Natural selection is a general process that operates in different populations. To characterise natural selection as a mechanism within the framework of the new mechanistic philosophy, it is required to identify a pertinent phenomenon for which natural selection is responsible. Firstly, every case identified by evolutionary biologists as instances of natural selection must align with this mechanistic characterisation. Secondly, natural selection should genuinely be responsible for the attributed phenomenon. While philosophers (...) often posit producing adaptation as the quintessential phenomenon, Pérez-González and Luque challenge this perspective, contending that not all instances of natural selection are cases where natural selection produces adaptation. This paper further supports Pérez-González and Luque’s objection and demonstrates that natural selection is also not responsible for the increased frequency of traits with a greater expected number of offspring. Furthermore, the paper argues that even if there is a phenomenon that allows for the mechanistic characterisation of natural selection to encompass all instances, it is improbable that natural selection assumes responsibility for it. Consequently, characterising natural selection as a mechanism emerges as an implausible stance. (shrink)

In this paper, I am clarifying and defending my argument in favor of the claim that cumulative selection can explain adaptation provided that the environmental resources are limited. Further, elaborate on what this limitation of environmental resources means and why it is relevant for the explanatory power of natural selection.

Here I advance two related evolutionary propositions. (1) Natural selection is most often considered to require competition between reproducing “individuals”, sometimes quite broadly conceived, as in cases of clonal, species or multispecies-community selection. But differential survival of non-competing and non-reproducing individuals will also result in increasing frequencies of survival-promoting “adaptations” among survivors, and thus is also a kind of natural selection. (2) Darwinists have challenged the view that the Earth’s biosphere is an evolved global homeostatic (...) system. Since there is only one biosphere, reproductive competition cannot have been involved in selection for such survival-promoting adaptations, they claim. But natural selection through survival could reconcile Gaia with evolutionary theory. (shrink)

The notion that natural selection is a process of fitness maximization gets a bad press in population genetics, yet in other areas of biology the view that organisms behave as if attempting to maximize their fitness remains widespread. Here I critically appraise the prospects for reconciliation. I first distinguish four varieties of fitness maximization. I then examine two recent developments that may appear to vindicate at least one of these varieties. The first is the ‘new’ interpretation of Fisher's (...) fundamental theorem of natural selection, on which the theorem is exactly true for any evolving population that satisfies some minimal assumptions. The second is the Formal Darwinism project, which forges links between gene frequency change and optimal strategy choice. In both cases, I argue that the results fail to establish a biologically significant maximization principle. I conclude that it may be a mistake to look for universal maximization principles justified by theory alone. A more promising approach may be to find maximization principles that apply conditionally and to show that the conditions were satisfied in the evolution of particular traits. (shrink)

Many people have argued that the evolution of the human language faculty cannot be explained by Darwinian natural selection. Chomsky and Gould have suggested that language may have evolved as the by-product of selection for other abilities or as a consequence of as-yet unknown laws of growth and form. Others have argued that a biological specialization for grammar is incompatible with every tenet of Darwinian theory – that it shows no genetic variation, could not exist in any (...) intermediate forms, confers no selective advantage, and would require more evolutionary time and genomic space than is available. We examine these arguments and show that they depend on inaccurate assumptions about biology or language or both. Evolutionary theory offers clear criteria for when a trait should be attributed to natural selection: complex design for some function, and the absence of alternative processes capable of explaining such complexity. Human language meets these criteria: Grammar is a complex mechanism tailored to the transmission of propositional structures through a serial interface. Autonomous and arbitrary grammatical phenomena have been offered as counterexamples to the position that language is an adaptation, but this reasoning is unsound: Communication protocols depend on arbitrary conventions that are adaptive as long as they are shared. Consequently, language acquisition in the child should systematically differ from language evolution in the species, and attempts to analogize them are misleading. Reviewing other arguments and data, we conclude that there is every reason to believe that a specialization for grammar evolved by a conventional neo-Darwinian process. (shrink)

