The variation and selection form of explanationcan be prescinded from the evolutionary biologyhome ground in which it was discovered and forwhich it has been most developed. When this isdone, variation and selection explanations arefound to have potential application to a widerange of phenomena, far beyond the classicalbiological ground and the contemporaryextensions into epistemological domains. Itappears as the form of explanation most suitedto phenomena of fit. It is also found toparticipate in multiple interestingrelationships with other forms of (...) explanation. We proceed with an examination of multiplekinds of phenomena, interrelationships withother members of the family of forms ofexplanation, and some novel applications evenwithin the home ground of evolutionary biology. (shrink)

If the general arguments concerning theinvolvement of variation and selection inexplanations of ``fit'' are valid, then variationand selection explanations should beappropriate, or at least potentiallyappropriate, outside the paradigm historisticdomains of biology and knowledge. In thisdiscussion, I wish to indicate some potentialroles for variation and selection infoundational physics – specifically inquantum field theory. I will not be attemptingany full coherent ontology for quantum fieldtheory – none currently exists, and none islikely for at least the short term (...) future. Instead, I wish to engage in some partiallyspeculative interpretations of some interestingresults in this area with the aim ofdemonstrating that variation and selectionnotions might play a role even here. Ifvariation and selection can survive in even asinhospitable and non-paradigmatic a terrain asfoundational physics, then it can surviveanywhere. (shrink)

Campbell (1960) proposed a “blind-variation and selective retention” model of creative cognition. Subsequent researchers have developed this BVSR model into a comprehensive theory of human creativity, one that recognizes that human creativity operates by more than one cognitive process. The question is then raised of how the BVSR model can be accommodated within the Hull et al. selectionist system.

The interaction of the organism with the environment requires not only reactive, but also active behavior (i.e., search activity) which helps subject to meet the challenge of the uncertainty of the environment. A positive feedback between active behavior and immune system makes the selection process effective.

Chance has been a focus of attention ever since the beginning of population genetics, but neutrality has not, as natural selection once appeared to be the only worthwhile issue. Neutral change became a major source of interest during the neutralist–selectionist debate, 1970–1980. It retained interest beyond this period for two reasons that contributed to its becoming foundational for evolutionary reasoning. On the one hand, neutral evolution was the first mathematical prediction to emerge from Mendelian inheritance: until then evolution by (...) natural selection was considered the alternative to the fixity of species; now it appears to be the alternative to continuous change. Second, neutral change generated a set of clear predictions on standing variation. These could be used as a reference for detecting more elusive alternative mechanisms of evolution including natural selection. In the wake of the transition from Mendelism to genomics, the combination of coalescent theory, DNA sequence variation, and numerical analysis made it possible to integrate contingent aspects of the history of species into a new null model, thus opening a new dimension in the concept of population that the Modern Synthesis formerly considered as a mere gene pool. (shrink)

Individual differences in performance on a variety of selection tasks were examined in three studies employing over 800 participants. Nondeontic tasks were solved disproportionately by individuals of higher cognitive ability. In contrast, responses on two deontic tasks that have shown robust performance facilitationthe Drinking-age Problem and the Sears Problem-were unrelated to cognitive ability. Performance on deontic and nondeontic tasks was consistently associated. Individuals in the correct/correct cell of the bivariate performance matrix were over-represented. That is, individuals giving the modal (...) response on a nondeontic task (P and Q) were significantly less likely to give the modal response on a deontic task (P and not-Q) than were individuals who made the non-modal P and not-Q selection on nondeontic problems. The implications of the results are discussed within the heuristic-analytic framework of Evans (1996; Evans & Over, 1996) and the optimal data selection model of Oaksford and Chater (1994). (shrink)

One of the major adaptations during the evolution of Homo sapiens was an increase in brain size. Here we present evidence that a significant and substantial proportion of variation in brain size may be related to changes in temperature. Based on a sample of 109 fossilized hominid skulls, we found that cranial capacities were highly correlated with paleoclimatic changes in temperature, as indexed by oxygen isotope data and sea-surface temperature. Indeed, as much as 52% of the variance in the (...) cranial capacity of these skulls could be accounted for by temperature variation at 100 ka intervals. As an index of more short-term seasonal fluctuations in temperature, we examined the latitude of the sites from which the crania originated. More than 22% of the variance in cranial capacity of these skulls could be accounted for by variation in equatorial distance. (shrink)

