Thomas Pradeu

Griffiths and Stotz’s Genetics and Philosophy: An Introduction offers a very good overview of scientific and philosophical issues raised by present-day genetics. Examining, in particular, the questions of how a “gene” should be defined and what a gene does from a causal point of view, the authors explore the different domains of the life sciences in which genetics has come to play a decisive role, from Mendelian genetics to molecular genetics, behavioural genetics, and evolution. In this review, I highlight what I consider as the two main theses of the book, namely: genes are better conceived as tools; genes become causes only in a context. I situate these two theses in the wider perspective of developmental systems theory. This leads me to emphasize that Griffiths and Stotz reflect very well an on going process in genetics, which I call the “epigenetization” of genetics, i.e., the growing interest in the complex processes by which gene activation is regulated. I then make a factual objection, which is that Griffiths and Stotz have almost entirely neglected the perspective of ecological developmental biology, and more precisely recent work on developmental symbioses, and I suggest that this omission is unfortunate in so far as an examination of developmental symbioses would have considerably strengthened Griffiths and Stotz’s own conclusions.

The definition of biological individuality is one of the most discussed topics in philosophy of biology, but current debate has focused almost exclusively on evolution-based accounts. Moreover, several participants in this debate consider the notions of a biological individual and an organism as equivalent. In this paper, I show that the debates would be considerably enriched and clarified if philosophers took into account two elements. First, physiological fields are crucial for the understanding of biological individuality. Second, the category of biological individuals should be divided into two subcategories: physiological individuals and evolutionary individuals, which suggests that the notions of organism and biological individual should not be used interchangeably. I suggest that the combination of an evolutionary and a physiological perspective will enable biologists and philosophers to supply an account of biological individuality that will be both more comprehensive and more in accordance with scientific practices.

Immunology — though deeply experimental in everyday practice — is also a theoretical discipline. Recent advances in the understanding of innate immunity, how it is triggered and how it shares features that have previously been uniquely ascribed to the adaptive immune system, can contribute to the refinement of the theoretical framework of immunology. In particular, natural killer cells and macrophages are activated by transient modifications, but adapt to long-lasting modifications that occur in the surrounding tissue environment. This process facilitates the maintenance of self-tolerance while permitting efficient immune responses. In this Essay we extend this idea to other components of the immune system and we propose some general principles that lay the foundations for a unifying theory of immunity — the discontinuity theory. According to this theoretical framework, effector immune responses (namely, activated responses that lead to the potential elimination of the target antigen) are induced by an antigenic discontinuity; that is, by the sudden modification of molecular motifs with which immune cells interact.

Le Précis de philosophie des sciences vise à présenter, de manière pédagogique, l'état actuel des grandes questions et des grands domaines de la philosophie des sciences. C'est un ouvrage de niveau "intermédiaire", entre les ouvrages d'initiation et les ouvrages de recherche. Il peut être utilisé comme manuel pour des cours de philosophie des sciences au niveau Master, ainsi que dans le cadre de la préparation aux nouvelles épreuves d'épistémologie des CAPES scientifiques. Il a notamment pour vocation de servir de support de cours pour des enseignements en épistémologie et philosophie des sciences de niveau L3, M1 et M2.

What are individuals? How can they be identified? These are crucial questions for philosophers and scientists alike. Criteria of individuality seem to differ markedly between metaphysics and the empirical sciences - and this might well explain why no work has hitherto attempted to relate the contributions of metaphysics, physics and biology on this question. This timely volume brings together various strands of research into 'individuality', examining how different sciences handle the issue, and reflecting on how this scientific work relates to metaphysical concerns. The collection makes a major contribution to clarifying and overcoming obstacles to the construction of a general conception of the individual adequate for both physics and biology, and perhaps even beyond.

Since the 1950s, the common view of development has been internalist: development is seen as the result of the unfolding of potentialities already present in the egg cell. In this article, I show that this view is incorrect because of the crucial influence of the environment on development. I focus on a fascinating example, that of the role played by symbioses in development, especially bacterial symbioses, a phenomenon found in virtually all organisms (plants, invertebrates, and vertebrates). I claim that we must consequently modify our conception of the boundaries of the developing entity, and I show how immunology can help us in accomplishing this task. I conclude that the developing entity encompasses many elements traditionally seen as “foreign,” while I reject the idea that there is no possible distinction between the organism and its environment.