Darwin provided us with a powerful theoretical framework to explain the evolution of living systems. Natural selection alone, however, has sometimes been seen as insufficient to explain the emergence of new levels of selection. The problem is one of “circularity” for evolutionary explanations: how to explain the origins of Darwinian properties without already invoking their presence at the level they emerge. That is, how does evolution by natural selection commence in the first place? Recent results (...) in experimental evolution suggest a way forward: Paul Rainey and his collaborators have shown that Darwinian properties could be exogenously imposed via what they call “ecological scaffolding.” This could solve the “black box” dilemma faced by Darwinian explanations of new levels of organization. Yet, despite “scaffolding” recently becoming a popular term in the study of cognition, culture, and evolution, the concept has suffered from vagueness and ambiguity. This article aims to show that scaffolding can be turned into a proper scientific concept able to do explanatory work within the context of the major evolutionary transitions. Doing so will allow us to once again extend the scope of the Darwinian model of evolution by natural selection. (shrink)

The epistemic status of Natural Selection has seemed intriguing to biologists and philosophers since the very beginning of the theory to our present times. One prominent contemporary example is Elliott Sober, who claims that NS, and some other theories in biology, and maybe in economics, are peculiar in including explanatory models/conditionals that are a priori in a sense in which explanatory models/conditionals in Classical Mechanics and most other standard theories are not. Sober’s argument focuses on some “would promote” (...) sentences that according to him, play a central role in NS explanations and are both causal and a priori. Lange and Rosenberg criticize Sober arguing that, though there may be some unspecific a priori causal claims, there are not a priori causal claims that specify particular causal factors. Although we basically agree with Lange and Rosenberg’s criticism, we think it remains silent about a second important element in Sober’s dialectics, namely his claim that, contrary to what happens in mechanics, in NS explanatory conditionals are a priori, and that this is so in quite specific explanatory models. In this paper we criticize this second element of Sober’s argument by analyzing what we take to be the four possible interpretations of Sober’s claim, and argue that, terminological preferences aside, the possible senses in which explanatory models in NS can qualify, or include elements that can qualify, as a priori, also apply to CM and other standard, highly unified theories. We conclude that this second claim is unsound, or at least that more needs to be said in order to sustain that NS explanatory models are a priori in a sense in which CM models are not. (shrink)

The book presents a new way of understanding Darwinism and evolution by natural selection, combining work in biology, philosophy, and other fields.

Recent discussions in the philosophy of biology have brought into question some fundamental assumptions regarding evolutionary processes, natural selection in particular. Some authors argue that natural selection is nothing but a population-level, statistical consequence of lower-level events (Matthen and Ariew [2002]; Walsh et al. [2002]). On this view, natural selection itself does not involve forces. Other authors reject this purely statistical, population-level account for an individual-level, causal account of natural selection (Bouchard and (...) Rosenberg [2004]). I argue that each of these positions is right in one way, but wrong in another; natural selection indeed takes place at the level of populations, but it is a causal process nonetheless. (shrink)

In their book What Darwin Got Wrong, Jerry Fodor and Massimo Piattelli-Palmarini construct an a priori philosophical argument and an empirical biological argument. The biological argument aims to show that natural selection is much less important in the evolutionary process than many biologists maintain. The a priori argument begins with the claim that there cannot be selection for one but not the other of two traits that are perfectly correlated in a population; it concludes that there cannot (...) be an evolutionary theory of adaptation. This article focuses mainly on the a priori argument. (shrink)

In this paper, using a multilevel approach, we defend the positive role of natural selection in the generation of organismal form. Despite the currently widespread opinion that natural selection only plays a negative role in the evolution of form, we argue, in contrast, that the Darwinian factor is a crucial (but not exclusive) factor in morphological organization. Analyzing some classic arguments, we propose incorporating the notion of ‘downward causation’ into the concept of ‘natural selection.’ (...) In our opinion, this kind of causation is fundamental to the operation of selection as a creative evolutionary process. (shrink)

In this paper, I discuss the concept of complexity. I show that the principle of natural selection as acting on complexity gives a solution to the problem of reconciling the seemingly contradictory notion of generally increasing complexity and the observation that most species don’t follow such a trend. I suggest the process of evolution to be illustrated by means of a schematic diagram of complexity versus time, interpreted as a form of the Tree of Life. The suggested model (...) implies that complexity is cumulatively increasing, giving evolution a direction, an arrow of time, thus also implying that the latest emerging species will be the one with the highest level of complexity. Since the human species is the last species evolved in the evolutionary process seen at large, this means that we are the species with the highest complexity. The model implies that the human species constitutes an integral part of organic evolution, yet rendering us the exclusive status as the species of the highest complexity. (shrink)

In this paper, I am clarifying and defending my argument in favor of the claim that cumulative selection can explain adaptation provided that the environmental resources are limited. Further, elaborate on what this limitation of environmental resources means and why it is relevant for the explanatory power of natural selection.