Building upon a non-standard understanding of evolutionary process focusing on variation and persistence, I will argue that communities and ecosystems can evolve by natural selection as emergent individuals. Evolutionary biology has relied ever increasingly on the modeling of population dynamics. Most have taken for granted that we all agree on what is a population. Recent work has reexamined this perceived consensus. I will argue that there are good reasons to restrict the term “population” to collections of monophyletically related (...) replicators and interactors, which explains why many existing models in population biology exclude by definition many genuine evolving biological individuals such as communities and ecosystems. By studying a case of community evolution (a symbiotic termite–fungus community), we will see that it is variation that is important to evolutionary processes, not populations. Variation within a population is only one of many types of variation that can lead to evolution by natural selection. The upshot of focusing on variation is that cases of community and ecosystem adaptive change become tractable in evolutionary terms. I will show that complex emergent individuals such as communities and ecosystems cannot be fully accommodated by conventional population/reproduction models but can be accommodated by variation/persistence models. (shrink)

According to the standard formulation, natural selection requires variation, differential fitness, and heritability. I argue that this formulation is inadequate because it fails to distinguish natural selection from artificial selection, intelligent design, forward-looking orthogenetic selection, and adaptation via the selection of nonrandom variation. I suggest adding a _no teleology_ condition. The no teleology condition says that the evolutionary process is not guided toward an endpoint represented in the mind of an agent, variation (...) is produced randomly with respect to adaptation, and selection pressures are not forward looking. (shrink)

This paper shows the relevance of an evolutionary model for the study of language change. We focus on a cognitive and usage-based approach to language change, namely the Theory of Utterance Selection developed by Croft (2000). Croft's evolutionary approach takes its inspiration from neo-Darwinian evolutionary theory, particularly the Generalized Theory of Selection developed by Hull (1988), a philosopher of science. Language is viewed as a system of use governed by convention, and language change results from breaking with convention (...) and propagating this innovation through the linguistic community until it becomes a new convention. Crucially, altered replication can be equated with language innovation, and propagation of individual changes is the linguistic counterpart of the differential perpetuation or selection of replicators. We will argue within the framework of Cognitive Linguistics (Geeraerts & Cuyckens, 2007) for a more systematic integration of cognitive and social factors in the explanation of language change. The mechanisms for language innovation are cognitive, as the pnnciples of cognitive efficiency like prototypicality constitute the main motivations for language change and metaphor and metonymy the main cognitive mechanisms of semantic change. The mechanisms for propagation are essentially social, including processes such as accommodation, identity and prestige. All of these mechanisms occur in individual communicative acts and operate like an "invisible hand" (Keller, 1994). We illustrate the sociocognitive evolutionary model of language change with some case studies on semantic change in Portuguese. (shrink)

Recent work on self organization promises an explanation of complex order which is independent of adaptation. Self-organizing systems are complex systems of simple units, projecting order as a consequence of localized and generally nonlinear interactions between these units. Stuart Kauffman offers one variation on the theme of self-organization, offering what he calls a ``statistical mechanics'' for complex systems. This paper explores the explanatory strategies deployed in this ``statistical mechanics,'' initially focusing on the autonomy of statistical explanation as it applies (...) in evolutionary settings and then turning to Kauffman's analysis. Two primary morals emerge as a consequence of this examination: first, the view that adaptation and self-organization should be seen as competing theories or models is misleading and simplistic; and second, while we need a synthesis treating self-organization and adaptation as geared toward different problems, at different levels of organization, and deploying different methods, we do not yet have such a synthesis. (shrink)

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)

Sociological, economic and evolutionary paradigms of human agency have often seen social agents either as the rational controllers of their fate or as marionettes on the strings of historical, functional or adaptive necessity. They found it therefore difficult to account for the variability, intentionality and creativity of human behaviour and for its frequently redundant or harmful results. This paper argues that human agency is a product of evolution, but that genetic variation and inheritance can only provide a limited explanation (...) of its complex nature. The primary evolutionary problem which human agents face while they are alive is not to adapt to stable environments, but to respond flexibly and creatively to a contingent, uncertain world. Variation and selection therefore take two connected but distinct forms, one external, genetic, and inherited across generations, the other internal and cognitive, and operating during the lifetime of individuals. An examination of this lived part of evolution provides a better understanding of key properties of agency. (shrink)

Selection as a mode of causation is central to operant psychology. Response variation and selection by consequences corresponds to phenotypic variation, to differential survivability, and to reproduction of variants. In natural selection, genes code for phylogenic history but no analogous processes exists for coding behavioral history. Neuroscience suggests potential processes but the conceptual status of these events requires clarification.

