During the battle of Iwo Jima in June 1944, Private First Class Jackylin Harold Lucas and three other U.S. Marines came under attack while making their way along a ravine. Upon seeing two grenades thrown near the soldiers, Lucas dove onto one grenade and pulled the other under his body, saving his companions from serious injury or death. Lucas survived, but his injuries were so grave that his companions left him for dead. Lucas’s act was one of spectacular and nearly (...) suicidal altruism. What does such an act show us about our nature and the human capacity for good and evil? Perhaps it offers a window onto our true nature—a nature ultimately good, though susceptible to corrupting influences. Or perhaps it seems extraordinary precisely because we are greedy and violent by nature but can, in rare instances, rise above those instincts. Questions about what human nature is and how we can learn about it are difficult to answer. They are difficult not just because humans are complex creatures whose behavior is deeply embedded in the cultural environment that they are a part of, but also because it is not obvious what a concept of human nature is supposed to do or what it is for. The concept of human nature is often used as a normative concept, one that can serve as a guide to action, showing us how we ought to behave. Less commonplace is an approach that seeks a descriptive account of human nature, one that characterizes what humans do and are disposed to do. I argue in this essay that the normative and descriptive approaches are at odds and that we should not expect a single concept of human nature to play both roles. Furthermore, there are deep problems with normative accounts. They often ignore or contradict the contemporary scientific worldview, and they often merely reflect biases about how we ought to be and what we ought to do. Human nature in this sense becomes politicized and serves in arguments about the moral status of issues like homosexuality, abortion, or biomedical enhancement. Because of the problems inherent in normative notions of human nature, I offer a descriptive alternative. My alternative attempts to align the scientific study of the human with human nature. (shrink)

Human nature is frequently evoked to characterize our species and describe how it differs from others. But how should we understand this concept? What is the nature of a species? Some take our nature to be an essence and argue that because humans lack an essence, they also lack a nature. Others argue for non-essentialist ways of understanding human nature, which usually aim to provide criteria for sorting human traits into one of two bins, the one belonging to our nature (...) and the other outside our nature. This Element argues that both the essentialist and trait bin approaches are misguided. Instead, the author develops a trait cluster account of human nature, which holds that human nature is based on the distribution of our traits over our (actual and possible) life histories. One benefit of this account is that it aligns human nature with the human sciences, rendering the central concern of the human sciences to be the study of human nature. (shrink)

Millions of scientific articles are published each year, making it difficult to stay abreast of advances within even the smallest subdisciplines. Traditional approaches to the study of science, such as the history and philosophy of science, involve closely reading a relatively small set of journal articles. And yet many questions benefit from casting a wider net: Is most scientific change gradual or revolutionary? What are the key sources of scientific novelty? Over the past several decades, a massive effort to digitize (...) the academic literature and equip computers with algorithms that can distantly read and analyze a digital database has taken us one step closer to answering these questions. The Dynamics of Science brings together a diverse array of contributors to examine the largely unexplored computational frontiers of history and philosophy of science. Together, they reveal how tools and data from automated textual analysis, or machine "reading," combined with methods and models from game theory and cultural evolutionary theory, can begin to answer fundamental questions about the nature and history of science. (shrink)

Evolutionary biology since Darwin has seen a dramatic entrenchment and elaboration of the role of chance in evolution. It is nearly impossible to discuss contemporary evolutionary theory in any depth at all without making reference to at least some concept of “chance” or “randomness.” Many processes are described as chancy, outcomes are characterized as random, and many evolutionary phenomena are thought to be best described by stochastic or probabilistic models. Chance is taken by various authors to be central to the (...) understanding of fitness, genetic drift, macroevolution, mutation, foraging theory, and environmental variation, to take but a few examples. And for each of these notions, there are yet more stories to tell. Each weaves itself into the various branches of evolutionary theory in myriad different ways, with a wide variety of effects on the history and current state of life on Earth. Each is grounded in a particular trajectory in the history of philosophy and the history of biology, and has inspired a variety of responses throughout science and culture. This book endeavors to offer a cross-section of biological, historical, philosophical, and theological approaches to understanding chance in evolutionary theory. (shrink)

