The many faces of biological individuality

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 (the tendency to focus on a single individuality criterion and/or a single biological field), theory-centrism (the tendency to discuss only theory-based individuation), ahistoricity (the tendency to neglect what biologists of the past and historians of biology have said about biological individuality), disciplinary isolationism (the tendency to isolate biological individuality from other scientific and philosophical domains that have investigated individuality), and the multiplication of conceptual uncertainties (the lack of a precise definition of “biological individual” and related terms). 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

Organisms in experimental research

Rachel A. Ankeny and Sabina Leonell

Ludwig Edinger: The Vertebrate Series and Comparative Neuroanatomy

At the end of the nineteenth century, Ludwig Edinger completed the first comparative survey of the microscopic anatomy of vertebrate brains. He is regarded as the founder of the field of comparative neuroanatomy. Modern commentators have misunderstood him to have espoused an anti-Darwinian linear view of brain evolution, harkening to the metaphysics of the scala naturae. This understanding arises, in part, from an increasingly contested view of nineteenth-century morphology in Germany. Edinger did espouse a progressionist, though not strictly linear, view of forebrain evolution, but his work also provided carefully documented evidence that brain stem structures vary in complexity independently from one another and across species in a manner that is not compatible with linear progress. This led Edinger to reject progressionism for all brain structures other than the forebrain roof, based on reasoning not too dissimilar from those his successors used to dismiss it for the forebrain roof

Rethinking Individuality: The Dialectics Of The Holobiont

Given immunity’s general role in the organism’s economy—both in terms of its internal environment as well as mediating its external relations—immune theory has expanded its traditional formulation of preserving individual autonomy to one that includes accounting for nutritional processes and symbiotic relationships that require immune tolerance. When such a full ecological alignment is adopted, the immune system becomes the mediator of both defensive and assimilative environmental intercourse, where a balance of immune rejection and tolerance governs the complex interactions of the organism’s ecological relationships. Accordingly, immunology, which historically had affiliated with the biology of individuals, now becomes a science concerned with the biology of communities. With this translocation, the ontological basis of the organism is undergoing a profound change. Indeed, the recent recognition of the ubiquity of symbiosis has challenged the traditional notions of biological individuality and requires a shift in the metaphysics undergirding biology, in which a philosophy of the organism must be characterized by ecological dialectics “all-the-way-down.