Objective: To analyse the time variation of topics in bioethical publications as a proxy of the relative importance.Methods: We searched the Medline database for bioethics publications using the words “ethics or bioethics”, and for 360 specific topics publications, associating Medical Subject Heading topic descriptors to those words. We calculated the ratio of bioethics publications to the total publications of Medline, and the ratio of each topic publications to the total bioethics publications, for five-year intervals, from 1970 to 2004. We (...) calculated the time variation of ratios, dividing the difference between the highest and lowest ratio of each topic by its highest ratio. Four topics were described, selected to illustrate different patterns of variation: “Induced Abortion”, “Conflict of Interest”, “Acquired Immunodeficiency Syndrome”, “Medical Education.”Results: The ratio of bioethics publications to total Medline publications increased from 0.003 to 0.012. The variation of the topic’s ratios was higher than 0.7 for 68% of the topics. The Induced Abortion ratios decreased from 0.12 to 0.02. Conflict of Interest ratios increased from zero to 0.07. The Acquired Immunodeficiency Syndrome ratios were nearly zero in the first three intervals, had a peak of 0.06 during 1985–9, followed by a decrease to 0.01. Medical Education ratios varied few, from 0.04 to 0.03.Conclusions: There was an increase of bioethical publications in the Medline database. The topics in bioethics literature have an important time variation. Some factors were suggested to explain this variation: current legal cases, resolution of the issue, saturation of a discussion and epidemiologic importance. (shrink)

According to the received view of evolution, only genes are inherited. From this view it follows that only genetically-caused phenotypic variation is selectable and, thereby, that all selection is at bottom genetic selection. This paper argues that the received view is wrong. In many species, there are intergenerationally-stable phenotypic differences due to environmental differences. Natural selection can act on these nongenetically-caused phenotypic differences in the same way it acts on genetically-caused phenotypic differences. Some selection is (...) at bottom nongenetic selection. The argument against the received view involves a reformulation of the concepts of inheritance and heritability. Inherited factors are all those developmental factors responsible for parent–offspring similarity; some inherited factors are genetic and some are not. Heritable variation is intergenerationally-stable phenotypic variation; some such variation is genetically-caused and some is not. The received view and its critics The possibility of nongenetic selection (the lucky butterfly) The reality of nongenetic selection 3.1 Imprinting mechanisms 3.2 Other learning mechanisms 3.3 Other nongenetic mechanisms Genetic and nongenetic inheritance mechanisms Genetic and nongenetic inherited factors Genetic and nongenetic heritability Conclusions + Current address: Dr Matteo Mameli, Research Fellow, King's College, Cambridge, CB2 1ST, United Kingdom, matteo.mameli{at}kings.cam.ac.uk' + u + '@' + d + ''//-->. (shrink)

The publication of Darwin's On the Origin of Species in 1859 ignited a public storm he neither wanted nor enjoyed. Having offered his book as a contribution to science, Darwin discovered to his dismay that it was received as an affront by many scientists and as a sacrilege by clergy and Christian citizens. To answer the criticism that his theory was a theory only, and a wild one at that, he published two volumes in 1868 to demonstrate that evolution was (...) obvious to anyone who cared to look at a bull in a pasture or a dog on a hearth. In response to those who insisted that species were distinct since creation, Darwin pointed to breeders of pigs and pigeons. In reply to those who protested that human intervention is one thing and natural selection another, he argued, "If organic beings had not possessed an inherent tendency to vary, man could have done nothing." To counter those who scorned his descriptions of species in exotic places, he submitted local evidence of cabbages and cauliflower. Based on a wide array of sources, from ancient pictographs to Polish roosters, from skins and from skeletons, from scientific journals and breeding manuals, Darwin assembled a mass of proof--and a hypothesis about species reversion that risked his reputation anew. The Variation of Animals and Plants under Domestication is a two-volume compilation of his thorough and intensive research and the revolutionary conclusions that resulted. The first portion of his work is dedicated to a meticulous analysis of various aspects of plant and animal life, including an inventory of varieties and their physical and behavioral characteristics, investigation of the impact of a species' surrounding environment and the role that both natural and forced changes in this environment have had. Darwin then turns to a richly detailed discussion of the roles of inheritance and crossing in the development of species. A wealth of illustrations further support and enhance his findings. This fascinating, invaluable, and courageous undertaking eventually formed the foundation for our current understanding of evolution. "In science as in politics the victors tend to write the history books. As a result, the record of the past is edited, intentionally or unintentionally, so that it focuses mainly on the precursors of contemporary orthodoxy. Such a focus may accurately represent the genealogy of modern ideas, but it almost inevitably misrepresents the historical experience of their progenitors... Even the powerful, persuasive, and ultimately triumphant theory of evolution by natural selection required not only defense, but repeated buttressing and revision. Variation showed Darwin hard at work on this rearguard action, using the materials he had at hand... His information was gleaned from the observations of fanciers, breeders, and amateur naturalists, as well as from the treatises of those on the cutting edge of zoology and botany. As hindsight narrows the historical spotlight, it imposes its own sense of hierarchy on the preoccupations of the past. But Darwin was interested in all of these topics, valued all of these sources, and belonged, to a greater or lesser extent, to all of these communities."--from the Introduction. (shrink)

