Sexual reproduction is almost ubiquitous among multicellular organisms even though it entails severe fitness costs. To resolve this apparent paradox, an extensive body of research has been devoted to identifying the selective advantages of recombination that counteract these costs. Yet, how easy is it to make the transition to asexual reproduction once sexual reproduction has been established for a long time? The present review approaches this question by considering factors that impede the evolution of parthenogenesis in animals. Most importantly, (...) eggs need a diploid chromosome set in most species in order to develop normally. Next, eggs may need to be activated by sperm, and sperm may also contribute centrioles and other paternal factors to the zygote. Depending on how diploidy is achieved mechanistically, further problems may arise in offspring that stem from ‘inbreeding depression’ or inappropriate sex determination systems. Finally, genomic imprinting is another well-known barrier to the evolution of asexuality in mammals. Studies on species with occasional, deficient parthenogenesis indicate that the relative importance of these constraints may vary widely. The intimate evolutionary relations between haplodiploidy and parthenogenesis as well as implications for the clade selection hypothesis of the maintenance of sexual reproduction are also discussed. (shrink)

Ontogenetic factors constrain the evolution of species-typical traits. Because human infants are born “prematurely” relative to other primates, the development of handedness during infancy can reveal important ontogenetic influences on handedness that may have contributed to the evolution of the human species-typical trait of a population-level right-hand dominance.

There is still a great deal of debate over what counts as a constraint and about how to assess experimentally the relative importance of constraints and selection in evolutionary history. I will argue that the notion of a constraint on variation, and thus the selection-constraint distinction, depends on two specifications: (1) what counts as a variant -- constraints limit or bias the production of what? and (2) range of assessment -- over what range of times or conditions is (...) the variation assessed? Specifications 1 and 2 help us to understand empirical work on the relative importance of constraint and selection in evolution. (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)

How linguistic structures evolve so as to become easier to process is addressed by Isbilen and Christiansen for the Now‐or‐Never bottleneck. The authors suggest that this fundamental challenge in language processing is coped with by rapid compression of the transient linguistic input into chunks then to be passed on. As linguistic structures that can be chunked more easily tend to stabilize and proliferate, language evolves to fit learners’ cognitive capabilities.

Kant’s notorious remark about the impossibility of there ever being a Newton of a blade of grass has often been interpreted as a misguided pre-emptive strike against Darwin and evolutionary theories in general: 'It would be absurd for humans even to make such an attempt or to hope that there may yet arise a Newton who could make comprehensible even the generation of a blade of grass according to natural laws that no intention has ordered; rather, we must absolutely deny (...) this insight to human beings. (CPJ 5:400) My aim in this chapter is to re-evaluate this claim in the context of Kant’s account of organic generation and argue that, contrary to what is usually thought, it does leave room for the possibility of evolution. After spelling out the constraints Kant identifies for any scientific study of the history of living beings, I examine his theory of generation and draw its implications for biological heredity, species diversity, and the role played by environmental factors in organic development. On this basis, I conclude that first, evolution is a possible albeit far-fetched hypothesis for Kant; second, Darwin’s theory of natural selection would have turned a far-fetched possibility into a plausible candidate; and third, it would not have disposed of the need for teleology. This is why, I argue, Darwin could never have been a Newton of a blade of grass. (shrink)

Social transmission is at the core of cultural evolutionary theory. It occurs when a demonstrator uses mental representations to produce some public displays which in turn allow a learner to acquire similar mental representations. Although cultural evolutionists do not dispute this view of social transmission, they typically abstract away from the multistep nature of the process when they speak of cultural variants at large, thereby referring both to variation and evolutionary change in mental representations as well as in their corresponding (...) public displays. This conflation suggests that differentiating each step of the transmission process is redundant. In this paper, I examine different forms of interplay between the multistep nature of social transmission and the metric spaces used by cultural evolutionists to measure cultural variation and to model cultural change. I offer a conceptual analysis of what assumptions seem to be at work when cultural evolutionists conflate the complex causal sequence of social transmission as a single space of variation in which populations evolve. To this aim, I use the framework of variation spaces, a formal framework commonly used in evolutionary biology, and I develop two theoretical concepts, ‘technique’ and ‘technical space’, for addressing cases where the complexity of social transmission defies the handy assumption of a single variation space for cultural change. (shrink)

