共查询到20条相似文献,搜索用时 31 毫秒
1.
Scott Woodcock 《Biology & philosophy》2006,21(2):213-234
My aim in this paper is to demonstrate that a very simple learning rule based on imitation can help to sustain altruism as
a culturally transmitted pattern or behaviour among agents playing a standard prisoner’s dilemma game. The point of this demonstration
is not to prove that imitation is single-handedly responsible for existing levels of altruism (a thesis that is false), nor
is the point to show that imitation is an important factor in explanations for the evolution of altruism (a thesis already
prominent in the existing literature). The point is to show that imitation contributes to the evolution of altruism in a particular
way that is not always fairly represented by evolutionary game theory models. Specifically, the paper uses a simple model
to illustrate that cultural transmission includes mechanisms that do not transmit phenotype vertically (i.e. from parent to
related offspring) and that these mechanisms can promote altruism in the absence of any direct biological propensity favouring
such behaviour. This is a noteworthy result because it shows that evolutionary models can be built to explicitly reflect the
contribution of non-vertical transmission in our explanations for the evolution of altruism among humans and other social
species. 相似文献
2.
Abstract. Gravistimulation was investigated as a potential and unwanted component in the interpretation of physiological investigations on plants. Using both seedlings and mature sunflower plants, two situations are described where gravistimulation contributes significantly to the outcome of an experiment not initially designed to include this parameter. The number of adventitious roots formed in derooted seedings decreased when the tops of the plants were allowed to bend over under their own weight, and the effect correlated positively with the rate of ethylene production by non-vertical stems. In droughted mature plants, and increase in leaf and stem ethylene caused by water stress was supplemented by additional ethylene produced in the lower halves of stems. Drought had caused these stem tissues to wilt, become gravistimulated, and thus produce more ethylene. Other situations in which gravistimulated ethylene production and its physiological consequences are likely to be complicating factors in experiments are discussed. It is concluded that procedures that unnecessarily place experimental material in non-vertical orientations should be avoided. 相似文献
3.
In this article, we argue that policymakers in America should reference a coherent, comprehensive, and child-centered framework for children. That is, based on an extensive review of the empirical literature on the first two decades of life, we conclude that policies should address the needs of young people throughout the first two decades of life. In addition, public policies should address the multiple contexts within which young people develop, and the multiple domains that represent positive development, such as cognitive, psychological, physical, social, emotional, and civic domains. By referencing such a framework, we posit that public policies would be more effective and efficient. We conclude with multiple recommendations that would be first steps to putting this framework into practice. 相似文献
4.
There are relatively few existing studies examining neuropsychological functioning in social phobia (SP), which collectively yield mixed results. Interpretation of results is further complicated by a number of methodological inconsistencies across studies, including the examination of neuropsychological domains in relative isolation from one another. The present study utilized a broader collection of neuropsychological tests to assess nine domains of functioning in 25 individuals diagnosed with generalized SP and 25 nonpsychiatric controls (NC). A mixed ANOVA revealed neither a significant group by domain interaction, nor a significant main effect of group. Furthermore, no significant group differences emerged between the SP and NC groups within each specific neuropsychological domain. These findings suggest that underlying neuropsychological deficits are not likely to account for the information processing biases observed in the empirical literature, and appear to be consistent with current theoretical models which argue for the specificity of these biases to social information. 相似文献
5.
Katharine MacDonald 《Human nature (Hawthorne, N.Y.)》2007,18(4):386-402
This paper is a cross-cultural examination of the development of hunting skills and the implications for the debate on the
role of learning in the evolution of human life history patterns. While life history theory has proven to be a powerful tool
for understanding the evolution of the human life course, other schools, such as cultural transmission and social learning
theory, also provide theoretical insights. These disparate theories are reviewed, and alternative and exclusive predictions
are identified. This study of cross-cultural regularities in how children learn hunting skills, based on the ethnographic
literature on traditional hunters, complements existing empirical work and highlights future areas for investigation. 相似文献
6.
