is natural selection that confers direction on the evolutionary process.This is, in part, due to a reaction against oversimplified teleology and against Lamarckism. In rejecting Lamarck's thesis that the activities of an animal directly affect its hereditary characters it is frequently assumed that this implies that such (...) activities are irrelevant to the study of evolution. This is a non-sequitur, for activities may affect evolution not directly, through heredity, but indirectly, by influencing the direction of the selective forces impinging on the organism. Reasons are given for concluding that changes in habits and behaviour frequently precede structural change and, in fact, determine the direction of the latter.As an example of a concept which deserves a more evolutionary treatment than it commonly receives, the subject of neoteny is considered. It appears that failure to think in terms of the selective forces involved has frequently led to error. An analysis in functional terms is made of the theory that the chordates represent secondarily glorified sea-squirts and it is concluded that this idea is unlikely to be correct. The characteristics of man that are commonly considered to be neotenous are also discussed. It is concluded that a facile and unanalytical application of the label “neoteny” to many of the evolutionary changes involved has tended to obscure rather than to clarify their significance: the neotenous features of man are not those that have been of primary importance in human evolution, but are secondary to the acquisition of new characters which are not to be found in either the adult or the young stages of any other primate.Aujourd'hui, un siècle après l'apparition de l'Originedes Espèces, la conviction est presque générale que la sélection naturelle dirige le procès de l'évolution. Néanmoins, les publications zoologiques actuelles révèlent souvent une compréhension insuffisante de ce qui en résulte.Ceci doit en partie être considéré comme réaction contre une téléologie simpliste et contre le Lamarckisme. En rejetant la thèse de Lamarck, que les activités d'un animal ont une influence directe sur ses caractéristiques héréditaires, on admet fréquemment que de pareilles activités n'ont rien à voir avec l'étude le l'évolution. Cependant, une telle conclusion n'est pas justifiée, car les activités peuvent influer sur l'évolution non pas directement, par la voie de l'hérédité, mais indirectement en agissant sur la direction des forces sélectives que l'organisme rencontre. Des raisons ont été données qui mènent à conclure que des changements dans les habitudes et dans le comportement précèdent maintes fois le changement structural et même déterminent la direction de celui-ci.Comme exemple d'un concept qui mérite un traitement plus évolutionniste qu'il ne reçoive en général, la néoténie a été examinée. Il paraît que l'on a fait beaucoup d'erreurs en ne tenant pas compte des forces sélectives engagées. Une analyse au pointde-vue de la fonction a été appliquée à la théorie que les chordées ne sont que des ascidies néoténiques transfigurées par après, et il s'ensuit que cette idée n'est probablement pas correcte. Aussi les caractéristiques de l'homme généralement regardées comme neoténiques ont été discutées. Il en résulte que, en désignant légèrement et sans analyse plusieurs changements évolutionnaires comme néoténie, on a plutôt obsurci qu'éclairci leur signification. Ce ne sont pas les traits néoteniques de l'homme qui ont joué le rôle principal dans l'évolution humaine; au contraire, ils n'apparaissent qu'après l'acquisition de quelques nouvelles caractéristiques qui ne se trouvent ni dans l'adulte ni dans les phases plus jeunes des autres primates.Sogar heutzutage, ein Jahrhundert nach dem Erscheinen der „Origin of Species”, zeigt die jetzige zoologische Literatur oft eine unzulängliche Einsicht in die Folgerungen, zu denen die jetzt allgemein akzeptierte Annahme leitet, dass die natürliche Selektion die Richtung des Evolutionsprozesses bedingt.Dies ist teilweise zu sehen als eine Reaktion gegen eine einseitige Teleologie und gegen das Lamarckismus. Bei der Ablehnung der TheseLamarck's, dass die Aktivitäten eines Tieres einen direkten Einfluss ausüben auf seine erbliche Konstitution, nimmt man oft an, dass dies bedeutet, dass derartige Aktivitäten demnach nichts zur Sache tun bei dem Studium der Evolution. Zu einer derartigen Konklusion ist man jedoch nicht berechtigt, denn, obwohl die Aktivitäten die Evolution nicht direkt beeinflussen können mittels der Erblichkeit, so können sie dies jedoch indirekt, weil sie die Richtung der selektiven Kräfte, welche auf das Organismus einwirken, bestimmen. Es werden Argumente gegeben, welche die Konklusion rechtfertigten, dass Änderungen in Gewohnheit und Verhalten oft Strukturänderungen vorhergehen und tatsächlich die Richtung dieser letztgenannten bestimmen. Die Neotenie wirdt als ein Beispiel eines Begriff betrachtet, welcher eine mehr evolutionäre Behandlung verdient als bisher geschehen ist. Es ergibt sich dass man viele Irrtümer hat gemacht, indem man den betreffenden selektiven Kräften keine Rechnung getragen hat. Eine Analyse der Theorie, welche die Chordaten als neotenische Ascidien betrachtet, wird von einem funktionellen Gesichtspunkt aus durchgeführt. Daraus scheint der Schluss berechtigt, dass diese Theorie falsch ist. Auch werden die menschlichen Kennzeichen, welche gewöhnlich als neotenische betrachtet werden, besprochen. Die Konklusion lautet, dass, wenn man leichtfertig und ohne genügende Analyse den Zettel „Neotenie“ für mancherlei evolutive Änderungen anwendet, man die richtige Bedeutung dieser Erscheinung vielmehr verdunkelt als aufklärt: nicht die neotenische Kennzeichen des Menschen sind am wichtigsten in seiner Evolution; in Gegenteil sie erscheinen nur sekundär, nachdem die neuen Kennzeichen, welche sich weder in den Erwachsenen noch in den jüngeren Stadien von den anderen Primaten finden lassen, erschienen sind. (shrink)

This paper gives a detailed narrative of a controversial empirical research in postwar population genetics, the analysis of the cytological polymorphisms of an Australian grasshopper, Moraba scurra. This research intertwined key technical developments in three research areas during the 1950s and 1960s: it involved Dobzhansky’s empirical research program on cytological polymorphisms, the mathematical theory of natural selection in two-locus systems, and the building of reliable estimates of natural selection in the wild. In the mid-1950s the cytologist (...) Michael White discovered an interesting case of epistasis in populations of Moraba scurra. These observations received a wide diffusion when theoretical population geneticist Richard Lewontin represented White’s data on adaptive topographies. These topographies connected the information on the genetic structure of these grasshopper populations with the formal framework of theoretical population genetics. As such, they appeared at the time as the most successful application of two-locus models of natural selection to an empirical study system. However, this connection generated paradoxical results: in the landscapes, all grasshopper populations were located on a ridge while they were expected to reach a peak. This puzzling result fueled years of research and triggered a controversy attracting contributors from Australia, the United States and the United Kingdom. While the original problem seemed, at first, purely empirical, the subsequent controversy affected the main mathematical tools used in the study of two-gene systems under natural selection. Adaptive topographies and their underlying mathematical structure, Wright’s mean fitness equations, were submitted to close scrutiny. Suspicion eventually shifted to the statistical machinery used in data analysis, reflecting the crucial role of statistical inference in applied population genetics. In the 1950s and 1960s, population geneticists were not simply in search for new generalizations about the evolutionary process and for new evidence about genetic variation: struggling against statistical artifacts, they were searching for reliable tests and descriptors to analyze their data. (shrink)