Fitness is a central concept in evolutionary theory. Just as it is central to biological evolution, so, it seems, it should be central to cultural evolutionary theory. But importing the biological fitness concept to CET is no straightforward task—there are many features unique to cultural evolution that make this difficult. This has led some theorists to argue that there are fundamental problems with cultural fitness that render it hopelessly confused. In this essay, we defend the coherency of cultural fitness against (...) those who call it into doubt. (shrink)

We introduce here evoText, a new tool for automated analysis of the literature in the biological sciences. evoText contains a database of hundreds of thousands of journal articles and an array of analysis tools for generating quantitative data on the nature and history of life science, especially ecology and evolutionary biology. This article describes the features of evoText, presents a variety of examples of the kinds of analyses that evoText can run, and offers a brief tutorial describing how to use (...) it. (shrink)

There are three related criteria that a concept of fitness should be able to meet: it should render the principle of natural selection non-tautologous and it should be explanatory and predictive. I argue that for fitness to be able to fulfill these criteria, it cannot be a property that changes over the course of an individual's life. Rather, I introduce a fitness concept--Block Fitness--and argue that an individual's genes and environment fix its fitness in such a way that each individual's (...) fitness has a fixed value over its lifetime. (shrink)

In this essay I examine a well-known articulation of human nature skepticism, a paper by Hull. I then review a recent reply to Hull by Machery, which argues for an account of human nature that he claims is both useful and scientifically robust. I challenge Machery’s account and introduce an alternative account—the “life-history trait cluster” conception of human nature—that I hold is scientifically sound and makes sense of our intuitions about—and desiderata for—human nature.

Homology is a biological sameness relation that is purported to hold in the face of changes in form, composition, and function. In spite of the centrality and importance of homology, there is no consensus on how we should understand this concept. The two leading views of homology, the genealogical and developmental accounts, have significant shortcomings. We propose a new account, the hierarchical-dependency account of homology, which avoids these shortcomings. Furthermore, our account provides for continuity between special, general, and serial homology.

The study of animal culture is a flourishing field, with culture being recorded in a wide range of taxa, including non-human primates, birds, cetaceans, and rodents. In spite of this research, however, the concept of culture itself remains elusive. There is no universally assented to concept of culture, and there is debate over the connection between culture and related concepts like tradition and social learning. Furthermore, it is not clear whether culture in humans and culture in non-human animals is really (...) the same thing, or merely loose analogues that go by the same name. The purpose of this paper is to explicate core desiderata for a concept of culture and then to construct a concept that meets these desiderata. The paper then applies this concept in both humans and non-human animals. (shrink)

In this paper, I argue (contra some recent philosophical work) that an objective distinction between natural selection and drift can be drawn. I draw this distinction by conceiving of drift, in the most fundamental sense, as an individual-level phenomenon. This goes against some other attempts to distinguish selection from drift, which have argued either that drift is a population-level process or that it is a population-level product. Instead of identifying drift with population-level features, the account introduced here can explain these (...) population-level features based on a property that I label driftability. Additionally, this account shows that biology’s “first law”—the Principle of Drift (Brandon, J Phil 102(7):319–335 2006)—is not a foundational law, but is a consequence of driftability. (shrink)

One contentious debate in the philosophy of biology is that between the statisticalists and causalists. The former understand core evolutionary concepts like fitness and selection to be mere statistical summaries of underlying causal processes. In this view, evolutionary changes cannot be causally explained by selection or fitness. The causalist side, on the other hand, holds that populations can change in response to selection—one can cite fitness differences or driftability in causal explanations of evolutionary change. But, on the causalist side, it (...) is often not clear how, precisely, one should understand these causes. Thus, much more could be said about what sort of causes fitness and driftability are. In this paper, I borrow Dretske's distinction between structuring and triggering causes and I suggest that fitness and driftability are structuring causes of evolution. (shrink)