Philip B. Greenspoon Nicole Mideo 《Evolution; international journal of organic evolution》2017,71(3):747-755
The theory that coevolving hosts and parasites create a fluctuating selective environment for one another (i.e., produce Red Queen dynamics) has deep roots in evolutionary biology; yet empirical evidence for Red Queen dynamics remains scarce. Fluctuating coevolutionary dynamics underpin the Red Queen hypothesis for the evolution of sex, as well as hypotheses explaining the persistence of genetic variation under sexual selection, local parasite adaptation, the evolution of mutation rate, and the evolution of nonrandom mating. Coevolutionary models that exhibit Red Queen dynamics typically assume that hosts and parasites encounter one another randomly. However, if related individuals aggregate into family groups or are clustered spatially, related hosts will be more likely to encounter parasites transmitted by genetically similar individuals. Using a model that incorporates familial parasite transmission, we show that a slight degree of familial parasite transmission is sufficient to halt coevolutionary fluctuations. Our results predict that evidence for Red Queen dynamics, and its evolutionary consequences, are most likely to be found in biological systems in which hosts and parasites mix mainly at random, and are less likely to be found in systems with familial aggregation. This presents a challenge to the Red Queen hypothesis and other hypotheses that depend on coevolutionary cycling. 相似文献
7.
The transmission success of free-living larval stages of endohelminths is generally modulated by a variety of abiotic and biotic environmental factors. Whereas the role of abiotic factors (including anthropogenic pollutants) has been in focus in numerous studies and summarized in reviews, the role of biotic factors has received much less attention. Here, we review the existing body of literature from the fields of parasitology and ecology and recognize 6 different types of biotic factors with the potential to alter larval transmission processes. We found that experimental studies generally indicate strong effects of biotic factors, and the latter emerge as potentially important, underestimated determinants in the transmission ecology of free-living endohelminth stages. This implies that biodiversity, in general, should have significant effects on parasite transmission and population dynamics. These effects are likely to interact with natural abiotic factors and anthropogenic pollutants. Investigating the interplay of abiotic and biotic factors will not only be crucial for a thorough understanding of parasite transmission processes, but will also be a prerequisite to anticipate the effects of climate and other global changes on helminth parasites and their host communities. 相似文献
8.
Adaptive sex ratio theory explains why gametocyte sex ratios are female-biased in many populations of apicomplexan parasites such as Plasmodium and Toxoplasma. Recently, Ferguson has criticized this framework and proposed two alternative explanations--one for vector-borne parasites (e.g. Plasmodium) and one for Toxoplasma. Ferguson raises some interesting issues that certainly deserve more empirical attention. However, it should be pointed out that: (1) there are theoretical and empirical problems for his alternative hypotheses; and (2) existing empirical data support the application of sex ratio theory to these parasites, not its rejection. 相似文献
9.
Henrich J Broesch J 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2011,366(1567):1139-1148
Unlike other animals, humans are heavily dependent on cumulative bodies of culturally learned information. Selective processes operating on this socially learned information can produce complex, functionally integrated, behavioural repertoires-cultural adaptations. To understand such non-genetic adaptations, evolutionary theorists propose that (i) natural selection has favoured the emergence of psychological biases for learning from those individuals most likely to possess adaptive information, and (ii) when these psychological learning biases operate in populations, over generations, they can generate cultural adaptations. Many laboratory experiments now provide evidence for these psychological biases. Here, we bridge from the laboratory to the field by examining if and how these biases emerge in a small-scale society. Data from three cultural domains-fishing, growing yams and using medicinal plants-show that Fijian villagers (ages 10 and up) are biased to learn from others perceived as more successful/knowledgeable, both within and across domains (prestige effects). We also find biases for sex and age, as well as proximity effects. These selective and centralized oblique transmission networks set up the conditions for adaptive cultural evolution. 相似文献
10.
Animal migration impacts organismal health and parasite transmission: migrants are simultaneously exposed to parasites and able to reduce infection for both individuals and populations. However, these dynamics are difficult to study; empirical studies reveal disparate results while existing theory makes assumptions that simplify natural complexity. Here, we systematically review empirical studies of migration and infection across taxa, highlighting key gaps in our understanding. Next, we develop a unified evolutionary framework incorporating different selective pressures of parasite–migration interactions while accounting for ecological complexity that goes beyond previous theory. Our framework generates diverse migration–infection patterns paralleling those seen in empirical systems, including partial and differential migration. Finally, we generate predictions about which mechanisms dominate which empirical systems to guide future studies. Our framework provides an overarching understanding of selective pressures shaping migration patterns in the context of animal health and disease, which is critical for predicting how environmental change may threaten migration. 相似文献
11.