This paper aims to clarify the consequences of new scientific and philosophical approaches for the practical-theoretical framework of modern developmental biology. I highlight normal development, and the instructive-permissive distinction, as key parts of this framework which shape how variation is conceptualised and managed. Furthermore, I establish the different dimensions of biological variation: the units, temporality and mode of variation. Using the analytical frame established by this, I interpret a selection of examples as challenges to the instructive-permissive (...) distinction. These examples include the phenomena of developmental plasticity and transdifferentiation, the role of the microbiome in development, and new methodological approaches to standardisation and the assessment of causes. Furthermore, I argue that investigations into organismal development should investigate the effects of a wider range of kinds of variation including variation in the units, modes and temporalities of development. I close by examining various possible opportunities for producing and using normal development free of the assumptions of the instructive-permissive distinction. These opportunities are afforded by recent developments, which include new ways of producing standards incorporating more natural variation and being based on function rather than structure, and the ability to produce, store, and process large quantities of data. (shrink)

Selection in behavior analysis fits the criteria of replication, variation and interaction proposed by the authors except for information under replication. If information requires physical structure, behavior analysis does not fit that model because functional analysis may provide parallels between behavior, neurology, and biochemistry but not sequencing. The three sciences are not unified by the model but another is available.

This paper considers a central objection to evolutionary epistemology. The objection is that biological and epistemic development are not analogous, since while biological variation is blind, epistemic variation is not. The generation of hypotheses, unlike the generation of genotypes, is not random. We argue that this objection is misguided and show how the central analogy of evolutionary epistemology can be preserved. The core of our reply is that much epistemic variation is indeed directed by heuristics, but these (...) heuristics are analogous to biological preadaptations which account for the evolution of complex organs. We also argue that many of these heuristics or epistemic preadaptations are not innate but were themselves generatedby a process of blind variation and selective retention. (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)

In this paper, we identify the parallels and the differences between language and life as evolvable systems in pursuit of a framework that will investigate language change from the perspective of a general theory of evolution. Despite the consensus that languages change similarly to species, as reflected in the construction of language trees, the field has mainly applied biological techniques to specific problems of historical linguistics and has not systematically engaged in disentangling the basic concepts (population, reproductive unit, inheritance, etc.) (...) and the core processes underlying evolutionary theory, namely mutation, selection, drift, and migration, as applied to language. We develop such a proposal. Treating language as an evolvable system places previous studies in a novel perspective, as it offers an elegant unifying framework that can accommodate current knowledge, utilize the rich theoretical framework of evolutionary biology, and synthesize many independent strands of inquiry, initiating a whole new research program. (shrink)

When Charles Darwin published his theory in 1859 the biological community gave very different receptions to the idea of evolution and to the theory of natural selection. Evolution was accepted as widely and rapidly as natural selection was rejected. Most biologists were ready to accept that evolution had occurred, but not that natural selection was its cause. They preferred other explanations of evolution, such as theories of big directed variation, or admitted that they did not know (...) its cause. Darwin himself never maintained that natural selection was the sole cause of evolution. He thought of it as one among several causes, and did not specify how much evolution had occurred by the natural selection of fortuitous variations, and how much by other factors such as the inherited effects of use and disuse. However, Darwin did maintain that natural selection was in principle capable of explaining all the observed properties of organisms. He did not think that there were some characteristics that were particularly likely to have evolved by natural selection, and other kinds that were not. Against this, many of this critics thought that there were characteristics that natural selection was particularly powerless to explain. Thus it could not account for characteristics that were detrimental, or those that seemed useless (such as species differences), or those that were of too little importance for natural selection to have favoured them. There were also characteristics of such complexity that it was unimaginable that natural selection could have built them up in tiny stages from fortuitous, undirected variants. The present essay will be concerned with just one, the last mentioned, of these kinds of characteristics. (shrink)

