Exaptation

The term exaptation, describing the phenomenon that an existing trait or tool proves to be of new adaptive value in a new context, is flourishing in recent literature from cultural evolution and cognitive archaeology. Yet there also exists an older literature from the nineteenth and twentieth centuries which studied more or less systematically the phenomenon of “change of function” in culture and tool use. Michel Foucault and Ludwig Noiré, who devoted themselves to the history of social institutions and material tools, (...) respectively, occupy an important place among them. This article offers a brief overview of this literature and attempts to show that it provided ideas that remain relevant to current approaches to cognitive archaeology, in particular regarding attempts to understand the impact of technological evolution on the human mind. (shrink)

The dominant theory of the evolution of moral cognition across a variety of fields is that moral cognition is a biological adaptation to foster social cooperation. This chapter argues, to the contrary, that moral cognition is likely an evolutionary exaptation: a form of cognition where neurobiological capacities selected for in our evolutionary history for a variety of different reasons—many unrelated to social cooperation—were put to a new, prosocial use after the fact through individual rationality, learning, and the development and transmission (...) of social norms. This chapter begins with a brief overview of the emerging behavioral neuroscience of moral cognition. It then outlines a novel theory of moral cognition that I have previously argued explains these findings better than alternatives. Finally, it shows how the evidence for this theory of moral cognition and human evolutionary history together suggest that moral cognition is likely not a biological adaptation. Instead, like reading sheet music or riding a bicycle, moral cognition is something that individuals learn to do—in this case, in response to sociocultural norms created in our ancestral history and passed down through the ages to enable cooperative living. (shrink)

To help bridge the explanatory gap of how normativity branched off into morality in the course of evolutionary history, I claim that morality is a form of social normativity, specifically a form of cultural normativity. Furthermore, with the origins of its behavioral capacities rooted in normative practice, morality should be considered as an exaptation, a secondary adaptation shaped through cultural selection and evolution. Cultural selection pressures differ across social groups, as well as various species. Empirical evidence has shown that animals (...) other than humans are capable of normative behavior, and that they can also be subject to processes of cultural transmission. With an inclusive approach to defining social behaviors, I argue that non-human, socio-cultural animals can engage in moral behavior. (shrink)

To help bridge the explanatory gap of how normativity branched off into morality in the course of evolutionary history, I claim that morality is a form of social normativity, specifically a form of cultural normativity. Furthermore, with the origins of its behavioral capacities rooted in normative practice, morality should be considered as an exaptation, a secondary adaptation shaped through cultural selection and evolution. Cultural selection pressures differ across social groups, as well as various species. Empirical evidence has shown that animals (...) other than humans are capable of normative behavior, and that they can also be subject to processes of cultural transmission. With an inclusive approach to defining social behaviors, I argue that non-human, socio-cultural animals can engage in moral behavior. (shrink)

In addition to theorizing about the role and value of mechanisms in scientific explanation or the causal structure of the world, there is a fundamental task of getting straight what a ‘mechanism’ is in the first place. Broadly, this paper is about the challenge of application: the challenge of aligning one's philosophical account of a scientific concept with the manner in which that concept is actually used in scientific practice. This paper considers a case study of the challenge of application (...) as it pertains to the concept of a mechanism: the debate about whether natural selection is a mechanism. By making clear what is and is not at stake in this debate, this paper considers various strategies for dealing with the challenge of application and makes a case for definitional pluralism about mechanism concepts. (shrink)

In On the Genealogy of Morality, Nietzsche sets up an opposition between the ‘naïveté of English biologists’ in their research on the evolution of life and a methodology that records the singularity and the contingency of natural events without introducing any finality: genealogy. Nietzsche shares with these scientists the need to trace the explanation of living beings back to a naturalistic framework liberated from theology, but he questions their linear and progressive conception of the evolution of life. This article explores (...) these two competing biological accounts of life. The first is informed by the adaptationist paradigm, namely the theoretical framework of contemporary ‘English biologists’; the second is elaborated by combining the theories of the palaeontologist Stephen J. Gould with the work of Nietzsche, Foucault and Esposito on life and genealogy. If the former account introduces a positive normative ground— rendering biology a synonym for destiny—the latter runs the risk of being secretly inhabited by a negative normative ground, which prescribes an infinite demand for liberation and transformation. (shrink)

