Sulser R Benjamin, MacPhee Ross D E
Division of Evolutionary Ecology, Institute of Ecology and Evolution, Universität Bern, Bern, Switzerland.
Department of Mammalogy, American Museum of Natural History, New York, NY, USA.
Commun Biol. 2025 Jul 23;8(1):1090. doi: 10.1038/s42003-025-08489-8.
Evolutionary theory predicts that sensory systems should adaptively respond to environmental selection. Different ecological niches should, in theory, then correlate with changes in sensory anatomy in lineages that have undergone extensive radiation. The afrotherian clade Tenrecomorpha, comprising of African potamogalines and Malagasy tenrecines, is of particular interest because of its variety: the clade reportedly includes fossorial, arboreal, semiaquatic, and even echolocating taxa. To investigate their sensory ecology, we provide geometric morphometric analyses of inner ear endocasts of 24 tenrec species. We expand this dataset with 9 iodine-stained specimens to study trigeminal organization. Although tenrecomorphs display cross-taxon differences in sensory structures, our analyses distinguish signals of conflicting strength and direction within the tenrec ear, with no single factor that might explain a substantial portion of observed variation when accounting for phylogeny. This contrasts with prior studies of the tenrec cranial endocast, where sensory ecotype and habitat are strongly associated with shape. Iodine-enhanced scans of the trigeminal nerve align with this, and other studies based on bony anatomy. The disparate patterns of shape evolution in Tenrecomorpha and the contrasts exhibited by the inner ear and trigeminal nerve provide a nuanced portrait of neurosensory adaptation, differing from expectations set by other mammalian groups.
进化理论预测，感觉系统应能对环境选择做出适应性反应。理论上，不同的生态位应该与经历广泛辐射的谱系中感觉解剖结构的变化相关联。非洲兽总目猬形亚目，包括非洲水鼩猬科和马达加斯加猬科，因其多样性而特别引人关注：据报道，该分支包括穴居、树栖、半水生甚至回声定位类群。为了研究它们的感觉生态学，我们对24种猬科动物的内耳内铸型进行了几何形态测量分析。我们用9个碘染色标本扩充了这个数据集，以研究三叉神经组织。尽管猬形亚目在感觉结构上表现出跨类群差异，但我们的分析区分了猬科动物耳朵内相互矛盾的强度和方向信号，在考虑系统发育时，没有单一因素可以解释观察到的大部分变异。这与之前对猬科动物颅骨内铸型的研究形成对比，在之前的研究中，感觉生态型和栖息地与形状密切相关。三叉神经的碘增强扫描结果与此一致，也与其他基于骨骼解剖学的研究结果一致。猬形亚目的形状进化模式各不相同，内耳和三叉神经所表现出的差异提供了一幅细致入微的神经感觉适应图景, 与其他哺乳动物类群的预期不同。
