Cancer is an evolutionary and ecological process in which complex interactions between tumour cells and their environment share many similarities with organismal evolution. Tumour cells with highest adaptive potential have a selective advantage over less fit cells. Naturally occurring transmissible cancers provide an ideal model system for investigating the evolutionary arms race between cancer cells and their surrounding micro‐environment and macro‐environment. However, the evolutionary landscapes in which contagious cancers reside have not been subjected to comprehensive investigation. Here, (...) we provide a multifocal analysis of transmissible tumour progression and discuss the selection forces that shape it. We demonstrate that transmissible cancers adapt to both their micro‐environment and macro‐environment, and evolutionary theories applied to organisms are also relevant to these unique diseases. The three naturally occurring transmissible cancers, canine transmissible venereal tumour (CTVT) and Tasmanian devil facial tumour disease (DFTD) and the recently discovered clam leukaemia, exhibit different evolutionary phases: (i) CTVT, the oldest naturally occurring cell line is remarkably stable; (ii) DFTD exhibits the signs of stepwise cancer evolution; and (iii) clam leukaemia shows genetic instability. While all three contagious cancers carry the signature of ongoing and fairly recent adaptations to selective forces, CTVT appears to have reached an evolutionary stalemate with its host, while DFTD and the clam leukaemia appear to be still at a more dynamic phase of their evolution. Parallel investigation of contagious cancer genomes and transcriptomes and of their micro‐environment and macro‐environment could shed light on the selective forces shaping tumour development at different time points: during the progressive phase and at the endpoint. A greater understanding of transmissible cancers from an evolutionary ecology perspective will provide novel avenues for the prevention and treatment of both contagious and non‐communicable cancers. (shrink)

Similar to parasites, malignant cells exploit the host for energy, resources and protection, thereby impairing host health and fitness. Although cancer is widespread in the animal kingdom, its impact on life history traits and strategies have rarely been documented. Devil facial tumour disease, a transmissible cancer, afflicting Tasmanian devils, provides an ideal model system to monitor the impact of cancer on host life-history, and to elucidate the evolutionary arms-race between malignant cells and their hosts. Here we provide an overview (...) of parasite-induced host life history adaptations, then both phenotypic plasticity of LH responses and changes in allele frequencies that affect LH traits of Tasmanian devils in response to DFTD are discussed. We conclude that akin to parasites, cancer can directly and indirectly affect devil LH traits and trigger host evolutionary responses. Consequently, it is important to consider oncogenic processes as a selective force in wildlife. Exposure to transmissible cancer cells, i.e., Tasmanian devil facial tumour cells, can cause changes to life history traits either as the result of phenotypic plasticity in response to exposure during the lifetime of the individual or as the result of evolutionary change in LH traits due to selection over generations.Photo credits: Frédéric Thomas, Sarah Peck, Geordie Jennings. (shrink)

This response (a) integrates non-equilibrium evolutionary genetic models, such as coevolutionary arms-races and recent selective sweeps, into a framework for understanding common, harmful, heritable mental disorders; (b) discusses the forms of ancestral neutrality or balancing selection that may explain some portion of mental disorder risk; and (c) emphasizes that normally functioning psychological adaptations work against a backdrop of mutational and environmental noise. (Published Online November 9 2006).

Leigh Van Valen was an American evolutionary biologist who made major contributions to evolutionary theory. He is particularly remembered for his groundbreaking paper “A New Evolutionary Law” (1973) where he provided evidence from fossil record data that the probability of extinction within any group remains essentially constant through time. In order to explain such an unexpected result, Van Valen formulated a very influential idea that he dubbed the “Red Queen hypothesis.” It states that the constant decay must (...) be a consequence of evolutionary interactions among connected species within ecological networks. In Van Valen’s picture, species do not merely evolve: they also coevolve with other species. As a consequence, when thinking about adaptation to an external environment, the other species must be considered as part (maybe a major part) of such an external world. Van Valen’s law provided the first complex systems theory of coevolutionary dynamics and inspired a whole range of theoretical and experimental developments from very diverse fields, percolating far beyond its original formulation. Red Queen arms races are nowadays considered a widespread feature of complex adaptive systems. (shrink)