The thesis that natural selection explains the frequencies of traits in populations, but not why individual organisms have the traits tehy do, is here defended and elaborated. A general concept of ‘distributive explanation’ is discussed.

Many have argued that there is no reason why natural selection should cause directional increases in measures such as body size or complexity across evolutionary history as a whole. In this paper I argue that this conclusion does not hold for selection for adaptations to environmental variability, and that, given the inevitability of environmental variability, trends in adaptations to variability are an expected feature of evolution by natural selection. As a concrete instance of this causal (...) structure, I outline how this may be applied to a trend in phenotypic plasticity. (shrink)

I have recently argued that origin essentialism regarding individual organisms entails that natural selection does not explain why individual organisms have the traits that they do. This paper defends this and related theses against Mohan Matthen's recent objections.

One controversy about the existence of so called evolutionary forces such as natural selection and random genetic drift concerns the sense in which such “forces” can be said to interact. In this paper I explain how natural selection and random drift can interact. In particular, I show how population-level probabilities can be derived from individual-level probabilities, and explain the sense in which natural selection and drift are embodied in these population-level probabilities. I argue that (...) whatever causal character the individual-level probabilities have is then shared by the population-level probabilities, and that natural selection and random drift then have that same causal character. Moreover, natural selection and drift can then be viewed as two aspects of probability distributions over frequencies in populations of organisms. My characterization of population-level probabilities is largely neutral about what interpretation of probability is required, allowing my approach to support various positions on biological probabilities, including those which give biological probabilities one or another sort of causal character. ‡This paper has benefited from feedback on and discussions of this and earlier work. I want to thank André Ariew, Matt Barker, Lindley Darden, Patrick Forber, Nancy Hall, Mohan Matthen, Samir Okasha, Jeremy Pober, Robert Richardson, Alex Rosenberg, Eric Seidel, Denis Walsh, and Bill Wimsatt. †To contact the author, please write to: Department of Philosophy, University of Alabama at Birmingham, HB 414A, 900 13th Street South, Birmingham, AL 35294-1260; e-mail: [email protected]. (shrink)

Many people have argued that the evolution of the human language faculty cannot be explained by Darwinian natural selection. Chomsky and Gould have suggested that language may have evolved as the by-product of selection for other abilities or as a consequence of as-yet unknown laws of growth and form. Others have argued that a biological specialization for grammar is incompatible with every tenet of Darwinian theory – that it shows no genetic variation, could not exist in any (...) intermediate forms, confers no selective advantage, and would require more evolutionary time and genomic space than is available. We examine these arguments and show that they depend on inaccurate assumptions about biology or language or both. Evolutionary theory offers clear criteria for when a trait should be attributed to natural selection: complex design for some function, and the absence of alternative processes capable of explaining such complexity. Human language meets these criteria: Grammar is a complex mechanism tailored to the transmission of propositional structures through a serial interface. Autonomous and arbitrary grammatical phenomena have been offered as counterexamples to the position that language is an adaptation, but this reasoning is unsound: Communication protocols depend on arbitrary conventions that are adaptive as long as they are shared. Consequently, language acquisition in the child should systematically differ from language evolution in the species, and attempts to analogize them are misleading. Reviewing other arguments and data, we conclude that there is every reason to believe that a specialization for grammar evolved by a conventional neo-Darwinian process. (shrink)

Does natural selection explain why individual organisms have the traits that they do? According to "the Negative View," natural selection does not explain why any individual organism has the traits that it does. According to "the Positive View," natural selection at least sometimes does explain why an individual organism has the traits that it does. In this paper, I argue that recent arguments for the Positive View fail in virtue of running afoul of the (...) doctrine of origin essentialism and I demonstrate that other recent defenses of the Negative View depend upon my own for their plausibility. (shrink)

True beliefs are better guides to the world than false ones. This is the common-sense assumption that undergirds theorizing in evolutionary epistemology. According to Alvin Plantinga, however, evolution by natural selection does not care about truth: it cares only about fitness. If our cognitive faculties are the products of blind evolution, we have no reason to trust them, anytime or anywhere. Evolutionary naturalism, consequently, is a self-defeating position. Following up on earlier objections, we uncover three additional flaws in (...) Plantinga's latest formulation of his argument: a failure to appreciate adaptive path dependency, an incoherent conception of content ascription, and a conflation of common-sense and scientific beliefs, which we diagnose as the ‘foundationalist fallacy’. More fundamentally, Plantinga's reductive formalism with respect to the issue of cognitive reliability is inadequate to deal with relevant empirical details. (shrink)

