The relatively new field of evolutionary developmental biology continues to attract considerable attention from biologists, philosophers, and historians, in part, because work in this field demonstrates that important changes are underway within biology. Though studies of development and evolution were closely connected during the 19th century, continued work in genetics fostered a general split between the two during the first decades of the twentieth century (e.g., Allen 1978; Gilbert 1978; Mayr and Provine 1980; Gilbert, Opitz and..

The Neo‐Darwinian concept of natural selection is plausible when one assumes a straightforward causation of phenotype by genotype. However, such simple 1:1 mapping must now give place to the modern concepts of gene regulatory networks and gene expression noise. Both can, in the absence of genetic mutations, jointly generate a diversity of inheritable randomly occupied phenotypic states that could also serve as a substrate for natural selection. This form of epigenetic dynamics challenges Neo‐Darwinism. It needs to incorporate the (...) non‐linear, stochastic dynamics of gene networks. A first step is to consider the mathematical correspondence between gene regulatory networks and Waddington's metaphoric ‘epigenetic landscape’, which actually represents the quasi‐potential function of global network dynamics. It explains the coexistence of multiple stable phenotypes within one genotype. The landscape's topography with its attractors is shaped by evolution through mutational re‐wiring of regulatory interactions – offering a link between genetic mutation and sudden, broad evolutionary changes. (shrink)

During the 1920s and 1930s, many biologists questioned the viability of Darwin’s theory as a mechanism of evolutionary change. In the early 1940s, and only after a number of alternatives were suggested, Darwinists succeeded to establish natural selection and gene mutation as the main evolutionary mechanisms. While that move, today known as the neo-Darwinian synthesis, is taken as signalling a triumph of evolutionary theory, certain critical problems in evolution—in particular the evolution of animal function—could not be addressed with this (...) approach. Here I demonstrate this through reconstruction of the evolutionary theory of Joseph Needham (1900–1995), who pioneered the biochemical study of evolution and development. In order to address such problems, Needham employed Herbert Spencer’s principles of emergence and Ernst Haeckel’s theory of recapitulation. While Needham did not reject Darwinian theory, Spencerian and Haeckelian frameworks happened to better fit his findings and their evolutionary relevance. He believed selectionist and genetic approaches to be important but far from sufficient for explaining how evolutionary transformations occur. (shrink)

In Difference and Repetition, Charles Darwin was the philosopher of individuals and the priority of individual differences. His theory of evolution inaugurated ‘the thought of individual difference’. (DR 248) For Darwin, the individual and its differences come first. Species-specific characteristics do not exist until natural selection does its work on individual differences over geological time. It is not the individual that is derivative in relation to the genus of the species, which was the conclusion of Aristotlean science. Rather, it is (...) the species that ‘is an illusion—inevitable and well founded, it is true—in relation to the play of the individual and individuation. . . . It is the individual which is above the species and precedes the species in principle’. (DR 250) Twelve years later, in A Thousand Plateaus, a neo-Darwinist theme intrudes. Individuals are described as effects of populations. Species-identity (‘form’) depends on codes, and codes apply only to populations, not individuals. ‘Organic form depends on an autonomous code’, a neo-Darwinist mantra they repeat four times in less than ten pages. Individuals are coded because they emerge amid populations that are coded, and changes in code primarily affect populations by affecting the ability of the code to propagate, which requires the agency of individual organisms. No code is impervious to decoding, organically expressed as mutation, genetic drift, and the re-purposing of redundancy. Fragments of code transfer across forms symbiotically. All organic forms become machinic, interlocking partial objects in an ecological economy. Forms depend on populations, populations imply codes, codes undergo decoding and displacement, natural selection does its work, and the rest is history. (shrink)

A new evolutionary concept is presented, based on the principle of biological diversity by organismal adaptation, more specifically the origin of the first variations and the process leading to speciation. The article suggests the mechanism of stimulation as the major promoter of genetic variation, making an overall assessment and accurate to the natural phenomenon responsible for this evolutionary step. Constantly, environmental forces interact with the organism, favoring changes to the organs toward adaptation. Stimulation focuses on this action?reaction between organism (...) and environment, trying to decipher the causes/consequences resulting. The article also addresses possible relationships and constraints with neo-Darwinism. (shrink)

Two hundred years after Darwin’s birth, the evolution of living systems is an accepted fact but there is scope for controversy on the mechanisms involved in such a process. Mainstream neo-Darwinism champions the role of natural selection (NS) as the fundamental cause of the evolutionary process as well as of random, contingent events at the genetic level as the main source of variation upon which NS performs its causal role. Thus, according to neo-Darwinism the course of biological evolution is (...) quite unpredictable and the past can only be partially reconstructed by means of a historical narrative.This second-class status for biology within the natural sciences as a merely descriptive, historical science results from the chronic neglect of biological form in the neo-Darwinian discourse. Hereunder I discuss the need for reintroducing form as the central object of biology, aiming at the identification of the general and fundamental principles of biological form. Such a formal biology may go beyond simple historical description achieving a complete, rational explanation of how previous and current morphologies corresponding to identifiable species were established, and so providing a rational foundation for predicting the possible outcomes of future biological evolution on earth and perhaps elsewhere in the universe. (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)

Three early 20th-century attempts at unifying separate areas of biology, in particular development, genetics, physiology, and evolution, are compared in regard to their success and fruitfulness for further research: Jacques Loeb’s reductionist project of unifying approaches by physico-chemical explanations; Richard Goldschmidt’s anti-reductionist attempts to unify by integration; and Sewall Wright’s combination of reductionist research and vision of hierarchical genetic systems. Loeb’s program, demanding that all aspects of biology, including evolution, be studied by the methods of the experimental sciences, proved (...) highly successful and indispensible for higher level investigations, even though evolutionary change and properties of biological systems up to now cannot be fully explained on the molecular level alone. Goldschmidt has been appraised as pioneer of physiological and developmental genetics and of a new evolutionary synthesis which transcended neo-Darwinism. However, this study concludes that his anti-reductionist attempts to integrate genetics, development and evolution have to be regarded as failures or dead ends. His grand speculations were based on the one hand on concepts and experimental systems that were too vague in order to stimulate further research, and on the other on experiments which in their core parts turned out not to be reproducible. In contrast, Sewall Wright, apart from being one of the architects of the neo-Darwinian synthesis of the 1930s, opened up new paths of testable quantitative developmental genetic investigations. He placed his research within a framework of logical reasoning, which resulted in the farsighted speculation that examinations of biological systems should be related to the regulation of hierarchical genetic subsystems, possibly providing a mechanism for development and evolution. I argue that his suggestion of basing the study of systems on clearly defined properties of the components has proved superior to Goldschmidt’s approach of studying systems as a whole, and that attempts to integrate different fields at a too early stage may prove futile or worse. © 2011 Elsevier Inc. (shrink)