Starting with Aristotle and moving on to Darwin, Marco Solinas outlines the basic steps from the birth, establishment and later rebirth of the traditional view of living beings, and its overturning by evolutionary revolution. The classic framework devised by Aristotle was still dominant in the 17th Century world of Galileo, Harvey and Ray, and remained hegemonic until the time of Lamarck and Cuvier in the 19th Century. Darwin's breakthrough thus takes on the dimensions of an abandonment of the traditional finalistic (...) theory. It was a transition exemplified in the morphological analysis of useless parts, such as the sightless eyes of moles, already discussed by Aristotle, which Darwin used as a crowbar to unhinge the systematic recourse to final causes. With many excerpts, a chronological sequence and an analytical approach, this book follows the course of the two conceptions that have shaped the destiny of life sciences in western culture. (shrink)

The book aims to offer a contribution to the historiographical and conceptual reconfiguration of the evolutionary revolution in the light of the centuries-old tenets of the Aristotelian biological tradition. Darwin’s breakthrough constitutes a thorough overturning of the fixist, essentialist and teleological framework created by Aristotle, a framework still dominant in the 17th Century world of Harvey and Ray, as well as Galileo, and then hegemonic until Linnaeus and Cuvier. This change is exemplified in the morphological analysis of useless parts, such (...) as the sightless eyes of moles, already discussed by Aristotle, and which Darwin used almost like a crowbar to unhinge the systematic recourse to final causes. This is an ancient teleological heritage present in various forms in the concept of natural selection, but by then confined within an eminently historical framework open to randomness. Un contributo alla riconfigurazione storiografica e concettuale della rivoluzione evoluzionistica alla luce della tenuta plurisecolare della tradizione biologica aristotelica. La svolta di Darwin si delinea quale puntuale rovesciamento dell'impianto fissista, essenzialista e teleologico coniato da Aristotele, ancora dominante nel Seicento di Harvey e di Ray, nonostante Galileo, e poi egemone fino a Linneo e Cuvier. Svolta esemplificata dall'analisi morfologica delle parti inutili, come gli occhi ciechi della talpa, tematizzate già da Aristotele, e che Darwin usò quale grimaldello per scardinare il ricorso sistematico alle cause finali. Antica eredità teleologica presente in varie forme nel concetto di selezione naturale, ma ormai calata entro una griglia eminentemente storica e aperta alla casualità. (shrink)

This paper examines the ethological notion of ritualization from the perspective of zoosemiotic studies. Instead of moving within the horizon of traditional semiotic approaches to this phenomenon, my aim is to propose an alternative attempt of modelling based on the linguistic and semiotic concepts of context and contextuality. At the same time, the paper identifies ritualization as a case of exaptation, suggesting the extension of the context-based model within evolutionary biology and the agenda of its semiotic description, namely biosemiotics. At (...) lenght, a potential application of the model is suggested with respect to human ritualization, essentially as a means to prevent inadequate adaptationist considerations. (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)

Abstract: The massive redeployment hypothesis (MRH) is a theory about the functional topography of the human brain, offering a middle course between strict localization on the one hand, and holism on the other. Central to MRH is the claim that cognitive evolution proceeded in a way analogous to component reuse in software engineering, whereby existing components-originally developed to serve some specific purpose-were used for new purposes and combined to support new capacities, without disrupting their participation in existing programs. If the (...) evolution of cognition was indeed driven by such exaptation, then we should be able to make some specific empirical predictions regarding the resulting functional topography of the brain. This essay discusses three such predictions, and some of the evidence supporting them. Then, using this account as a background, the essay considers the implications of these findings for an account of the functional integration of cognitive operations. For instance, MRH suggests that in order to determine the functional role of a given brain area it is necessary to consider its participation across multiple task categories, and not just focus on one, as has been the typical practice in cognitive neuroscience. This change of methodology will motivate (even perhaps necessitate) the development of a new, domain-neutral vocabulary for characterizing the contribution of individual brain areas to larger functional complexes, and direct particular attention to the question of how these various area roles are integrated and coordinated to result in the observed cognitive effect. Finally, the details of the mix of cognitive functions a given area supports should tell us something interesting not just about the likely computational role of that area, but about the nature of and relations between the cognitive functions themselves. For instance, growing evidence of the role of “motor” areas like M1, SMA and PMC in language processing, and of “language” areas like Broca’s area in motor control, offers the possibility for significantly reconceptualizing the nature both of language and of motor control. (shrink)