Innovation is a key component of most definitions of culture and intelligence. Additionally, innovations may affect a species' ecology and evolution. Nonetheless, conceptual and empirical work on innovation has only recently begun. In particular, largely because the existing operational definition (first occurrence in a population) requires long-term studies of populations, there has been no systematic study of innovation in wild animals. To facilitate such study, we have produced a new definition of innovation: Innovation is the process that generates in an (...) individual a novel learned behavior that is not simply a consequence of social learning or environmental induction. Using this definition, we propose a new operational approach for distinguishing innovations in the field. The operational criteria employ information from the following sources: (1) the behavior's geographic and local prevalence and individual frequency; (2) properties of the behavior, such as the social role of the behavior, the context in which the behavior is exhibited, and its similarity to other behaviors; (3) changes in the occurrence of the behavior over time; and (4) knowledge of spontaneous or experimentally induced behavior in captivity. These criteria do not require long-term studies at a single site, but information from multiple populations of a species will generally be needed. These criteria are systematized into a dichotomous key that can be used to assess whether a behavior observed in the field is likely to be an innovation. (shrink)

The propensity interpretation of fitness (PIF) is commonly taken to be subject to a set of simple counterexamples. We argue that three of the most important of these are not counterexamples to the PIF itself, but only to the traditional mathematical model of this propensity: fitness as expected number of offspring. They fail to demonstrate that a new mathematical model of the PIF could not succeed where this older model fails. We then propose a new formalization of the PIF that (...) avoids these (and other) counterexamples. By producing a counterexample-free model of the PIF, we call into question one of the primary motivations for adopting the statisticalist interpretation of fitness. In addition, this new model has the benefit of being more closely allied with contemporary mathematical biology than the traditional model of the PIF. (shrink)

Philosophy of science is expanding via the introduction of new digital data and tools for their analysis. The data comprise digitized published books and journal articles, as well as heretofore unpublished material such as images, archival text, notebooks, meeting notes, and programs. The growth in available data is matched by the extensive development of automated analysis tools. The variety of data sources and tools can be overwhelming. In this article, we survey the state of digital work in the philosophy of (...) science, showing what kinds of questions can be answered and how one can go about answering them. (shrink)

A major debate in the philosophy of biology centers on the question of how we should understand the causal structure of natural selection. This debate is polarized into the causal and statistical positions. The main arguments from the statistical side are that a causal construal of the theory of natural selection's central concept, fitness, either (i) leads to inaccurate predictions about population dynamics, or (ii) leads to an incoherent set of causal commitments. In this essay, I argue that neither the (...) predictive inaccuracy nor the incoherency arguments successfully undermine the causal account of fitness. 1 Introduction2 The Importance of Trait Fitness3 Trait Fitness is not a Silver Bullet4 The Fundamental Incoherency Argument5 Car Racing and Trait Fitness Reversals6 Population Subdivisions and Evolution7 The STP and the Argument for the Incoherency of the Causal Account of Fitness8 Conclusions. (shrink)

The validity and utility of the proximate-ultimate distinction in biology have recently been under debate. Opponents of the distinction argue that it rules out individual-level organismic processes from evolutionary explanations, thereby leading to an unfounded separation between organismic causation and evolutionary causation. Proponents of the proximate-ultimate distinction, on the other hand, argue that it serves an important epistemological role in forming different kinds of explanation-seeking questions in biology. In this paper we offer an interpretation the proximate-ultimate distinction not only as (...) a means of forming explanation-seeking questions, but also as a distinction that can help highlight the way in which individual-level organismic processes can be evolutionary causes. We do this by interpreting the distinction between proximate and ultimate causes as a distinction between structuring and triggering causes. (shrink)

Biological fitness is a foundational concept in the theory of natural selection. Natural selection is often defined in terms of fitness differences as “any consistent difference in fitness (i.e., survival and reproduction) among phenotypically different biological entities” (Futuyma 1998, 349). And in Lewontin’s (1970) classic articulation of the theory of natural selection, he lists fitness differences as one of the necessary conditions for evolution by natural selection to occur. Despite this foundational position of fitness, there remains much debate over the (...) nature of fitness, especially whether fitness differences can truly be said to cause evolutionary change. In recent years these debates have crystalized into two camps: (1) causalists, who see fitness differences as being one of the causes of evolutionary change, and (2) statisticalists, who deny the causal efficacy of fitness and instead hold that “fitness is a mere statistical, noncausal property of trait types” (Walsh 2010, 148). (shrink)

