This article discusses the contribution to evolutionary theory of Leonard Darwin, the eighth child of Charles Darwin. By analysing the correspondence Leonard Darwin maintained with Ronald Aylmer Fisher in conjunction with an assessment of his books and other written works between the 1910s and 1930s, this article argues for a more prominent role played by him than the previously recognised in the literature as an informal mentor of Fisher. The paper discusses Leonard’s efforts to amalgamate Mendelism with both Eugenics and (...) Darwinism in order for the first to base their policies on new scientific developments and to help the second in finding a target for natural selection. Without a formal qualification in biological sciences and as such mistrusted by some “formal” scientists, Leonard Darwin engaged with key themes of Darwinism such as mimicry, the role of mutations on speciation and the process of genetic variability, arriving at important conclusions concerning the usefulness of Mendelian genetics for his father’s theory. (shrink)

Darwin’s insight that species are mutable, and descent, and origin by means of natural selection is one of the most widely acknowledged strategies for the origin of species and their survival in nature. In his famous contribution, however, Darwin also writes that he is convinced that “... Natural Selection has been the main but not exclusive means of modification ” (Darwin in The origin of species. Oxford Univeristy Press, Oxford, p. 7, 1996 ). This research suggests robustness as another fundamental (...) strategy for survival in nature. The paper does not contradict the popular view, which usually sees robustness as a feature making systems fault-tolerant, thereby focusing on the identification of strategies and techniques for making systems robust (i.e., how to achieve robustness). The paper rather extends this view with an interpretation resting on the question—WHY is robustness omnipresent in the world around us? From this point of view, robustness is interpreted as a fundamental mechanism that is in place because of another fundamental feature in nature—the design and use of sub-optimal systems. The paper argues that, in a sense, nature under-specifies systems but compensates for this by providing systems with various degrees of robustness. We believe that this interpretation may lead to fundamentally new design approaches and insights in several fields. (shrink)

The human adventure in education is one of imperfect expression, punctuated by moments of insight. Education cultivates these epiphanies and nurtures their possible continuation. But even without major or minor insights, education cultivates the appreciation of the good, the beautiful, and the true. An experimentalist's sensibility lies amid the humanist's grasp of the myriad ways of trying to understand our existence. To bridge discourse is to appreciate the languages of other cultures, which reveal the nuances of life and experience.

This article answers several calls—coming as well from corporate governance practitioners as from corporate governance researchers—concerning the possibility of complying simultaneously with requirements of innovation and ethics. Revealing the long-term orientation as the variable which permits us to link the principal goal of organization, being “survival,” with innovation and ethic, the article devises a framework for incorporating ethics into a company’s processes and strategies for innovation. With the principal goal of organizations being “survival” in the long-term, it is assumed that (...) innovation is necessary in order to realize a going concern. Firms that do not innovate and adapt to rapidly changing business environments are less likely to be sustainable. Thus, it is in a business’ best interests to adopt an innovation process for long-term success. We posit that there are two simultaneous sources of innovation and change that are unavoidable and embedded in the corporate landscape. First, we argue for genetically embedded, Darwinian explanations for adaptations that enable an entity’s survival. This view is combined with more conventional, social science explanations for change. Our new, comprehensive model of the governance of innovation processes hinges on the one hand on an organization’s long-term orientation, which we argue, is not possible without a consideration of an ethical dimension. On the other hand, the model employs, for the first time, the concept of duality, in order to make the positive coexistence of innovation and ethic analytically visible. Guided by this concept the roots of the ethic within innovation are traced from both natural science forces for change, and cultural pressures operating on members of an organization. We present our Integrated Causal Model of Innovation and propose theoretical relationships that will generate numerous avenues for future research in the field, and help managers to reorient their governance strategies. (shrink)