Three puzzles about self-deception make this mental phenomenon an intriguing explanatory target. The first relates to how to define it without paradox; the second is about how to make sense of self-deception in light of the interpretive view of the mental that has become widespread in philosophy; and the third concerns why it exists at all. In this paper I address the first and third puzzles. First, I define self-deception. Second, I criticize Robert Trivers' attempt to use adaptionist evolutionary psychology (...) to solve the third puzzle (existence). Third, I sketch a theory to replace that of Trivers. Self-deception is not an adaptation, but a spandrel in the sense that Gould and Lewontin give the term: a byproduct of other features of human (cognitive) architecture. Self-deception is so undeniable a fact of human life that if anyone tried to deny its existence, the proper response would be to accuse this person of it. (Allen Wood, 1988). (shrink)

One important difference between adaptive and nonadaptive explanations can be found in the evolutionary sequence of structural and functional modifications. Phylogenetic analysis (cladistics) provides a powerful methodology for distinguishing exaptation from adaptation, by indicating whether character traits have predated, accompanied, or followed evolution of particular functions. Such analysis yields falsifiable hypotheses that can help to distinguish causal relationships from mere correlation.

To understand adaptation (and exaptation), a more comprehensive view of development is required: one beyond a constraining force. Developmental plasticity may be an adaptation by natural selection simultaneously favored (or sometimes in conflict) at multiple levels of biological organization (e.g., cells, individuals, groups, etc.). To understand the interrelationships between developmental plasticity and adaptive evolution I borrow heavily from West-Eberhard (2003) and Frank (1995; 1997). Developmental plasticity facilitates evolution, results in particular patterns of evolutionary change, and may produce exaptations by design (...) rather than by chance. (shrink)

In 1993, biologist Margie Profet captured the attention of the popular press with the publication of her radical thesis: menstruation has a function. Traditional theories, she claims, typically view menstruation as a functionless by-product of cyclic flux. The details of Profet's functional account are similarly radical: she argues that menstruation has been naturally selected to defend the female reproductive tract from sperm-borne pathogens. There are a number of weaknesses in Profet's evolutionary analysis. However, I focus on a set of pragmatic (...) problems that arise prior to any details of her evolutionary account. In arguing for the importance of pragmatic considerations, I draw from the linguistic analyses of Nelson Goodman. I conclude that critical investigation of the evolutionary details of Profet's pathogen defense account will be more feasible if and when biologists more frequently feature the female system of pathogen defense in their inductive generalisations. The system needs to be better entrenched before its functional components, such as menstruation, can be thoroughly investigated. (shrink)

I claim that our desire to be special motivates us to suppose that if we were not God created, we must be self-created. I also claim that Stephen J Gould's claims about punctuated equilibrium, the absence of directional selection, and exaptations, when taken together, lead to kind of secular creationism. I introduce the notion of “adaptive effects” and argue that a focus on the actual physiological and psychological mechanisms that produce adaptations provides a way out of the exaptation dilemma.

It is anthropomorphic to speak of Nature designing adaptations for a specific function, as if with conscious intent. Any effect constitutes an adaptive function if it contributes to survival and to reproduction. Natural selection is blind to what might have been the original function. Mutations arise by purest accident and are selected based on whatever fortuitous effects they might produce.

Since formulating the theory of punctuated equilibria in 1972, a group of prominent evolutionary biologists, geneticists, and paleontologists have contributed towards a significant reinterpretation of the neo-Darwinian image of evolution that had consolidated during the second half of the twentieth century. We believe a research program, which we might define as "evolutionary pluralism" or "post-Darwinism," has been outlined, one that is centered on the discovery of the complexity and multiplicity of elements that work together to produce changes in our evolutionary (...) systems. We are talking about a three-dimensional multiplicity: a multiplicity of rhythms in evolution (i.e., the theory of punctuated equilibria); a multiplicity of evolutionary units and levels (i.e., the hierarchical theory of evolution); and a multiplicity of factors and causes in evolution (i.e., the concept of exaptation). Although the reductionistic and deterministic view of natural history interprets the intelligence of evolution as a panoptic and executory rationality, evolutionary pluralism, going back to the original flexibility of the Darwinian opus, sees in the intelligence of evolution an ingenious m tis, an imperfect but very creative, craftsmanlike cleverness. The new metaphors of change introduced by evolutionary pluralism and the consequent criticism of the adaptational paradigm offer some very interesting spin-offs for the study of evolutionary systems in widely differing fields, from theoretical economics to the cognitive sciences. I propose a particular hypothesis concerning the possibility and usefulness of expanding the concept of exaptation into a general theory of developmental processes, both in biology as well as in the cognitive sciences. (shrink)