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)

Although the construction of neo-Darwinism grew out of Thomas Hunt Morgan's melding of Darwinism and Mendelism, his evidence did not soley support a model of gradual change. To the contrary, he was confronted with observations that could have led him to a more "evo-devo" understanding of the emergence of novel features. Indeed, since Morgan was an embryologist before he became a fruit-fly geneticist, one would have predicted that the combination of these two lines of research would have resulted in (...) early formulations of concepts relevant to evolutionary developmental biology. It is thus of interest to review Morgan's thought processes and arguments for at first rejecting both Darwinism and Mendelism, and then for later dismissing data that would have yielded a model of rapid morphological change in favor of a model of change based on the accumulation of minor mutations and their morphological consequences. (shrink)

An increasing number of biologists are expressing discontent with the prevailing theory of neo-Darwinism. In particular, the tendency of neo-Darwinians to adopt genetic determinism and atomistic notions of both genes and organisms is seen as grossly unfair to the body of developmental theory. One faction of dissenteers, the Process Structuralists, take their inspiration from the rational morphologists who preceded Darwin. These neo-rationalists argue that a mature biology must possess universal laws and that these generative laws should be sought within (...) organismal development. Such a rational biology will only be possible once the neo-Darwinian paradigm, with its reliance on inherently stochastic processes, is overthrown.To facilitate this revolution, process structuralism launches a broad attack on the theoritical adequacy of its opponent. It is charged that neo-Darwinism is untestable and therefore its hypotheses are nothing more than adaptive stories. Further, the lamentable tendencies toward genetic determinism and atomism by modern biologists is seen as the inescapable consequences of adopting the neo-Darwinian outlook. (shrink)

Small gaseous molecules play important roles in biological signaling in both animal and plant physiology. The hydrocarbon gas ethylene has long been known to regulate diverse aspects of plant growth and development, including fruit ripening, leaf senescence and flower abscission. Recent progress has been made toward identifying components involved in ethylene signal transduction in the plant Arabidopsis thaliana. Ethylene is perceived by five receptors that have similarity to two‐component signaling proteins. The hydrophobic amino‐terminus of the receptors binds ethylene, and (...) class='Hi'>mutations in this domain both prevent ethylene binding and confer ethylene insensitivity to the plant; the carboxyl‐terminal portion of the receptors has similarity to bacterial his tidine protein kinases. Genetic data suggest a model in which ethylene binding inhibits receptor signaling, yet precisely how these receptors function is unclear. Two of the receptors have been found to associate with a negative regulator of ethylene responses called CTR1, which appears to be a mitogen‐activated protein kinase (MAPK) kinase kinase. BioEssays 23:619–627, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

Although the Neo-Darwin Theory of Evolution is one of the most celebrated theories in science, nonetheless it has received many criticisms. These criticisms are documented and a new transdisciplinary theory of origin is introduced. Darwin's original argument was that natural selection, through heritable changes, changed simple organisms over time. These heritable changes are responsible for the complex plethora of life seen around us today. Darwin's original theory, however, was deconstructed after the fact into a mutation-based theory. This mutation-based theory in (...) its current form is an insufficient and indeed unnecessary transdisciplinary explanation. A subsequent statistical comparison between the six extant scientifically based primary theories of origin was undertaken and based on current biological knowledge a statistically significantly best fit phenotypic model emerged. (shrink)

C.H. Waddington is today remembered chiefly as a Drosophila developmental geneticist who developed the concepts of “canalization” and “the epigenetic landscape.” In his lifetime, however, he was widely perceived primarily as a critic of Neo-Darwinian evolutionary theory. His criticisms of Neo-Darwinian evolutionary theory were focused on what he saw as unrealistic, “atomistic” models of both gene selection and trait evolution. In particular, he felt that the Neo-Darwinians badly neglected the phenomenon of extensive gene interactions and that the “randomness” of mutational (...) effects, posited in the theory, was a false postulate. This last criticism dealt with the phenomenon known today as “developmental constraints.” Although population genetics itself has evolved considerably from its form at mid-20th century, much of Waddington’s critique, it is argued here, retains cogency. Yet, he did not attempt to develop a full-fledged alternative theory himself. Perhaps most surprisingly, in retrospect, is that he did not try to marry his work on gene interactions in development with his evolutionary interests, to create a theory of “genetic networks” and their evolution. Whether evolutionary genetics today will incorporate “network thinking” as a central element or whether there will be a general retreat to the more atomistic approach offered by genomics, remains an open question. (shrink)

In the 1940s, the ‘modern synthesis’ (MS) of Darwinism and genetics cast genetic mutation and recombination as the source of variability from which environmental events naturally select the fittest, such ‘natural selection’ constituting the cause of evolution. Recent biology increasingly challenges this view by casting genes as followers and awarding the leading role in the genesis of adaptations to the agency and plasticity of developing phenotypes—making natural selection a consequence of other causal processes. Both views of natural selection claim (...) to capture the core of Darwin’s arguments in On the Origin of Species. Today, historians largely concur with the MS’s reading of Origin as a book aimed to prove natural selection the cause (vera causa) of adaptive change. This paper finds the evidence for that conclusion wanting. I undertake to examine the context and meaning of all Darwin’s known uses of the phrase vera causa, documenting in particular Darwin’s resistance to the pressure to prove natural selection a vera causa in letters written early in 1860. His resistance underlines the logical dependence of natural selection, an unobservable phenomenon, on the causal processes producing the observable events captured by the laws of inheritance, variation, and the struggle for existence, established in Chapters 1–3 of Origin. (shrink)

