This paper analyzes recent attempts to reject reproduction with lineage formation as a necessary condition for evolution by means of natural selection :560–570, 2008; Stud Hist Philos Sci Part C Stud Hist Philos Biol Biomed Sci 42:106–114, 2011; Bourrat in Biol Philos 29:517–538, 2014; Br J Philos Sci 66:883–903, 2015; Charbonneau in Philos Sci 81:727–740, 2014; Doolittle and Inkpen in Proc Natl Acad Sci 115:4006–4014, 2018). Building on the strengths of these attempts and avoiding their pitfalls, it is argued that (...) a robust formulation of evolution by natural selection without reproduction can be established. The main contribution of this paper is a reformulation of Lewontin’s three principles stating that minimal evolution by natural selection occurs when two conditions are met in a population: fitness-related variation and memory. Paradigmatic evolution by natural selection, which can generate adaptations, takes place when an additional condition is present, namely regeneration. (shrink)

Philosophers are approaching a consensus that biological individuality, including evolutionary individuality, comes in degrees. Graded evolutionary individuality presents a puzzle when juxtaposed with another widely embraced view: that evolutionary individuality follows from being a selectable member of a Darwinian population. Population membership is, on the orthodox view, a bivalent condition, so how can members of Darwinian populations vary in their degree of individuality? This article offers a solution to the puzzle, by locating difference in degree of evolutionary individuality at the (...) level of population lineages, some of which are more Darwinian than others. In doing so, it sheds light on graded individuality in overlapping and nested population lineages, such as those that arise in multilevel selection and symbiotic collectives. (shrink)

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. (shrink)

This paper is an application of the principles of individuality found in Guay and Pradeu to illuminate biological individuality in mushrooms. I begin with the distinction between logico-cognitive individuals and ontological individuals, and then I argue for genidentity plus material continuity, as a minimum conception of ontological individuality in biology. Of the many materially-continuous genidenticals found in fungi, only those with functional roles in biological theory, either evolutionary or physiological, warrant consideration. Given numerous ways that theory picks out materially-continuous genidenticals (...) in fungi, I argue for a pluralistic account of mushroom individuality. (shrink)

This paper argues that a plant together with the symbiotic fungus attached to its roots, a mycorrhizal collective, is an evolutionary individual, and further, that mycorrhizal individuality has important implications for evolutionary theory. Theoretical individuation is defended and then employed to show that mycorrhizal collectives function as interactors according to David Hull’s replicator-interactor model of evolution by natural selection, and because they have the potential to engage in pseudo-vertical transmission, mycorrhizal collectives also function as Darwinian individuals, according to Peter Godfrey-Smith’s (...) Darwinian Populations model of evolution by natural selection. Mycorrhizae in nature usually connect the roots of multiple plants, so mycorrhizal individuality entails the existence of overlapping evolutionary individuals, and because the potential to engage in pseudo-vertical transmission comes in degrees, it follows that these overlapping evolutionary individuals also come in degrees. I suggest here that the degree of evolutionary individuality in a symbiotic collective corresponds to its probability of reproducing with vertical or pseudo-vertical transmission. This probability constitutes a fourth parameter of graded Darwinian individuality in collective reproducers and warrants an update to Godfrey-Smith’s 3D model. (shrink)

What are the prospects for a monistic view of biological individuality given the multiple epistemic roles the concept must satisfy? In this paper, I examine the epistemic adequacy of two recent accounts based on the capacity to undergo natural selection. One is from Ellen Clarke, and the other is by Peter Godfrey-Smith. Clarke’s position reflects a strong monism, in that she aims to characterize individuality in purely functional terms and refrains from privileging any specific material properties as important in their (...) own right. I argue that Clarke’s functionalism impairs the epistemic adequacy of her account compared to a middle-ground position taken by Godfrey-Smith. In comparing Clarke and Godfrey-Smith’s account, two pathways emerge to pluralism about biological individuality. The first develops from the contrast between functionalist and materialist approaches, and the second from an underlying temporal structure involved in using evolutionary processes to define individuality. (shrink)

This article defends lineage pluralism; the view that biological lineages are not a single, unified type of entity. I analyze aspects of evolutionary theory, phylogenetics, and developmental biology to show that these areas appeal to distinct notions of lineage. I formulate three arguments for lineage pluralism. These arguments undercut the main motivations for lineage monism; the view that biological lineages are a single, unified type of entity. Although this view is rarely made explicit, it is often assumed in philosophy and (...) biology. Hence, this article sheds light on this monistic assumption and shows why lineage pluralism should be adopted instead. (shrink)

What changes when an evolutionary transition in individuality takes place? Many different answers have been given, in respect of different cases of actual transition, but some have suggested a general answer: that a major transition is a change in the extent to which selection acts at one hierarchical level rather than another. The current paper evaluates some different ways to develop this general answer as a way to characterise the property ‘evolutionary individuality’; and offers a justification of the option taken (...) in Clarke :413–435, 2013)—to define evolutionary individuality in terms of an object’s capacity to undergo selection at its own level. In addition, I suggest a method by which the property can be measured and argue that a problem which is often considered to be fatal to that method—the problem of ‘cross-level by-products’—can be avoided. (shrink)

The paper links discussions of two topics: biological individuality and the simplest forms of mentality. I discuss several attempts to locate the boundary between metabolic activity and ‘minimal cognition.’ I then look at differences between the kinds of individuality present in unicellular life, multicellular life in general, and animals of several kinds. Nervous systems, which are clearly relevant to cognition and subjectivity, also play an important role in the form of individuality seen in animals. The last part of the paper (...) links these biological transitions to the evolutionary history of subjective experience. (shrink)

The ‘Major Transitions in Evolution’ framework has emerged as the dominant paradigm for understanding the origins of life's hierarchical organization, but it has been criticized on the grounds that it lacks theoretical unity, that is, that the events included in the framework do not constitute a coherent category. I agree with this criticism, and I argue that the best response is to modify the framework so that the events it includes do comprise a coherent category, one whose members share fundamental (...) similarities. Specifically, I recommend defining major transitions as all those, and only those, events and processes that result in the emergence of a new population of evolutionary individuals. Two sorts of change will be required to achieve this. First, events and processes that do not meet this criterion, such as the origins of the genetic code and of human language, should be excluded. Second, events and processes that do meet the criterion, but which have generally been neglected, should be included. These changes would have the dual benefits of making MTEs a philosophically coherent category and of increasing the sample size on which we may infer trends and general principles that may apply to all MTEs. (shrink)

This article focuses on recent discussions about holobionts and evolutionary individuality to evaluate the merits of integrative pluralism. I argue that integrative pluralism is the wrong approach to take when it comes to holobiont research because integrative pluralism is not liberal enough to accommodate both single-species and multispecies individuals. I conclude by suggesting two points. First, a pluralistic view helps us better understand holobiont research. Second, the case of holobionts helps us develop a better account of scientific pluralism.