The molecular evolution of pituitary growth hormone and prolactin in mammals shows two unusual features: episodes of markedly accelerated evolution and, in some species, complex families of related proteins expressed in placenta and resulting from multiple gene duplications. Explanations of these phenomena in terms of physiological adaptations seem unconvincing. Here, I propose an alternative explanation, namely that these evolutionary features reflect the use of the hormones (and their receptors) as viral receptors. Episodes of rapid evolution can then be explained (...) as due to “arms races” in which changes in the hormone lead to reduced interaction with the virus, and subsequent changes in the virus counteract this. Placental paralogues of the hormones could provide decoys that bind viruses, and protect the foetus against infection. The hypothesis implies that the extensive changes introduced into growth hormone, prolactin and their receptors during the course of mammalian evolution reflect viral interactions, not endocrine adaptations. (shrink)

To be human is to imitate. This is a strong claim, and a contentious one. It implies that the turning point in hominid evolution was when our ancestors first began to copy each other’s sounds and actions, and that this new ability was responsible for transforming an ordinary ape into one with a big brain, language, a curious penchant for music and art, and complex cumulative culture. The argument, briefly, is this. All evolutionary processes depend on information being copied (...) with variation and selection. Most living things on earth are the product of evolution based on the copying, varying and selection of genes. However, once humans began to imitate they provided a new kind of copying and so let loose an evolutionary process based on the copying, varying and selection of memes. This new evolutionary system co-evolved with the old to turn us into more than gene machines. We, alone on this planet, are also meme machines. We are selective imitation devices in an evolutionary arms race with a new replicator. This is why we are so different from other creatures; this is why we alone have big brains, language and complex culture. There are many contentious issues here; the nature and status of memes, the validity of the concept of a replicator, the difference between this and other theories of gene-culture co-evolution, and whether memetics really is necessary, as I believe it is, to explain human nature. I shall outline the basic principles of memetics, show how memes could have driven human evolution, and consider some of these questions along the way. (shrink)

We consider modifications to the standard David Lewis signaling game and relax a number of unrealistic implicit assumptions that are often built into the framework. In particular, we motivate and explore various asymmetries that exist between the sender and receiver roles. We find that endowing receivers with a more realistic set of responses significantly decreases the likelihood of signaling, while allowing for unequal selection pressure often has the opposite effect. We argue that the results of this article can also help (...) make sense of a well-known evolutionary puzzle regarding the absence of an evolutionary arms race between sender and receiver in conflict-of-interest signaling games. (shrink)

If evolutionary history were to be replayed from the beginning, what would be the same, and what would be likely different? Would there be a human-like species, multicellularity, or even DNA? There is a great variety in the answers biologists give to this question, despite having the same access to empirical data and biological theory. For instance, Stephen J. Gould has claimed that evolutionary history is radically contingent, while Conway Morris holds that it converges onto specific biological structures (...) that are favored by natural selection. Others such have proposed that evolutionary history is characterized by an inexorable increase in complexity, while others see it as an evolutionary arms race. In this dissertation I investigate the fundaments underlying claims biologists make about contingency and directionality in evolutionary history as a whole. The topics of convergence and contingency have received attention from philosophers of biology in recent years, but the foundations of interpretations of evolutionary history as a whole remains a relatively neglected field. Hence the primary objective of this dissertation was not to defend this or that account, but rather to show a method by which these fundamental issues can be identified and analyzed constructively. The dissertation is organized into two parts, each dedicated to a single problem. The first part concerns the problem of ‘description dependence’: claims about the contingency of evolutionary outcomes depend on how these outcomes and the evolutionary process itself are described. I set out to map the different ways in which the contingency of outcomes changes as the phenomena are described in more and in less detail, and as broader or narrower subsets of evolutionary history are taken into account. That such an analysis is useful to pursue, I attempt to show by applying it to two of the most prominent interpretations of evolutionary history, those of Gould and Conway Morris. According to how their claims about evolutionary history are analyzed, one can arrive at opposing conclusions about the contingency of evolutionary outcomes. The second part concerns the problem of ‘causal complexity’: evolutionary history is a complex mess of unrelated causal processes, and for every generalization there is an exception. This raises the question whether non-speculative generalizations over evolutionary history as a whole are even possible. Limiting the scope of the investigation to the mechanism of natural selection alone, I consider first whether and how natural selection may be expected to give rise to trends at all. Some philosophers reject that natural selection is a cause at all, and that all evolution is simply an accumulation of births and deaths. If any trend occurs at all, it is due to a confluence of unrelated causal processes that could easily not have occurred. I argue against this by showing that these philosophers overlook the issue of time-scale: causal processes may make a difference for reproductive outcome at a time-scale of a single generation without them making a difference at the time-scale of multiple generations. With this distinction in mind, one can argue that natural selection causes a population to tend towards equilibrium. If a yet longer time-scale is taken – not that of multiple generations in a single environment, but that of many species and genuses across many environments – the challenge of causal complexity becomes much more difficult to overcome. Drawing on the phenomenon of phenotypic plasticity and niche construction, I argue that selection for plasticity ‘feeds’ on this complexity and variability in the environment. The trend in plasticity is unique in this regard, since trends in other types of adaptation are interrupted by the variability of complex environments. (shrink)