Culture in humans connotes tradition, norms, ritual, technology, and social learning, but also cultural events like operas or gallery openings. Culture is in part about what we do, but also sometimes about what we ought to do. Human culture is inextricably intertwined with language and much of what we learn and transmit to others comes through written or spoken language. Given the complexities of human culture, it might seem that we are the only species that exhibits culture. How, then, are (...) we to make sense of culture in animals? The study of animal culture is a booming research area. Culture is said to occur in a wide range of vertebrates from our close kin, chimpanzees and orangutans, to more distant relatives like rats and whales. Could these studies be misleading in that they are not actually studying culture but simply misapplying the term ‘culture’? Or is what is labeled culture in animals at the core of human culture, so that although human culture is more elaborate than animal culture, it is different in degree, not kind? While it is certainly easy to intentionally define culture in a way that makes it unique to humans, because of the growing field of animal culture, it would be most useful to attempt to offer a definition of culture that makes sense of how it is used by psychologists, biologists, anthropologists, and others who use the term culture in studies of animal behavior. The challenge is to produce a concept that is broad enough to be able to apply across humans and animals, but not be so anemic that it cannot do justice to human culture. Because of this, I will here construct a definition of animal culture and draw out some of its implications. (shrink)

Culture in humans connotes tradition, norms, ritual, technology, and social learning, but also cultural events like operas or gallery openings. Culture is in part about what we do, but also sometimes about what we ought to do. Human culture is inextricably intertwined with language and much of what we learn and transmit to others comes through written or spoken language. Given the complexities of human culture, it might seem that we are the only species that exhibits culture. How, then, are (...) we to make sense of culture in animals? The study of animal culture is a booming research area. Culture is said to occur in a wide range of vertebrates from our close kin, chimpanzees and orangutans, to more distant relatives like rats and whales. Could these studies be misleading in that they are not actually studying culture but simply misapplying the term ‘culture’? Or is what is labeled culture in animals at the core of human culture, so that although human culture is more elaborate than animal culture, it is different in degree, not kind? While it is certainly easy to intentionally define culture in a way that makes it unique to humans, because of the growing field of animal culture, it would be most useful to attempt to offer a definition of culture that makes sense of how it is used by psychologists, biologists, anthropologists, and others who use the term culture in studies of animal behavior. The challenge is to produce a concept that is broad enough to be able to apply across humans and animals, but not be so anemic that it cannot do justice to human culture. Because of this, I will here construct a definition of animal culture and draw out some of its implications. (shrink)

In this commentary on Lewens, I argue that although his criticisms of Machery's conception of human nature are sound, I disagree with his conclusion that human nature cannot inform us regarding issues of human enhancement. I introduce a framework for understanding human nature, the “life history trait cluster account,” which aligns the concept of human nature with the human sciences and allows human nature to inform questions of human enhancement.

Reciprocal altruism was originally formulated in terms of individual selection and most theorists continue to view it in this way. However, this interpretation of reciprocal altruism has been challenged by Sober and Wilson (1998). They argue that reciprocal altruism (as well as all other forms of altruism) evolves by the process of group selection. In this paper, we argue that the original interpretation of reciprocal altruism is the correct one. We accomplish this by arguing that if fitness attaches to (at (...) minimum) entire life cycles, then the kind of fitness exchanges needed to form the group-level in such situations is not available. Reciprocal altruism is thus a result of individual selection and when it evolves, it does so because it is individually advantageous. (shrink)

Questions about what human nature is and how we can learn about it are difficult to answer. They are difficult not just because humans are complex creatures whose behavior is deeply embedded in the cultural environment that they are a part of, but also because it is not obvious what a concept of human nature is supposed to do or what it is for. The concept of human nature is often used as a normative concept, one that can serve as (...) a guide to action, showing us how we ought to behave. Less commonplace is an approach that seeks a descriptive account of human nature, one that characterizes what humans do and are disposed to do. I argue in this essay that the normative and descriptive approaches are at odds and that we should not expect a single concept of human nature to play both roles. Furthermore, there are deep problems with normative accounts. They often ignore or contradict the contemporary scientific worldview, and they often merely reflect biases about how we ought to be and what we ought to do. Human nature in this sense becomes politicized and serves in arguments about the moral status of issues like homosexuality, abortion, or biomedical enhancement. Because of the problems inherent in normative notions of human nature, I offer a descriptive alternative. My alternative attempts to align the scientific study of the human with human nature. (shrink)

