The notion that closely related species resemble each other in ecological niche space (i.e., phylogenetic dependence) has been a long‐standing, contentious paradigm in evolutionary biology, the incidence of which is important for predicting the ecosystem‐level effects of species loss. Despite being examined across a multitude of terrestrial taxa, many aspects of niche conservatism have yet to be explored in marine species, especially for characteristics related to resource use and trophic behavior (Eltonian niche characteristics, ENCs). We combined ENCs derived from stable isotope ratios at assemblage‐ and species‐levels with phylogenetic comparative methods, to test the hypotheses that benthic marine fishes (1) exhibit similar assemblage‐wide ENCs regardless of geographic location and (2) display phylogenetically dependent ENCs at the species level. We used a 12‐species sub‐set of the monophyletic group Rajidae sampled from three independent assemblages (Central California, Gulf of Alaska, and Northwest Atlantic), which span two ocean basins. Assemblage‐level ENCs implied low trophic diversity and high evenness, suggesting that Rajidae assemblages may exhibit a well‐defined trophic role, a trend consistent regardless of geographic location. At the species level, we found evidence for phylogenetic dependence of ENCs relating to trophic diversity (i.e., isotopic niche width; SEAc). Whether individuals can be considered functional equivalents across assemblages is hard to ascertain because we did not detect a significant phylogenetic signal for ENCs relating to trophic function (e.g., trophic position). Thus, additional, complimentary approaches are required to further examine the phylogenetic dependence of species functionality. Our approach illustrates the potential of stable isotope‐derived niche characteristics to provide insight on macroecological processes occurring across evolutionary time, which could help predict how assemblages may respond to the effects of species loss.

中文翻译：

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拉吉科物种已实现的埃尔顿生态位的演变

密切相关的物种在生态位空间中彼此相似（即系统发生依赖性）的观点一直是进化生物学中长期存在的争议性范式，其发生率对于预测物种丧失的生态系统水平影响至关重要。尽管已对多种陆生类群进行了研究，但生态位保守性的许多方面仍未在海洋物种中进行探索，尤其是与资源利用和营养行为有关的特征（Eltonian生态位特征，ENC）。我们将在组合和物种水平上从稳定同位素比率得出的ENC与系统发育比较方法相结合，为了检验以下假设：底栖海鱼（1）不论地理位置如何，都显示出相似的组合范围的ENC；（2）在物种级别上显示出系统发育相关的ENC。我们使用了单物种组的12种亚类Rajidae是从三个独立的组合（加利福尼亚中部，阿拉斯加湾和西北大西洋）中取样的，它们跨越两个海洋盆地。集合层次的ENC暗示营养低多样性和高均匀性，表明Rajidae组合可能表现出明确的营养作用，无论地理位置如何，趋势都是一致的。在物种一级，我们发现了ENC与营养多样性（即同位素生态位宽度； SEAc）有关的系统发育依赖性证据。由于我们没有检测到与营养功能（例如，营养位置）有关的ENC的重要系统发生信号，因此很难确定是否可以将个体视为整个组合的功能等同物。因此，需要其他互补的方法来进一步检查物种功能的系统发育依赖性。我们的方法说明了稳定的同位素生态位特征潜在的潜力，可以洞悉整个进化过程中发生的宏观生态过程，这可以帮助预测集合体如何响应物种丧失的影响。