Skipper and Millstein (2005) argued that existing conceptions of mechanisms failed to "get at" natural selection, but left open the possibility that a refined conception of mechanisms could resolve the problems that they identified. I respond to Skipper and Millstein, and argue that while many of their points have merit, their objections can be overcome and that natural selection can be characterized as a mechanism. In making this argument, I discuss the role of regularity in mechanisms, (...) and develop an account of stochastic (i.e., probabilistic) mechanisms. Explaining the phenomenon of adaptation through the mechanism of natural selection illustrates the power and flexibility of using mechanistic strategies to explain natural phenomena. (shrink)

The Darwinian concept of natural selection was conceived within a set of Newtonian background assumptions about systems dynamics. Mendelian genetics at first did not sit well with the gradualist assumptions of the Darwinian theory. Eventually, however, Mendelism and Darwinism were fused by reformulating natural selection in statistical terms. This reflected a shift to a more probabilistic set of background assumptions based upon Boltzmannian systems dynamics. Recent developments in molecular genetics and paleontology have put pressure on Darwinism (...) once again. Current work on self-organizing systems may provide a stimulus not only for increased problem solving within the Darwinian tradition, especially with respect to origins of life, developmental genetics, phylogenetic pattern, and energy-flow ecology, but for deeper understanding of the very phenomenon of natural selection itself. Since self-organizational phenomena depend deeply on stochastic processes, self-organizational systems dynamics advance the probability revolution. In our view, natural selection is an emergent phenomenon of physical and chemical selection. These developments suggest that natural selection may be grounded in physical law more deeply than is allowed by advocates of the autonomy of biology, while still making it possible to deny, with autonomists, that evolutionary explanations can be modeled in terms of a deductive relationship between laws and cases. We explore the relationship between, chance, self-organization, and selection as sources of order in biological systems in order to make these points. (shrink)

Natural selection [Darwin 1859] is perhaps the most important component of evolutionary theory, since it is the only known process that can bring about the adaptation of living organisms to their environments [Gould 2002]. And yet, its study is conceptually and methodologically complex, and much attention needs to be paid to a variety of phenomena that can limit the efficacy of selection [Antonovics 1976; Pigliucci and Kaplan 2000]. In this essay, I will use examples of recent work (...) carried out in my laboratory to illustrate basic research on natural selection as conducted using a variety of approaches, including field work, laboratory experiments, and molecular genetics. I also discuss the application of this array of tools to questions pertinent to conservation biology, and in particular to the all-important problem of what makes invasive species so good at creating the sort of problems they are infamous for [Lee 2002]. (shrink)

In “Spandrels,” Gould and Lewontin criticized what they took to be an all-too-common conviction, namely, that adaptation to current environments determines organic form. They stressed instead the importance of history. In this paper, we elaborate upon their concerns by appealing to other writings in which those issues are treated in greater detail. Gould and Lewontin’s combined emphasis on history was three-fold. First, evolution by natural selection does not start from scratch, but always refashions preexisting forms. Second, preexisting forms (...) are refashioned by the selection of whatever mutational variations happen to arise: the historical order of mutations needs to be taken into account. Third, the order of environments and selection pressures also needs to be taken into account. (shrink)

Altruism is one of the most studied topics in theoretical evolutionary biology. The debate surrounding the evolution of altruism has generally focused on the conditions under which altruism can evolve and whether it is better explained by kin selection or multilevel selection. This debate has occupied the forefront of the stage and left behind a number of equally important questions. One of them, which is the subject of this article, is whether the word “selection” in “kin (...) class='Hi'>selection” and “multilevel selection” necessarily refers to “evolution by natural selection.” I show, using a simple individual-centered model, that once clear conditions for natural selection and altruism are specified, one can distinguish two kinds of evolution of altruism, only one of which corresponds to the evolution of altruism by natural selection, the other resulting from other evolutionary processes. (shrink)

