Organismic Selection

In evolutionary biology and ecology, ontological and epistemological perspectives based on the replicator and the interactor have become the background that makes it possible to transcend traditional biological levels of organization and to achieve a unified view of evolution in which replication and interaction are fundamental operating processes. Using the transactional perspective proposed originally by John Dewey and Arthur Fisher Bentley, a new ontological and methodological category is proposed here: the transactor. The transactional perspective, based on the concept of the (...) transactor, bridges the dichotomy between organisms and environment that characterizes the interactional perspective on evolution and provides epistemological support for the emergentist, systemic view of evolutionary and developmental processes. (shrink)

Various results show the ‘formal equivalence’ of kin and group selectionist methodologies, but this does not preclude there being a real and useful distinction between kin and group selection processes. I distinguish individual and population-centred approaches to drawing such a distinction, and I proceed to develop the latter. On the account I advance, the differences between kin and group selection are differences of degree in the structural properties of populations. A spatial metaphor provides a useful framework for thinking about these (...) differences: kin and group selection may be conceptualized as large, overlapping regions of K-G space. I then consider some implications of the account, defend it from possible objections, and further argue that the structural features characteristic of both kin and group selection may recur at multiple levels of biological organization. (shrink)

Among mycologists, questions persist about what entities should be treated as the fundamental units of fungal populations. This article articulates a coherent view about populations of heterokaryotic fungi and the individuals that comprise them. Using Godfrey-Smith’s minimal concept of a Darwinian population, I argue that entities at two levels of the biological hierarchy satisfy the minimal concept in heterokaryotic fungi: mycelia and nuclei. I provide a preliminary answer to the question of how to understand the relation between these two populations. (...) This article contributes to discussions about the nature of biological individuality, organismality, and evolutionary transitions. (shrink)

In this landmark volume, an international group of scientists has synthesized their collective expertise and insight into a newly unified vision of insect ...

Review of Maria Kronfeldner, Darwinian Creativity and Memetics, Acumen, 2011.

It is difficult to understand questions about the evolution of ants. It seems often to be assumed that there are specific features that ants possess because of the "survival value" of such features. This makes very little sense, because it is very hard to believe that there are any features at all that can be viewed as having survival value for ants.

My general aim is to clarify the foundational difference between Stephen Jay Gould and Richard Dawkins concerning what biological entities are the units of selection in the process of evolution by natural selection. First, I recapitulate Gould’s central objection to Dawkins’s view that genes are the exclusive units of selection. According to Gould, it is absurd for Dawkins to think that genes are the exclusive units of selection when, after all, genes are not the exclusive interactors: those agents directly engaged (...) with, directly impacted by, environmental pressures. Second, I argue that Gould’s objection still goes through even when we take into consideration Sterelny and Kitcher’s defense of gene selectionism in their admirable paper “The Return of the Gene.” Third, I propose a strategy for defending Dawkins that I believe obviates Gould’s objection. Drawing upon Elisabeth Lloyd’s careful taxonomy of the various understandings of the unit of selection at play in the philosophy of biology literature, my proposal involves realizing that Dawkins endorses a different understanding of the unit of selection than Gould holds him to, an understanding that does not require genes to be the exclusive interactors. (shrink)

This book brings together important essays by one of the leading philosophers of science at work today. Elisabeth A. Lloyd examines several of the central topics in philosophy of biology, including the structure of evolutionary theory, units of selection, and evolutionary psychology, as well as the Science Wars, feminism and science, and sexuality and objectivity. Lloyd challenges the current evolutionary accounts of the female orgasm and analyses them for bias. She also offers an innovative analysis of the concept of objectivity. (...) Lloyd analyses the structure of evolutionary theory and unlocks the puzzle of the units of selection debates into four distinct aspects, illuminating several mysteries in the biology literature. Central to all essays in this book is the author's abiding concern for evidence and empirical data. (shrink)

