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Fitness consequences of sexual cannibalism in female<Emphasis Type="Italic"> Argiope bruennichi</Emphasis> 总被引:4,自引:0,他引:4
Lutz?Fromhage Gabriele?Uhl Jutta?M.?SchneiderEmail author 《Behavioral ecology and sociobiology》2003,55(1):60-64
The evolution of sexual cannibalism as the most extreme form of nuptial feeding is still poorly understood. Although increasing evidence suggests that female aggressiveness is related to other aspects of foraging behaviour, it is not clear whether the nutritional value of a male is sufficient to provide an adaptive significance for sexual cannibalism. A widely cited though rarely tested explanation is based on a paternal investment model, and predicts that consumption of a male results in increased female fecundity. The available evidence is either correlational or restricted to species with relatively large and potentially nutritious males, and different studies have come to different conclusions. Here we present a test of the paternal investment hypothesis using the very cannibalistic and highly size-dimorphic spider Argiope bruennichi. After a preset schedule, we had females consume none, one or two males independent of the female's cannibalistic behaviour. Consumption of male bodies did not result in any detectable fitness benefit for the female: neither the number of clutches, nor clutch size or hatching success were affected by consumption of males. The frequency of cannibalism was around 80%, independent of the female mating status. We did not observe male complicity, but cannibalism was associated with prolonged copulation. This suggests a sexually selected benefit of cannibalism for males. We conclude that the paternal investment hypothesis does not explain the existence of sexual cannibalism in A. bruennichi and probably not in other spider species with a pronounced sexual size dimorphism.Communicated by L. Simmons 相似文献
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首先介绍了自然环境对装备的影响,提出了装备环境适应能力的问题,回顾了伊拉克战争中美军遇到的装备环境适应性问题并对美军采取的应对措施作了全面的介绍,最后对如何提高我军装备环境适应能力作了阐述。 相似文献
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熊会兵 《中国人口.资源与环境》2004,14(3):116-118
本文分析了关于企业发展的两种观点:企业环境决定论和企业资源决定论;提出了实现企业发展的“环境-资源”平衡战略的理念;为了达到企业环境与资源两者的整合和平衡,保持持续竞争优势,企业应以创新为核心,确立核心业务,重视组织的学习,作为一种特殊的企业资源,企业家精神和能力对企业的生存和发展起着重要作用。 相似文献
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企业安全资源的资源观分析 总被引:1,自引:1,他引:1
依据资源理论对资源优势与竞争优势之间关系的研究成果,笔者提出安全资源优势是企业形成整体资源优势的必备条件之一,良好的安全资源能够为企业创造竞争优势。为此,首先指出,企业的安全意识、安全制度与安全设施等均属企业中的安全资源之列,按照资源理论对企业资源的分类,该类安全资源贯穿于企业的各种资源之中;随后,论述了安全资源与企业中的其他资源一样,具有价值性、稀缺性、不可模仿性和不可替代性等优势资源禀赋;根据资源理论中对竞争优势的经济学解释,分析了安全资源本身,以及安全资源与企业中其他资源的组合使用是如何为企业创造竞争优势的,安全资源优势通过降低企业的长期平均生产成本、延长其他资源的使用寿命从而提高产品产量等途径,能够为企业创造租金,进而形成企业的竞争优势。该论述以全新视角认识企业安全资源,有助于企业改变以往对安全资源建设的错误认识,调动企业对安全资源投资的积极性和主动性 相似文献
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铜梁龙文化资源及其开发对策 总被引:2,自引:0,他引:2
当今旅游发展日益强调文化旅游,而重庆铜梁龙文化资源独具魅力。通过对铜梁龙文化资源的独特优势及开发潜力的深入分析,提出铜梁龙文化资源开发的基本对策。 相似文献
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尹兆友 《中国环境管理干部学院学报》2002,12(1):62-64
通过调查访问、对比实验的方法,对普通高校专项体育课的教形式进行了比较分析,结果表明:男女合班教学更容易被学生所接受,且教学效果优于男女分班教学。 相似文献