Adaptive Significance of Intra- and Interspecific Differences in the Feeding Repertoires of Cichlid Fishes
Adaptive Significance of Intra- and Interspecific Differences in the Feeding Repertoires of Cichlid Fishes
复制标题
丽鱼科鱼类摄食种类内和种间差异的适应性意义
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
K. Liem
中科院分区：
文献类型：
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作者：
K. Liem
肌电图揭示的慈鲷摄食机制中的种内调节多重性对小尺度营养事件具有深远的影响，而小尺度营养事件的叠加是大尺度种群进化现象的核心，如营养利用效率、生态位宽度、重叠竞争和适应等。慈鲷科鱼类摄食方式的种内和种间差异研究中出现的最大矛盾是，最特化的分类群不仅是狭义上的杰出专家，而且是多面手。如果专家同时是万事通，他们怎么可能根据广泛接受的假设而进化，即扩大可用资源的范围可以防止物种专攻于个体类型？
Intraspecific modulatory multiplicity in the feeding mechanism of cichlids as elucidated by electromyography has profound implications on small-scale trophic events the sum of which is the very core of such large-scale population and evolutionary phenomena as efficiency of trophic exploitation niche width and overlap competition and adaptation. The greatest paradox emerging from the study on intra and interspecific differences in feeding repertoires of cichlid fishes is that the most specialized taxa are not only remarkable specialists in a narrow sense but also jacks-of-all-trades. If specialists are simultaneously jacks of-all-trades how could they have evolved according to the widely accepted hypothesis that broadening the range of usable resources prevents species from specializing on individual types?
The organism can be considered to be composed of structural elements and functional components that exert mutual influences. As a result, a network of interacting constraints is set up. The nature of the network determines the direction and range of evolutionary changes the possibilities of optimizing adaptations and built-in variability of the trait. A change in the network can put a static trait into a different context to become dynamic. These changes in variability due to changes in the structure of the network cannot be explained in terms of simple adaptation to the external environment. Fitness is considered to depend on the nature of a network of interacting constraints. The possibilities of optimization the sensitivity of the phenotypic traits to environmental differences and the correlated evolutionary responses of different traits are all related to this network of interacting constraints between the elements and components of the organism. Thus the experimental and comparative studies of these networks of interacting constraints should become an increasingly more important focus for morphologists as they attempt to refine their understanding of adaptation.