938 resultados para Thought in a hostile world: the evolution of human cognition


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In 1990, the Australian life insurance industry was rocked by a scandal that threatened to destabilize consumer confidence in the ability of insurance providers to meet policyholder liabilities. The incident highlighted the nature of the agency problems that arise when conditions of asymmetric information exist. It revealed systemic weaknesses in accounting, solvency and disclosure standards as they applied to life insurers. This article uses an evolutionary concept of agency to analyse government and industry responses to this event. It is argued that initial adaptive responses stabilized the industry and averted a more serious crisis. Longer term innovative responses led to the introduction of a new and more rigorous approach to reporting and solvency standards, which has improved information flows and agency outcomes.

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While the Temporary Protection Visa (TPV) regime was formally introduced in October 1999 by the Howard Government, the concept of temporary protection was not totally alien to the Australian humanitarian landscape. Earlier examples reflected a standard use of temporary protection as a complementary or interim protection mechanism, offering short-term group-based protection where individual assessment under the 1951 Convention was both impractical and untimely. This paper focuses on the wider and more controversial changes in the use of temporary protection mechanisms that were to follow with the introduction of the TPV in 1999, which offered substitute protection for individually assessed Convention refugees who had arrived onshore without valid travel documents. It examines the history and evolution of the TPV policy regime from 1999 to the announcement of its abolition in 2008, arguing that the introduction and subsequent development of the policy may be understood as a product of a conservative, exclusionist political climate in Australia, following the unprecedented impact of the populist One Nation party in 1998, and later, the impact of September 11th. It also examines later amendments to the regime as a response to growing domestic disquiet about the impacts of the policy, and the abolition of the TPV policy under a new Australian government elected in late 2007.

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The evolutionary distribution of chloroplast and mitochondrial division proteins has been investigated, gleaning new insights to the evolution of organelle division: specifically the use and features of FtsZ and dynamin-like proteins. Additional novel proteins that are potentially involved in mitochondrial division have been identified in Dictyostelium discoideum.

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Michael Polanyi and Karl Popper offer contrasting accounts of social tradition. Popper is steeped in the heritage of the Enlightenment, while Polanyi interweaves religious and diverse secular strands of thought. Explaining the liberal tradition, Polanyi features tacit knowledge of rules, standards, applications and interpretations being transmitted by “craftsmen” to “apprentices.” Each generation adopts the liberal tradition on “faith,” commits to creatively developing its art of knowledge-in-practice, and is drawn to the spiritual reality of ideal ends. Of particular interest to Popper is the rationality of social traditions. Likened by him to scientific theories, Popper’s traditions are criticizable and improvable, assisting agents to understand, and act in, the world as stable and predictable. Polanyi’s is the more informative rendering of tradition. Polanyi delves deeply into important areas where Popper only scratches their surface: the tacit dimension, transmission by way of apprenticeship, the meaning of tradition for those who participate in it, and the extent of its authority over them.

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The plumages of parrots provide some of the most striking colouration in nature.We summarise the diversity of mechanisms producing colour in parrots and the current evidence for the adaptive significance of variation in the colour of parrot plumages. Only recently have detailed studies begun to unravel the mechanisms of their colour-production and colour vision systems. Parrots produce much of their plumage colouration through a unique suite of pigments (psittacofulvins), or through a feather tissue nanostructure that results in coherent scattering of light, or a combination of the two (producing green). Psittacofulvins are found nowhere else in nature, and may even generate fluorescence in many parrot species.Compared with other avian taxa, the adaptive significance of parrot plumage colouration remains poorly understood, although some studies suggest that plumage colouration may form important sexual signals and may be used in mate-choice by several species. There is evidence to suggest that parrot colouration can be subject to both environmental and genetic control. We emphasise that parrots offer a distinctive and useful colouration system for further study. Further research is required to unravel how the dramatic colour patterns of parrots evolved, and what roles colour signals may play in the life histories of parrots.