Homology can provide strong evidence against exapted learning mechanism (ELM) explanations for psychological and behavioral traits. Homologous traits are constructed by commonly inherited developmental mechanisms. As such, demonstration of homology for a trait argues for its construction by an inherited rather than an exapted developmental process. We conclude that comparative evidence can play an important evidentiary role within evolutionary psychology.

The authors present a balanced critique of the adaptation/exaptation debate and specify some of the hard evidentiary criteria that are needed to advance our understanding of human evolution. Investigators must build more “special design” criteria into their theorizing and research. By documenting that certain traits meet these rigorous criteria, the evolutionary sciences will ultimately rest on a firmer theoretical foundation.

The target article adopts an adaptationist research strategy that, while logically coherent, suffers from various limitations, including problems in reconstructing past selective environments, ambiguity in how narrowly to define adaptive problems or selection pressures, and an overemphasis on specialization in evolved psychological mechanisms. To remedy these problems, I support a more flexible approach involving phenotypic adaptation and cultural evolution.

The expression exapted as is offered as a substitute for the target article's exaptation for and exaptation to on the grounds that exapted as is less likely to foster the pernicious intuition that natural selection designs for future consequences.

Andrews et al.'s analysis suffers from a series of conceptual confusions they inherit from Gould's work. Their proposal that adaptations can be distinguished from exaptations essentially by specific design criteria fails because exaptations are often maintained and secondarily adapted by natural selection and therefore, over evolutionary time, can come to have similar levels of design specificity to adaptations.

Gigerenzer et al.'s is an extremely important book. The ecological validity of the key heuristics is strengthened by their relation to ubiquitous Poisson processes. The recognition heuristic is also used in conspecific cueing processes in ecology. Three additional classes of problem-solving heuristics are proposed for further study: families based on near-decomposability analysis, exaptive construction of functional structures, and robustness.

The neutral theory often is presented as a theory of "noise" or silent changes at an isolated "molecular level", relevant to marking the steady pace of divergence, but not to the origin of biological structure, function, or complexity. Nevertheless, precisely these issues can be addressed in neutral models, such as those elaborated here in regard to scrambled ciliate genes, gRNA-mediated RNA editing, the transition from self-splicing to spliceosomal splicing, and the retention of duplicate genes. All of these are instances of (...) a more general scheme of "constructive neutral evolution" that invokes biased variation, epistatic interactions, and excess capacities to account for a complex series of steps giving rise to novel structures or operations. The directional and constructive outcomes of these models are not due to neutral allele fixations per se, but to these other factors. Neutral models of this type may help to clarify the poorly understood role of non-selective factors in evolutionary innovation and directionality. (shrink)

In 1979, Lewontin and I borrowed the archi- tectural term “spandrel” (using the pendentives of San Marco in Venice as an example) to designate the class of forms and spaces that arise as necessary byproducts of another decision in design, and not as adaptations for direct utility in them- selves. This proposal has generated a large literature featur- ing two critiques: (i) the terminological claim that the span- drels of San Marco are not true spandrels at all and (ii) the (...) conceptual claim that they are adaptations and not byprod- ucts. The features of the San Marco pendentives that we explicitly defined as spandrel-properties—their necessary number (four) and shape (roughly triangular)—are inevitable architectural byproducts, whatever the structural attributes of the pendentives themselves. The term spandrel may be extended from its particular architectural use for two- dimensional byproducts to the generality of “spaces left over,” a definition that properly includes the San Marco pendentives. Evolutionary biology needs such an explicit term for features arising as byproducts, rather than adaptations, whatever their subsequent exaptive utility. The concept of biological span- drels—including the examples here given of masculinized genitalia in female hyenas, exaptive use of an umbilicus as a brooding chamber by snails, the shoulder hump of the giant Irish deer, and several key features of human mentality— anchors the critique of overreliance upon adaptive scenarios in evolutionary explanation. Causes of historical origin must always be separated from current utilities; their conf lation has seriously hampered the evolutionary analysis of form in the history of life. (shrink)