Genetic Explanations

Genetic Explanations: Sense and Nonsense

Copyright Date: 2013
Published by: Harvard University Press
Pages: 348
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  • Book Info
    Genetic Explanations
    Book Description:

    No longer viewed by scientists as the cell’s fixed master molecule, DNA is a dynamic script that is ad-libbed at each stage of development. What our parents hand down to us is just the beginning. Genetic Explanations urges us to replace our faith in genetic determinism with scientific knowledge about genetic plasticity and epigenetic inheritance.

    eISBN: 978-0-674-06776-9
    Subjects: Ecology & Evolutionary Biology, History of Science & Technology, Sociology

Table of Contents

  1. Front Matter
    (pp. i-vi)
  2. Table of Contents
    (pp. vii-viii)
  3. Foreword
    (pp. ix-xiv)
    Richard Lewontin

    We must never lose sight of the immensely powerful role played by metaphors in our understanding of the natural world. Nothing has influenced our explanation of the properties of living organisms more than Descartes’sbête machineand the later inclusion of humans in the metaphor as thehomme machineby La Mettrie. If living organisms, including humans, are to be understood as machines, then the nature of the materials of which they are composed and the exact way in which those materials are put together must provide us with an explanation of the organisms’ properties. In particular, how are we...

  4. Introduction: Evolving Narratives of Genetic Explanation across Disciplines
    (pp. 1-14)

    In the aftermath of every major breakthrough or revolution in the natural sciences, each newly adopted theory evolves into four narrative forms. First, there is the canonical form of the theory introduced by the person or persons identified with the discovery, usually in their published writings. These are the primary texts of discovery, which include Newton’sPrincipiaand Einstein’s 1905 paper on relativity. Second, there are extensions to and extrapolations from the canonical theory by other scientists in the same field, usually over a period of years. Gaps are filled, corrections are made, interpretations are offered, and questions are raised...

  5. PART ONE New Understanding of Genetic Science
    • CHAPTER ONE The Mismeasure of the Gene
      (pp. 17-25)

      Science is an interpretation of nature and, like other forms of interpretation, fits into the cultural framework of its time. I shall illustrate this fact by tracing some of the threads that, in the course of the twentieth century, have led to the notion that genes determine virtually all physical and social characteristics of humans and other animals. Currently, everything about us is “in the genes,” and this view offers the hope that once we learn to read our “genetic blueprint,” we will be able to change it and live happily ever after.

      The most obvious place to begin this...

    • CHAPTER TWO Evolution Is Not Mainly a Matter of Genes
      (pp. 26-33)

      The 200th anniversary of Charles Darwin’s birth and the 150th anniversary of the publication of hisOn the Origin of Species by Means of Natural Selection,both falling in 2009, focused the attention of scientists, philosophers, historians, and substantial portions of the general public throughout the world on the phenomenon of organic evolution. Scholarly and popular books, museum and television shows, technical and public conferences, and organized pilgrimages to Darwin’s country house and to the Galápagos Islands, a key venue in his scientific development, all attest to the iconic status of this thinker and particularly to the concept of natural...

    • CHAPTER THREE Genes as Difference Makers
      (pp. 34-42)

      Genetics is a field of study, a branch of biology, but what, in fact, is it about? How one answers this question, of course, depends on when and where one looks. But for classical genetics, and especially for the paradigmatic school of T. H. Morgan, genetics was about tracking the transmission patterns of units called “genes.” What was a gene? No one knew, but notwithstanding this ignorance, a gene was assumed to be a unit that could be identified by the appearance of mutants in wild-type populations. That is, a phenotypic difference in some trait (a mutant) was taken to...

    • CHAPTER FOUR Big B, Little b: Myth #1 Is That Mendelian Genes Actually Exist
      (pp. 43-50)

      While i was waiting to catch a flight out of Columbus, Ohio, I heard an evening news story about the discovery of a genetic mutation that supposedly allows affected individuals to get away with fewer than eight hours of sleep each night. Beyond the specifics of the story, there was nothing particularly special about it; these days, it is difficult to pass through a 24-hour news cycle without some reference being made to a new discovery in the realm of genetics. But the story drew my attention because there was a central assumption buried in it, one that most people...