《Ethology and sociobiology》1992,13(2):87-113
This paper contains an investigation of the interaction between protocultural processes in animals, generated by social learning and the processes of biological evolution. It addresses the question of whether mechanisms of social learning and transmission can play an evolutionary role by allowing learned patterns of behavior to spread through animal populations, in the process changing the selection pressures acting on them. Simple models of social transmission and gene-meme coevolution are developed to investigate three hypotheses related to the role of social transmission in animal evolution. Simulations using the models suggest that social transmission would have to be particularly stable and be associated with estremely strong selection, if it were to result in the fixation of alleles. A more likely hypothesis is that social transmission might allow animals to respond adaptively to novelty in their environment, rendering a genetic response unnecessary, or only partially necessary. Socially transmitted traits appear to spread sufficiently rapidly, relative to changes in gene frequency, that it would be quite feasible for a socially transmitted response to an environmental change to occur, preempting a genetic response. Social transmission is probably more likely to slow down evolutionary rates than to speed them up through changing selection pressures. However, cultural and evolutionary processes are likely to interact in complex ways, and a “behavioral drive” effect cannot be ruled out. 相似文献
12.
A central prediction of classical theories of senescence states that environments posing a high risk of mortality favor the evolution of rapid intrinsic deterioration, or ageing. Although widely cited as being largely corroborated by existing data, empirical support for this prediction has been mixed. Recent theory suggests that this expectation should only be realized under particular circumstances, and this could account for the equivocal empirical findings. Here, we highlight the salient features of some of the recent developments in this field and suggest some ways in which progress might be made. We argue that it is necessary to move beyond the simplistic classical expectation and to take a more comprehensive and precise approach to studies of senescence, both theoretically and empirically. 相似文献
13.
Daisuke Kyogoku 《Population Ecology》2020,62(2):196-206
Reproductive interference is interspecific sexual interactions that are costly to at least one species involved. Although many studies have reported a substantial fitness cost associated with reproductive interference, suggesting its ecological significance, others have not observed reproductive interference in study species. Reproductive interference that incurs a large fitness cost is more likely to occur during secondary contacts than between long-coexisting species. I first explain the rationale underlying this prediction using existing literature. Next, I present a conceptual framework to classify pairs of interacting species into one of four states, defined by the ecological and evolutionary stabilities of the species pairs. I discuss how the stability states of species pairs are likely to change over time, along with changes in the demographic and evolutionary role of reproductive interference. I then perform literature survey to test the prediction that reproductive interference should be more prevalent in secondary contact. Finally, I discuss the implications of the proposed conceptual framework and literature survey result. 相似文献
14.
Raphael K. Didham 《Oikos》2006,113(2):357-362
T. Fukami and W. G. Lee argue that the logical expectation from ecological theory is that competitively-structured assemblages will be more likely to exhibit alternative stable states than abiotically-structured assemblages. We suggest that there are several important misinterpretations in their arguments, and that the substance of their hypothesis has both a weak basis in ecological theory and is not supported by empirical evidence which shows that alternative stable states occur more frequently in natural systems subject to moderate- to harsh abiotic extremes. While this debate is founded in ecological theory, it has important applied implications for restoration management. Sound theoretical predictions about when to expect alternative stable states can only aid more effective restoration if theoretical expectations can be shown to translate into predictable empirical outcomes. If strongly abiotically- or disturbance-structured systems are more likely to exhibit catastrophic phase shifts in community structure that can be resilient to management efforts, then restoration ecologists will need to treat these systems differently in terms of the types of management inputs that are required. 相似文献
15.
Marc Lipsitch Steven Siller Martin A. Nowak 《Evolution; international journal of organic evolution》1996,50(5):1729-1741
The idea that vertical transmission of parasites selects for lower virulence is widely accepted. However, little theoretical work has considered the evolution of virulence for parasites with mixed horizontal plus vertical transmission. Many human, animal, and plant parasites are transmitted both vertically and horizontally, and some horizontal transmission is generally necessary to maintain parasites at all. We present a population-dynamical model for the evolution of virulence when both vertical and horizontal transmission are present. In the simplest such model, up to two infectious strains can coexist within one host population. Virulent, vertically transmitted pathogens can persist in a population when they provide protection against more virulent, horizontally transmitted strains. When virulence is maintained by a correlation with horizontal transmission rates, increased levels of vertical transmission always lower the evolutionarily stable (ESS) level of virulence. Contrary to existing theory, however, increases in opportunities for horizontal transmission also lower the ESS level of virulence. We explain these findings in light of earlier work and confirm them in simulations including imperfect vertical transmission. We describe further simulations, in which both vertical and horizontal transmission rates are allowed to evolve. The outcome of these simulations depends on whether high levels of vertical transmission are possible with low virulence. Finally, we argue against the notion of a virulence-avirulence continuum between horizontal and vertical transmission, and discuss our results in relation to empirical studies of transmission and virulence. 相似文献
16.