This article answers several calls—coming as well from corporate governance practitioners as from corporate governance researchers—concerning the possibility of complying simultaneously with requirements of innovation and ethics. Revealing the long-term orientation as the variable which permits us to link the principal goal of organization, being “survival,” with innovation and ethic, the article devises a framework for incorporating ethics into a company’s processes and strategies for innovation. With the principal goal of organizations being “survival” in the long-term, it is assumed that (...) innovation is necessary in order to realize a going concern. Firms that do not innovate and adapt to rapidly changing business environments are less likely to be sustainable. Thus, it is in a business’ best interests to adopt an innovation process for long-term success. We posit that there are two simultaneous sources of innovation and change that are unavoidable and embedded in the corporate landscape. First, we argue for genetically embedded, Darwinian explanations for adaptations that enable an entity’s survival. This view is combined with more conventional, social science explanations for change. Our new, comprehensive model of the governance of innovation processes hinges on the one hand on an organization’s long-term orientation, which we argue, is not possible without a consideration of an ethical dimension. On the other hand, the model employs, for the first time, the concept of duality, in order to make the positive coexistence of innovation and ethic analytically visible. Guided by this concept the roots of the ethic within innovation are traced from both natural science forces for change, and cultural pressures operating on members of an organization. We present our Integrated Causal Model of Innovation and propose theoretical relationships that will generate numerous avenues for future research in the field, and help managers to reorient their governance strategies. (shrink)

Classical pragmatism construed mind as an adaptive organ rooted in biology; biology was not one side and culture on the other. The cognitive systems underlie adaptation in response to the precarious and in the search for the stable and more secure that result in diverse forms of inquiry. Cognitive systems are rooted in action, and classical pragmatism knotted our sense of ourselves in response to nature and our cultural evolution. Cognitive systems should be demythologized away from Cartesian detachment, and towards (...) transactions with others and with nature. (shrink)

Biacentrism has recently gained increasing interest and approval, since it is regarded as the only scientific and hence wholly rational way of under-standing man and his relationships with the environment, and founding an ethics not based on myth. There is thus an assumed or stated need to reduce ethics, aesthetics, politics and religions to paradigms of reference for history and the interactions that maintain the equilibrium of the bio-sphere. Ethics and bioethics share a common identity. The Gaia paradigm and the (...) Neo-Darwinian paradigm, the two biological paradigms currently most in favour, lend themselves equally well to the justification of biocentrism. The Gaia paradigm regards the Earth as a complex living system capable of self-adjustment, yet exposed to the risk of collapse or profound changes mainly due to man's impact on the environment. It gives preference to the synchronic ecological approach and introduces the concepts of non-linear response, regularity, order and finalism. There can thus be no hierarchical differences between organisms, man included, as all are indispensable to this equilibrium. The Neo-Darwinian paradigm accords preference to the dia- chronic approach to evolution and introduces as its causes chance and selection of new forms through the struggle for existence. Finalism is abolished, but a hierachy is retained, since the most evolved forms are heading in the “direction” of evolution, whereas the least fit are eliminated by competition. The two paradigms are in conflict, though united by their insufficiency as the basis of an ethic. Both, in fact, can with equally logical consistency be used in support of widely differing and conflicting religious, ethical and political and socioeconomic models. In other words, the biocentric paradigms, despite the great confidence reposed in them, do not allow a rational choice to be made between the ethical and sociopolitical models proposed by the so-called human sciences, nor do they provide a base for the construction of new models. (shrink)

Abstract One of the most important things that the Darwinian revolution affected is the previous teleological thinking. In particular, the attribution of functions to various entities of the natural world with explanatory pretensions. In this change, his theory of natural selection played an important role. We all agree on that, but the diversity and heterogeneity of the answers that try to explain what Darwin did exactly with functional biology are overwhelming. In this paper I will try to show how Darwin (...) modified previous functional biology. Pre-Darwinian naturalists did not hesitate to attribute functions in which, for example, the traits of one species were in the service of other species. I will try to show that this has consequences on the discussion regarding the nature of functional language, since the main approaches, the systemic and the etiological, do not adequately account for these changes and therefore do not account for the way functional biology regulates the kind of legitimate functions. I will outline a possible new solution to this problem: appropriate functional attributions in Darwinian functional biology could be regulated by a theory or a set of laws that provide the criteria for determining its fundamental concepts. -/- Resumen: Una de las cosas más importantes a las que la revolución darwiniana afectó es el pensamiento teleológico previo. En particular, la atribución de funciones a diversas entidades del mundo natural con pretensiones explicativas. En este cambio, su teoría de la selección natural desempeñó un papel importante. Todos estamos de acuerdo en ello, pero la diversidad y heterogeneidad de las respuestas que tratan de explicar lo que Darwin hizo exactamente con la biología funcional son abrumadoras. En este artículo intentaré mostrar cómo Darwin modificó la biología funcional anterior. Los naturalistas predarwinianos no dudaban en atribuir funciones en las que, por ejemplo, los rasgos de una especie estaban al servicio de otras especies. Intentaré mostrar que esto tiene consecuencias en la discusión sobre la naturaleza del lenguaje funcional, pues los principales enfoques, el sistémico y el etiológico, no dan cuenta adecuadamente de estos cambios y, por tanto, no dan cuenta de la forma en que la biología funcional regula el tipo de funciones legítimas. Esbozaré una posible nueva solución a este problema: las atribuciones funcionales apropiadas en la biología funcional darwiniana podrían estar reguladas por una teoría o un conjunto de leyes que proporcionen los criterios para determinar sus conceptos fundamentales. -/- . (shrink)