Language and culture endow humans with access to conceptual information that far exceeds any which could be accessed by a non-human animal. Yet, it is possible that, even without language or specific experiences, non-human animals represent and infer some aspects of similarity relations between objects in the same way as humans. Here, we show that monkeys’ discrimination sensitivity when identifying images of animals is predicted by established measures of semantic similarity derived from human conceptual judgments. We used metrics from computer (...) vision and computational neuroscience to show that monkeys’ and humans’ performance cannot be explained by low-level visual similarity alone. The results demonstrate that at least some of the underlying structure of object representations in humans is shared with non-human primates, at an abstract level that extends beyond low-level visual similarity. Because the monkeys had no experience with the objects we tested, the results suggest that monkeys and humans share a primitive representation of object similarity that is independent of formal knowledge and cultural experience, and likely derived from common evolutionary constraints on object representation. (shrink)

Scientific models may be more useful for false assumptions they make than true ones when one is interested not in the fit of the model, but in the form of the residuals. Modeling Darwin’s “blending” theory of inheritance shows how it illuminates features of Mendelian theory. Insufficient understanding of it leads to incorrect moves in modeling population structure. But it may prove even more useful for organizing a theory of cultural evolution. Analysis of “blending” inheritance gives new tools for (...) recognizing population structure for culture and for understanding differences between biological and cultural inheritance. (shrink)

Scientific models may be more useful for false assumptions they make than true ones when one is interested not in the fit of the model, but in the form of the residuals. Modeling Darwin's “blending” theory of inheritance shows how it illuminates features of Mendelian theory. Insufficient understanding of it leads to incorrect moves in modeling population structure. But it may prove even more useful for organizing a theory of cultural evolution. Analysis of “blending” inheritance gives new tools for (...) recognizing population structure for culture and for understanding differences between biological and cultural inheritance. (shrink)

It has been suggested that language disorders can serve as real windows onto language evolution. We examine this claim in this paper. We see ourselves forced to qualify three central assumptions of the the ‘disorders-as-windows’ hypothesis. After discussing the main outcome of decades of research on the linguistic ontogeny of pathological populations, we argue that language disorders should be construed as conditions for which canalization has failed to cope fully with developmental perturbations. We conclude that a robust link exists (...) between developmental disturbances and evolutionary history that allows language disorders to be used as real windows onto the evolution of the neuronal substrate of language, and emphasize that our conclusion is more compatible with views of language evolution as the result of reorganizational changes as opposed to radically novel emergences. (shrink)

Evolutionary scholars advance two major sorts of hypotheses to explain big events, such as the origin of agriculture. One hypothesis assumes that natural selection is so powerful that organisms are always close to an evolutionary equilibrium with current environment. Thus, any major changes will be a result of external processes having to do with the environment. The other camp imagines that evolution is a slow, halting, and biased process that is limited and directed by internal obstacles that thwart what (...) natural selection favors, for example, a particular somatic arrangement that is difficult to “engineer” quickly. Both kinds of constraints were probably involved in the trajectory leading to agriculture but perhaps at different timescales. (shrink)

Understanding the role mechanistic constraints play in shaping evolution can relieve the tension between the generally accepted intuition that there are no strict laws in biology and empirical findings showing that evolutionary processes are biased toward preferred outcomes. Mechanistic constraints explain why some evolutionary outcomes are more probable than others and allow for predictions in specific lineages. At the same time, mechanistic constraints are neither necessary nor universal in the way laws are traditionally characterized: they remain (...) contingent on the past evolution of the biological mechanisms underpinning them and only constrain the future evolution of the organisms possessing them. (shrink)