Capturing a scientific change in thinking about personality and individual differences that has been building over the past 15 years, this volume stands at an important moment in the development of psychology as a discipline. Rather than viewing individual differences as merely the raw material upon which selection operates, the contributing authors provide theories and empirical evidence which suggest that personality and individual differences are central to evolved psychological mechanisms and behavioral functioning. The book draws theoretical inspiration from life history (...) theory, evolutionary genetics, molecular genetics, developmental psychology, personality psychology, and evolutionary psychology, while utilizing the theories of the "best and the brightest" international scientists working on this cutting edge paradigm shift. In the first of three sections, the authors analyze personality and the adaptive landscape; here, the authors offer a novel conceptual framework for examining "personality assessment adaptations." Because individuals in a social environment have momentous consequences for creating and solving adaptive problems, humans have evolved "difference-detecting mechanisms" designed to make crucial social decisions such as mate selection, friend selection, kin investment, coalition formation, and hierarchy negotiation. In the second section, the authors examine developmental and life-history theoretical perspectives to explore the origins and development of personality over the lifespan. The third section focuses on the relatively new field of evolutionary genetics and explores which of the major evolutionary forces--such as balancing selection, mutation, co-evolutionary arms races, and drift--are responsible for the origins of personality and individual differences. Existing as a seminal work in the newly emerging evolutionary psychology field, this book is a "must-read" for anyone invested in the development of psychology as a field. (shrink)

Electronics can be defined as electromagnetic technology dealing with information, and meta-electronics as a field encompassing all the synergistic technologies in which electronics plays a dominant role. Examining the broad field corresponding to this definition we realize that its history starts some seventy years earlier than the customarily accepted birth of electronics, and, what is more significant, that electronics undergoes a true evolution. This new evolution creates rich, diverse structures similar to those created by the biological evolution. Like biology, electronics (...) is non-teleological, which allows for its unlimited evolutionary development. We propose electronic analogies of all essential biological categories, at all levels: population, speciation, common ancestor, phenotype, extended phenotype, co-evolution, convergent evolution, evolutionary arms race, extinction and mass extinction, hierarchical levels, generative entrenchment, genes, alleles, genome, genetic pool, recombination, mutation, genetic drift, lateral gene transfer, etc. The evolutionary algorithm operating in electronics, like a Darwinian one, includes variation within a population of device models, heredity, natural selection, and a form of selection based on aesthetics and fashion which resembles sexual selection. Algorithm is especially similar to artificial selection, thus possessing directionality in the variational part. Electronic development is orders of magnitude faster than biological, accelerated by that directionality and by other distinct, identifiable mechanisms. Speciation in electronics, as in biology, is best represented on a phylogenetic tree, which starts from a common ancestor, but lately exhibits a unification trend. If continued, this trend may lead to the appearance of a common descendant absent in biology. Our analysis may explain emerging anti-social aspects of electronics and our conclusions add new urgency to recent concerns with unchecked development of Artificial Intelligence. (shrink)