There is clearly a plurality of forms of altruism. Classically, biological altruism is distinguished from psychological altruism. Recent discussions of altruism have attempted to distinguish even more forms of altruism. I will focus on three altruism concepts, biological altruism, psychological altruism, and helping altruism. The questions I am concerned with here are, first, how should we understand these concepts? and second, what relationship do these concepts bear to one another? In particular, is there an essence to altruism that unifies these (...) concepts? I suggest that while there is no essence to altruism, this does not mean that the array of altruism concepts is completely disunified. Instead, I propose we place all the concepts into a common framework-an altruism space-that could lead to new questions about how this space can be filled. (shrink)

In this paper, we distinguish two different approaches to cultural evolution. One approach is meme-centered, the other organism-centered. We argue that in situations in which the meme- and organism-centered approaches are competing alternatives, the organism-centered approach is in many ways superior. Furthermore, the organism-centered approach can go a long way toward understanding the evolution of institutions. Although the organism-centered approach is preferable for a broad class of situations, we do leave room for super-organismic (group based) or sub-organismic (meme-based) explanations of (...) some cultural phenomena. (shrink)

This paper argues that there is a general constraint on the evolution of culture. This constraint – what I am calling the Fundamental Constraint – must be satisfied in order for a cultural system to be adaptive. The Fundamental Constraint is this: for culture to be adaptive there must be a positive correlation between the fitness of cultural variants and their fitness impact on the organisms adopting those variants. Two ways of satisfying the Fundamental Constraint are introduced, structural solutions and (...) evaluative solutions. Because of the limitations on these solutions, this constraint helps explain why there is not more culture in nature, why the culture that does exist has the form it has, and why complex, cumulative culture is restricted to the human species. (shrink)

Population-level theories of evolution—the stock and trade of population genetics—are statistical theories par excellence. But what accounts for the statistical character of population-level phenomena? One view is that the population-level statistics are a product of, are generated by, probabilities that attach to the individuals in the population. On this conception, population-level phenomena are explained by individual-level probabilities and their population-level combinations. Another view, which arguably goes back to Fisher but has been defended recently, is that the population-level statistics are sui (...) generis, that they somehow emerge from the underlying deterministic behavior of the individuals composing the population. Walsh et al. label this the statistical interpretation. We are not willing to give them that term, since everyone will admit that the population-level theories of evolution are statistical, so we will call this the emergentist statistical interpretation. Our goals are to show that: This interpretation is based on gross factual errors concerning the practice of evolutionary biology, concerning both what is done and what can be done; its adoption would entail giving up on most of the explanatory and predictive projects of evolutionary biology; and finally a rival interpretation, which we will label the propensity statistical interpretation succeeds exactly where the emergentist interpretation fails. (shrink)

Fitness is a central theoretical concept in evolutionary theory. Despite its importance, much debate has occurred over how to conceptualize and formalize fitness. One point of debate concerns the roles of organismic and trait fitness. In a recent addition to this debate, Elliott Sober argues that trait fitness is the central fitness concept, and that organismic fitness is of little value. In this paper, by contrast, we argue that it is organismic fitness that lies at the bases of both the (...) conceptual role of fitness, as well as its role as a measure of evolutionary dynamics. (shrink)

Recent evolutionary perspectives on guilt tend to focus on how guilt functions as a means for the individual to self-regulate behavior and as a mechanism for reinforcing cooperative tendencies. While these accounts highlight important dimensions of guilt and provide important insights into its evolutionary emergence, they pay scant attention to the large empirical literature on its maladaptive effects on individuals. This paper considers the nature of guilt, explores its biological function, and provides an evolutionary perspective on whether it is an (...) individual-level or group selected trait. After surveying philosophical and psychological analyses of guilt, we consider which psychological mechanisms underlie the capacity to experience and act from guilt and whether they point to an emergence of guilt in early humans or to guilt having a longer phylogenetic history. Because guilt is a characteristically social emotion, we then examine its contemporary role in social and legal contexts, which may p... (shrink)

"Correlation is not causation" is one of the mantras of the sciences—a cautionary warning especially to fields like epidemiology and pharmacology where the seduction of compelling correlations naturally leads to causal hypotheses. The standard view from the epistemology of causation is that to tell whether one correlated variable is causing the other, one needs to intervene on the system—the best sort of intervention being a trial that is both randomized and controlled. In this paper, we argue that some purely correlational (...) data contains information that allows us to draw causal inferences: statistical noise. Methods for extracting causal knowledge from noise provide us with an alternative to randomized controlled trials that allows us to reach causal conclusions from purely correlational data. (shrink)