This essay is an exploratory reflection on a theme drawn from the work of Pierre Hadot and Juliusz Domański regarding “philosophy as a way of life.” I approach the matter from the naturalistic outlook of classic pragmatism and its own limitations. This approach stresses the possible improvement of the analysis of normativity by way of some neglected contributions regarding the nature of history and the evolution of Homo sapiens applied to the formation of the human self or person. I (...) take Hadot’s proposal seriously, therefore, as contributing to a mature conception of philosophy. But I deliberately restrict my own conjectures to naturalistic constraints, which begins to suggest an enlargement of pragmatism itself and an assessment of Hadot’s Greco-Roman and Christian themes. (shrink)

The emergence of shared symbol systems is considered to be a pivotal moment in human evolution and human development. These changes are normally explained by reference to changes in people's internal cognitive processes. We present 2 experiments which provide evidence that changes in the external, collaborative processes that people use to communicate can also affect the structure and organization of symbol systems independently of cognitive change. We propose that mutual‐modifiability—opportunities for people to edit or manipulate each other's contributions—is a (...) key constraint on the emergence of complex symbol systems. We discuss the implications for models of language development and the origins of compositionality. (shrink)

A set of constraints forces trade-offs which prevent us from achieving the best possible definitions of the ‘level’ and ‘unit’ of natural selection. This set consists in decisions concerning conflicting pre-analytic intuitions in problematic cases, the relative roles of various conceptual resources in the definitions, which facts need to be accounted for using the definitions, how the relation between selection and evolution orients the definitions, and the relation between the level and unit concepts. Systematic reconstruction and evaluation of (...) leading analyses along these dimensions favors a new functional analysis over Williams’ consequentialist analysis, Sober’s causal analysis, and Dawkins’ teleological analysis. (shrink)

A set of constraints forces trade-offs which prevent us from achieving the best possible definitions of the ‘level’ and ‘unit’ of natural selection. This set consists in decisions concerning conflicting pre-analytic intuitions in problematic cases, the relative roles of various conceptual resources in the definitions, which facts need to be accounted for using the definitions, how the relation between selection and evolution orients the definitions, and the relation between the level and unit concepts. Systematic reconstruction and evaluation of (...) leading analyses along these dimensions favors a new functional analysis over Williams’ consequentialist analysis, Sober’s causal analysis, and Dawkins’ teleological analysis. (shrink)

A new conceptual framework is proposed to situate and integrate the parallel theories of Turchin, Powers, Campbell and Simon. A system is defined as a constraint on variety. This entails a 2 × 2 × 2 classification scheme for “higher‐order” systems, using the dimensions of constraint, (static) variety, and (dynamic) variation. The scheme distinguishes two classes of metasystems from supersystems and other types of emergent phenomena. Metasystems are defined as constrained variations of constrained variety. Control is characterized as a constraint (...) exerted by a separate system. The emergence of hierarchical systems is motivated by evolutionary principles. The positive feedback between variety and constraint, which underlies the “branching growth of the penultimate level,” leads to the interpretation of metasystem transitions as phases of accelerated change in a continuous evolutionary progression toward increasing variety. The most important MSTs in the history of evolution are reinterpreted in this framework: mechanical motion, dissipative structuration, life, multicellular differentiation, sexuality, simple reflex, complex reflex, associating, thinking, metarationality and social interaction. (shrink)