In this paper, I address the question of what the Developmental Systems Theory (DST) aims at explaining. I distinguish two lines of thought in DST, one which deals specifically with development, and tries to explain the development of the individual organism, and the other which presents itself as a reconceptualization of evolution, and tries to explain the evolution of populations of developmental systems (organism-environment units). I emphasize that, despite the claiming of the contrary by DST proponents, there are two very different definitions of the ‘developmental system’, and therefore DST is not a unified theory of evolution and development. I show that the DST loses the most interesting aspects of its reconceptualization of development when it tries to reconceptualize evolutionary theory. I suggest that DST is about development per se, and that it fails at offering a new view on evolution.

The main objective of immunology is to establish why and when an immune response occurs, that is, to determine a criterion of immunogenicity. According to the consensus view, the proper criterion of immunogenicity lies in the discrimination between self and nonself. Here we challenge this consensus by suggesting a simpler and more comprehensive criterion, the criterion of continuity. Moreover, we show that this criterion may be considered as an interpretation of the immune 'self'. We conclude that immunologists can continue to speak of the self, provided that they admit that the self/nonself discrimination is not an adequate criterion of immunogenicity

Is it possible to explain and predict the development of living things? What is development? Articulate answers to these seemingly innocuous questions are far from straightforward. To date, no systematic, targeted effort has been made to construct a unifying theory of development. This novel work offers a unique exploration of the foundations of ontogeny by asking how the development of living things should be understood. It explores the key concepts of developmental biology, asks whether general principles of development can be discovered, and examines the role of models and theories.The two editors have assembled a team of leading contributors who are representative of the scientific and philosophical community within which a diversity of thoughts are growing, and out of which a theory of development may eventually emerge. They analyse a wealth of approaches to concepts, models and theories of development, such as gene regulatory networks, accounts based on systems biology and on physics of soft matter, the different articulations of evolution and development, symbiont-induced development, as well as the widely discussed concepts of positional information and morphogenetic field, the idea of a

The Developmental Systems Theory (DST) presented by its proponents as a challenging approach in biology is aimed at transforming the workings of the life sciences from both a theoretical and experimental point of view (see, in particular, Oyama [1985] 2000; Oyama et al. 2001). Even though some may have the impression that the enthusiasm surrounding DST has faded in very recent years, some of the key concepts, ideas, and visions of DST have in fact pervaded biology and philosophy of biology. It seems crucial to us both to establish which of these ideas are truly specific to DST, and to shift through these ideas in order to determine the criticisms they have drawn, or may draw (e.g., Sterelny et al. 1996; Griesemer 2000; Sterelny 2000; Kitcher 2001; Keller 2005; Waters 2007)

Though viruses have generally been characterized by their pathogenic and more generally harmful effects, many examples of mutualistic viruses exist. Here I explain how the idea of mutualistic viruses has been defended in recent virology, and I explore four important conceptual and practical consequences of this idea. I ask to what extent this research modifies the way scientists might search for new viruses, our notion of how the host immune system interacts with microbes, the development of new therapeutic approaches, and, finally, the role played by the criterion of autonomy in our understanding of living things. Overall, I suggest that the recognition of mutualistic viruses plays a major role in a wider ongoing revision of our conception of viruses.

In this article, I address the question of what Developmental Systems Theory aims at explaining. I distinguish two lines of thought in DST, one that deals specifically with development and tries to explain the development of the individual organism, and the other that presents itself as a reconceptualization of evolution and tries to explain the evolution of populations of developmental systems. I emphasize that, despite the claim of the contrary by DST proponents, there are two very different definitions of the “developmental system,” and therefore DST is not a unified theory of evolution and development. I show that DST loses the most interesting aspects of its reconceptualization of development when it tries to reconceptualize evolutionary theory. I suggest that DST is about development per se, and that it fails at offering a new view on evolution