Darwinians are realists about the force of selection, but there has been surprisingly little discussion about what form this realism should take. Arguments about the units of selection in general and genic selectionism in particular reveal two realist assumptions: (1) for any selection process, there is a uniquely correct identification of the operative selective forces and the level at which each impinges; and (2) selective forces must satisfy the Pareto-style requirement of probabilistic causation. I argue that both assumptions are false; (...) we must temper realism about the force of selection and revise the way we think about probabilistic causation. (shrink)

Evolutionary theory is awash with probabilities. For example, natural selection is said to occur when there is variation in fitness, and fitness is standardly decomposed into two components, viability and fertility, each of which is understood probabilistically. With respect to viability, a fertilized egg is said to have a certain chance of surviving to reproductive age; with respect to fertility, an adult is said to have an expected number of offspring.1 There is more to evolutionary theory than the theory of (...) natural selection, and here too one finds probabilistic concepts aplenty. When there is no selection, the theory of neutral evolution says that a gene’s chance of eventually reaching fixation is 1/(2N), where N is the number of organisms in the generation of the diploid population to which the gene belongs. The evolutionary consequences of mutation are likewise conceptualized in terms of the probability per unit time a gene has of changing from one state to another. The examples just mentioned are all “forwarddirected” probabilities; they describe the probability of later events, conditional on earlier events. However, evolutionary theory also uses “backwards probabilities” that describe the probability of a cause conditional on its effects; for example, coalescence theory allows one to calculate the expected number of generations in the past that the genes in the present generation find their most recent common ancestor. (shrink)

The theory of evolution by natural selection is, perhaps, the crowning intellectual achievement of the biological sciences. There is, however, considerable debate about which entity or entities are selected and what it is that fits them for that role. This article aims to clarify what is at issue in these debates by identifying four distinct, though often confused, concerns and then identifying how the debates on what constitute the units of selection depend to a significant degree on which of these (...) four questions a thinker regards as central. (shrink)

The history and theoretical role of the concept of a ``replicator''is discussed, starting with Dawkins' and Hull's classic treatmentsand working forward. I argue that the replicator concept is still auseful one for evolutionary theory, but it should be revised insome ways. The most important revision is the recognition that notall processes of evolution by natural selection require thatsomething play the role of a replicator.

The Paradox of the Ravens (a.k.a,, The Paradox of Confirmation) is indeed an old chestnut. A great many things have been written and said about this paradox and its implications for the logic of evidential support. The first part of this paper will provide a brief survey of the early history of the paradox. This will include the original formulation of the paradox and the early responses of Hempel, Goodman, and Quine. The second part of the paper will describe attempts (...) to resolve the paradox within a Bayesian framework, and show how to improve upon them. This part begins with a discussion of how probabilistic methods can help to clarify the statement of the paradox itself. And it describes some of the early responses to probabilistic explications. We then inspect the assumptions employed by traditional (canonical) Bayesian approaches to the paradox. These assumptions may appear to be overly strong. So, drawing on weaker assumptions, we formulate a new-and-improved Bayesian confirmation-theoretic resolution of the Paradox of the Ravens. (shrink)

This paper considers recent heated debates led by Jerry A. Coyne andMichael J. Wade on issues stemming from the 1929–1962 R.A. Fisher-Sewall Wrightcontroversy in population genetics. William B. Provine once remarked that theFisher-Wright controversy is central, fundamental, and very influential.Indeed,it is also persistent. The argumentative structure of therecent (1997–2000) debates is analyzed with the aim of eliminating a logicalconflict in them, viz., that the two sides in the debates havedifferent aims and that, as such, they are talking past each other. (...) Given aphilosophical analysis of the argumentative structure of the debates,suggestions supportive of Wade's work on the debate are made that areaimed, modestly, at putting the persistent Fisher-Wright controversy on thecourse to resolution. (shrink)