This paper approaches the question of how to describe the higher-level internal structures and representations of cognitive systems across various kinds of nonhuman (neuro)cognitive systems. While much research in cognitive (neuro)science and comparative cognition is dedicated to the exploration of the (neuro)cognitive mechanisms and processes with a focus on brain-behavior relations across different non-human species, not much has been done to connect (neuro)cognitive mechanisms and processes and the associated behaviors to plausible higher-level structures and representations of distinct kinds of cognitive (...) systems in non-humans. Although the study of (neuro)cognitive mechanisms and processes can certainly be revealing, (neuro)cognitive mechanisms and processes are underspecified with respect to internal structures and representations of non-human cognitive systems because multiple such mechanisms can target, or be mapped onto, the same internal structure or vice versa. This paper outlines a biosemiotic approach to this linking problem in order to bridge the gap between functions of (neuro)cognitive systems in different species and the higher-level cognitive structures and representations. It is contended that the higher-level internal structures and representations of various cognitive systems are biosemiotic constraints on the (biological) functions of (neuro)cognitive systems that serve to restrict the range of functions (neuro)cognitive systems have or are selected for. This turns out to have implications for issues on the convergent evolution of cognitive traits. (shrink)

This essay explores the universal cognitive bases of biological taxonomy and taxonomic inference using cross-cultural experimental work with urbanized Americans and forest-dwelling Maya Indians. A universal, essentialist appreciation of generic species appears as the causal foundation for the taxonomic arrangement of biodiversity, and for inference about the distribution of causally-related properties that underlie biodiversity. Universal folkbiological taxonomy is domain-specific: its structure does not spontaneously or invariably arise in other cognitive domains, like substances, artifacts or persons. It is plausibly an innately-determined (...) evolutionary adaptation to relevant and recurrent aspects of ancestral hominid environments, such as the need to recognize, locate, react to, and profit from many ambient species. Folkbiological concepts are special players in cultural evolution, whose native stability attaches to more variable and difficult-to-learn representational forms, thus enhancing the latter's prospects for regularity and recurrence in transmission within and across cultures. This includes knowledge that cumulatively enriches (folk expertise), overrides (religious belief) or otherwise transcends (science) the commonsense ontology prescribed by folkbiology. Finally, the studies summarized here indicate that results gathered from “standard populations” in regard to biological categorization and reasoning more often than not fail to generalize in straightforward ways to humanity at large. This suggests the need for much more serious attention to cross-cultural research on basic cognitive processes. (shrink)

Biology seems to present local and transitory regularities rather than immutable laws. To account for these historically constituted regularities and to distinguish them from mathematical invariants, Montévil and Mossio (Journal of Theoretical Biology 372:179–191, 2015) have proposed to speak of constraints. In this article we analyse the causal power of these constraints in the evolution of biodiversity, i.e., their positivity, but also the modality of their action on the directions taken by evolution. We argue that to (...) fully account for the causal power of these constraints on evolution, they must be thought of in terms of normativity. In this way, we want to highlight two characteristics of the evolutionary constraints. The first, already emphasised as reported by Gould (The structure of evolutionary theory, Harvard University Press, 2002), is that these constraints are both produced by and producing biological evolution and that this circular causation creates true novelties. The second is that this specific causality, which generates unpredictability in evolution, stems not only from the historicity of biological constraints, but also from their internalisation through the practices of living beings. (shrink)

Memory is fleeting. New material rapidly obliterates previous material. How, then, can the brain deal successfully with the continual deluge of linguistic input? We argue that, to deal with this “Now-or-Never” bottleneck, the brain must compress and recode linguistic input as rapidly as possible. This observation has strong implications for the nature of language processing: (1) the language system must “eagerly” recode and compress linguistic input; (2) as the bottleneck recurs at each new representational level, the language system must build (...) a multilevel linguistic representation; and (3) the language system must deploy all available information predictively to ensure that local linguistic ambiguities are dealt with “Right-First-Time”; once the original input is lost, there is no way for the language system to recover. This is “Chunk-and-Pass” processing. Similarly, language learning must also occur in the here and now, which implies that language acquisition is learning to process, rather than inducing, a grammar. Moreover, this perspective provides a cognitive foundation for grammaticalization and other aspects of language change. Chunk-and-Pass processing also helps explain a variety of core properties of language, including its multilevel representational structure and duality of patterning. This approach promises to create a direct relationship between psycholinguistics and linguistic theory. More generally, we outline a framework within which to integrate often disconnected inquiries into language processing, language acquisition, and language change and evolution. (shrink)

Can we understand brain lateralization in humans by analysis in terms of an evolutionarily stable strategy? The attempt to demonstrate a link between lateralization in humans and that in, for example, fish appears to hinge critically on whether the isomorphism is viewed as a matter of homology or homoplasy. Consideration of human handedness presents a number of challenges to the proposed framework.