Genetic changes arising in human pluripotent stem cells (hPSC) upon culture may bestow unwanted or detrimental phenotypes to cells, thus potentially impacting on the applications of hPSCs for clinical use and basic research. In the 20 years since the first report of culture‐acquired genetic aberrations in hPSCs, a characteristic spectrum of recurrent aberrations has emerged. The preponderance of such aberrations implies that they provide a selective growth advantage to hPSCs upon expansion. However, understanding the consequences of culture‐acquired variants (...) for specific applications in cell therapy or research has been more elusive. The rapid progress of hPSC‐based therapies to clinics is galvanizing the field to address this uncertainty and provide definitive ways both for risk assessment of variants and reducing their prevalence in culture. Here, we aim to provide a timely update on almost 20 years of research on this fascinating, but a still unresolved and concerning, phenomenon. (shrink)

A growing number of linguistic attempts to explain how languages change use cultural-evolutionary models involving selection or drift. Developmental constraints and biases, which take center stage in evolutionary developmental biology or evo-devo, seem to be absent within this framework, even though linguistics is home to numerous notions of constraint. In this paper, we show how these evo-devo concepts could be applied to linguistic change and why they should. This requires some conceptual groundwork, due to important differences between linguistic (...) and biotic evolution. In biological evolution, development generates the organism's variable traits on which selection and drift act. In linguistic evolution by analogy, we say development generates the linguistic variants on which selection and drift can act. “Linguistic development” then picks out how individual speakers produce and comprehend language. It involves much more than just learning. Using this broad notion of development, we distinguish between different types of bias that could operate in the processes of linguistic innovation and transmission, which correspond to genetic mutation and biological reproduction, respectively. Having thus sharpened our conceptual toolbox, we then reanalyze two well-documented cases of linguistic change and show that, in both these cases, linguists have only considered Neo-Darwinian evolutionary explanations, falsely deploying an exclusive disjunction of selection and drift. We show that there is at least a third relevant alternative in these examples, namely developmental constraint or bias in the sense we explicate here. (shrink)

Darwinism is defined here as an evolving research tradition based upon the concepts of natural selection acting upon heritable variation articulated via background assumptions about systems dynamics. Darwin’s theory of evolution was developed within a context of the background assumptions of Newtonian systems dynamics. The Modern Evolutionary Synthesis, or neo-Darwinism, successfully joined Darwinian selection and Mendelian genetics by developing population genetics informed by background assumptions of Boltzmannian systems dynamics. Currently the Darwinian Research Tradition is changing as it incorporates new information (...) and ideas from molecular biology, paleontology, developmental biology, and systems ecology. This putative expanded and extended synthesis is most perspicuously deployed using background assumptions from complex systems dynamics. Such attempts seek to not only broaden the range of phenomena encompassed by the Darwinian Research Tradition, such as neutral molecular evolution, punctuated equilibrium, as well as developmental biology, and systems ecology more generally, but to also address issues of the emergence of evolutionary novelties as well as of life itself. (shrink)

This paper looks at the neo-Kantian response to Darwinism as a historical science. I distinguish four responses to this aspect of Darwin’s thought from within the neo-Kantian tradition. The first line of response, represented by August Stadler and Bruno Bauch, views Darwin’s model of historical explanation as a fulfilment of Kant’s criteria of scientific intelligibility. The second, represented by Otto Liebmann, regards historical explanation as intrinsically limited, because it cannot tell us why nature develops as it does. The third line (...) of response questions whether we can give a historical account of qualitative change. Friedrich Lange expresses this scepticism in general terms, while Alois Riehl and Ernst Cassirer extend it to human beings specifically. A fourth line of response, represented by Heinrich Rickert, challenges the misperception that Darwinian explanatory principles such as natural selection have normative or socio-political significance. (shrink)

A substantial portion of the human genome has been found to consist of simple sequence repeats, including microsatellites and minisatellites. Microsatellites, tandem repeats of 1–6 nucleotides, form the template for dynamic mutations, which involve heritable changes in the lengths of repeat sequences. In recent years, a large number of human disorders have been found to be caused by dynamic mutations, the most common of which are trinucleotide repeat expansion diseases. Dynamic mutations are common to numerous nervous system (...) disorders, including Huntington's disease, various spinocerebellar ataxias, fragile X syndrome, fragile X tremor/ataxia syndrome, Friedreich ataxia and other neurodegenerative disorders. The involvement of dynamic mutations in brain disorders will be reviewed, with a focus on the large group caused by CAG/glutamine repeat expansions. We will also outline a proposed role of tandem repeat polymorphisms (TRPs), with unique ‘digital’ genetic distributions, in modulating brain development and normal function, so as to generate additional mutational diversity upon which natural selection may act. BioEssays 29:525–535, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

It may be concluded that Mitchell's peace evolutionism incorporated most of the features of the cooperationist and Novicovian traditions. He questioned the conflict paradigm that underpinned biological militarism, and reinforced a holistic and more peaceful model of nature by reference to the emerging discipline of ecology. His “restrictionist” objections to the deterministic tendencies of much prevailing biosocial thought combined philosophical with biological arguments to assert that human history was sui generis, based upon the unique development of human consciousness and the (...) cultural transmission of knowledge. Mitchell's opposition to biological militarism reflected Victorian anxieties about the legitimacy of evolutionary ethics. However, he introduced an innovatory note, linked to the “modernist” intellectual milieu of the time, when he put objections to the use of analogy on the grounds (1) that the Darwinist paradigm had not been properly established, and (2) that scientific laws themselves were uncertain and subjective.The first objection related to the bitter controversies that racked the biological world in the 1900s when mutation theory thrust the Darwinian concept of natural selection into temporary disrepute. In this respect Mitchell encoutered continuing Darwinist orthodoxy, not least from peace biology itself, while confusion was added by his personal devotion to Darwinism and his sociopolitical suspicion of Mendelian hereditarianism. The later triumph of a new Darwinian synthesis under men like R. A. Fisher made Mitchell's criticisms seem outmoded. In the second respect, Mitchell's attack on the primacy of naturalistic science echoed the epistemology of the “new physics” and movements such as German neo-Kantianism. However, positivism was still deeply embedded in Britain, indeed enjoying a resurgence from the last decade of the nineteenth century.79 Mitchell's critique of the Darwinist version of it seems to have been too novel and puzzling to influence a generation still convinced of the soundness of the science.Mitchell made more impact when he put his objections to the use of analogy on the grounds of professional methodology. As a naturalist, he could argue:It is impossible to make correct comparisons even between an insect and spider, two creatures so closely allied that only zoologists would separate them, unless we could trace the qualities of the insect and of the spider respectively down to their common ancestor, and in so doing we should almost certainly lose all that made the comparison interesting and significant, and be left with little more than the qualities common to all protoplasm..., It is quite true that the whole web of life is in physical and physiological community, but considerations drawn from any part of it require so much modification before they can be applied to any other part, that they become merely verbal.80This type of criticism was to have a more lasting heritage. Chalmers Mitchell is worth remembering as an articulate early spokesman of a persistent, if often embattled, modern tradition that has resisted interpretations of human nature and history based upon genetic determinants or immutable biological laws, or upon the use of animal analogies to generalize too freely about human aggression and war. (shrink)