Evolution in its contemporary meaning in biology typically refers to the changes in the proportions of biological types in a population over time (see the entry on the concept of evolution to 1872 for earlier meanings). As evolution is too large of a topic to address thoroughly in one entry, the primary goal of this entry is to serve as a broad overview of contemporary issues in evolution with links to other entries where more in-depth discussion can be found. The (...) entry begins with a brief survey of definitions of evolution, followed by a discussion of the different modes of evolution and related philosophical issues, and ends with a summary of other topics in the philosophy of evolution focusing particularly on topics covered in this encyclopedia. (shrink)

The Units of Selection debate is a dispute about the causes of population change. I argue that it is generated by a particular `dynamical'' interpretation of natural selection theory, according to which natural selection causes differential survival and reproduction of individuals and natural selection explanations cite these causes. I argue that the dynamical interpretation is mistaken and offer in outline an alternative, `statistical'' interpretation, according to which natural selection theory is a fancy kind of `bookkeeping''. It explains by citing the (...) statistical structure of a population and not by citing the causes of survival and reproduction. From the perspective of the statistical interpretation there is no substantive Units of Selection issue. (shrink)

Complexity is pleased to announce the installment of Prof Hiroki Sayama as its new Chief Editor. In this Editorial, Prof Sayama describes his feelings about his recent appointment, discusses some of the journal’s journey and relevance to current issues, and shares his vision and aspirations for its future.

This paper pursues the question, To what extent does the propensity approach to probability contribute to plausible solutions to various anomalies which occur in quantum mechanics? The position I shall defend is that of the three interpretations — the frequency, the subjective, and the propensity — only the third accommodates the possibility, in principle, of providing a realistic interpretation of ontic indeterminism. If these considerations are correct, then they lend support to Popper's contention that the propensity construction tends to remove (...) (at least some of) the mystery from quantum phenomena. (shrink)

Darwinism designates a distinctive form of evolutionary explanation for the history and diversity of life on earth. Its original formulation is provided in the first edition of On the Origin of Species in 1859. This entry first formulates ‘Darwin's Darwinism’ in terms of five philosophically distinctive themes: (i) probability and chance, (ii) the nature, power and scope of selection, (iii) adaptation and teleology, (iv) nominalism vs. essentialism about species and (v) the tempo and mode of evolutionary change. Both Darwin and (...) his critics recognized that his approach to evolution was distinctive on each of these topics, and it remains true that, though Darwinism has developed in many ways unforeseen by Darwin, its proponents and critics continue to differentiate it from other approaches in evolutionary biology by focusing on these themes. This point is illustrated in the second half of the entry by looking at current debates in the philosophy of evolutionary biology on these five themes, with a special focus on Stephen Jay Gould's The Structure of Evolutionary Theory. (shrink)

This survey of major developments in North American philosophy of science begins with the mid-1960s consolidation of the disciplinary synthesis of internalist history and philosophy of science (HPS) as a response to criticisms of logical empiricism. These developments are grouped for discussion under the following headings: historical metamethodologies, scientific realisms, philosophies of the special sciences, revivals of empiricism, cognitivist naturalisms, social epistemologies, feminist theories of science, studies of experiment and the disunity of science, and studies of science as practice and (...) culture. A unifying theme of the survey is the relation between historical metamethodologists and scientific realists, which dominated philosophical work in the late 1970s. I argue that many of the alternative cognitive naturalisms, social epistemologies, and feminist theories that have been proposed can be understood as analogues to the differences between metamethodological theories of scientific rationality and realist accounts of successful reference to real causal processes. Recent work on experiment, scientific practice, and the culture of science may, however, challenge the underlying conception of the field according to which realism and historical rationalism (or their descendants) are the important alternatives available, and thus may take philosophy of science in new directions. (shrink)

I argue that to the extent to which philosophical theories of objective probability have offered theoretically adequate conceptions of objective probability , they have failed to satisfy a methodological standard -- roughly, a requirement to the effect that the conception offered be specified with the precision appropriate for a physical interpretation of an abstract formal calculus and be fully explicated in terms of concepts, objects or phenomena understood independently of the idea of physical probability. The significance of this, and of (...) the suggested methodological standard, is then briefly discussed. (shrink)