In this article, we consider small-sample statistical inference for rate ratio (RR) in a correlated 2 x 2 table with a structural zero in one of the off-diagonal cells. Existing Wald's test statistic and logarithmic transformation test statistic will be adopted for this purpose. Hypothesis testing and confidence interval construction based on large-sample theory will be reviewed first. We then propose reliable small-sample exact unconditional procedures for hypothesis testing and confidence interval construction. We present empirical results to evince the better confidence interval performance of our proposed exact unconditional procedures over the traditional large-sample procedures in small-sample designs. Unlike the findings given in Lui (1998, Biometrics 54, 706-711), our empirical studies show that the existing asymptotic procedures may not attain a prespecified confidence level even in moderate sample-size designs (e.g., n = 50). Our exact unconditional procedures on the other hand do not suffer from this problem. Hence, the asymptotic procedures should be applied with caution. We propose two approximate unconditional confidence interval construction methods that outperform the existing asymptotic ones in terms of coverage probability and expected interval width. Also, we empirically demonstrate that the approximate unconditional tests are more powerful than their associated exact unconditional tests. A real data set from a two-step tuberculosis testing study is used to illustrate the methodologies. 相似文献
17.
The coevolutionary dynamics of obligate ant social parasite systems--between prudence and antagonism
Brandt M Foitzik S Fischer-Blass B Heinze J 《Biological reviews of the Cambridge Philosophical Society》2005,80(2):251-267
In this synthesis we apply coevolutionary models to the interactions between socially parasitic ants and their hosts. Obligate social parasite systems are ideal models for coevolution, because the close phylogenetic relationship between these parasites and their hosts results in similar evolutionary potentials, thus making mutual adaptations in a stepwise fashion especially likely to occur. The evolutionary dynamics of host-parasite interactions are influenced by a number of parameters, for example the parasite's transmission mode and rate, the genetic structure of host and parasite populations, the antagonists' migration rates, and the degree of mutual specialisation. For the three types of obligate ant social parasites, queen-tolerant and queen-intolerant inquilines and slavemakers, several of these parameters, and thus the evolutionary trajectory, are likely to differ. Because of the fundamental differences in lifestyle between these social parasite systems, coevolution should further select for different traits in the parasites and their hosts. Queen-tolerant inquilines are true parasites that exert a low selection pressure on their host, because of their rarity and the fact that they do not conduct slave raids to replenish their labour force. Due to their high degree of specialisation and the potential for vertical transmission, coevolutionary theory would predict interactions between these workerless parasites and their hosts to become even more benign over time. Queen-intolerant inquilines that kill the host queen during colony take-over are best described as parasitoids, and their reproductive success is limited by the existing worker force of the invaded host nest. These parasites should therefore evolve strategies to best exploit this fixed resource. Slavemaking ants, by contrast, act as parasites only during colony foundation, while their frequent slave raids follow a predator prey dynamic. They often exploit a number of host species at a given site, and theory predicts that their associations are best described in terms of a highly antagonistic coevolutionary arms race. 相似文献
18.