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Theoretical predictions suggest that species-specific signals used in the attraction of mates should evolve to reduce the risk of mismating and hybridization. These predictions lead to the hypothesis that the signals of spatially overlapping (i.e. sympatric or syntopic) species should differ more substantially than those of non-overlapping species. Earlier studies have tested this prediction for auditory and visual signals. Here we test the hypothesis using olfactory signals, specifically the aggregation pheromones of species from two genera of bark beetles, Dendroctonus and Ips. We found no direct evidence from within these genera regarding the fact that the chemical blends that make up these pheromones differ more substantially in species that overlap in their geographical ranges and/or host-tree use than in allopatric taxa. However, when comparing between genera, the pheromones of overlapping species appear to be more similar than non-overlapping species. We hypothesize that the species of host tree utilized by the beetles may have some influence on their pheromone blends. Additionally, within genera, species that overlap in host use tend to be more closely related than species that use different hosts. These results may provide indirect evidence for an effect of species overlap on the evolution of bark beetle pheromones.

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The males of some species of moths possess elaborate feathery antennae. It is widely assumed that these striking morphological features have evolved through selection for males with greater sensitivity to the female sex pheromone, which is typically released in minute quantities. Accordingly, females of species in which males have elaborate (i.e., pectinate, bipectinate, or quadripectinate) antennae should produce the smallest quantities of pheromone. Alternatively, antennal morphology may be associated with the chemical properties of the pheromone components, with elaborate antennae being associated with pheromones that diffuse more quickly (i.e., have lower molecular weights). Finally, antennal morphology may reflect population structure, with low population abundance selecting for higher sensitivity and hence more elaborate antennae. We conducted a phylogenetic comparative analysis to test these explanations using pheromone chemical data and trapping data for 152 moth species. Elaborate antennae are associated with larger body size (longer forewing length), which suggests a biological cost that smaller moth species cannot bear. Body size is also positively correlated with pheromone titre and negatively correlated with population abundance (estimated by male abundance). Removing the effects of body size revealed no association between the shape of antennae and either pheromone titre, male abundance, or mean molecular weight of the pheromone components. However, among species with elaborate antennae, longer antennae were typically associated with lower male abundances and pheromone compounds with lower molecular weight, suggesting that male distribution and a more rapidly diffusing female sex pheromone may influence the size but not the general shape of male antennae.

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The data is the result of hot deformation tests conducted on magnesium alloy AZ31. It includes stress strain data for a range of deformation conditions and different initial microstructures. It also includes data for the developed grain size and the degree of dynamic recrystallisation.

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Many species have elaborate and complex coloration and patterning, which often differ between the sexes. Sexual selection may increase the size or intensity of color patches (elaboration) in one sex or drive the evolution of novel signal elements (innovation). The latter potentially increases color pattern complexity. Color pattern complexity may also be influenced by ecological factors related to predation and environment; however, very few studies have investigated the effects of both sexual and natural selection on color pattern complexity across species. We used a phylogenetic comparative approach to examine these effects in 85 species and subspecies of Australian dragon lizards (family Agamidae). We quantified color pattern complexity by adapting the Shannon–Wiener diversity index. There were clear sex differences in color pattern complexity, which were positively correlated with both sexual dichromatism and sexual size dimorphism, consistent with the idea that sexual selection plays a significant role in the evolution of color pattern complexity. By contrast, we found little evidence of a link between environmental factors and color pattern complexity on body regions exposed to predators. Our results suggest that sexual selection rather than natural selection has led to increased color pattern complexity in males.

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From the 1980s, Chinese experts from some mainland universities, such as Tongji Universtiy in Shanghai and Tsinghua University in Beijing, commenced research into heritage management and historic architectural conservation in China. With the announcement of the First and Second Lists of 10 Chinese Historic and Cultural Districts in 2009 and 2010, the conservation of historic districts was generally received and elevated in agreements from state-level government to local level governments. This paper considers literature about international and Chinese regulations and presents the evolution of historic district conservation in China. The paper explores the effective and ineffective results of the “Selection Contest of Chinese Top 10 Historic and Cultural Districts” in two cases selected from the First and Second Lists of 10 Chinese Historical and Cultural Districts during upon recent research and investigations. In each example, the paper provides a detailed examination of public awareness and their evaluation of conservation effectiveness through questionnaires.