Although much has been written about the vigorous debates over science and religion in the Victorian era, little attention has been paid to their continuing importance in early twentieth-century Britain. Reconciling Science and Religion provides a comprehensive survey of the interplay between British science and religion from the late nineteenth century to World War II. Peter J. Bowler argues that unlike the United States, where a strong fundamentalist opposition to evolutionism developed in the 1920s (most famously expressed in the Scopes (...) "monkey trial" of 1925), in Britain there was a concerted effort to reconcile science and religion. Intellectually conservative scientists championed the reconciliation and were supported by liberal theologians in the Free Churches and the Church of England, especially the Anglican "Modernists." Popular writers such as Julian Huxley and George Bernard Shaw sought to create a non-Christian religion similar in some respects to the Modernist position. Younger scientists and secularists—including Rationalists such as H. G. Wells and the Marxists—tended to oppose these efforts, as did conservative Christians, who saw the liberal position as a betrayal of the true spirit of their religion. With the increased social tensions of the 1930s, as the churches moved toward a neo-orthodoxy unfriendly to natural theology and biologists adopted the "Modern Synthesis" of genetics and evolutionary theory, the proposed reconciliation fell apart. Because the tensions between science and religion—and efforts at reconciling the two—are still very much with us today, Bowler's book will be important for everyone interested in these issues. Contents: Illustrations Preface Introduction: A Legacy of Conflict? Confrontation, Cooperation, or Coexistence? Victorian Background Science and Religion in the New Century Part One: The Sciences and Religion 1. The Religion of Scientists Changing Patterns of Belief Scientists and Christianity Scientists and Theism Method and Meaning Science and Values 2. Scientists against Superstition Science and Rationalism Religion without Revelation Marxists and Other Radicals Science, Religion, and the History of Science 3. Physics and Cosmology Ether and Spirit The New Physics The Earth and the Universe 4. Evolution and the New Natural Theology Science and Creation Evolution and Progress The Role of Lamarckism Darwinism Revived 5. Matter, Life, and Mind The Origin of Life Vitalism and Organicism Mind and Body Psychology and Religion Part Two: The Churches and Science 6. The Churches in the New Century The Challenge of the New The Churches’ Response 7. The New Theology in the Free Churches Precursors of the New Theology Campbell and the New Theology Modernism in the Free Churches 8. Anglican Modernism Modernism and the New Natural Theology Charles F. D’Arcy E. W. Barnes W. R. Inge Charles Raven 9. The Reaction against Modernism Evangelicals against Evolution Liberal Catholicism The Menace of the New Psychology Science and Modern Life Theology in the Thirties Roman Catholicism Part Three: The Wider Debate 10. Science and Secularism Against Idealism Popular Rationalism The Social Reformers 11. Religion’s Defenders From Idealism to Spiritualism Creative and Emergent Evolution Evolution and the Human Spirit Progress through Struggle The Christian Response Epilogue Biographical Appendix Bibliography Index. (shrink)

The article challenges the view that the Neo-Darwinian theory of evolution is sufficient to explain the ongoing evolution. The classical evolutionary algorithms based on that theory suffer from the loss of diversity, stagnation and premature convergence. The author claims that the cosmetic changes of those tools are not sufficient to overcome this situation and the change of overall theoretical framework is required. The proposition of a semiotic theory of evolution created by Charles Sanders Peirce is revealed as an alternative (...) to the classical Modern Synthesis. This alternative model of evolution is implemented in two kinds of evolutionary algorithms: P-EA and SEAM, which simulate evolution by virtue of cooperation and symbiosis respectively. The new approach to algorithms constructs shows significant benefits upon classical evolutionary algorithms in benchmark tests, which may support the original claim that the accepted theory of evolution needs rethinking today. (shrink)

In his thought-provoking book, Alex Mesoudi argues for an evolutionary, unifying framework for the social sciences, which is based on the principles of Darwinian theory. Mesoudi maintains that cultural change can be illuminated by using the genotype-phenotype distinction, and that it is sufficiently similar to biological change to warrant a theory of culture-change based on evolutionary models. He describes examples of cultural microevolution, within-population changes, and the biologically inspired population genetics models used to study them. He also (...) shows that some aspects of large-scale cultural transformation can be studied by using ecological models and phylogenetic comparative techniques. We argue that although Mesoudi's evolution-based perspective offers many useful insights, his ambition—the unification of the social sciences within a Darwinian framework through the use of the methods and models he describes—suffers from a major theoretical limitation. His reductive approach leads to overlooking culture as a system with emergent processes and features. Mesoudi therefore does not engage with any of the central past and present theories in sociology and anthropology for which the systems view of culture is central, and he does not analyze the emergent, high-level properties of human cultural-social systems. We suggest that a systems perspective, using some analogies and metaphors from developmental biology, can complement the evolutionary approach and is more in tune with a systems view of society. Such an approach, which stresses feedback and self-sustaining interactions within social networks, and engages with the insights of sociological and anthropological theories, can contribute to the understanding of cultural systems by highlighting the evolution of processes of social cohesion, and by making use of the mathematical approaches of complexity theory. (shrink)