This chapter appeals to natural selection in order to show that the failure of many humans and animals to flourish is strong evidence against the existence of an omnipotent, omniscient, and morally perfect God. Treating theism and naturalism as hypotheses that aim to explain certain features of our world, Draper sets out to test each hypothesis against various known facts, including facts about human and animal suffering. After demonstrating that, prior to such testing, naturalism is more probable than (...) theism in virtue of its smaller scope (i.e. greater modesty) and greater simplicity, Draper goes on to argue that naturalism has far greater "predictive power" than theism, concluding that this provides strong grounds for rejecting theism. (shrink)

Demonstration of illusiveness of basic beliefs of the Modern Synthesis implies the existence of evolutionary mechanisms that do not require natural selection for the origin of adaptations. This requires adaptive changes that occur independently from replication, but can occasionally become heritable. Plastic self-organizational changes regulated by genome are largely incorporable into the old theory. A fundamentally different source of adaptability is semiosis which includes the agent’s free choice. Adding semiosis into the theory of Extended Evolutionary Synthesis completes the (...) distancing from the Modern Synthesis. I focus here on the importance of semiosis as the necessary factor in organisms’ meaning making. (shrink)

In the recent philosophical literature, two questions have arisen concerning the status of natural selection: (1) Is it a population-level phenomenon, or is it an organism-level phenomenon? (2) Is it a causal process, or is it a purely statistical summary of lower-level processes? In an earlier work (Millstein, Br J Philos Sci, 57(4):627–653, 2006), I argue that natural selection should be understood as a population-level causal process, rather than a purely statistical population-level summation of lower-level processes (...) or as an organism-level causal process. In a 2009 essay entitled “Productivity, relevance, and natural selection,” Stuart Glennan argues in reply that natural selection is produced by causal pro- cesses operating at the level of individual organisms, but he maintains that there is no causal productivity at the population level. However, there are, he claims, many population-level properties that are causally relevant to the dynamics of evolution- ary processes. Glennan’s claims rely on a causal pluralism that holds that there are two types of causes: causal production and causal relevance. Without calling into question Glennan’s causal pluralism or his claims concerning the causal relevance of natural selection, I argue that natural selection does in fact exhibit causal production at the population level. It is true that natural selection does not fit with accounts of mechanisms that involve decomposition of wholes into parts, such as Glennan’s own. However, it does fit with causal production accounts that do not require decomposition, such as Salmon’s Mark Transmission account, given the extent to which populations act as interacting “objects” in the process of natural selection. (shrink)

The article examines two cases of adoption of evolutionary ways of thinking by modern economists: Nelson and Winter’s (Evolutionary Theory of Economic Change, 1982), and evolutionary game theory (1990s and after). In both cases, the authors explicitly refer to natural selection in an economic context. I show that natural selection is taken in two different senses, which correspond to two general conceptions of the principle of natural selection, one of which contains reproduction and heredity (...) as key elements, whereas the other does not. (shrink)

Darwin's theory of evolution by natural selection provided the first, and only, causal-mechanistic account of the existence of adaptations in nature. As such, it provided the first, and only, scientific alternative to the “argument from design”. That alone would account for its philosophical significance. But the theory also raises other philosophical questions not encountered in the study of the theories of physics. Unfortunately the concept of natural selection is intimately intertwined with the other basic concepts of (...) evolutionary theory—such as the concepts of fitness and adaptation —that are themselves philosophically controversial. Fortunately we can make considerable headway in getting clear on natural selection without solving all of those outstanding problems. (shrink)

In this paper I critically evaluate Reisman and Forber’s :1113–1123, 2005) arguments that drift and natural selection are population-level causes of evolution based on what they call the manipulation condition. Although I agree that this condition is an important step for identifying causes for evolutionary change, it is insufficient. Following Woodward, I argue that the invariance of a relationship is another crucial parameter to take into consideration for causal explanations. Starting from Reisman and Forber’s example on drift and (...) after having briefly presented the criterion of invariance, I show that once both the manipulation condition and the criterion of invariance are taken into account, drift, in this example, should better be understood as an individual-level rather than a population-level cause. Later, I concede that it is legitimate to interpret natural selection and drift as population-level causes when they rely on genuinely indeterministic events and some cases of frequency-dependent selection. (shrink)

Struggle for existence -- Natural selection -- Difficulties on theory -- Conclusion.

