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| Articles about Asymmetry |
| The Psychological Asymmetry of Islamist Warfare | | 2008-03-04 13:55:00 | | U.S. military lawyers acknowledge that "civilians may not be used … to render an area immune from military operations… [or] to shield a defensive position, to hide military objectives, or to screen an attack. Neither may they be forced to leave their homes or shelters in order to disrupt the movement of an adversary." Such restraint is not unique to the United States but also extends to Europe, Israel, and in the post-World War II era, many Asian countries as well. Increasingly, though, Israel's Arab foes and Islamist groups discount such constraints in order to seek psychological advantage against technologically superior foes. Western governments are challenged today by an enemy whose behavior is inspired by theological doctrines that not only disregard the Western concept of ethical combat but for whom the killing of civilians—on both sides of a conflict—also serves a vital purpose.Policymakers and military officials often discuss asymmetrical warfare in the context of strat | | By: THE NEW BABYLON TIMES | | |
| | From symmetry to asymmetry: Phylogenetic patterns of asymmetry variation | | 2006-10-25 10:27:38 | | [A. Richard Palmer, PNAS, Dec '96]From symmetry to asymmetry: Phylogenetic patterns of asymmetry variation in animals and their evolutionary significanceAbstract:Phylogenetic analyses of asymmetry variation offer a powerful tool for exploring the interplay between ontogeny and evolution because (i) conspicuous asymmetries exist in many higher metazoans with widely varying modes of development, (ii) patterns of bilateral variation within species may identify genetically and environmentally triggered asymmetries, and (iii) asymmetries arising at different times during development may be more sensitive to internal cytoplasmic inhomogeneities compared to external environmental stimuli. Using four broadly comparable asymmetry states (symmetry, antisymmetry, dextral, and sinistral), and two stages at which asymmetry appears developmentally (larval and postlarval), I evaluated relations between ontogenetic and phylogenetic patterns of asymmetry variation. Among 140 inferred phylogenetic transitions between asymmetry states, recorded from 11 classes in five phyla, directional asymmetry (dextral or sinistral) evolved directly from symmetrical ancestors proportionally more frequently among larval asymmetries. In contrast, antisymmetry, either as an end state or as a transitional stage preceding directional asymmetry, was confined primarily to postlarval asymmetries. The ontogenetic origin of asymmetry thus significantly influences its subsequent evolution. Furthermore, because antisymmetry typically signals an environmentally triggered asymmetry, the phylogenetic transition from antisymmetry to directional asymmetry suggests that many cases of laterally fixed asymmetries evolved via genetic assimilation.------- Books on Symmetry from the Science and Evolution Bookshop: UK | US technorati tags: asymmetry, variation, ontogeny, evolution, development, symmetry, antisymmetry, phyla, directional, origin, genetic+assimilation
| | By: Evolution Research - Main Blog | | |
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