Bedhomme S Chippindale AK Prasad NG Delcourt M Abbott JK Mallet MA Rundle HD 《Journal of genetics》2011,90(3):443-452
Sexually dimorphic traits are likely to have evolved through sexually antagonistic selection. However, recent empirical data suggest that intralocus sexual conflict often persists, even when traits have diverged between males and females. This implies that evolved dimorphism is often incomplete in resolving intralocus conflict, providing a mechanism for the maintenance of genetic variance in fitness-related traits. We used experimental evolution in Drosophila melanogaster to directly test for ongoing conflict over a suite of sexually dimorphic cuticular hydrocarbons (CHCs) that are likely targets of sex-specific selection. Using a set of experimental populations in which the transmission of genetic material had been restricted to males for 82 generations, we show that CHCs did not evolve, providing experimental evidence for the absence of current intralocus sexual conflict over these traits. The absence of ongoing conflict could indicate that CHCs have never been the target of sexually antagonistic selection, although this would require the existing dimorphism to have evolved via completely sexlinked mutations or as a result of former, but now absent, pleiotropic effects of the underlying loci on another trait under sexually antagonistic selection. An alternative interpretation, and which we believe to be more likely, is that the extensive CHC sexual dimorphism is the result of past intralocus sexual conflict that has been fully resolved, implying that these traits have evolved genetic independence between the sexes and that genetic variation in them is therefore maintained by alternative mechanisms. This latter interpretation is consistent with the known roles of CHCs in sexual communication in this species and with previous studies suggesting the genetic independence of CHCs between males and females. Nevertheless, direct estimates of sexually antagonistic selection will be important to fully resolve these alternatives. 相似文献
19.
This paper lays the groundwork for a theory of time allocation across the life course, based on the idea that strength and
skill vary as a function of age, and that return rates for different activities vary as a function of the combination of strength
and skills involved in performing those tasks. We apply the model to traditional human subsistence patterns. The model predicts
that young children engage most heavily in low-strength/low-skill activities, middle-aged adults in high-strength/high-skill
activities, and older adults in low-strength/high-skill activities. Tests among Machiguenga and Piro forager-horticulturalists
of southeastern Peru show that males and females focus on low-strength/low-skill tasks early in life (domestic tasks and several
forms of fishing), switch to higher-strength/higher-skill activities in their twenties and thirties (hunting, fishing, and
gardening for males; fishing and gardening for females), and shift focus to high-skill activities late in life (manufacture/repair,
food processing).
Michael Gurven is an assistant professor of anthropology at the University of California-Santa Barbara. He received his Ph.D.
from the University of New Mexico in 2000. He has conducted fieldwork in Paraguay and Bolivia with Ache and Tsimane forager-horticulturalists.
His research interests include intragroup cooperation and problems of collective action, and the application of life history
theory to explaining human longevity, cognitive development, delayed maturation, and sociality. Since 2002, Gurven and Kaplan
have co-directed the Tsimane Health and Life History Initiative, a five-year project to develop theory and test implications
of different models of human life history evolution.
Hillard Kaplan is a professor of anthropology at University of New Mexico. He received his Ph.D. from the University of Utah
in 1983. He has conducted fieldwork in Paraguay, Brazil, Botswana, and Bolivia. His research interests include evolutionary
perspectives on life course development and senescence, and brain evolution. He has launched theoretical and empirical investigations
into each of these areas, uniting evolutionary and economic approaches. He has applied human capital theory toward explaining
human life history evolution, and the proximate physiological and psychological mechanisms governing fertility and parental
investment in both traditional, high-fertility, subsistence economies and modern, low-fertility, industrial societies. 相似文献
20.
Quinn S. McFrederick Jose D. Fuentes T’ai Roulston James C. Kathilankal Manuel Lerdau 《Oecologia》2009,160(3):411-420
Chemical signals play important roles in ecological interactions but are vulnerable to perturbation by air pollution. In polluted
air masses, signals may travel shorter distances before being destroyed by chemical reactions with pollutants, thus losing
their specificity. To determine which scent-mediated interactions are likely to be affected, we review existing literature
to build a picture of what chemicals are commonly found in such interactions and the spatial scales at which interactions
occur. We find that pollination, attraction of natural enemies of plant pests, aggregation pheromones, and mate attraction
are likely to be affected. We review the scant literature on this topic and extend the hypothesis to include heretofore unexplored
interactions. New research should investigate whether air pollution deleteriously affects populations of organisms that rely
on scent plumes. Additionally, we need to investigate whether or not breakdown products created by the reaction of signaling
chemicals with pollutants can provide usable signals, and whether or not there has been adaptation on the part of scent emitters
or receivers to use either breakdown products or more robust chemical signals. The proposed research will necessarily draw
on tools from atmospheric science, evolutionary biology, and ecology in furthering our understanding of the ecological implications
of how air pollution modifies the scentscape. 相似文献