Fitness plays many roles throughout evolutionary theory, from a measure of populations in the wild to a central element in abstract theoretical presentations of natural selection. It has thus been the subject of an extensive philosophical literature, which has primarily centered on the way to understand the relationship between fitness values and reproductive outcomes. If fitness is a probabilistic or statistical quantity, how is it to be defined in general theoretical contexts? How can it be measured? Can a single conceptual (...) model for fitness be offered that applies in all biological cases, or must fitness measures be case-specific? Philosophers have explored these questions over the last several decades, largely in the context of an influential definition of fitness proposed in the late 1970s: the propensity interpretation. This interpretation as first described undeniably suffers from significant difficulties, and debate regarding the tenability of amendments and alternatives to it remains unsettled. (shrink)

There is clearly a plurality of forms of altruism. Classically, biological altruism is distinguished from psychological altruism. Recent discussions of altruism have attempted to distinguish even more forms of altruism. I will focus on three altruism concepts, biological altruism, psychological altruism, and helping altruism. The questions I am concerned with here are, first, how should we understand these concepts? and second, what relationship do these concepts bear to one another? In particular, is there an essence to altruism that unifies these (...) concepts? I suggest that while there is no essence to altruism, this does not mean that the array of altruism concepts is completely disunified. Instead, I propose we place all the concepts into a common framework--an altruism space--that could lead to new questions about how this space can be filled. (shrink)

Guilt poses a unique evolutionary problem. Unlike other dysphoric emotions, it is not immediately clear what its adaptive significance is. One can imagine thriving despite or even because of a lack of guilt. In this article, we review solutions offered by Scott James, Richard Joyce, and Robert Frank and show that although their solutions have merit, none adequately solves the puzzle. We offer an alternative solution, one that emphasizes the role of empathy and posttransgression behavior in the evolution of guilt. (...) Our solution, we contend, offers a better account of why guilt evolved to play its distinctive social role. (shrink)

In multicellular organisms, cells are frequently programmed to die. This makes good sense: cells that fail to, or are no longer playing important roles are eliminated. From the cell’s perspective, this also makes sense, since somatic cells in multicellular organisms require the cooperation of clonal relatives. In unicellular organisms, however, programmed cell death poses a difficult and unresolved evolutionary problem. The empirical evidence for PCD in diverse microbial taxa has spurred debates about what precisely PCD means in the case of (...) unicellular organisms. In this article, we survey the concepts of PCD in the literature and the selective pressures associated with its evolution. We show that definitions of PCD have been almost entirely mechanistic and fail to separate questions concerning what PCD fundamentally is from questions about the kinds of mechanisms that realize PCD. We conclude that an evolutionary definition is best able to distinguish PCD from closely related phenomena. Specifically, we define “true” PCD as an adaptation for death triggered by abiotic or biotic environmental stresses. True PCD is thus not only an evolutionary product but must also have been a target of selection. Apparent PCD resulting from pleiotropy, genetic drift, or trade-offs is not true PCD. We call this “ersatz PCD.”. (shrink)

The levels of selection debate is generally taken to be a debate about how natural selection can occur at the various levels of biological organization. In this paper, we argue that questions about levels of selection should be analyzed separately from questions about levels of organization. In the deflationary proposal we defend, all that is necessary for multilevel selection is that there are cases in which particles are nested in collectives, and that both the collectives and the particles that compose (...) them each separately undergo natural selection. We argue that adopting this deflationary account helps to disentangle the levels of selection and the levels of organization, and thereby contributes to advancing the levels of selection debate. (shrink)

The commentaries have both drawn out the implications of, and challenged, our definition and operationalization of innovation. In this response, we reply to these concerns, discuss the differences between our operationalization and the preexisting operationalization if innovation, and make suggestions for the advancement of the challenging and exciting field of animal innovation.

