Adaptation to herbivory and detritivory drives the convergent evolution of large abdominal cavities in a diverse freshwater fish radiation (Otophysi: Characiformes)
Adaptation to herbivory and detritivory drives the convergent evolution of large abdominal cavities in a diverse freshwater fish radiation (Otophysi: Characiformes)
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DOI：
10.1111/evo.14178
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发表时间：
2021-02-08
期刊：
影响因子：
3.3
通讯作者：
Burns, Michael D.
中科院分区：
文献类型：
--
作者：
Burns, Michael D.
趋同进化通常被解释为自然选择在适应过程中有利于最佳表型的证据。在饮食趋同的谱系中经常发现形态趋同，但大多数研究都集中在仅与食品处理和加工相关的形态特征上。在脊椎动物中，肠道长度和营养级之间存在很强的反比关系。然而，对于低营养水平的适应是否会影响可容纳更大肠道的腹腔的进化，人们知之甚少。在这里，我重建了营养生态学的进化史，并检查了 157 种鲹形目鱼类的腹腔形状，以确定对草食性和碎食性饮食的适应是否会驱动大腹腔的趋同进化。食草-碎食物种进化出比其他营养类群明显更大的腹腔，并且反复趋于相似的腹腔形态。其他营养群体随机地或通过未经测试的生态特征的选择性压力进化出腹腔形态。这些发现表明，对较大肠道的选择性需求促进了草食性-碎食性有形鱼类内大腹腔的反复汇聚，同时允许其他谱系随机进化或适应其他选择压力，从而促进了该目的整体体形的多样性。
Convergent evolution is often interpreted as evidence of natural selection favoring an optimal phenotype during adaptation. Morphological convergence is frequently found among lineages that converge on diet, but most studies have focused on morphological traits that relate exclusively to food handling and processing. In vertebrates, there is a strong inverse relationship between intestine length and trophic level. However, little is known about whether adaptation to a low trophic level influences the evolution of abdominal cavities that can accommodate larger intestines. Here, I reconstruct the evolutionary history of trophic ecology and examine abdominal cavity shape across 157 species of the fish order Characiformes to determine whether adaptation to an herbivorous-detritivorous diet drives convergent evolution of large abdominal cavities. Herbivorous-detritivorous species evolved significantly larger abdominal cavities than other trophic groups and repeatedly converged on a similar abdominal cavity morphology. Other trophic groups evolved abdominal cavity morphologies either stochastically or by selective pressures from an untested ecological character. These findings demonstrate that the selective demands of a larger intestinal tract promote the repeated convergence of a large abdominal cavity within herbivorous-detritivorous characiform fishes, while allowing other lineages to evolve randomly or adapt in response to other selection pressures, contributing to the overall body shape diversity of the order.