Against the background of “arms race” style competitive explanations for complex human cognition, such as the Social Intelligence Hypothesis Growing points in ethology, Cambridge University Press, pp 303–317, 1976; Jolly in Science, 10.1126/science.153.3735.501, 1966), and theories that tie complex cognition with environmental variability more broadly The evolution of intelligence, Lawrence Earlbaum and Associates, 2001), the idea that culturally inherited mechanisms for social cognition would be more capable of responding to the labile social environment is a compelling one. Whilst it is (...) tempting to think that the evolvability of culturally inherited cognitive mechanisms such as Cecilia Heyes’ cognitive gadgets would be akin to culturally inherited tools like axes or canoes, I draw on established theory in evolutionary developmental biology to show that this is a mistake. Their causal translucency, along with the degree to which they would be integrated within the organism, make cognitive gadgets far more like genetically inherited traits with respect to their evolvability. Consequently, their evolution is unlikely to be particularly fast or nimble. In making clear the constraints on the evolution of culturally inherited cognition and how they must influence our theorising the discussion also highlights the value of thinking about evolvability in this domain. (shrink)

Despite wide acceptance that the attributes of living creatures have appeared through a cumulative evolutionary process guided chiefly by natural selection, many human activities have seemed analytically inaccessible through such an approach. Prominent evolutionary biologists, for example, have described morality as contrary to the direction of biological evolution, and moral philosophers rarely regard evolution as relevant to their discussions. -/- The Biology of Moral Systems adopts the position that moral questions arise out of conflicts of interest, and that (...) moral systems are ways of using confluences of interest at lower levels of social organiation to deal with conflicts of interest at higher levels. Moral systems are described as systems of indirect reciprocity: humans gain and lose socially and reproductively not only by direct transactions, but also by the reputations they gain from the everyday flow of social interactions. -/- The author develops a general theory of human interests, using senescence and effort theory from biology, to help analye the patterning of human lifetimes. He argues that the ultimate interests of humans are reproductive, and that the concept of morality has arisen within groups because of its contribution to unity in the context, ultimately, of success in intergroup competition. He contends that morality is not easily relatable to universals, and he carries this argument into a discussion of what he calls the greatest of all moral problems, the nuclear arms race. (shrink)

Some practical criteria for free-will are suggested where free-will is a matter of degree. It is argued that these are more appropriate than some extremely idealised conceptions. Thus although the paper takes lessons from philosophy it avoids idealistic approaches as irrelevant. A mechanism for allowing an agent to meet these criteria is suggested: that of facilitating the gradual emergence of free-will in the brain via an internal evolutionary process. This meets the requirement that not only must the choice of (...) action be free but also choice in the method of choice, and choice in the method of choice of the method of choice etc. This is directly analogous to the emergence of life from non-life. Such an emergence of indeterminism with respect to the conditions of the agent fits well with the `Machiavellian Intelligence Hypothesis' which posits that our intelligence evolved (at least partially) to enable us to deal with social complexity and modelling `arms races'. There is a clear evolutionary advantage in being internally coherent in seeking to fulfil ones goals and unpredictable by ones peers. To fully achieve this vision several other aspects of cognition are necessary: open-ended strategy development; the meta-evolution of the evolutionary process; the facility to anticipate the results of strategies; and the situating of this process in a society of competitive peers. Finally the requirement that reports of the deliberations that lead to actions need to be socially acceptable leads to the suggestion that the language that the strategies are developed within be subject to a normative process in parallel with the development of free-will. An appendix outlines a philosophical position in support of my position. (shrink)

Recently, we found that the Pseudomonas aeruginosa type II secreted protease IV functions as a unique Arabidopsis innate immunity elicitor. The protease IV‐activated pathway involves G protein signaling and raises the question of how protease elicitation leads to the activation of G protein‐mediated signaling, because plants do not appear to have metazoan‐like G protein‐coupled receptors. Importantly, our data suggest that Arabidopsis has evolved a mechanism to detect the proteolytic activity of a pathogen‐encoded protease, supporting the host‐pathogen arms race model. In (...) the case of opportunistic multi‐host pathogens like P. aeruginosa, however, it is not plausible that P. aeruginosa is simultaneously co‐evolving in a gene‐for‐gene manner with all of its potential hosts, which include plants, nematodes, insects, and mammals. This prompts us to ask what is the driving force for co‐evolution of defense response in Arabidopsis and pathogenesis of P. aeruginosa, which might not have been subject to iterative cycles of evolutionary selections. (shrink)