Susan Mills and John Beatty proposed a propensity interpretation of fitness (1979) to show that Darwinian explanations are not circular, but they did not address the critics' chief complaint that the principle of the survival of the fittest is either tautological or untestable. I show that the propensity interpretation cannot rescue the principle from the critics' charges. The critics, however, incorrectly assume that there is nothing more to Darwin's theory than the survival of the fittest. While Darwinians all scoff at (...) this assumption, they do not agree about what role, if any, this principle plays in Darwin's theory of natural selection. I argue that the principle has no place in Darwin's theory. His theory does include the idea that some organisms are fitter than others. But greater reproductive success is simply inferred from higher fitness. There is no reason to embody this inference in the form of a special principle of the survival of the fittest. (shrink)

This article defends the Negative View of natural selection explanation, according to which natural selection cannot explain of any given individual why it has the traits it does. Over the years, this view has been criticized on empirical, metaphysical, and explanatory grounds. I review the debate and offer additional reasons for rejecting the empirical and metaphysical objections. The explanatory objection, which holds that the Negative View is rooted in a flawed account of contrastive explanation, initially seems (...) plausible. However, I argue that a closer consideration of the desiderata of contrastive explanation shows that this objection fails as well. (shrink)

Natural selection is commonly seen not just as an explanation for adaptive evolution, but as the inevitable consequence of “heritable variation in fitness among individuals”. Although it remains embedded in biological concepts, such a formalisation makes it tempting to explore whether this precondition may be met not only in life as we know it, but also in other physical systems. This would imply that these systems are subject to natural selection and may perhaps be investigated in (...) a biological framework, where properties are typically examined in light of their putative functions. Here we relate the major questions that were debated during a three-day workshop devoted to discussing whether natural selection may take place in non-living physical systems. We start this report with a brief overview of research fields dealing with “life-like” or “proto-biotic” systems, where mimicking evolution by natural selection in test tubes stands as a major objective. We contend the challenge may be as much conceptual as technical. Taking the problem from a physical angle, we then discuss the framework of dissipative structures. Although life is viewed in this context as a particular case within a larger ensemble of physical phenomena, this approach does not provide general principles from which natural selection can be derived. Turning back to evolutionary biology, we ask to what extent the most general formulations of the necessary conditions or signatures of natural selection may be applicable beyond biology. In our view, such a cross-disciplinary jump is impeded by reliance on individuality as a central yet implicit and loosely defined concept. Overall, these discussions thus lead us to conjecture that understanding, in physico-chemical terms, how individuality emerges and how it can be recognised, will be essential in the search for instances of evolution by natural selection outside of living systems. (shrink)

In this defense of Reliabilism, I argue that there has been 'selection for' accurate indexical beliefs. I offer empirical evidence and examples to suggest that Steve Stich's defense of the opposite claim in The Fragmentation of Reason is misguided.

The concept of fitness has generated a lot of discussion in philosophy of biology. There is, however, relative agreement about the need to distinguish at least two uses of the term: ecological fitness on the one hand, and population genetics fitness on the other. The goal of this paper is to give an explication of the concept of ecological fitness by providing a reconstruction of the theory of natural selection in which this concept was framed, that is, based (...) on the way the theory was put to use in Darwin’s main texts. I will contend that this reconstruction enables us to account for the current use of the theory of natural selection. The framework presupposed in the analysis will be that of metatheoretical structuralism. This framework will provide both a better understanding of the nature of ecological fitness and a more complete reconstruction of the theory. In particular, it will provide what I think is a better way of understanding how the concept of fitness is applied through heterogeneous cases. One of the major advantages of my way of thinking about natural selection theory is that it would not have the peculiar metatheoretical status that it has in other available views. I will argue that in order to achieve these goals it is necessary to make several concepts explicit, concepts that are frequently omitted in usual reconstructions. (shrink)

Ruth Millikan and others advocate theories which attempt to naturalize wide mental content (e.g. beliefs.

It is tempting to invoke organismal selection as perpetually optimizing the function of any given gene. However, natural selection can drive genic functional change without improvement of biochemical activity, even to the extinction of gene activity. Detrimental mutations can creep in owing to linkage with other selectively favored loci. Selection can promote functional degradation, irrespective of genetic drift, when adaptation occurs by loss of gene function. Even stabilizing selection on a trait can lead to divergence (...) of the underlying molecular constituents. Selfish genetic elements can also proliferate independent of any functional benefits to the host genome. Here we review the logic and evidence for these diverse processes acting in genome evolution. This collection of distinct evolutionary phenomena – while operating through easily understandable mechanisms – all contribute to the seemingly counterintuitive notion that maintenance or improvement of a gene's biochemical function sometimes do not determine its evolutionary fate. (shrink)

