Thomas Pradeu

The question “What is an organism?”, formerly considered as essential in biology, has now been increasingly replaced by a larger question, “What is a biological individual?”. On the grounds that i) individuation is theory-dependent, and ii) physiology does not offer a theory, biologists and philosophers of biology have claimed that it is the theory of evolution by natural selection which tells us what counts as a biological individual. Here I show that one physiological field, immunology, offers a theory, which makes possible a biological individuation based on physiological grounds. I give a new answer to the question of the individuation of an organism by linking together the evolutionary and the immunological approaches to biological individuation

Biological individuality is a major topic of discussion in biology and philosophy of biology. Recently, several objections have been raised against traditional accounts of biological individuality, including the objections of monism, theory-centrism, ahistoricity, disciplinary isolationism, and the multiplication of conceptual uncertainties. In this introduction, I will examine the current philosophical landscape about biological individuality, and show how the contributions gathered in this special issue address these five objections. Overall, the aim of this issue is to offer a more diverse, unifying, and scientifically informed conception of what a biological individual is.

This volume is the best available tool to compare and appraise the different approaches of today’s biology and their conceptual frameworks, serving as a springboard for new research on a clarified conceptual basis. It is expected to constitute a key reference work for biologists and philosophers of biology, as well as for all scientists interested in understanding what is at stake in the present transformations of biological models and theories. The volume is distinguished by including, for the first time, self-reflections and exchanges of views on practice and theoretical attitudes by important participants in recent biological debates. The questions of how biological models and theories are constructed, how concepts are chosen and how different models can be articulated, are asked. Then the book explores some of these convergences between different models or theoretical frameworks. Confronting views on adaptive complexity are investigated, as well as the role of self-organization in evolution; niche construction meets developmental biology; the promises of the emergent field of ecological-evolutionary-development are examined. In sum, this book is a marvellous account of the dynamism of today’s theoretical biology. Foreword: Carving Nature at its Joints? Richard Lewontin Chapter 1: Introduction Anouk Barberousse, Michel Morange, Thomas Pradeu Chapter 2: Articulating Different Modes of Explanation: The Present Boundary in Biological Research Michel Morange Chapter 3: Compromising Positions: The Minding of Matter Susan Oyama Chapter 4:ions, Idealizations, and Evolutionary Biology Peter Godfrey-Smith Chapter 5: The Adequacy of Model Systems for Evo-Devo: Modeling the Formation Of Organisms / Modeling the Formation Of Society Scott F. Gilbert Chapter 6: Niche Construction in Evolution, Ecosystems and Developmental Biology John Odling-Smee Chapter 7: Novelty, Plasticity and Niche Construction: The Influence of Phenotypic Variation on Evolution Kim Sterelny Chapter 8: The Evolution of Complexity Mark A. Bedau Chapter 9: Self-Organization, Self-Assembly, and the Origin of Life Evelyn Fox Keller Chapter 10: Self-Organization and Complexity in Evolutionary Theory, or, In this Life the Bread Always Falls Jammy Side Down Michael Ruse.

The self/non-self model, first proposed by F.M. Burnet, has dominated immunology for 60 years now. According to this model, any foreign element will trigger an immune reaction in an organism, whereas endogenous elements will not, in normal circumstances, induce an immune reaction. In this paper we show that the self/non-self model is no longer an appropriate explanation of experimental data in immunology, and that this inadequacy may be rooted in an excessively strong metaphysical conception of biological identity. We suggest that another hypothesis, one based on the notion of continuity, gives a better account of immune phenomena. Finally, we underscore the mapping between this metaphysical deflation from self to continuity in immunology and the philosophical debate between substantialism and empiricism about identity.

The concept of genidentity has been proposed as a way to better understand identity through time, especially in physics and biology. The genidentity view is utterly anti-substantialist in so far as it suggests that the identity of X through time does not presuppose whatsoever the existence of a permanent “core” or “substrate” of X. Yet applications of this concept to real science have been scarce and unsatisfying. In this paper, our aim is to show that a well-defined concept of functional genidentity can be crucial to shed light on identity through time in classical physics and especially in biology. Finally, we show that understanding identity on the basis of continuity suggests a move towards an ontology of processes.

Since, it has become clear that individuality is not to be considered as a given, but rather as something which needs to be explained. How has individuality emerged through evolution, and how has it subsequently been maintained? In particular, why is it that multicellular organisms appeared and persisted, despite the obvious interest of each cell of favoring its own replication? Several biologists see the immune system as one of the key components for explaining the maintenance of multicellular organisms’ individuality. Indeed, the immune system exerts a constant surveillance on all the constituents of the organism, including “cheaters” like tumor cells, which favor their own replication at the expense of the whole organism. In most cases, the immune system eliminates those cheaters. This is the “immune surveillance” hypothesis, first suggested by Burnet and Thomas. In this paper, I account for recent findings on immune surveillance in order to determine the precise role of the immune system in the emergence and maintenance of individuality. This investigation gives rise to a critical question for the domain of biological individuality: should immunity be considered as something unique to multicellular organisms? If it is indeed unique, should the multicellular organism be considered as an individual to a higher degree than any other living entity? If it is not unique, what precisely are the equivalents of the immune system in other living individuals?