Two recent hypotheses have proposed that non‐green plant colouration evolved as a defence against herbivores, either as protective colouration promoting handicap signals indicating plant fitness or by undermining their crypsis. The handicap hypothesis posits a co‐evolutionary process between plants and herbivores, whereas the anti‐crypsis hypothesis suggests that an arms race between insects and plants is the evolutionary mechanism. Both explanations assume that insects are the evolutionary origin causing plants' colouration. Here, we propose a different hypothesis, termed the (...) “Defence Indication hypothesis”. This idea focuses on the multiple protective functions of anthocyanins and carotenoids as pigments, and suggests that plant colouration evolved primarily in response to various stressors. Because pigments and defensive compounds share a common biosynthesis, the production of pigments also provides elevated defensive strengths against herbivores, a process termed priming. In effect, the Defence Indication hypothesis predicts that pleiotropic effects of the pigments and, more generally, plants' shared defence responses, explain why insects might react to plant colouration. BioEssays 28:65–71, 2006. © 2005 Wiley Periodicals, Inc. (shrink)

Species evolve, very slowly, through selection of genes which give rise to phenotypes well adapted to their environments. The cultures, including the languages, of human communities evolve, much faster, maintaining at least a minimum level of adaptedness to the external, non- cultural environment. In the phylogenetic evolution of species, the transmission of information across generations is via copying of molecules, and innovation is by mutation and sexual recombination. In cultural evolution, the transmission of information across generations is by learning, and (...) innovation is by sporadic invention or borrowing from other cultures. This much is the foundational bedrock of evolutionary theory. But things get more complicated; there can be gene-culture co-evolution. Prior to the rise of culture, the physical environment is the only force shaping biological evolution from outside the organism, and cultures themselves are clearly constrained by the evolved biological characteristics of their members. But cultures become part of the external environment, and influence the course of biological evolution. For example, altruistic cultures with developed medical knowledge reduce the cost to the individual of carrying genes disposing to certain pathologies (such as diabetes); and such genes become more widespread in the populations maintaining such cultures. Assortative mating can affect biological evolution, and particular cultures may influence the factors which are sorted for in mating. (For a careful discussion of the effects of cultural evolution on natural selection, see Cavalli-Sforza and Bodmer, 1971:774- 804). This paper examines mechanisms involved in the co-evolution of a biological trait, the critical period for language acquisition, and a property of human cultures, the size of their languages. A gene/culture interaction will be shown that can be described as a kind of symbiosis, but perhaps more aptly as an `arms race'. In this introduction, we will sketch the basic mechanics of the interaction in very broad terms; the rest of the paper will explain and justify the details. The implications of our model for second language acquisition are given toward the end of the paper. (shrink)

Evolutionary attempts to explain morality tend to say very little about what morality is. If evolutionary game theory aspires not merely to solve the ‘problem of altruism', but to explain human morality or justice in particular, it requires an appropriate conception of that subject matter. This paper argues that one plausible conception of morality (a sanction-based conception) creates some important constraints on the kinds of evolutionary explanations that can shed light on morality. Game theoretic approaches must either (...) meet these constraints, or defend an alternative conception of morality. Skyrms’ model of the evolution of justice is found to violate the constraints imposed by the sanction-based conception. (shrink)

We model the evolution of international conflict as a game of sequential decisions and show that arms races are neither necessary nor sufficient for peace or war. Peaceful intentions are not adequate to insure peace, even when both rivals wish to avoid violence. Peaceful intentions together with complete information are sufficient for peace. A preference for forcefully pursuing foreign policy goals also is not sufficient to preclude the peaceful resolution of disputes, and this is true even if there is complete (...) information. In some circumstances, the absence of an arms race can precipitate violence, even giving the military advantage to a nation that unilaterlaly stopped getting ready for a war it would initiate. Finally, we also show that empirical research is likely to be biased in favor of the hypothesis that deterrence leads to peace. (shrink)