Ervin Laszlo's Science and the Akashic Field is vital to our transition from a long epoch of empire building - of the drive to control Earth's resources by fierce competition in a situation of perceived scarcity - to a future of truly cooperative global family. Laszlo's universe is a far cry from the one Western science has taught us and compatible with my own views as a "post-Darwinian" evolution biologist. In fact, no small number of Western scientists today have defected (...) from the official scientific story of How Things Are to create or adopt various versions of the new scientific worldview Laszlo presents - a worldview rooted in older sciences and cultures such as Vedic, yet ultimately not just timely, but futuristic. These new scientific models, integrating ancient and modern knowledge, represent a paradigm shift greater than the Copernican revolution and are crucial to the next stage in humanity's evolution as a planetary species. (shrink)

In this paper we attempt to reconcile two important, current intellectual traditions: Darwinism and social constructionism. We believe that these two schools have important points of contact that have been obscured because each school has feared that the other wanted to put it out of business. We try to show that both traditions have much to of offer psychology, a discipline that has often been too individualistic, too concerned with the private and the subjective. The spirit of American pragmatism can (...) be found in both camps; like the social constructivists, pragmatists focused on social transaction rather than internal happening, and like the Darwinian they were rooted in functionalism and the biological. (shrink)

How is moral thinking, ethics, related to evolutionary theorizing? There are two approaches, epitomized by Charles Darwin who works under the metaphor of the world as a machine, and by Herbert Spencer who works under the metaphor of the world as an organism. Although the author prefers the first approach, the aim of this paper is to give a disinterested account of both approaches.

Francis Collins, the director of the NEH and well-known Christian, has said that agnosticism is a bit of a cop-out. Either be a Christian or be an atheism, but have the guts to make up your mind. I shall argue in a positive way for agnosticism, showing that it can be as vibrant a position as belief or non-belief. It gives you a renewed appreciation of life and the world in which we live.

Modern biology is ambivalent about the notion of evolutionary progress. Although most evolutionists imply in their writings that they still understand large-scale macroevolution as a somewhat progressive process, the use of the term “progress” is increasingly criticized and avoided. The paper shows that this ambivalence has a long history and results mainly from three problems: (1) The term “progress” carries historical, theoretical and social implications which are not congruent with modern knowledge of the course of evolution; (2) An incongruence exists (...) between the notion of progress and Darwin’s theory of selection; (3) It is still not possible to give more than a rudimentary definition of the general patterns that were generated during the macroevolution of organisms. The paper consists of two parts: the first is a historical overview of the roots of the term “progress” in evolutionary biology, the second discusses epistemological, ontological and empirical problems. It is stated that the term has so far served as a metaphor for general patterns generated amongst organisms during evolution. It is proposed that a reformulation is needed to eliminate historically imported implications and that it is necessary to develop a concept for an appropriate empirical description of macroevolutionary patterns. This is the third way between, on the one hand, using the term indiscriminately and, on the other hand, ignoring the general patterns that evolution has produced. (shrink)

La figura de Alfred Russel Wallace dentro de la antropología ha sido escasamente reconocida dentro de la historia de la disciplina. Un punto importante es ubicar al autor dentro de las discusiones antropológicas de la época victoriana, desde su interés temprano como naturalista por historizar a los seres humanos, hasta su labor institucional como el primer presidente de un departamento de antropología en Inglaterra. En ese contexto, el objetivo del trabajo es presentar la visión de Wallace respecto a la antropología (...) física, a partir de su obra antropológica, que incluye referencias al origen de las razas humanas en términos naturalistas, al desarrollo de características físicas distintivas de los seres humanos o a la relación evolutiva entre primates. Con esto, se amplía la perspectiva sobre el desarrollo de la antropología física en el siglo XIX, al abrir el abanico a autores que contribuyeron de manera importante a su desarrollo. (shrink)