In recent years, an increasing number of medical books and papers attempting to analyse the concepts of health and disease from the perspective of evolutionary biology have been published.This paper introduces the evolutionary approach to health and disease in an attempt to illuminate the premisses and the framework of Darwinian medicine. My primary aim is to analyse to what extent evolutionary theory provides for a biological definition of the concept of disease. This analysis reveals some important differences between functional explanations (...) in the field of evolutionary biology and functional explanations in the field of medicine. Moreover, I shall argue that the biological functions relevant to the health of an organism cannot be determined on the basis of evolutionary theory. Accordingly, it seems that Darwinian medicine does not provide for the definition of a biological concept of disease. Still,Darwinian medicine may suggest why we are susceptible to certain diseases; it might also prove a suggestive heuristic on the basis of which new hypotheses concerning relevant treatments of various diseases might be advanced. (shrink)

The application of evolutionary ideas to socioeconomic systems has been an increasingly prominent theme in the work of Friedrich Hayek, and the motif has become dominant in his recent book. In an earlier issue of this journal, Viktor Vanberg raises two substantive criticisms of Friedrich Hayek' theory of cultural evolution that invoke some important questions concerning use of the evolutionary analogy in social science.

In The Levels of Selection (Brandon, 1984), Robert Brandon provides a suggestive but ultimately unsuccessful attempt to use the probabilistic notion ofscreening off in providing a schema for dealing with an aspect of the units of selection question in the philosophy of biology. I characterize that failure, and suggest a revision and expansion of Brandon's account which addresses its key shortcoming.

In an important article, Kim Sterelny and Philip Kitcher challenge the common assumption that for any biological phenomenon requiring a selectionist explanation, it is possible to identify a uniquely correct account of the relevant selection process. They argue that selection events can be modeled in any of a number of different, equally correct ways. They call their view ' Pluralism,' and explicitly connect it with various antirealist positions in the philosophy of science. I critically evaluate Sterelny and Kitcher's Pluralism along (...) with its attendant antirealist theses. In particular, I argue that there are serious problems with their pluralistic antirealism regarding units of selection. By correctly diagnosing these problems a more adequate position can be constructed. I defend such a position, which I designate Inclusive Hierarchical Monism, and show how it captures the important virtues of Sterelny and Kitcher's approach while avoiding its problems. (shrink)

I explore the problem of ``probabilistic causal preemption'' in the context of a``propensity trajectory'' theory of singular probabilistic causation. This involvesa particular conception of events and a substantive thesis concerning events soconceived.

To clarify and illuminate the place of probability in science Ellery Eells and James H. Fetzer have brought together some of the most distinguished philosophers ...

Climate policy decisions are decisions under uncertainty and are, therefore, based on a range of future climate scenarios, describing possible consequences of alternative policies. Accordingly, the methodology for setting up such a scenario range becomes pivotal in climate policy advice. The preferred methodology of the Intergovernmental Panel on Climate Change will be characterised as ,,modal verificationism"; it suffers from severe shortcomings which disqualify it for scientific policy advice. Modal falsificationism, as a more sound alternative, would radically alter the way the (...) climate scenario range is set up. Climate science's inability to find robust upper bounds for future temperature rise in line with modal falsificationism does not disprove that methodology, rather, this very fact prescribes even more drastic efforts to curb CO2 emissions than currently proposed. (shrink)

This chapter offers a review of standard views about the requirements for natural selection to shape evolution and for the sorts of ‘units’ on which selection might operate. It then summarizes traditional arguments for genic selectionism, i.e., the view that selection operates primarily on genes (e.g., those of G. C. Williams, Richard Dawkins, and David Hull) and traditional counterarguments (e.g., those of William Wimsatt, Richard Lewontin, and Elliott Sober, and a diffuse group based on life history strategies). It then offers (...) a series of responses to the arguments, based on more contemporary considerations from molecular genetics, offered by Carmen Sapienza. A key issue raised by Sapienza concerns the degree to which a small number of genes might be able to control much of the variation relevant to selection operating on such selectively critical organs as hearts. The response to these arguments suggests that selection acts on many levels at once and that sporadic selection, acting with strong effects, can act successively on different key traits (and genes) while maintaining a balance among many potentially conflicting demands faced by organisms within an evolving lineage. (shrink)

W&S correctly ask if groups can be like individuals in the harmony and cooperation of their parts, but in their answer, they ignore the importance of the difference between genetically related and unrelated components, and also misconstrue the import of the Hutterites.