According to the somatic mutation theory (SMT), cancer begins with a genetic change in a single cell that passes it on to its progeny, thereby generating a clone of malignant cells. It is strongly supported by observations of leukemias that bear specific chromosome translocations, such as Burkitt's lymphoma, in which a translocation activates the c‐myc gene, and chronic myeloid leukemia (CML), in which the Philadelphia chromosome causes production of the BCR‐ABL oncoprotein. Although the SMT has been modified and (...) extended to encompass tumor suppressor genes, epigenetic inheritance, and tumor progression through accumulation of further mutations, perhaps the strongest validation comes from the successful treatment of certain malignancies with drugs that directly target the product of the mutant gene.magnified imageDavid Vaux is at the Walter and Eliza Hall Institute and La Trobe Institute for Molecular Science, Melbourne, Australia. (shrink)

In his book The Biotech Century Jeremy Rifkin makes arguments about the dangers of market-driven genetic biotechnology in medical and agricultural contexts. Believing that Darwinism is too compromised by a competitive ethic to resist capitalist depredations of the genetic commons, and perhaps hoping to pick up anti-Darwinian allies, he turns for support to unorthodox non-Darwinian views of evolution. The Darwinian tradition, more closely examined, contains resources that might better serve his argument. The robust tradition associated with Theodosius Dobzhansky, (...) Ernst Mayr, and others provides an alternative, scientifically sound basis for challenging the rhetoric of genetic reductionism. (shrink)

The Kantian legacy has had a key impact on the landscape of theoretical philosophy in the first half of the twentieth century. Philosophers both in Germany and in Russia saw Immanuel Kant’s ideas as seminal for their philosophical research. The main schools of that era were formed in discussions of the problems and the solutions which were proposed by Kant. The methodological legacy of the critical philosophy effectively became the main benchmark of the thinking of a whole generation of intellectuals. (...) Research into the unity of “form” in the structure of human cognition was also in many ways mediated by the Kantian tradition. To prove this thesis I first look at the philosophy of Gustav Shpet who creatively interpreted the German tradition and proposed an original project of his own, and then I examine the theory of Ernst Cassirer, an outstanding representative of Neo-Kantianism who in the later period of his work proposed considering the phenomena of the humanities to be symbolic forms closest to the spontaneity of the biological. The common feature of the approaches of the two philosophers is their attempt to preserve the integrity of cognition which is destroyed by mathematisation of the common denominator (ultimate categorisation) and hierarchisation of the phenomena of human life. The alternative is the metaphor of mutational change, through which the concept of “form” acquires a new meaning. In conclusion I show that the analysis of the projects of Shpet and Cassirer has heuristic value for the historical-philosophical understanding of the fate of the Kantian philosophy and for modern philosophical culture. (shrink)

We hypothesize that heritable epigenetic changes can affect rates of fitness increase as well as patterns of genotypic and phenotypic change during adaptation. In particular, we suggest that when natural selection acts on pure epigenetic variation in addition to genetic variation, populations adapt faster, and adaptive phenotypes can arise before any genetic changes. This may make it difficult to reconcile the timing of adaptive events detected using conventional population genetics tools based on DNA sequence data with environmental (...) drivers of adaptation, such as changes in climate. Epigenetic modifications are frequently associated with somatic cell differentiation, but recently epigenetic changes have been found that can be transmitted over many generations. Here, we show how the interplay of these heritable epigenetic changes with genetic changes can affect adaptive evolution, and how epigenetic changes affect the signature of selection in the genetic record. (shrink)

Background: When a genetic mutation is identified in a family member, internationally, it is usually the proband’s or another responsible family member’s role to disclose the information to at-risk relatives. However, both active and passive non-disclosure in families occurs: choosing not to communicate the information or failing to communicate the information despite intention to do so, respectively. The ethical obligations to prevent harm to at-risk relatives and promote the duty of care by genetic health professionals is in conflict (...) with Privacy laws and professional regulations that prohibits disclosure of information to a third party without the consent of the proband. In New South Wales, Australia, amendments to Privacy legislation permits such disclosure to living genetic relatives with the process defined under guidelines although there is no legal duty to warn. This study assessed NSW GHP’s awareness and experience of the legislation and guidelines. Methods: An online survey collected demographics; theoretical knowledge; clinical scenarios to assess application knowledge; attitudes; confidence; experience with active non-disclosure. A link to correct answers was provided after completion. Knowledge scores above the median for non-parametric data or above the mean for parametric data were classified as ‘good’ or ‘poor’. Chi square tests assessed associations between confidence and knowledge scores. Results: While many of the 37 participants reported reading the guidelines, there was limited awareness of their scope and clinical application; that there is no legal duty to warn; and that the threat does not need to be imminent to warrant disclosure. No association between confidence and ‘good’ theoretical or applied clinical knowledge was identified. Uncertainty of their professional responsibility was identified and in the several case examples of active non-disclosure that were reported this uncertainty reflected the need for further understanding of the guidelines in regard to the processes required before disclosure was initiated. Conclusions: There is a need for further education and training about the guidelines associated with the legislation that would be relevant to support disclosure. The findings may inform future strategies to support introduction of policy changes in other jurisdictions where similar regulatory regimes are introduced. (shrink)

The fifth base in human DNA, 5‐methylcytosine, is inherently mutagenic. This has led to marked changes in the distribution of the CpG methyl acceptor site and an 80% depletion in its frequency of occurrence in vertebrate DNA. The coding regions of many genes contain CpGs which are methylated in sperm and serve as hot spots for mutation in human genetic diseases. Fully 30–40% of all human germline point mutations are thought to be methylation induced even though the CpG (...) dinucleotide is under‐represented and efficient cellular repair systems exist. Importantly, tumor suppressor genes such as p53 also contain methylated CpGs and these serve as hot spots for mutations in some, but not all, human cancers. Comparison of the spectrum of mutations present in this gene in different human cancers allows for predictions to be made on the molecular mechanisms of tumorigenesis. (shrink)

