FUNCTIONAL EQUIVALENCE OF MORPHOLOGIES ENABLES MORPHOLOGICAL AND ECOLOGICAL DIVERSITY
FUNCTIONAL EQUIVALENCE OF MORPHOLOGIES ENABLES MORPHOLOGICAL AND ECOLOGICAL DIVERSITY
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DOI：
10.1111/j.1558-5646.2007.00210.x
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发表时间：
2007-11
期刊：
影响因子：
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通讯作者：
R. L. Young;T. Haselkorn;A. Badyaev
中科院分区：
文献类型：
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作者：
R. L. Young;T. Haselkorn;A. Badyaev
分类群中生物形式的多样性被认为反映了不同环境下不同的选择压力。这种期望的核心假设是，经历相似选择的分类群对这种选择有相似的反应。然而，由于选择作用于性状功能，因此选择响应中的类群相似性主要取决于功能和形态之间的关系。此外，当一个性状由多个部分组成时，响应选择的功能变化可能是由不同部分的修饰引起的，对相同环境的适应可能导致功能上的而不是形态上的相似性。在这里，我们讨论了在何种程度上，咀嚼器官的功能和形态多样性反映了一个共同的生态特征，它们的饮食类型。我们通过评估特征功能（下颌生物力学）、生态和系统发育对下颌特征物种相似性的相对贡献，研究了限制鼩鼱物种形态差异的因素。我们发现，共享饮食类型的物种在功能上相似，但在形态上不相似。多个半独立性状的存在使得复合觅食形态的功能等效，并导致对相似日粮选择的不同反应。我们发现，多种形态的功能等效使得专门食用相同食物的物种之间的栖息地利用差异（例如栖息地湿度和覆盖度）持续存在。我们讨论了性状之间的发育和功能整合对于产生等效功能的形态结构的进化多样化的重要性。
Abstract Diversity in organismal forms among taxa is thought to reflect distinct selection pressures across environments. The central assumption underlying this expectation is that taxa experiencing similar selection have similar response to that selection. However, because selection acts on trait function, taxa similarity in selection response depends crucially on the relationship between function and morphology. Further, when a trait consists of multiple parts, changes in function in response to selection can result from modification of different parts, and adaptation to the same environment might result in functional but not morphological similarity. Here, we address the extent to which functional and morphological diversity in masticatory apparatus of soricid shrews reflects a shared ecological characteristic of their diet type. We examine the factors limiting morphological variation across shrew species by assessing the relative contribution of trait function (biomechanics of the jaw), ecology, and phylogeny to species similarity in mandibular traits. We found that species that shared diet type were functionally but not morphologically similar. The presence of multiple semi-independently varying traits enabled functional equivalence of composite foraging morphologies and resulted in variable response to selection exerted by similar diet. We show that functional equivalence of multiple morphologies enabled persistence of differences in habitat use (e.g., habitat moisture and coverage) among species that specialize on the same diet. We discuss the importance of developmental and functional integration among traits for evolutionary diversification of morphological structures that generate equivalent functions.