The theory and practice of contemporary comparative biology and phylogeny reconstruction (systematics) emphasizes algorithmic aspects but neglects a concern for the evidence. The character data used in systematics to formulate hypotheses of relationships in many ways constitute a black box, subject to uncritical assessment and social influence. Concerned that such a state of affairs leaves systematics and the phylogenetic theories it generates severely underdetermined, we investigate the nature of the criteria of homology and their application to character conceptualization in the (...) context of transformationist and generative paradigms. Noting the potential for indeterminacy in character conceptualization, we conclude that character congruence (the coherence of character statements) relative to a hierarchy is a necessary, but not a sufficient, condition for phylogeny reconstruction. Specifically, it is insufficient due to the lack of causal grounding of character hypotheses. Conceptualizing characters as homeostatic property cluster natural kinds is in accordance with the empirical practice of systematists. It also accounts for the lack of sharpness in character conceptualization, yet requires character identification and re-identification to be tied to causal processes. (shrink)

A long-standing debate has dominated systematic biology and the ontological commitments made by its theories. The debate has contrasted individuals and the part – whole relationship with classes and the membership relation. This essay proposes to conceptualize the hierarchy of higher taxa is terms of a hierarchy of homeostatic property cluster natural kinds (biological species remain largely excluded from the present discussion). The reference of natural kind terms that apply to supraspecific taxa is initially fixed descriptively; the extension of those (...) natural kind terms is subsequently established by empirical investigation. In that sense, classification precedes generalization, and description provides guidance to empirical investigation. The reconstruction of a hierarchy of (homeostatic property cluster) natural kinds is discussed in the light of cladistic methods of phylogeny reconstruction. (shrink)

The dominance of string theory in the research landscape of quantum gravity physics (despite any direct experimental evidence) can, I think, be justified in a variety of ways. Here I focus on an argument from mathematical fertility, broadly similar to Hilary Putnam’s ‘no miracles argument’ that, I argue, many string theorists in fact espouse in some form or other. String theory has generated many surprising, useful, and well-confirmed mathematical ‘predictions’—here I focus on mirror symmetry and the mirror theorem. These predictions (...) were made on the basis of general physical principles entering into string theory. The success of the mathematical predictions are then seen as evidence for the framework that generated them. I shall attempt to defend this argument, but there are nonetheless some serious objections to be faced. These objections can only be evaded at a considerably high (philosophical) price. (shrink)

Biological understanding of human cognitive functions is incomplete because of failure to understand the evolution of complex functions and organisms in general. Here, that failure is attributed to an aspect of the standard neo-Darwinian synthesis, namely commitment to evolution by natural selection of genetic programs in stable environments, a position that cannot easily explain the evolution of complexity. When we turn to consider more realistic, highly changeable environments, however, another possibility becomes clearer. An alternative to genetic programs—dubbed “biogrammars”—is proposed here (...) to deal with complex, changing environments and explain evolving complexity from pre-genetic life to human socio-cognitive functions. (shrink)

While evolutionary thinking is increasingly becoming popular in fields of investigation outside the biological sciences, it remains unclear how helpful it is there and whether it actually yields good explanations of the phenomena under study. Here we examine the ontology of a recent approach to applying evolutionary thinking outside biology, the generalized Darwinism approach proposed by Geoffrey Hodgson and Thorbjørn Knudsen. We examine the ontology of populations in biology and in GD, and argue that biological evolutionary theory sets ontological criteria (...) that GD fails to meet. We suggest two options to revise the population concept in GD: reformulating the concept in terms of inheritance and reproduction such that it comes to pick out individuals similar to evolving populations, or trying to build an adequate population concept on a principle of differential retention instead of differential reproduction. 1 Introduction2 Generalized Darwinism2.1 What is generalized Darwinism?2.2 Darwinian principles3 The Ontology of Generalized Darwinism: What Are Populations?3.1 The population concept of generalized Darwinism3.2 The population concept in evolutionary theory4 Locating Evolving Systems in Generalized Darwinism5 Conclusion. (shrink)