We model the evolution of international conflict as a game of sequential decisions and show that arms races are neither necessary nor sufficient for peace or war. Peaceful intentions are not adequate to insure peace, even when both rivals wish to avoid violence. Peaceful intentions together with complete information are sufficient for peace. A preference for forcefully pursuing foreign policy goals also is not sufficient to preclude the peaceful resolution of disputes, and this is true even if there is complete (...) information. In some circumstances, the absence of an arms race can precipitate violence, even giving the military advantage to a nation that unilaterally stopped getting ready for a war it would initiate. Finally, we also show that empirical research is likely to be biased in favor of the hypothesis that deterrence leads to peace. (shrink)

By using interactive computer graphics (ICG), it is possible to discuss the numerical aspects of some arms race issues with more specificity and in a visual way. The number of variables involved in these issues can be quite large; computers operated in the interactive, graphical mode, can allow exploration of the variables, leading to a greater understanding of the issues. This paper will examine some examples of interactive computer graphics: (1) The relationship between silo hardening and the accuracy, yield, and (...) reliability of ICBMs; (2) Target vulnerability (Minuteman, Dense Pack); (3) Counterforce vs. countervalue weapons; (4) Civil defense; (5) Gravitational bias error; (6) MIRV; (7) National vulnerability to a preemptive first strike; (8) Radioactive fallout; and (9) Digital image processing with charge-coupled devices. (shrink)

Large-scale weapons systems have increasingly become part of a patronage system justified by claims about national defense. American politics tends to proceed by distribution, redistribution, and compromise. The disjunction between the "virtually" autonomous processes of worldwide weapons innovation and American incrementalism lead to a potentially disastrous situation. This situation is characterized by potential chaos in the integration of complex, interdependent combat and communication systems as well as a mindless arms race that seems to defy political control. A modest proposal is (...) made to suggest a potential bureaucratic change agent. (shrink)

This article defends the view that markets in education need to be restricted, in light of the problem posed by what I call the ‘educational arms race’. Markets in education have a tendency to distort an important balance between education’s role as a gatekeeper – its ‘screening’ function – and its role in helping children develop as part of a preparation for adult life. This tendency is not merely a contingent fact about markets: It can be traced to ways in (...) which education is a partly positional good and how markets respond to demand for positional goods over non-positional goods. The problem with arms races is that they allow markets to facilitate wider use of defection in a collective action problem. Using these claims, I argue that markets in education have a distinctive tendency to become objectionably exploitative. I conclude by applying some of my conclusions to illuminate various egalitarian claims about justice in education. (shrink)

Despite progress in negotiating treaties to ban deployment of particular classes of weapons, such as the Intermediate Nuclear Forces Treaty, the "qualitative" arms race remains largely uncontrolled. Supposed theoretical obstacles, based on various versions of technological determinism, need not be a barrier to practical efforts, however. The reasoning usually cited to explain the competition does not preclude agreement to control it. The varcous perspectives on weapons procurement—realist, action-reaction, bureaucratic politics, technological imperative, and economic—are, as the case of the Strategic Defense (...) Initiative indicates, all subordinate to the "primacy of politics. " Given political will, even the qualitative arms race is amenable to control. (shrink)

Traditional concern for the gradual, incremental effects of climate change remains; but now greater attention is being paid to the possibility of breaching major thresholds in the climate system with catastrophic consequences. It might be thought that the potential for abrupt climate change (a) undermines the usual (economic, psychological, and intergenerational) analyses of the climate change problem, and (b) in doing so helps us to act. Against this, I argue both that much of the psychological and intergenerational analyses remains in (...) place, and that abrupt climate change may make action more difficult, perhaps even setting off an intergenerational arms race. (shrink)

ABSTRACT This paper considers the four ways that the concept of ‘irrationality’ has been employed by members of the European peace movement in their evaluation of current bloc tensions. Against Bernard Williams who has recently taken issue with the peace movement's alleged tendency to dismiss political realities, the present author argues that the use of the language of irrationality reveals just the opposite orientation. Finally, it is argued that although the language of irrationality constitutes a powerful descriptive and normative instrument, (...) as an explanation of the Cold War it is a nonstarter. (shrink)