A great deal is known about the technical issues surrounding the introduction of Hugo De Vries's mutation theory and the subsequent development of the modern genetical theory of natural selection. But so far little has been done to relate these events to the wider issues of the time. This article suggests that extra-scientific factors played a significant role, and substantiates this by comparing De Vries's respect for the original Darwinian spirit with Thomas Hunt Morgan's use of the mutation theory as (...) part of an attack on the whole philosophy of Darwinism. In particular, it is argued that Morgan's attitude was dictated by his moral objections to the picture of a world dominated by struggle. (shrink)

The use of a reporter gene in transgenic mice indicates that there are many local mutations and large genomic rearrangements per somatic cell that accumulate with age at different rates per organ and without visible effects. Dissociation of the cells for monolayer culture brings out great heterogeneity of size and loss of function among cells that presumably reflect genetic and epigenetic differences among the cells, but are masked in organized tissue. The regulatory power of a mass of contiguous (...) normal cells is expressed in its capacity to normalize the appearance and growth behavior of solitary homophilic neoplastic cells, and to redirect differentiation of solitary heterophilic stem‐like cells. Intimate contact between the interacting cells is required to induce these changes. The normalization of the neoplastic phenotype does not require gap junctional communication between cells, though transdifferentiation might. These varied relationships are manifestations of the unifying biological principle of “order in the large over heterogeneity in the small”. BioEssays 28: 515–524, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

For some the gene-centered reductionism that permeates contemporary neo-Darwinism is an obstacle for finding a common explanatory framework for both biological and cultural evolution. Thus social scientists are tempted to find new concepts that might bridge the divide between biology and sociology. Yet since Aristotle we know that the level of explanation must be commensurate with the particular question to be answered. In modern natural science there are many instances where a reductionist approach has failed to provide the right answer (...) to the corresponding question. Thus social scientists risk becoming non-relevant when mimicking some features of the natural sciences (such as hard or soft reductionism) just for the sake of it, instead of finding autonomous explanations commensurate with the level of phenomena studied by social science. (shrink)

The human gene pool displays exuberant genetic variation; this is normal for a sexual species. Even small isolated populations contain a large percentage of the total variability, emphasizing the basic genetic unity of our species. As modern man spread across the world from its African source, the genetic basis for man''s unique mental acuity was retained everywhere. Nevertheless, some geographical genetic variation such as skin color, stature and physiognomy was established. These changes were biologically relatively insignificant. (...) Most of the genetic load in the genome has been carried throughout the history of the species. There is little hope of purging all of these harmful genes; we must accept them and continue to treat their syndromes medically. All populations carry extensive genetic variation due to genes that encode variations in quantitative traits. Of greatest importance among these is ubiquitous polygenic variability in brain function and intelligence. Mental acuity is what sets us apart from the rest of the biological world. Throughout our history, genetic recombination among the many genes involved in brain function has occurred. This has provided a genetic basis for the action of natural selection that favors intelligence in meeting the demands of the environment. As environments change in the future, this type of genetic variability will continue to be a crucial resource. (shrink)

Modern medicine emphasizes treatment of the sick. It is often said that the widespread genetic testing soon to follow the completion of the Human Genome Project will usher in a new era of preventive medicine. Such changes require new ways of thinking, however. For example, there may be nothing clinically wrong with a healthy patient who requests genetic testing, even if the tests reveal disease genes. Since all individuals have genetic skeletons in their closets, it is important (...) to be careful not to confuse having disease genes with having the diseases that they cause. Unfortunately, many in the public have adopted a kind of genetic determinism that sees genes as destiny: for example, having the gene associated with colon cancer means they will develop colon cancer. Physicians tend to be more careful, yet even they are not immune to subtle versions of genetic determinism. One example of this is the uncritical categorization of certain diseases as “genetic”. In fact, an adequate concept of genetic disease is extremely difficult to come by. The simplest notion would require a 1:1 correspondence between a disease and its genes, but this is the exception rather than the rule. For example, cystic fibrosis (CF) is often put forward as a good example of a genetic disease, since it seems to result from mutations in a single gene, CFTR. Even in this case, however, the exact relationship between CFTR mutations and disease is not clear, as virtually every possible combination of sweat chloride test results, genetic test results, and symptoms has been observed.[1] If a patient presents with the classic symptoms of CF and is found to have a mutation in the CFTR gene, the physician might understandably infer that the mutation caused the disease. But if an asymptomatic patient is tested and it is discovered that he or she has a CFTR mutation, it is unclear what this means. The doctor might tell the patient the gene is abnormal and that he or she is likely to develop pulmonary problems, etc., but it’s not really known whether even this qualified prognosis is true.. (shrink)

A recent article by Galitski and Roth(1) characterizes adaptive reversion of chromosomal lac− mutations in Salmonella typhimurium LT2. Using a classical genetic approach they show that adaptive reversion, as characterized by the appearance of late revertant colonies, is an exception rather than a general phenomenon for reversion of nonsense, missense, frameshift and insertion mutations. For certain mutations, however, the number of late revertants exceeds the predicted number. These excess revertants suggest that adaptive mutability is applicable to (...) chromosomal genes as well as to genetic changes involving F plasmids and lysogenic phages. (shrink)

Population genetics attempts to measure the influence of the causes of evolution, viz., mutation, migration, natural selection, and random genetic drift, by understanding the way those causes change the genetics of populations. But how does it accomplish this goal? After a short introduction, we begin in section (2) with a brief historical outline of the origins of population genetics. In section (3), we sketch the model theoretic structure of population genetics, providing the flavor of the ways in which (...) population genetics theory might be understood as incorporating causes. In sections (4) and (5) we discuss two specific problems concerning the relationship between population genetics and evolutionary causes, viz., the problem of conceptually distinguishing natural selection from random genetic drift, and the problem of interpreting fitness. In section (6), we briefly discuss the methodology and key epistemological problems faced by population geneticists in uncovering the causes of evolution. Section (7) of the essay contains concluding remarks. (shrink)