Background: One of the all-time questions in evolutionary biology regards the evolution of organismal shapes, and in particular why certain forms appear repeatedly in the history of life, others only seldom and still others not at all. Recent research in this field has deployed the conceptual framework of constraints and natural selection as measured by quantitative genetic methods. Scope: In this paper I argue that quantitative genetics can by necessity only provide us with useful statistical sum- maries that (...) may lead researchers to formulate testable causal hypotheses, but that any inferential attempt beyond this is unreasonable. Instead, I suggest that thinking in terms of coordinates in phenotypic spaces, and approaching the problem using a variety of empirical methods (seeking a consilience of evidence), is more likely to lead to solid inferences regarding the causal basis of the historical patterns that make up most of the data available on phenotypic evolution. (shrink)

Three-legged animals do not exist today and such an animal is not found in the fossil record. Which constraints operate to result in the lack of a triped phenotype? Consideration of animal locomotion and robotic studies suggests that physical constraints would not prevent a triped from being functional or advantageous. As is reviewed here, the strongest constraint on the evolution of a triped is phylogenetic: namely, the early genetic adoption of a bilaterally symmetrical body plan occurring before (...) the advent of limbs. Presumably, this would greatly constrain any three-legged animal from ever evolving. Tripedalism is employed only by a few animals, but many use a tripod stance while engaged in a variety of activities. Because terms are often used interchangeably in the literature, a standardization of locomotion terminology is proposed. Understanding the constraints behind “forbidden” phenotypes forces us to confront gaps in our evolutionary understanding of which we may be unaware. (shrink)

Our understanding of language, its origins and subsequent evolution, is shaped not only by data and theories from the language sciences, but also fundamentally by the biological sciences. Recent developments in genetics and evolutionary theory offer both very strong constraints on what scenarios of language evolution are possible and probable, but also offer exciting opportunities for understanding otherwise puzzling phenomena. Due to the intrinsic breathtaking rate of advancement in these fields, and the complexity, subtlety, and sometimes apparent (...) non-intuitiveness of the phenomena discovered, some of these recent developments have either being completely missed by language scientists or misperceived and misrepresented. In this short paper, we offer an update on some of these findings and theoretical developments through a selection of illustrative examples and discussions that cast new light on current debates in the language sciences. The main message of our paper is that life is much more complex and nuanced than anybody could have predicted even a few decades ago, and that we need to be flexible in our theorizing instead of embracing a priori dogmas and trying to patch paradigms that are no longer satisfactory. (shrink)

A fundamental question in biology is whether phenotypes can be predicted by ecological or genomic rules. At least five cases of convergent evolution of the crab‐like body plan (with a wide and flattened shape, and a bent abdomen) are known in decapod crustaceans, and have, for over 140 years, been known as “carcinization.” The repeated loss of this body plan has been identified as “decarcinization.” In reviewing the field, we offer phylogenetic strategies to include poorly known groups, and direct (...) evidence from fossils, that will resolve the history of crab evolution and the degree of phenotypic variation within crabs. Proposed ecological advantages of the crab body are summarized into a hypothesis of phenotypic integration suggesting correlated evolution of the carapace shape and abdomen. Our premise provides fertile ground for future studies of the genomic and developmental basis, and the predictability, of the crab‐like body form. (shrink)