    • CHAPTER FIVE The Myth of the Machine-Organism: From Genetic Mechanisms to Living Beings
      (pp. 51-68)

      The gene myth is not just a myth about genes. It is a story about the nature of the organism and the character of biological explanation. Inspired by our experience with machines, the story (in one of its versions) is narrated in a language of causal analysis, where some things make other things happen, and our investigation of a collection of parts, one by one, enables us to piece together a knowledge of the integrated whole. The continual elucidation of explanatory “mechanisms” has seemed to vindicate the story, supported further by promises of a better life for humans and a...

  6. PART TWO Medical Genetics
    • CHAPTER SIX Some Problems with Genetic Horoscopes
      (pp. 71-80)

      The view that dominated biological thought in general, and evolutionary biology in particular, from the 1940s until the beginning of the twenty-first century was focused on the gene. Development was seen as the product of genes’ actions, and ecology as the context for the natural selection of genes. This view was well reflected in textbooks of evolutionary biology and in popular books like Richard Dawkins’sThe Selfish Gene.¹ The dominance of the gene and its material incarnation, DNA, led, as Nelkin and Lindee have noted, to the perception of DNA as the secular equivalent of the soul.² But because, unlike...

    • CHAPTER SEVEN Cancer Genes: The Vestigial Remains of a Fallen Theory
      (pp. 81-93)

      Rare is the week when the media make no reference to the genes that are supposed to control our physiological and even psychological functions. These interpretations misleadingly assign individual genes in our genomes to definitive phenotypic outcomes. In truth, the complexity of phenotypic development cannot be found in the DNA contained within each of an individual’s many trillion cells. In this particular regard, according to the central dogma of molecular biology, it has been widely acknowledged that DNA “codes” for proteins; uncritically, however, many have reinterpreted this axiom as meaning that DNA “codes” for phenotypes. This inference has been reinforced...

    • CHAPTER EIGHT The Fruitless Search for Genes in Psychiatry and Psychology: Time to Reexamine a Paradigm
      (pp. 94-106)

      The June 2009 edition of theJournal of the American Medical Associationreported the results of a meta-analysis by Neil Risch and colleagues.¹ These researchers showed that a 2003 study by Caspi and colleagues, where the investigators believed that they had found a genetic variant associated with depression when it was combined with stressful life events, did not stand up to replication attempts. Caspi and colleagues’ original study had been widely reported in the media and elsewhere as constituting a major genetic discovery in psychiatry.²

      However, to the critical observers of genetic research in psychiatry and psychology, including those who...

    • CHAPTER NINE Assessing Genes as Causes of Human Disease in a Multicausal World
      (pp. 107-121)

      When my home water system is working properly, a faucet is turned on, and the water pressure drops below 25 pounds, the pressure pump turns on. When the pump builds up pressure, it turns off at 50 pounds. Thus one might think that the cause of the pump turning on and off is the change in water pressure. Although we are likely to say this and to attribute causation to a drop in water pressure, this is an oversimplification. For the pump to switch on, many components and conditions must be present and functioning well. The electricity and the breaker...

    • CHAPTER TEN Autism: From Static Genetic Brain Defect to Dynamic Gene-Environment-Modulated Pathophysiology
      (pp. 122-146)

      To put the myth of genetic reductionism bluntly: DNA makes the rules; everything else obeys. It follows, then, that a complete understanding of living systems will ultimately be achieved—in fact, can only be achieved—by completing our genetic understanding.

      Autism would appear to be a good, although disheartening, example. Autism has been considered to be a genetically hardwired neurodevelopmental disorder and is defined in the American Psychiatric Association’sDiagnostic and Statistical Manual of Mental Disordersby a set of behavioral dysfunctions: impaired social interaction, impaired communication, and restricted and repetitive behavior.¹ In plain terms, autistic people tend not to...

    • CHAPTER ELEVEN The Prospects of Personalized Medicine
      (pp. 147-170)

      The advent of the Human Genome Project created unprecedented enthusiasm for the prospects of genetic science and medicine. Francis Collins, who led the effort for the National Institutes of Health (NIH), showed little modesty about the project as it neared completion in 1999. Invoking the legacies of Lewis and Clark, Sir Edmund Hillary, and Neil Armstrong, he described the project’s “audacious goal”: “To wrest from nature the secrets which have perplexed philosophers in all ages, to track to their sources the causes of disease, to correlate the vast stores of knowledge, that they may be quickly available for the prevention...