: The accelerated discovery of gene mutations that lead to increased risk of disease has led to the rapid development of predictive genetic tests. These tests improve the accuracy of assigning risk, but at a time when intervention or prevention strategies are largely unproved. In coming years, however, data will become increasingly available to guide treatment of genetic diseases. Eventually genetic testing will be performed for common diseases as well as for rare genetic conditions. This (...) will challenge genetic counseling practice. The ethical principles that now guide this practice take into account the personal nature of test decision making, the need to respect individual self-determination, and the importance of client confidentiality. Certain of these principles may have to be modified as genetic testing becomes more widespread in order to meet the changing needs of clients and society. This paper offers recommendations to ensure that genetic counselors will take a leading role in the future delivery of ethical genetic services. (shrink)

William Keith Brooks was an American zoologist at Johns Hopkins University from 1876 until his death in 1908. Over the course of his career, Brooks staunchly defended Darwinism, arguing for the centrality of natural selection in evolutionary theory at a time when alternative theories, such as neo-Lamarckism, grew prominent in American biology. In his book The Law of Heredity, Brooks addressed problems raised by Darwin’s theory of pangenesis. In modifying and developing Darwin’s pangenesis, Brooks proposed a new theory of heredity (...) that sought to avoid the pitfalls of Darwin’s hypothesis. In so doing he strengthened Darwin’s theory of natural selection by undermining arguments for the inheritance of acquired characteristics. In later attacks on neo-Lamarckism, Brooks consistently defended Darwin’s theory of natural selection on logical grounds, continued to challenge the idea of the inheritance of acquired characteristics, and argued that natural selection best explained a wide range of adaptations. Finally, he critiqued Galton’s statistical view of heredity and argued that Galton had resurrected an outmoded typological concept of species, one which Darwin and other naturalists had shown to be incorrect. Brooks’s ideas resemble the “biological species concept” of the twentieth century, as developed by evolutionary biologist Ernst Mayr and others. The late-nineteenth century was not a period of total “eclipse” of Darwinism, as biologists and historians have hitherto seen it. Although the “Modern Synthesis” refers to the reconciliation of post-Mendelian genetics with evolution by natural selection, we might adjust our understanding of how the synthesis developed by seeing it as the culmination of a longer discussion that extends back to the late-nineteenth century. (shrink)

The neo-Darwinian paradigm, focusing on natural selection of genes responsible for differential adaption, provides the foundation for explaining evolutionary processes. The modern synthesis is broader, however, focusing on organisms rather than on gene transmissions per se. Yet, strands of current biology argue for further supplementation of Darwinian theory, pointing to nonbiotic drivers of evolutionary development, for example, self-organization of physical structures, and the interaction between individual organisms, groups of organisms, and their nonbiotic environments. According to niche construction theory, when organisms (...) and groups develop, they not only adapt to their environments but modify their environments, creating new habitats for later generations. Insofar as ecological niches persist beyond the lifecycle of individual organisms, an ecological inheritance system exists alongside genetic inheritance. Such ecological structures may even facilitate the development of a cultural inheritance system, as we see in humans. The article discusses theological perspectives of such new developments within holistic biology. (shrink)

Epidemiology is a science of disease which specifies rates . Evolution is a science of life which specifies changes . ‘Evolutionary Epidemiology’ is a synthesis of these two sciences which combines the empirical power of classical methods in genetical epidemiology with the interpretive capacities of neo-darwinian evolutionary genetics. In particular, prevalence rates of genetical diseases are important data points when reformulated for the purpose of analysis in terms of their evolutionary frequencies. Traits which exceedprevalences beyond the rates of mutation or (...) evidence unusualrange of phenotypic reaction are of special interest. This is because traits which did not confer advantages in the environment of evolutionary adaptation cannot accede, through natural selection, to anything but low rates of genomic prevalence.Evolutionary epidemiology is, in all of medicine, of particular promise in ongoing efforts to better understand psychopathology. Many complexities of phenotypic adjustment arise when new developmental demands are placed on an ‘old’ genome. The new and complex biosocial ecology of human mass society now evokes different phenotypes than those in the prehistorical ecology to which the genome is structurally and functionally better adapted. Some of these new phenotypes are darwinian failures. In this paper, the theoretical implications of evolutionary epidemiology are extended and some tentative points of clinical application are offered. (shrink)

The Theory of Evolution has, since Darwin, been sustained by contributions from many sciences, most especially from molecular biology. Philosophers, like biologists and the man in the street, have accepted the idea that the contemporary form of evolutionary theory has arrived at a convincing and final structure. As it now stands, natural selection is thought to work through the information-handling mechanism of the DNA molecule. Variation in the genome?s constructive message is achieved through random errors of processing called mutations. (...) How that mechanism and its revision works, and how much information it can hold are fundamental questions for the Neo-Darwinian theory to face. It is argued here that neither the operation nor the data content of the genome, as science understand them, can underpin the role Darwinism assigns to natural selection. It follows that we cannot put our confidence in the explanatory force of Darwinian reasoning, but neither is there an alternative to it. (shrink)

Waddington’s experiments on genetic assimilation showed that selection on environmentally induced phenotypic variants can cause inherited evolutionary changes in the phenotype. We have recently extended this work by demonstrating that it is possible to select for a polyphenism in a monophenic species . We found that a mutation in the juvenile hormone regulatory pathway in Manduca sexta enabled heat stress to reveal a hidden reaction norm of larval coloration. Artificial selection for increased color change in response to heat-shock (...) resulted in the genetic accommodation of a black/green larval color polyphenism, caused by an environment-sensitive threshold switch mediated by the endocrine system. (shrink)

Galatea, or the Future of Darwinism W Russell Brain Originally published in 1927 "A brilliant exposition…of the evolutionary hypothesis." The Guardian "Should prove invaluable…" Literary Guide This non-technical but closely-reasoned book is a challenge to the orthodox teaching on evolution known as Neo-Darwinism. The author claims that although Neo-Darwinian theories can possibly account for the evolution of forms, they are quite inadequate to explain the evolution of functions. 88pp ************** Daedalus or Science and the Future J B S Haldane Originally (...) published in 1924. "The essay is brilliant. Sparkling with wit and bristling with challenges." British Medical Journal "Predicts the most startling changes." Morning Post This volume examines the future of scientific research from religious, philosophical social and economic standpoints. 94pp Automaton, or the Future of Mechanical Man H Stafford Hatfield Originally published in 1928 "It is impossible to do justice to his volume in a brief review…"Daily Herald At the time of original publication mankind’s chief inventions had been extensions of his senses or limbs. This work prophesies the dawn of an era in which substitutes will gradually be found even for the human brain. 96pp Gallio or the Tyranny of Science J W N Sullivan Originally published in 1927 "So packed with ideas it is not possible to give any adequate résumé of its contents." Times Literary Supplement "Remarkable monograph…devastating summary of materialism…" Spectator An attack on the values which science is so successfully imposing upon civilization. 90pp. (shrink)

Astract Sex investigates the impact of advances in contemporary science and information technology on conceptions of sex. Evolutionary theory and the technologies of viral information transfer, cloning and genetic engineering are changing the way we think about human sex, reproduction and the communication of genetic information. Abstract Sex presents a philosophical exploration of this new world of sexual, informatic and capitalist multiplicity, of the accelerated mutation of nature and culture.