The biogenesis of RNAs and proteins is a threat to the cell. Indeed, the act of transcription and nascent RNAs challenge DNA stability. Both RNAs and nascent proteins can also initiate the formation of toxic aggregates because of their physicochemical properties. In reviewing the literature, I show that co-transcriptional and co-translational biophysical constraints can trigger DNA instability that in turn increases the likelihood that sequences that alleviate the constraints emerge over evolutionary time. These directed genetic variations rely on (...) the biogenesis of small RNAs that are transcribed directly from challenged DNA regions or processed from the transcripts that directly or indirectly generate constraints or aggregates. These small RNAs can then target the genomic regions from which they initially originate and increase the local mutation rate of the targeted loci. This mechanism is based on molecular pathways involved in anti-parasite genome defence systems, and implies that gene expression-related biophysical constraints represent a driving force of genome evolution. Are randomly generated mutations the only source of genetic variation during evolution? This paper describes the molecular mechanisms by which co-transcriptional and co-translational biophysical constraints trigger genetic variations in targeted-genomic sequences in an RNA-depending manner. This directed-mutational process that drives genome evolution is related to antiparasite genome defence systems. (shrink)

This volume presents a collection of refereed papers reflecting the state of the art in the area of over-constrained systems. Besides 11 revised full papers, selected from the 24 submissions to the OCS workshop held in conjunction with the First International Conference on Principles and Practice of Constraint Programming, CP '95, held in Marseilles in September 1995, the book includes three comprehensive background papers of central importance for the workshop papers and the whole field. Also included is an introduction by (...) one of the volume editors together with a bibliography listing 243 entries. All in all this is a very useful reference book relevant for all researchers and practitioners interested in hierarchical, partial, and over-constrained systems. (shrink)

Why do the two sexes have different lifespans and rates of aging? Two hypotheses based on asymmetric inheritance of sex chromosomes (“unguarded X”) or mitochondrial genomes (“mother's curse”) explain sex differences in lifespan as sex‐specific maladaptation leading to increased mortality in the shorter‐lived sex. While asymmetric inheritance hypotheses equate long life with high fitness, considerable empirical evidence suggests that sexes resolve the fundamental tradeoff between reproduction and survival differently resulting in sex‐specific optima for lifespan. However, selection for sex‐specific values in (...) life‐history traits is constrained by intersexual genetic correlations resulting in intra‐locus sexual conflict over optimal lifespan. The available data suggest that the evolution of sexual dimorphism only partially resolves these conflicts. Sexual conflict over optimal trait values, which has been demonstrated in model organisms and in humans, is likely to play a key role in shaping the evolution of lifespan, as well as in maintaining genetic variation for sex‐specific diseases. (shrink)

The article of Finlay et al. is an excellent example of identifying constraints in the development of the brain, and their implications on brain architecture in evolution. Here we further illustrate the importance of constraints by presenting a few examples of how a small number of biophysical mechanisms or even a single life history parameter can have an enormous impact on brain evolution.

The growing interest and major advances of the last decades in evolutionary developmental biology (EvoDevo) have led to the recognition of the incompleteness of the Modern Synthesis of evolutionary theory. Here we discuss how paleontology makes significant contributions to integrate evolution and development. First, extinct organisms often inform us about developmental processes by showing a combination of features unrecorded in living species. We illustrate this point using the vertebrate fossil record and studies relating bone ossification to life history traits. (...) Second, we discuss exceptionally preserved fossils that document rare ontogenetic sequences and illustrate this case with the patterns of heterochrony observed in Cambrian crustacean larvae preserved three-dimensionally. Third, most fossils potentially document the evolutionary patterns of allometry and modularity, as well as some of the (paleo)ecological factors that had influenced them. The temporal persistence of adaptive patterns in rodent evolution serves to address the importance of ecological constraints in evolution. Fourth, we discuss how the macroevolutionary patterns observed in the tetrapod limb, in the mammal molar proportions, and in the molluscan shell provide independent tests of the validity of morphogenetic models proposed on living species. Reciprocally, these macroevolutionary patterns often act as a source of inspiration to investigate the underlying rules of development, because, at the end, they are the patterns that the neo-Darwinian theory was unable to account for. (shrink)