I address the controversy in evolutionary biology concerning which levels of biological entity (units) can and do undergo natural selection. I refine a definition of the unit of selection, first presented by William Wimsatt, that is grounded in the structure of natural selection models. I examine Elliott Sober's objection to this structural definition, the "homogeneous populations" problem; I find that neither the proposed definition nor Sober's own causal account can solve the problem. Sober, in his solution using his causal view, (...) imports precisely the information needed to make the structural definition effective. Finally, I indicate how the proposed definition can clarify which sorts of evidence could be brought to bear on the controversial case of the Myxoma virus. (shrink)

Most models of generational succession in sexually reproducing populations necessarily move back and forth between genic and genotypic spaces. We show that transitions between and within these spaces are usually hidden by unstated assumptions about processes in these spaces. We also examine a widely endorsed claim regarding the mathematical equivalence of kin-, group-, individual-, and allelic-selection models made by Lee Dugatkin and Kern Reeve. We show that the claimed mathematical equivalence of the models does not hold. *Received January 2007; revised (...) April 2008. †To contact the authors, please write to: Elisabeth Lloyd, Department of History and Philosophy of Science, 130 Goodbody Hall, Indiana University, Bloomington, IN 47405; e-mail: ealloyd@indiana.edu; Richard Lewontin, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138; Marcus Feldman, Department of Biological Sciences, Stanford University, Stanford, CA 94305; e-mail: marc@charles.stanford.edu. (shrink)

this requirement for adaptations. Emergent characters are always potential adaptations. Not all selection processes produce adaptations, however. The key issue, in delineating a selection process, is the relationship between a character and fitness. The emergent character approach is more restrictive than alternative schemas that delineate selection..

According to a once influential view of selection, it consists of repeated cycles of replication and interaction. It has been argued that this view is wrong: replication is not necessary for evolution by natural selection. I analyze the nine most influential arguments for this claim and defend the replication–interaction conception of selection against these objections. In order to do so, however, the replication–interaction conception of selection needs to be modified significantly. My proposal is that replication is not the copying of (...) an entity, the replicator, but the copying of a property. Thus, we can have a replication process without there being a replicator that is being copied. (shrink)

It is now widely accepted that microorganisms play many important roles in the lives of plants and animals. Every macroorganism has been shaped in some way by microorganisms. The recognition of the ubiquity and importance of microorganisms has led some to argue for a revolution in how we understand biological individuality and the primary units of natural selection. The term “holobiont” was introduced as a name for the biological unit made up by a host and all of its associated microorganisms, (...) and much of this new debate about biological individuality has focused on whether holobionts are integrated individuals or communities. In this paper, I show how parts of the holobiont can span both characterizations. I argue that most holobionts share more affinities with communities than they do with organisms, and that, except for maybe in rare cases, holobionts do not meet the criteria for being organisms, evolutionary individuals, or units of selection. (shrink)

This paper takes a close look at the role of behavior in the “major transitions” in evolution—events during which inheritance and development, and therefore the process of adaptation by natural selection, are reorganized at a new level of compositional hierarchy—and at the requirements for sufficiently explaining these important events in the history of life. I argue that behavior played a crucial role in driving at least some of the major transitions. Because behavioral interactions can become stably organized in novel ways (...) on timescales faster than the lifetime of an organism, behavior can lead the way into a transition—becoming organized at the new level prior to inheritance and development. It is widely acknowledged that behavioral plasticity can play an important role in evolution; environmental novelty can elicit novel behavior that may feed back on the evolutionary process through niche selection or cultural inheritance, for example (Jablonka and Lamb 2005). I argue here that not just novel behaviors but novel forms of behavioral organization (distributed or hierarchical control that produces functional coherence) can emerge, binding the evolutionary fates of a group of organisms which were previously independent in terms of behavior as well as reproduction, and leading the way into a transition to an aggregative or “higher-level” mode of reproduction. (shrink)