Many evolutionary models assume that behaviors are caused directly by genes. An implication is that behavioral uniformity should be found only in groups that are genetically uniform. Yet, the members of human social groups often behave in a uniform fashion, despite the fact that they are genetically diverse. Behavioral uniformity can occur through a variety of psychological mechanisms and social processes, such as imitation, consensus decision making, or the imposition of social norms. We present a series of models in which (...) genes code for social transmission rules, which in turn govern the behaviors that are adopted. Transmission rules can evolve in randomly formed groups that concentrate phenotypic variation at the between-group level, favoring the evolution of altruistic behaviors and other group-advantageous traits. In addition, a direct bias toward adopting altruistic behaviors can evolve. Our models begin to show how group selection can be a strong force in human evolution, despite the absence of extreme genetic variation among groups. (shrink)

The 1940s and 1950s were marked by intense debates over the origin of drug resistance in microbes. Bacteriologists had traditionally invoked the notions of ‘training’ and ‘adaptation’ to account for the ability of microbes to acquire new traits. As the field of bacterial genetics emerged, however, its participants rejected ‘Lamarckian’ views of microbial heredity, and offered statistical evidence that drug resistance resulted from the selection of random resistant mutants. Antibiotic resistance became a key issue among those disputing physiological vs. (...) genetic explanations of variation in bacteria. Postwar developments connected with the Lysenko affair gave this debate a new political valence.Proponents of the neo-Darwinian synthesis weighed in with support for the genetic theory. However, certain features of drug resistance seemed inexplicable by mutation and selection, particularly the phenomenon of ‘multiple resistance’—the emergence of resistance in a single strain against several unrelated antibiotics. In the late 1950s, Tsutomu Watanabe and his collaborators solved this puzzle by determining that resistance could be conferred by cytoplasmic resistance factors rather than chromosomal mutation. These R factors could carry resistance to many antibiotics and seemed able to promote their own dissemination in bacterial populations. In the end, the vindication of the genetic view of drug resistance was accompanied by a recasting of the ‘gene’ to include extrachromosomal hereditary units carried on viruses and plasmids. (shrink)

This chapter contains sections titled: Introduction Natural Selection Operates within Genomes without Regard for Phenotypic Effect Selective Forces, Heritable Variation, and the Definition of Function Natural Selection Can, and Does, Act on the Products of Individual Genes Natural Selection Can Act Directly on Genes Themselves What Are the Limitations on the Unit of Selection Being “the Gene”? The “Complexity” Argument: Do Complex Phenotypes Require Complex Explanations? Do “Epigenes/Epialleles” Provide a “Non‐genetic” Source of Heritable Variation (...) Upon Which Natural Selection May Act? Summary Points: The Usual Unit of Selection Is the Gene Postscript: Counterpoint Note References. (shrink)

Authors frequently refer to gene-based selection in biological evolution, the reaction of the immune system to antigens, and operant learning as exemplifying selection processes in the same sense of this term. However, as obvious as this claim may seem on the surface, setting out an account of “selection” that is general enough to incorporate all three of these processes without becoming so general as to be vacuous is far from easy. In this target article, we set out (...) such a general account of selection to see how well it accommodates these very different sorts of selection. The three fundamental elements of this account are replication, variation, and environmental interaction. For selection to occur, these three processes must be related in a very specific way. In particular, replication must alternate with environmental interaction so that any changes that occur in replication are passed on differentially because of environmental interaction. One of the main differences among the three sorts of selection that we investigate concerns the role of organisms. In traditional biological evolution, organisms play a central role with respect to environmental interaction. Although environmental interaction can occur at other levels of the organizational hierarchy, organisms are the primary focus of environmental interaction. In the functioning of the immune system, organisms function as containers. The interactions that result in selection of antibodies during a lifetime are between entities (antibodies and antigens) contained within the organism. Resulting changes in the immune system of one organism are not passed on to later organisms. Nor are changes in operant behavior resulting from behavioral selection passed on to later organisms. But operant behavior is not contained in the organism because most of the interactions that lead to differential replication include parts of the world outside the organism. Changes in the organism's nervous system are the effects of those interactions. The role of genes also varies in these three systems. Biological evolution is gene-based (i.e., genes are the primary replicators). Genes play very different roles in operant behavior and the immune system. However, in all three systems, iteration is central. All three selection processes are also incredibly wasteful and inefficient. They can generate complexity and novelty primarily because they are so wasteful and inefficient. Key Words: evolution; immunology; interaction; operant behavior; operant learning; replication; selection; variation. (shrink)