Game theoretic explanations of the evolution of human behavior have become increasingly widespread. At their best, they allow us to abstract from misleading particulars in order to better recognize and appreciate broad patterns in the phenomena of human social life. We discuss this explanatory strategy, contrasting it with the particularist methodology of contemporary evolutionary psychology. We introduce some guidelines for the assessment of evolutionary game theoretic explanations of human behavior: such explanations should be representative, robust, and flexible. Distinguishing (...) these features sharply can help to clarify the import and accuracy of game theorists' claims about the robustness and stability of their explanatory schemes. Our central example is the work of Brian Skyrms, who offers a game theoretic account of the evolution of our sense of justice. Modeling the same Nash game as Skyrms, we show that, while Skyrms' account is robust with respect to certain kinds of variation, it fares less well in other respects. (shrink)

This article questions the ability of strategic planners to assess adequately the kinds of weapons development and deployment decisions they make, given that the strategic weapons system lacks any usable definition of system failure. Lacking a coherent understanding of system failure means that the positive feedback loops within the system are unrestrained by effective negative feedback In such circumstances, it is not surprising that subunits of the larger system substitute definitions of success for the subunit for definitions applicable to the (...) total system. (shrink)

Contingencies of the early nuclear arms race Content Type Journal Article Pages 1-23 DOI 10.1007/s11016-010-9495-z Authors S. S. Schweber, Department of the History of Science, Harvard University, Science Center 371, Cambridge, MA 02138, USA Alex Wellerstein, Department of the History of Science, Harvard University, Science Center 371, Cambridge, MA 02138, USA Ethan Pollock, Department of History, Box N, Brown University, Providence, RI 02912, USA Barton J. Bernstein, History Department, Building 200, Stanford University, Stanford, CA 94305-2024, USA Michael D. Gordin, History (...) Department, 305 Dickinson Hall, Princeton University, Princeton, NJ 08544, USA Journal Metascience Online ISSN 1467-9981 Print ISSN 0815-0796. (shrink)

Plants have evolved systems analogous to animal innate immunity that recognise pathogen‐associated molecular patterns (PAMPs). PAMP detection is an important component of non‐host resistance in plants and serves as an early warning system for the presence of potential pathogens. Binding of a PAMP to the appropriate pattern recognition receptor leads to downstream signalling events and, ultimately, to the induction of basal defence systems. To overcome non‐host resistance, pathogens have evolved effectors that target specific regulatory components of the basal defence system. (...) In turn, this has led to the evolution in plants of cultivar‐specific resistance mediated by R proteins, which guard the targets of effectors against pathogen manipulation; the arms race continues. BioEssays 28: 880–889, 2006. © 2006 Wiley periodicals, Inc. (shrink)

This paper argues that there is an urgent need for an international doctrine for cyberspace skirmishes before they escalate into conventional warfare.

I review six bad arguments for banning performance-enhancing drugs from sports--and a seventh good one.

One characteristic of the transition from the Middle Paleolithic to the Upper Paleolithic in Europe was the emergence of representational charcoal drawings and engravings by Aurignacian and Gravettian artists. European Neanderthals never engaged in representational drawing during the Middle and Early Upper Paleolithic, a property that might reflect less developed visuomotor coordination. This article postulates a causal relationship between an evolved ability of anatomically modern humans to throw spears accurately while hunting and their ability to draw representational images from working (...) memory. Unlike Neanderthals, archaic and anatomically modern humans in sub-Saharan Africa adopted longer-range hunting practices using hand-cast spears as a compensation for the emergence of increasingly wary game. For Neanderthals, paleoclimatic fluctuations likely precluded consistent hunting of cold-adapted game, a property making game more approachable for close-range hunting with thrusting spears. As evidence of less historical wariness of humans, many of the species hunted by Neanderthals were eventually domesticated. Due to strong sources of natural selection on archaic and anatomically modern humans for effective hunting, the parietal cortex that integrates visual imagery and motor coordination expanded progressively, yielding the globular shape of the human cranium that is not evident in Neanderthals. To characterize how the cognitive properties employed for throwing spears and drawing line work are similar, the Upper Paleolithic drawings of animals in Chauvet cave, France, are discussed in the speculative context of how these artists engaged simultaneously in overt attention to guide their hand movements and covert attention to their mental images during the drawing process. (shrink)

"I know of no safe repository of the utlimate power of society but the people. And if we think them not enlightened enough, the remedy is not to take power from them, but to inform them by education." Thomas Jefferson, 1820.