This chapter contains sections titled: Highlights of Past Literature Current Work Future Work.

In both biology and the human sciences, social groups are sometimes treated as adaptive units whose organization cannot be reduced to individual interactions. This group-level view is opposed by a more individualistic one that treats social organization as a byproduct of self-interest. According to biologists, group-level adaptations can evolve only by a process of natural selection at the group level. Most biologists rejected group selection as an important evolutionary force during the 1960s and 1970s but a positive literature began to (...) grow during the 1970s and is rapidly expanding today. We review this recent literature and its implications for human evolutionary biology. We show that the rejection of group selection was based on a misplaced emphasis on genes as "replicators" which is in fact irrelevant to the question of whether groups can be like individuals in their functional organization. The fundamental question is whether social groups and other higher-level entities can be "vehicles" of selection. When this elementary fact is recognized, group selection emerges as an important force in nature and what seem to be competing theories, such as kin selection and reciprocity, reappear as special cases of group selection. The result is a unified theory of natural selection that operates on a nested hierarchy of units. The vehicle-based theory makes it clear that group selection is an important force to consider in human evolution. Humans can facultatively span the full range from self-interested individuals to "organs" of group-level "organisms." Human behavior not only reflects the balance between levels of selection but it can also alter the balance through the construction of social structures that have the effect of reducing fitness differences within groups, concentrating natural selection (and functional organization) at the group level. These social structures and the cognitive abilities that produce them allow group selection to be important even among large groups of unrelated individuals. (shrink)

The dissertation criticizes two analogical applications of Darwinism to the spheres of mind and culture: the Darwinian approach to creativity and memetics. These theories rely on three basic analogies: the ontological analogy states that the basic ontological units of culture are so-called memes, which are replicators like genes; the origination analogy states that novelty in human creativity emerges in a "blind" Darwinian manner; and the explanatory units of selection analogy states that memes are "egoistic" and that they can spread independently (...) of our mind. The detailed philosophical analysis offered in the dissertation shows that these three analogies rely on either wrong or trivial statements: they provide either wrong or no new descriptions or explanations of the phenomena at hand. In Chapter One, I introduce the diverse ways, in which contemporary Darwinism is used today outside of evolutionary biology. Chapter Two explains what it means to claim that something evolves in a Darwinian manner. Chapter Three to Five address each of the three analogies separately. Darwinism applied to culture and mind, at least in the way discussed in this study, is not a dangerous idea. It leads either to wrong claims or to a re-telling in Darwinian terms of what we have already known. (shrink)

This chapter contains section titled: Introduction Darwin's Life Darwin's Darwinism Philosophical Problems with Darwin's Darwinism The Core Problems and Darwinism Conclusion References Further Reading.

Traditional model systems such as fly, mouse, and chick have formed the foundation of the EvoDevo research program. These animal systems have provided a wealth of information on the patterns and mechanisms of developmental change over large phylogenetic scales. However, the almost exclusive focus on individual embryos as model organisms has also limited the field’s ability to address the central roles that natural selection and life history adaptation play in the evolution of developmental systems. Likewise, focus on this small set (...) of “unitary” model organisms may also constrain the explanatory reach and theoretical robustness of EvoDevo if we consider that many core developmental processes like homeostatic regulation, ontogenetic differentiation, and norms of reaction are also manifest at other levels of biological organization, such as colonial organisms. The study of social insect systems can help bridge these considerable gaps in EvoDevo’s current approach. Because social insect colonies span the fine line between simple associations of “unitary” organisms and full-fledged “superorganisms,” these systems help elucidate what kinds of processes fundamentally characterize developmental systems and their evolution. What is more, the traits of social insect colonies show high degrees of population-level variability that can be linked directly to selective factors in the environment, making them ideal systems in which to more fully integrate EcoEvoDevo approaches. (shrink)