This paper describes a computational model of how ideas, or memes, evolve through the processes of variation, selection, and replication. Every iteration, each neural-network based agent in an artificial society has the opportunity to acquire a new meme, either through 1) INNOVATION, by mutating a previously-learned meme, or 2) IMITATION, by copying a meme performed by a neighbor. Imitation, mental simulation, and using past experience to bias mutation all increase the rate at which fitter memes evolve. Memes at (...) epistatic loci converged more slowly than memes at over- or underdominant loci. The higher the ratio of innovation to imitation, the greater the meme diversity, and the higher the fitness of the fittest meme. Optimization is fastest for the society as a whole with an innovation to imitation ratio of 2:1, but diversity is comprimized. (shrink)

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

This article discusses language universality and language variation, and suggests that there is no feature variation in initial syntax, featural variation arising by metamorphosis under transfer from syntax to PF-morphology. In particular, it explores the Zero Hypothesis, stating that Universal Grammar, UG, only provides two building elements, Root Zero and Edge Feature Zero, zero, as they are purely structural/formal elements with no semantic content in UG. Their potential content is provided by the Concept Mine, a mind-internal but (...) language-external department. UG and narrow syntax has access to the Concept Mine, and this Syntax-Concept Access is unique to humans, a prerequisite for the evolution of language (Section 1). A related idea (also inSection 1) is coined the Generalized Edge Feature Approach, GEFA. It states that Merge always involves at least one edge feature, which precludes symmetric structures and enables Simplest Merge (no Pair-Merge, no Hilbert epsilon operator). The article advocates that there is no syntactic feature selection (Section 2), all syntactic features being universally accessible in the Concept Mine, via Root Zero and Edge Feature Zero. In contrast, there is feature selection in PF (including morphology), yielding variation (Section 3), Gender being a clear example (Section 4). However, there is a widely neglected syntax-to-PF-morphology metamorphosis (Section 5), such that morphological features like [past] are distinct from albeit related to syntactic features like Speech Time. Parameters operate on selected PF features, and not on purely syntactic features, so parameter setting is plausibly closely tied to the syntax-to-PF-morphology metamorphosis (the concludingSection 6). It is suggested that parameters are on the externalization side of language, part of or related to the sensory-motor system, facilitating motoric learning in language acquisition. (shrink)

Natural selection is an important force that shapes the evolution of all living things by determining which individuals contribute the most descendents to future generations. The biological unit upon which selection acts has been the subject of serious debate, with reasonable arguments made on behalf of populations, individuals, individual phenotypic characters and, finally, individual genes themselves. In this essay, I argue that the usual unit of selection is the gene. There are powerful logical arguments in favor of (...) this conclusion, as well as many real-world examples. I also explore the possibility that epigenetic differences between individuals may be heritable between generations. Although few such examples exist, epigenetic differences provide an exciting source of potentially heritable variation that may allow rapid evolutionary change to occur, perhaps in response to environmental influences. (shrink)

Evolutionary processes have two underlying mechanisms: variation (expanding options) and selection (narrowing options). Darwin and Darwinism focused on the selectional mechanism, i.e., natural selection. If an evolutionary process is seen as pushing towards higher altitudes on a multi-peaked and cloudy “fitness landscape,” then selection is a hill-climbing mechanism while a mechanism for variation would explore to find higher hills. Selection without variation might get stuck on a low hill. Our thesis is that the (...) best solution for the problem of variation is parallel experimentation with the different probes having some semi-isolation from selectional pressure and where results in the experiments can be cross-communicated and compared to ratchet up the performance of the whole group. Our approach is by seeking out the common elements addressing the problem of variation in evolutionary theory (Sewall Wright’s shifting balance theory), in various search procedures, in the selection of economic projects, and in science and technology development. The opposite strategy is series experimentation which assumes that one is already climbing the highest peak so consideration of other peaks is irrelevant. The main critical applications are to global institutions such as the World Bank or IMF who do not condone parallel experimentation since they already “know” what is the highest peak—and, more generally, to those in power on top of a low hill who know that any real variation would be downhill for them. (shrink)