The current mainstream in cancer research favours the idea that malignant tumour initiation is the result of a genetic mutation. Tumour development and progression is then explained as a sort of micro-evolutionary process, whereby an initial genetic alteration leads to abnormal proliferation of a single cell that leads to a population of clonally derived cells. It is widely claimed that tumour progression is driven by natural selection, based on the assumption that the initial tumour cells acquire some properties (...) that endow such cells with a selective advantage over the normal cells from which the tumour cells are derived. The standard view assumes that the transformed bodily cell somehow acquires "responsiveness" to natural selection independently of the whole organism to which the cell belongs. Yet, it is never explained where such an acquired capacity to respond to natural selection by the individual bodily cell comes from. This situation poses many difficult questions that so far have been left unanswered. For example, there is no explanation why some cells belonging to an organised whole and as such having no independent capacity for survival, apparently become 'independent' entities, able to respond to selective pressures in an autonomous fashion and then to be evaluated by natural selection. Hereunder it is argued that such a qualitative change cannot be the consequence of specific genetic mutations. Moreover, it is shown that natural selection is unlikely to be acting within the organism during tumour development and progression and that tumour evolution is a random, non-adaptive process, driven by no fundamental biological principle. Thus, mutations in the so-called oncogenes and tumour suppressor genes observed in epithelial cancers (that constitute more than 90% of all cancers) are not the result of selection for better cellular growth or survival under restrictive conditions. Instead, here it is suggested that they are the consequence of genetic drift acting upon gene functions that become non-relevant, either for the individual or the species fitness, once the organism is past its reproductive prime and as such, they also become superfluous for cell survival in the short term. It is proposed that the origin of cancer is epigenetic and it is a consequence of the need for a continued turnover of the individuals that constitute a species. (shrink)

The 1940s and 1950s were marked by intense debates over the origin of drug resistance in microbes. Bacteriologists had traditionally invoked the notions of ‘training’ and ‘adaptation’ to account for the ability of microbes to acquire new traits. As the field of bacterial genetics emerged, however, its participants rejected ‘Lamarckian’ views of microbial heredity, and offered statistical evidence that drug resistance resulted from the selection of random resistant mutants. Antibiotic resistance became a key issue among those disputing physiological vs. (...) class='Hi'>genetic explanations of variation in bacteria. Postwar developments connected with the Lysenko affair gave this debate a new political valence.Proponents of the neo-Darwinian synthesis weighed in with support for the genetic theory. However, certain features of drug resistance seemed inexplicable by mutation and selection, particularly the phenomenon of ‘multiple resistance’—the emergence of resistance in a single strain against several unrelated antibiotics. In the late 1950s, Tsutomu Watanabe and his collaborators solved this puzzle by determining that resistance could be conferred by cytoplasmic resistance factors rather than chromosomal mutation. These R factors could carry resistance to many antibiotics and seemed able to promote their own dissemination in bacterial populations. In the end, the vindication of the genetic view of drug resistance was accompanied by a recasting of the ‘gene’ to include extrachromosomal hereditary units carried on viruses and plasmids. (shrink)

The recent finding that the human version of a neurodevelopmental enhancer of the Wnt receptor Frizzled 8 (FZD8) gene alters neural progenitor cell cycle timing and brain size is a step forward to understanding human brain evolution. The human brain is distinctive in terms of its cognitive abilities as well as its susceptibility to neurological disease. Identifying which of the millions of genomic changes that occurred during human evolution led to these and other uniquely human traits is extremely challenging. Recent (...) studies have demonstrated that many of the fastest evolving regions of the human genome function as gene regulatory enhancers during embryonic development and that the human‐specific mutations in them might alter expression patterns. However, elucidating molecular and cellular effects of sequence or expression pattern changes is a major obstacle to discovering the genetic bases of the evolution of our species. There is much work to do before human‐specific genetic and genomic changes are linked to complex human traits. (shrink)

Information about the structure, function and regulation of the maize Suppressormutator (Spm) transposable element has emerged from the genetic and molecular characterization of both deletion mutations and an unconventional type of reversible genetic change (epimutation). The element is subject to an epigenetic mechanism that can either stably inactivate it or specify one of a variety of heritable programs of differential element expression in development. The essay explores the relationship between the Spm element's epigenetic developmental programming mechanism (...) and the determinative events central to plant development and differentiation. (shrink)

The scientific discovery of a range of genetic mutations has meant that people with a strong family history of cancer can find out whether they are at risk of developing cancer well before they have any symptoms. Genetic testing has opened up the possibility for otherwise healthy mutation carriers to access prophylactic treatments in order to minimise their risk. These include surgery to remove at-risk body parts, treatment with cancer drugs, medical surveillance strategies, self-surveillance and change (...) in lifestyle. Clinical experience to date has shown considerable resistance to the uptake of medical preventative measures despite their promise of risk reduction. This paper provides a summary review of the available literature on the medical, psychological, counselling and social aspects of genetic testing and the use of risk-reducing treatments by people who have been diagnosed with a genetic predisposition to cancer. It acknowledges what has been learned from these approaches but points to the similarity of the philosophical underpinnings of most of the research. It concludes by tentatively making some suggestions, informed by the literature, about new directions for guiding our understanding the genetically at risk and the factors that influence their decision-making. (shrink)