Conceptions of human nature fall under two broad categories, trait bin accounts and trait cluster accounts. Trait bin accounts take there to be a special bin of traits, one composed of all and only those traits constituting our nature. For those arguing for a trait bin account of human nature, the challenge is to articulate what it is that marks a trait as being in or outside of the bin. For some, the bin is filled by the traits essential to (...) being human. Others, such as Machery in his contribution to this volume, offer a non-essentialist trait bin conception of human nature. In this chapter, I argue that trait bin approaches to human nature are misguided, that there is no good way of dividing human traits into those that are a part of our nature and those that are not. Instead, I argue for a trait cluster account, which sees human nature not as a special bin of traits, but as the relationship among traits. Under this account, human nature lies in the patterns of trait expression within and across human life histories. This account does a superior job characterizing what humans are like and aligning human nature with the human sciences. (shrink)

Niche construction theory concerns how organisms can change selection pressures by altering the feature–factor relationship between themselves and their environment. These alterations are standardly understood to be brought about through two kinds of organism–environment interaction: perturbative and relocational niche construction. We argue that a reconceptualization is needed on the grounds that if a niche is understood as the feature–factor relationship, then there are three fundamental ways in which organisms can engage in niche construction: constitutive, relational, and external niche construction. We (...) further motivate our reconceptualization by showing some examples of organismic activities that fall outside of the current categorization of niche construction, but nonetheless should be included. We end by discussing two objections to niche construction and show how our reconceptualization helps to undercut these objections. 1Introduction2Niche Construction Theory 2.1The standard account of niche construction2.2Two problems with the standard account of niche construction3Three Kinds of Niche Construction 3.1Constitutive niche construction3.2Relational niche construction3.3External niche construction4Conceptual Improvement on Niche Construction Theory 4.1Constitutive niche construction4.2Relational niche construction4.3External niche construction5The Status of Niche Construction Theory within Evolutionary Theory 5.1Is niche construction a helpful addition to evolutionary theory?5.2Is niche construction an evolutionary process?6Conclusion. (shrink)

Organismal death is foundational to the evolution of life, and many biological concepts such as natural selection and life history strategy are so fashioned only because individuals are mortal. Organisms, irrespective of their organization, are composed of basic functional units—cells—and it is our understanding of cell death that lies at the heart of most general explanatory frameworks for organismal mortality. Cell death can be exogenous, arising from transmissible diseases, predation, or other misfortunes, but there are also endogenous forms of death (...) that are sometimes the result of adaptive evolution. These endogenous forms of death—often labeled programmed cell death, PCD—originated in the earliest cells and are maintained across the tree of life. Here, we consider two problematic issues related to PCD (and cell mortality generally). First, we trace the original discoveries of cell death from the nineteenth century and place current conceptions of PCD in their historical context. Revisions of our understanding of PCD demand a reassessment of its origin. Our second aim is thus to structure the proposed origin explanations of PCD into coherent arguments. In our analysis we argue for the evolutionary concept of PCD and the viral defense-immunity hypothesis for the origin of PCD. We suggest that this framework offers a plausible account of PCD early in the history of life, and also provides an epistemic basis for the future development of a general evolutionary account of mortality. (shrink)

Claims that our species is an “evolutionary success” typically do not feature prominently in academic articles. However, they do seem to be a recurring trope in science popularization. Why do we seem to be attracted to viewing human evolution through the lense of “success”? In this chapter we discuss how evolutionary success has both causal-descriptive and ethical-normative components, and how its ethical status is ambiguous, with possible hints of anthropocentrism. We also place the concept of “success” in a wider context (...) of biological thought, contrasting it with two other value-laden concepts: evolutionary progress and human uniqueness. Claiming the human species to be an evolutionary success is ostensibly grounded in metrics such as the dominance or the size of the human population, but often goes beyond this, suggesting that humans are a unique species or the pinnacle of evolutionary progress. (shrink)

In this paper, we distinguish two different approaches to cultural evolution. One approach is meme-centered, the other organism-centered. We argue that in situations in which the meme- and organism-centered approaches are competing alternatives, the organism-centered approach is in many ways superior. Furthermore, the organism-centered approach can go a long way toward understanding the evolution of institutions. Although the organism-centered approach is preferable for a broad class of situations, we do leave room for super-organismic or sub-organismic explanations of some cultural phenomena.