Early nineteenth century systematists sought to describe what they called the Natural System or the Natural Classification. In the nineteenth century, there was no agreement about the basis of observed patterns of similarity between organisms. What did these systematists think they were doing, when they named taxa, proposed relationships between taxa, and arranged taxa into representational schemes? In this paper I explicate Charles Frederic Girard’s (1822–1895) theory and method of systematics. A student of Louis Agassiz, and subsequently (1850–1858) a collaborator (...) with Spencer Baird, Girard claimed that natural classificatory methods do not presuppose either a special creationist or an evolutionary theory of the natural world. The natural system, in Girard’s view, comprises three distinct ways in which organisms can be related to each other. Girard analyzed these relationships, and justified his classificatory methodology, by appeal to his embryological and physiological work. Girard offers an explicit theoretical answer to the question, what characters are evidence for natural classificatory hypotheses? I show that the challenge of simultaneously depicting the three distinct types of relationship led Girard to add a third dimension to his classificatory diagrams. (shrink)

Most research on mate choice in modern societies is based on data that may or may not reflect actual mating behavior (e.g., stated preferences, personal advertisements). In the present study, real-life matings were reported by a large representative sample of men and women (N = 1,133). These data were used to test an evolutionary model in which mate choice is hypothesized to depend on resources potentially contributed to reproduction by each sex. Consistent with the model, it was found that (a) (...) men (but not women) of higher social status acquire more mating partners, suggesting that male status is an important criterion in female choice; (b) women’s (but not men’s) number of partners decreases linearly with age, suggesting that female reproductive potential is an important criterion in male choice; and (c) women (but not men) display a significant relationship between marital dissolution and promiscuity, suggesting that female sexual exclusivity is an important criterion in male choice. These results are discussed in relation to understanding mate choice mechanisms from behavioral data. (shrink)

I argue for the centrality of the concepts of biophysical and human nature in science-and-religion studies, consider five different metaphors, or “visions,” of nature, and explore possibilities and challenges in reconciling them. These visions include (a) evolutionary nature, built on the powerful explanatory framework of evolutionary theory; (b) emergent nature, arising from recent research in complex systems and self-organization; (c) malleable nature, indicating both the recombinant potential of biotechnology and the postmodern challenge to a fixed ontology; (d) nature as sacred, (...) a diffuse popular concept fundamental to cultural analysis; and (e) nature as culture, an admission of epistemological constructivism. These multiple visions suggest the famous story of the blind men and the elephant, in which each man made the classic mistake of part-whole substitution in believing that what he grasped (the tail, for example) represented the elephant as a whole. Indeed, given the inescapability of metaphor, we may have to admit that the ultimate truth about the “elephant” (nature, or the reality toward which science and religion point) is a mystery, and the best we can hope for is to confess the limitations of any particular vision. (shrink)

In “The Origin of Species,” Darwin describes a hypothetical example illustrating that large, slowly reproducing mammals such as the elephant can reach very large numbers if population growth is not affected by regulating factors. The elephant example has since been cited in various forms in a wide variety of books, ranging from educational material to encyclopedias. However, Darwin’s text was changed over the six editions of the book, although some errors in the mathematics persisted throughout. In addition, full details of (...) the problem remained hidden in his correspondence with readers of the Origin. As a result, Darwin’s example is very often misinterpreted, misunderstood or presented as if it were a fact. We show that the population growth of Darwin’s elephant population can be modeled by the Leslie matrix method, which we generalize here to males as well. Darwin’s most often cited figure, about 19 million elephants after 750 years is not a typical outcome, actually a very unlikely result under more realistic, although still hypothetical situations. We provide a recursion formula suggesting that Darwin’s original model corresponds to a tribonacci series, a proof showing that sex ratio is constant over all age classes, and a derivation of a generating function of the sequence. (shrink)

Many of the commentaries cohere around two major points of criticism. The first is that we have omitted discussion of the mechanisms that are assumed to operate at levels 2, 3, and 4.Campbell, Cloak, Dewsbury, Eckberg, Mundinger, Pulliam, Richerson & Boyd, Slobodkin, Simon, Williams, andWahlstenall make comments that bear on this point. The second point is that we have omitted discussion of the fact that "organisms change the environment by their activities" and thereby modify the selection pressures that act on (...) them. Apart from Lewontin, this point has been raised in different forms byBarkow, Chase, Hull, Perzigian, Ruyle, and less directly bySlobodkin. Stemming from these two basic omissions there is a third general criticism. Numerous commentators have pointed out that we have failed to discuss sufficiently either the extent or nature of the constraints that may or may not be operating on supraordinate evolutionary processes as a function of their nested relationships to subordinate evolutionary processes within our scheme. We start by acknowledging these three basic omissions. We agree that they exist and that they are serious. (shrink)