This paper couples the variation and selection analogy utilized in evolutionary epistemology with the hermeneutical insight that novel data and theoretical texts are obscure in meaning. Dissensus must be valued as a distancing mechanism of variation on the space of possible meanings while argumentation attacks the initial obscurity. The objection that evolutionary accounts can only describe practice is countered by indicating how dissensus has normative purchase wherever science is producing novel text.

Sexual selection processes have received much attention in recent years, attention reflected in interest in human mate preferences. Among these mate preferences are preferences for physical attractiveness. Preferences in and of themselves, however, do not fully explain the nature of the relationships that individuals attain. A tacit negotiation process underlies relationship formation and maintenance. The notion that preferences for physical attractiveness evolved under parasite-driven “good genes” sexual selection leads to predictions about the nature of trade-offs that individuals make (...) between mates’ physical attractiveness and investment potential. These predictions and relevant data are explored, with a primary emphasis on women’s preferences for men’s qualities. In addition, further implications of trade-offs are examined, most notably (a) the impact of environmental variations on the nature of mating and (b) some effects of trade-offs on infidelity and male attempts to control women. (shrink)

An analysis of biological selection aimed at deriving a mechanism-independent definition removes Hull et al.'s obligatory requirement for replication of the carriers of information, under conditions, such as those obtaining in the nervous system, where the information content of a carrier can be modified without duplication by an amount controlled by the outcome of interactions with the environment.

Recent research into human origins has largely focused on deducing past events and processes from current patterns of genetic variation. Some human genes possess unexpectedly low diversity, seemingly resulting from events of the late Pleistocene. Such anomalies have previously been ascribed to population bottlenecks or selection on genes. For four species of matrilineal whale, evidence suggests that cultural evolution may have reduced the diversity of genes which have similar transmission characteristics to selective cultural traits, through a process called (...) cultural hitchhiking. Cultural evolution is characteristic of human societies and so should be considered as a potential determinant of human genetic diversity. A stochastic simulation of gene and cultural dynamics in an array of hunter-gatherer tribes shows that cultural selection has the potential to severely reduce genetic diversity if: inter-tribe gene flows are reasonably low (<~0.6-15 genes/tribe/generation); cultural evolution changes fitness by >~0.3-3%/generation; and fitness is changed more by cultural innovation within a tribe than cultural assimilation from neighboring tribes. Thus cultural hitchhiking may explain low diversity and short coalescence times in mitochondrial and, especially, Y-linked human genes. (shrink)

This paper gives a detailed narrative of a controversial empirical research in postwar population genetics, the analysis of the cytological polymorphisms of an Australian grasshopper, Moraba scurra. This research intertwined key technical developments in three research areas during the 1950s and 1960s: it involved Dobzhansky’s empirical research program on cytological polymorphisms, the mathematical theory of natural selection in two-locus systems, and the building of reliable estimates of natural selection in the wild. In the mid-1950s the cytologist Michael White (...) discovered an interesting case of epistasis in populations of Moraba scurra. These observations received a wide diffusion when theoretical population geneticist Richard Lewontin represented White’s data on adaptive topographies. These topographies connected the information on the genetic structure of these grasshopper populations with the formal framework of theoretical population genetics. As such, they appeared at the time as the most successful application of two-locus models of natural selection to an empirical study system. However, this connection generated paradoxical results: in the landscapes, all grasshopper populations were located on a ridge while they were expected to reach a peak. This puzzling result fueled years of research and triggered a controversy attracting contributors from Australia, the United States and the United Kingdom. While the original problem seemed, at first, purely empirical, the subsequent controversy affected the main mathematical tools used in the study of two-gene systems under natural selection. Adaptive topographies and their underlying mathematical structure, Wright’s mean fitness equations, were submitted to close scrutiny. Suspicion eventually shifted to the statistical machinery used in data analysis, reflecting the crucial role of statistical inference in applied population genetics. In the 1950s and 1960s, population geneticists were not simply in search for new generalizations about the evolutionary process and for new evidence about genetic variation: struggling against statistical artifacts, they were searching for reliable tests and descriptors to analyze their data. (shrink)