  7. PART THREE Genetics in Human Behavior and Culture
    • CHAPTER TWELVE The Persistent Influence of Failed Scientific Ideas
      (pp. 173-185)

      They sound like the Jukes and the Kallikaks.” When I was a kid in the 1940s, my mother would occasionally blurt this out while talking about some problematic family. She apparently accepted the claims about these two icons of family genetic inferiority. Two books about the Jukes and the Kallikaks, one appearing in the late nineteenth century and the other in the early twentieth century, made these families famous and infamous. The Kallikaks, whose notoriety lasted well past the middle of the twentieth century, were described by psychologist Henry Herbert Goddard in his 1912 bookThe Kallikak Family: A Study...

    • CHAPTER THIRTEEN Map Your Own Genes! The DNA Experience
      (pp. 186-200)

      In the 1960s, in response to the truly strange climate of creationism in the United States, the Russian-born evolutionary biologist Theodosius Dobzhansky proclaimed that “nothing in biology makes sense except in the light of evolution.”¹ I want to modify Dobzhansky’s claim for the new century: increasingly, nothing in biology makes sense except in the light of the marketplace. Markets justify what would be inexplicable to the generation of geneticists, including Dobzhansky, who founded the American Society of Human Genetics and worried about radiation effects on heredity in the 1950s and 1960s.² That group of genetic pioneers would presumably be puzzled...

    • CHAPTER FOURTEEN Creating a “Better Baby”: The Role of Genetics in Contemporary Reproductive Practices
      (pp. 201-226)

      Scientific advances in assisted reproductive technology (ART) enable individuals to overcome diverse medical, social, and personal challenges and give rise to new reproductive practices and parental relations. Furthermore, many individuals and couples around the world are increasingly assuming the power of heredity and turning to diverse reproductive technologies with the hope of creating what they typically perceive to be a “better baby,” that is, a child who is free of various genetic disorders, embodies their preferred sex, and potentially expresses their aesthetic criteria or other desirable traits.

      This chapter offers a general overview and a critical discussion from diverse ethical...

    • CHAPTER FIFTEEN Forensic DNA Evidence: The Myth of Infallibility
      (pp. 227-255)

      Promoters of forensic DNA testing have claimed from the beginning that DNA evidence is virtually infallible.¹ In advertising materials, publications, and courtroom testimony they have claimed that DNA tests produce either the right result or no result. These claims took hold early in appellate-court opinions, which often parroted promotional hyperbole. They were bolstered by the impressive “random-match probabilities” presented in connection with DNA evidence, which suggest that the chances of a false match are vanishingly small. They were reinforced in the public imagination by news accounts of postconviction DNA exonerations. Wrongfully convicted people were shown being released from prison, while...

    • CHAPTER SIXTEEN Nurturing Nature: How Parental Care Changes Genes
      (pp. 256-269)
      MAE-WAN HO

      It has been thirty years since I first met Ruth Hubbard and her husband George Wald at the conference “Towards a Liberatory Biology” in Bressanone in the Italian Alps.¹ From a broad sociopolitical perspective, Hubbard was already a leading light in the radical critique of genetic determinism—the idea that organisms are hardwired in their genetic makeup. As a research scientist who had worked on visual pigments for many years, she was by no means unaware of the hormones and enzymes encoded by genes that enable an organism to transform energy, grow, and develop in a certain way, but she...

    • Conclusion: The Unfulfilled Promise of Genomics
      (pp. 270-282)

      These are exciting times for genomics research. New tools and techniques are increasingly allowing researchers to dig ever deeper into the workings of biological processes. Scientists are discovering new disease pathways, identifying genes linked to Mendelian disorders and allowing for early intervention, making some advances in the use of biomarkers for pharmacogenomics and therapeutic interventions with cancer patients, and offering parents a growing list of pre- and postnatal screenings for inherited abnormalities.

      Perhaps the greatest advances have been made in sequencing technologies, where both size and price have dropped dramatically, although added costs from preparing and isolating DNA and assembling...

  8. Notes
    (pp. 285-352)
  9. Selected Readings
    (pp. 353-354)
  10. Acknowledgments
    (pp. 355-356)
  11. Contributors
    (pp. 357-360)
  12. Index
    (pp. 361-368)