The fundamental tenet of contemporary sociobiology, namely the assumption of a single process of evolution involving the selection of genes, is critically examined. An alternative multiple-level, multiple-process model of evolution is presented which posits that the primary process that operates via selection upon the genes cannot account for certain kinds of biological phenomena, especially complex, learned, social behaviours. The primary process has evolved subsidiary evolutionary levels and processes that act to bridge the gap between genes and these complex behaviours. The (...) subsidiary levels are development, individual animal learning, and socioculture itself. It is argued that individual learning is pivotal to the derivation and biological analysis of culture. The differences between cultural and noncultural societies are stressed. It is concluded that such a multiple-level model of evolution can form the basis for reconciling opposing sides in the sociobiology debate. (shrink)

Sewall Wright introduced the metaphor of evolution on “adaptive landscapes” in a pair of papers published in 1931 and 1932. The metaphor has been one of the most influential in modern evolutionary biology, although recent theoretical advancements show that it is deeply flawed and may have actually created research questions that are not, in fact, fecund. In this paper I examine in detail what Wright actually said in the 1932 paper, as well as what he thought of the matter at (...) the very end of his career, in 1988. While the metaphor is flawed, some of the problems which Wright was attempting to address are still with us today, and are in the process of being reformulated as part of a forthcoming Extended Evolutionary Synthesis. (shrink)

William Bateson (1861-1926) has long occupied a controversial role in the history of biology at the turn of the twentieth century. For the most part, Bateson has been situated as the British translator of Mendel or as the outspoken antagonist of W. F. R. Weldon and Karl Pearson's biometrics program. Less has been made of Bateson's transition from embryologist to advocate for discontinuous variation, and the precise role of British and American influences in that transition, in the years leading up (...) to the publication of his massive Materials for the Study of Variation (1894). In this paper, I first attempt to trace Bateson's development in his early career before turning to search for the development of the moniker "anti-Darwinist" that has been attached to Bateson in well-known histories of the neo-Darwinian Synthesis. (shrink)

William Bateson has long occupied a controversial role in the history of biology at the turn of the twentieth century. For the most part, Bateson has been situated as the British translator of Mendel or as the outspoken antagonist of W. F. R. Weldon and Karl Pearson's biometrics program. Less has been made of Bateson's transition from embryologist to advocate for discontinuous variation, and the precise role of British and American influences in that transition, in the years leading up to (...) the publication of his massive Materials for the Study of Variation. In this paper, I first attempt to trace Bateson's development in his early career before turning to search for the development of the moniker "anti-Darwinist" that has been attached to Bateson in well-known histories of the neo-Darwinian Synthesis. (shrink)

(2013). Money and the Local Economy. World Futures: Vol. 69, Reclaiming Free Enterprise: The Scientific and Human Story, pp. 515-530.

The mental realm seems different to the physical realm; the mental is thought to be dependent on, yet distinct from the physical. But how, exactly, are the two realms supposed to be different, and what, exactly, creates the seemingly insurmountable juxtaposition between the mental and the physical? This review identifies and discusses five marks of the mental, features that set characteristically mental phenomena apart from the characteristically physical phenomena. These five marks (intentionality, consciousness, free will, teleology, and normativity) are not (...) presented as a set of features that define mentality. Rather, each of them is something we seem to associate with phenomena we consider mental, and each of them seems to be in tension with the physical view of reality in its own particular way. It is thus suggested how there is no single mind-body problem, but a set of distinct but interconnected problems. Each of these separate problems is analyzed, and their differences, similarities and connections are identified. This provides a useful basis for future theoretical work on psychology and philosophy of mind, that until now has too often suffered from unclarities, inadequacies, and conflations. (shrink)

In our target article, we argued that there is a profound functional discontinuity between the cognitive abilities of modern humans and those of all other extant species. Unsurprisingly, our hypothesis elicited a wide range of responses from commentators. After responding to the commentaries, we conclude that our hypothesis lies closer to Darwin's views on the matter than to those of many of our contemporaries.