Two kinds of factors set the tempo and direction of organic and cultural evolution, those external to biotic evolutionary process, such as changes in the earth’s physical and chemical environments, and those internal to it, such as the time required for chance factors to lead lineages across adaptive valleys to a new niche space (Valentine 1985). The relative importance of these two sorts of processes is widely debated. Valentine (1973) argued that marine invertebrate diversity patterns responded to seafloor spreading (...) as this process generated more or less niche space. He suggested that natural selection is a powerful force and that earth’s biota are in near equilibrium with the niches available on the geological time scale. Walker and Valentine (1984) modeled the evolution of species assuming a logistic speciation rate limited by internal factors and a diversity-independent death rate caused by ongoing environmental change. Fitting this model to the observed evolution of shelled marine invertebrates suggests that the lag between extinctions and the evolution of new species leaves perhaps 30% of ecological niches unfilled. In this model, the biota lag environmental change by perhaps a few million years. However, as Valentine (1985) notes, if adaptive landscapes have whole suites of niches protected by deep maladaptive valleys, the waiting time for some pioneering species to cross the divide may be very long, generating the rare events that set new body plans and generate major adaptive radiations. Eldredge and Gould (1972) and Gould (2002) championed the idea that internal processes such as genetic and developmental constraints, coupled with the complexity of the adaptive landscape, resulted in a highly historically contingent evolutionary process. On Gould’s account, most of the history of life had to do not with a relatively close tracking of a changing environment but with the halting evolutionary exploration a deeply fissured niche space, mostly by rapid bursts of evolution as a fissure was crossed, followed by long periods of stasis.. (shrink)

We argue four points. First, perception always relies on environmental constraints, not only in special cases. Second, constraints are taken advantage of by detecting information granted by the constraints rather than by internalizing them. Third, apparent motion phenomena reveal reliance on constraints that are irrelevant in everyday perception. Fourth, constraints are selected through individual learning as well as evolution. The “perceptual-concept-of-velocity” phenomenon is featured as a relevant case. [Hecht; Kubovy & Epstein; Shepard].

The relativistic quantum mechanics with Lorentz-invariant evolution parameter and indefinite mass is a very elegant theory. But it cannot be derived by quantizing the usual classical relativity in which there is the mass-shell constraint. In this paper the classical theory is modified so that it remains Lorentz invariant, but the constraint disappears; mass is no longer fixed—it is an arbitrary constant of motion. The quantization of this unconstrained theory gives the relativistic quantum mechanics in which wave functions are localized (...) and normalized in spacetime. Though many authors have published good works in support for such a localization in time, the latter has been generally considered as problematic. Here I show that wave packets restricted to a finite region of spacetime are not a nuisance, but just the contrary. They have the physical interpretation in the fact that an observer perceives a world line event by event, as his experience of “now” proceeds in spacetime. Quantum mechanically this means that at a certain value of the evolution parameter τ the event is most probably to occur within the spacetime region around {ie1005-1} occupied by the wave packet; at later value of τ the position {ie1005-2}—and hence the time coordinate t—of the wave packet is changed. This is closely related to the interpretation of quantum mechanics in general. (shrink)

Despite obvious advantages, no generalised ideographic codes have evolved through cultural evolution to rely on iconicity. Morin suggests that this is because of missing means of standardisation, which glottographic codes get from natural languages. Although we agree, we also point to the important role of the available media, which might support some forms of reference more effectively than others.