It is often claimed that our knowledge of the evolutionary process adds an extra dimension to the classical problem of natural evil and makes this problem worse. Especially the principle of natural selection is often portrayed as morally inappropriate or “unfitting” for a perfectly good God to use as a means for creating biological complexity. In this article, I argue that this common view is misconceived, and that natural selection is a wholly innocuous principle. The (...) real source of evolutionary evils is the fact that resources in nature are scarce – a fact that was known long before Darwin. The problem of natural and evolutionary evil, therefore, is best construed as a question about why God permits scarcity in nature. I argue that recent research about the interrelation between competition and cooperation in the evolutionary process provides resources for answering this perennial question in a more satisfactory way than could be done before the advent of evolutionary theory. (shrink)

The latter half of the twentieth century has been marked by debates in evolutionary biology over the relative significance of natural selection and random drift: the so-called “neutralist/selectionist” debates. Yet John Beatty has argued that it is difficult, if not impossible, to distinguish the concept of random drift from the concept of natural selection, a claim that has been accepted by many philosophers of biology. If this claim is correct, then the neutralist/selectionist debates seem at best (...) futile, and at worst, meaningless. I reexamine the issues that Beatty raises, and argue that random drift and natural selection, conceived as processes, can be distinguished from one another. (shrink)

Through a series of essays, the author discusses the conflict between cultural and biological evolution, covering intelligent design, gender differences, and the meaning of life while offering insight into the ethical aspects of civilization.

Recent papers by a number of philosophers have been concerned with the question of whether natural selection is a causal process, and if it is, whether the causes of selection are properties of individuals or properties of populations. I shall argue that much confusion in this debate arises because of a failure to distinguish between causal productivity and causal relevance. Causal productivity is a relation that holds between events connected via continuous causal processes, while causal relevance is (...) a relationship that can hold between a variety of different kinds of facts and the events that counterfactually depend upon them. I shall argue that the productive character of natural selection derives from the aggregation of individual processes in which organisms live, reproduce and die. At the same time, a causal explanation of the distribution of traits will necessarily appeal both to causally relevant properties of individuals and to causally relevant properties that exist only at the level of the population. (shrink)