Some unpleasant emotions, like fear and disgust, appear straightforwardly susceptible to evolutionary explanation on account of the benefits they seem to provide to individuals. But guilt is more puzzling in this respect. Like other unpleasant emotions, guilt is often associated with a host of negative effects on the individual, such as psychological suffering and social withdrawal. Moreover, many guilt-induced behaviors, such as revealing one’s offenses and placing oneself before the mercy of others, could levy a cost to individuals that is (...) not outweighed by guilt’s benefits. Supposing there is an evolutionary story to tell about the origins of guilt, the question is how such negative effects were sufficiently outweighed by the potential fitness payoffs that guilt might have yielded to individuals. In this article, we consider which forms of evolution could have resulted in guilt, and whether current evidence can tell us which form of evolution most likely occurred. (shrink)

Adaptationism is often taken to be the thesis that most traits are adaptations. In order to assess this thesis, it seems we must be able to establish either an exhaustive set of all traits or a representative sample of this set. Either task requires a more systematic and principled way of individuating traits than is currently available. Moreover, different trait individuation criteria can make adaptationism turn out true or false. For instance, individuation based on natural selection may render adaptationism true, (...) but may do so by presupposing adaptationism. In this paper, we show how adaptationism depends on trait individuation and that the latter is an open and unsolved problem. (shrink)

What does it mean for our species—or for any species—to be successful? Human Success: Evolutionary Origins and Ethical Implications examines the concept of human success from a variety of disciplinary perspectives, with contributions from leading paleobiologists, anthropologists, geologists, philosophers of science, and ethicists. It tells the tale of how the human species grew in success-linked metrics, such as population size and geographical range, and how it came to dominate ecological systems across the globe. It explores how culture, technology, and creativity (...) have contributed to human success. However, there is a darker side of human success, as has become apparent in a world affected by climate change and the destruction of biodiversity. This leads us to ask whether the human species can really be called successful, and what our future success will look like in terms of our bodies, minds, morals, and our place in the universe. The essays in this book probe us to reflect on what has led to our apparent evolutionary success—and, most important, what this success implies for the future of our species. (shrink)

The dynamics of epiphytic bryophyte communities following natural and human disturbance have rarely been quantified. We describe the response of bryophyte communities on bigleaf maple trees in Olympia, Washington, following their experimental removal. Approximately 8% of the exposed area was recolonized by bryophytes 1 year after clearing, and 27% after 3 years. Lateral encroachment from bryophytes on the sides of the 20-cm-long plots accounted for 75% of this recolonization, with growth from residual plant parts or aerially dispersed diaspores accounting for (...) the remaining 25%. Though it was not possible to distinguish between the latter two sources of cover, the number of clear de novo colonization events over the course of the year was low. Disturbance appeared to reduce bryophyte diversity at this successional stage, as alpha and gamma diversity remained low after 1 year and had not recovered after 3 years. Reflecting the preponderance of lateral encroachment as the mechanism for recolonization, disturbance size may significantly affect the time needed to recolonize disturbed branch substrates. In addition to contributing to ecologists' understanding of processes of succession, these experiments may help to develop sustainable practices for moss-harvesting in the Pacific Northwest.Key words: succession, bryophytes, epiphytes, Acer macrophyllum, recolonization, canopy studies. (shrink)

Programmed cell death (PCD) in unicellular organisms is in some instances an altruistic trait. When the beneficiaries are clones or close kin, kin selection theory may be used to explain the evolution of the trait, and when the trait evolves in groups of distantly related individuals, group or multilevel selection theory is invoked. In mixed microbial communities, the benefits are also available to unrelated taxa. But the evolutionary ecology of PCD in communities is poorly understood. Few hypotheses have been offered (...) concerning the community role of PCD despite its far-reaching effects. The hypothesis we consider here is that PCD is a black queen. The Black Queen Hypothesis (BQH) outlines how public goods arising from a leaky function are exploited by other taxa in the community. Black Queen (BQ) traits are essential for community survival, but only some members bear the cost of possessing them, while others lose the trait In addition, BQ traits have been defined in terms of adaptive gene loss, and it is unknown whether this has occurred for PCD. Our conclusion is that PCD fulfils the two most important criteria of a BQ (leakiness and costliness), but that more empirical data are needed for assessing the remaining two criteria. In addition, we hold that for viewing PCD as a BQ, the original BQH needs to include social traits. Thus, despite some empirical and conceptual shortcomings, the BQH provides a helpful avenue for investigating PCD in microbial communities. (shrink)