Since Darwin, the idea of psychological continuity between humans and other animals has dominated theory and research in investigating the minds of other species. Indeed, the field of comparative psychology was founded on two assumptions. First, it was assumed that introspection could provide humans with reliable knowledge about the causal connection between specific mental states and specific behaviors. Second, it was assumed that in those cases in which other species exhibited behaviors similar to our own, similar psychological causes were at (...) work. In this paper. we show how this argument by analogy is flowed with respect to the case of second-order mental states. As a test case, we focus on the question of how other species conceive of visual attention, and in particular whether chimpanzees interpret seeing as a mentalistic event involving internal states of perception, attention, and belief. We conclude that chimpanzees do not reason about seeing in this manner, and indeed, there is considerable reason to suppose that they do not harbor representations of mental states in general. We propose a reinterpretation model in which the majority of the rich social behaviors that humans and other primates share in common emerged long before the human lineage evolved the psychological means of interpreting those behaviors in mentalistic terms. Although humans, chimpanzees, and most other species may be said to possess mental states, humans alone may have evolved a cognitive specialization for reasoning about such states. (shrink)

Phenotypic Evolution explicitly recognizes organisms as complex genetic-epigenetic systems developing in response to changing internal and external environments. As a key to a better understanding of how phenotypes evolve, the authors have developed a framework that centers on the concept of the Developmental Reaction Norm. This encompasses their views: (1) that organisms are better considered as integrated units than as disconnected parts (allometry and phenotypic integration); (2) that an understanding of ontogeny is vital for evaluating evolution of adult (...) forms (ontogenetic trajectories, epigenetics, and constraints); and (3) that environmental heterogeneity is ubiquitous and must be acknowledged for its pervasive role in phenotypic expression. (shrink)

Many philosophers invoke the "wisdom of nature" in arguing for varying degrees of caution in the development and use of genetic enhancement technologies. Because they view natural selection as akin to a master engineer that creates functionally and morally optimal design, these authors tend to regard genetic intervention with suspicion. In Part II, we examine and ultimately reject the evolutionary assumptions that underlie the master engineer analogy (MEA). By highlighting the constraints on ordinary unassisted evolution, we show how (...) intentional genetic modification can overcome many of the natural impediments to the human good. Our contention is that genetic engineering offers a solution that is more eff icient, reliable, versatile, and morally palatable than the lumbering juggernaut of Darwinian evolution. In Part III, we evaluate a recent attempt to ground precautionary enhancement heuristics in adaptive etiology. Our problem with this approach is two-fold: first, it is based on the same "strong adaptationist" interpretation of evolution that motivates the flawed MEA, and second, the etiological concept of function on which it relies provides indirect and potentially misleading information about the likely consequences of genetic intervention. We offer instead enhancement criteria based on causal relationships in ontogeny. We conclude that rather than grounding a presumption against deliberate genetic modification, the causal structure of the living world gives us good moral reason to pursue it. (shrink)

Embryos, cells, genes, and organisms : reflections on the history of evolutionary developmental biology / Manfred D. Laubichler and Jane Maienschein The organismic systems approach : streamlining the naturalistic agenda / Werner Callebaut, Gerd B. Müller, and Stuart A. Newman Complex traits : genetics, development, and evolution / H. Frederik Nijhout Functional and developmental constraints on life-cycle evolution : an attempt on the architecture of constraints / Gerhard Schlosser Legacies of adaptive development / Roger Sansom Evo-devo (...) meets the mind : toward a developmental evolutionary psychology / Paul E. Griffiths Reproducing entrenchments to scaffold culture : the central role of development in cultural evolution / William C. Wimsatt and James R. Griesemer. (shrink)

In this paper I argue, first, that human lifeways depend on cognitive capital that has typically been built over many generations. This process of gradual accumulation produces an adaptive fit between human agents and their environments; an adaptive fit that is the result of hidden‐hand, evolutionary mechanisms. To explain distinctive features of human life, we need to understand how cultures evolve. Second, I distinguish a range of different evolutionary models of culture. Third, I argue that none of meme‐based models, dual (...) inheritance models, nor Boyd and Richerson's models fully succeed in explaining this adaptive fit between agent and the world. I then briefly develop an alternative. Finally, I explore (in a preliminary way) constraints on cultural adaptation. The processes of cultural evolution sometimes built a fit between agents and their environment, but they do not always do so. Why is folk medicine, for example, so much less reliable than folk natural history? (shrink)