Even today, a century after the publication of the “Origin of Species”, current zoological literature often reveals an insufficient grasp of the implications of the now generally accepted view that it is natural selection that confers direction on the evolutionary process.This is, in part, due to a reaction against oversimplified teleology and against Lamarckism. In rejecting Lamarck's thesis that the activities of an animal directly affect its hereditary characters it is frequently assumed that this implies that such activities (...) are irrelevant to the study of evolution. This is a non-sequitur, for activities may affect evolution not directly, through heredity, but indirectly, by influencing the direction of the selective forces impinging on the organism. Reasons are given for concluding that changes in habits and behaviour frequently precede structural change and, in fact, determine the direction of the latter.As an example of a concept which deserves a more evolutionary treatment than it commonly receives, the subject of neoteny is considered. It appears that failure to think in terms of the selective forces involved has frequently led to error. An analysis in functional terms is made of the theory that the chordates represent secondarily glorified sea-squirts and it is concluded that this idea is unlikely to be correct. The characteristics of man that are commonly considered to be neotenous are also discussed. It is concluded that a facile and unanalytical application of the label “neoteny” to many of the evolutionary changes involved has tended to obscure rather than to clarify their significance: the neotenous features of man are not those that have been of primary importance in human evolution, but are secondary to the acquisition of new characters which are not to be found in either the adult or the young stages of any other primate.Aujourd'hui, un siècle après l'apparition de l'Originedes Espèces, la conviction est presque générale que la sélection naturelle dirige le procès de l'évolution. Néanmoins, les publications zoologiques actuelles révèlent souvent une compréhension insuffisante de ce qui en résulte.Ceci doit en partie être considéré comme réaction contre une téléologie simpliste et contre le Lamarckisme. En rejetant la thèse de Lamarck, que les activités d'un animal ont une influence directe sur ses caractéristiques héréditaires, on admet fréquemment que de pareilles activités n'ont rien à voir avec l'étude le l'évolution. Cependant, une telle conclusion n'est pas justifiée, car les activités peuvent influer sur l'évolution non pas directement, par la voie de l'hérédité, mais indirectement en agissant sur la direction des forces sélectives que l'organisme rencontre. Des raisons ont été données qui mènent à conclure que des changements dans les habitudes et dans le comportement précèdent maintes fois le changement structural et même déterminent la direction de celui-ci.Comme exemple d'un concept qui mérite un traitement plus évolutionniste qu'il ne reçoive en général, la néoténie a été examinée. Il paraît que l'on a fait beaucoup d'erreurs en ne tenant pas compte des forces sélectives engagées. Une analyse au pointde-vue de la fonction a été appliquée à la théorie que les chordées ne sont que des ascidies néoténiques transfigurées par après, et il s'ensuit que cette idée n'est probablement pas correcte. Aussi les caractéristiques de l'homme généralement regardées comme neoténiques ont été discutées. Il en résulte que, en désignant légèrement et sans analyse plusieurs changements évolutionnaires comme néoténie, on a plutôt obsurci qu'éclairci leur signification. Ce ne sont pas les traits néoteniques de l'homme qui ont joué le rôle principal dans l'évolution humaine; au contraire, ils n'apparaissent qu'après l'acquisition de quelques nouvelles caractéristiques qui ne se trouvent ni dans l'adulte ni dans les phases plus jeunes des autres primates.Sogar heutzutage, ein Jahrhundert nach dem Erscheinen der „Origin of Species”, zeigt die jetzige zoologische Literatur oft eine unzulängliche Einsicht in die Folgerungen, zu denen die jetzt allgemein akzeptierte Annahme leitet, dass die natürliche Selektion die Richtung des Evolutionsprozesses bedingt.Dies ist teilweise zu sehen als eine Reaktion gegen eine einseitige Teleologie und gegen das Lamarckismus. Bei der Ablehnung der TheseLamarck's, dass die Aktivitäten eines Tieres einen direkten Einfluss ausüben auf seine erbliche Konstitution, nimmt man oft an, dass dies bedeutet, dass derartige Aktivitäten demnach nichts zur Sache tun bei dem Studium der Evolution. Zu einer derartigen Konklusion ist man jedoch nicht berechtigt, denn, obwohl die Aktivitäten die Evolution nicht direkt beeinflussen können mittels der Erblichkeit, so können sie dies jedoch indirekt, weil sie die Richtung der selektiven Kräfte, welche auf das Organismus einwirken, bestimmen. Es werden Argumente gegeben, welche die Konklusion rechtfertigten, dass Änderungen in Gewohnheit und Verhalten oft Strukturänderungen vorhergehen und tatsächlich die Richtung dieser letztgenannten bestimmen. Die Neotenie wirdt als ein Beispiel eines Begriff betrachtet, welcher eine mehr evolutionäre Behandlung verdient als bisher geschehen ist. Es ergibt sich dass man viele Irrtümer hat gemacht, indem man den betreffenden selektiven Kräften keine Rechnung getragen hat. Eine Analyse der Theorie, welche die Chordaten als neotenische Ascidien betrachtet, wird von einem funktionellen Gesichtspunkt aus durchgeführt. Daraus scheint der Schluss berechtigt, dass diese Theorie falsch ist. Auch werden die menschlichen Kennzeichen, welche gewöhnlich als neotenische betrachtet werden, besprochen. Die Konklusion lautet, dass, wenn man leichtfertig und ohne genügende Analyse den Zettel „Neotenie“ für mancherlei evolutive Änderungen anwendet, man die richtige Bedeutung dieser Erscheinung vielmehr verdunkelt als aufklärt: nicht die neotenische Kennzeichen des Menschen sind am wichtigsten in seiner Evolution; in Gegenteil sie erscheinen nur sekundär, nachdem die neuen Kennzeichen, welche sich weder in den Erwachsenen noch in den jüngeren Stadien von den anderen Primaten finden lassen, erschienen sind. (shrink)

We argue that the fragility of contemporary marriages—and the corresponding high rates of divorce—can be explained (in large part) by a three-part mismatch: between our relationship values, our evolved psychobiological natures, and our modern social, physical, and technological environment. “Love drugs” could help address this mismatch by boosting our psychobiologies while keeping our values and our environment intact. While individual couples should be free to use pharmacological interventions to sustain and improve their romantic connection, we suggest that they may have (...) an obligation to do so as well, in certain cases. Specifically, we argue that couples with offspring may have a special responsibility to enhance their relationships for the sake of their children. We outline an evolutionarily informed research program for identifying promising biomedical enhancements of love and commitment. (shrink)