School of Biological Sciences, University of Bristol, Woodland Road, Bristol, BS8 1UG, UK.
Science. 2012 Nov 16;338(6109):968-71. doi: 10.1126/science.1225271.
In mammals, hearing is dependent on three canonical processing stages: (i) an eardrum collecting sound, (ii) a middle ear impedance converter, and (iii) a cochlear frequency analyzer. Here, we show that some insects, such as rainforest katydids, possess equivalent biophysical mechanisms for auditory processing. Although katydid ears are among the smallest in all organisms, these ears perform the crucial stage of air-to-liquid impedance conversion and signal amplification, with the use of a distinct tympanal lever system. Further along the chain of hearing, spectral sound analysis is achieved through dispersive wave propagation across a fluid substrate, as in the mammalian cochlea. Thus, two phylogenetically remote organisms, katydids and mammals, have evolved a series of convergent solutions to common biophysical problems, despite their reliance on very different morphological substrates.
在哺乳动物中，听觉依赖于三个典型的处理阶段：（i）鼓膜收集声音，（ii）中耳阻抗转换器，以及（iii）耳蜗频率分析器。在这里，我们表明，一些昆虫，如雨林蝉，具有等效的听觉处理生物物理机制。尽管蝉的耳朵是所有生物中最小的之一，但这些耳朵执行着至关重要的空气到液体阻抗转换和信号放大阶段，使用独特的鼓膜杠杆系统。在听觉链的进一步延伸中，通过在流体基底上传播离散波来实现声音的频谱分析，就像在哺乳动物耳蜗中一样。因此，尽管蝉和哺乳动物依赖于非常不同的形态学基质，但它们已经进化出一系列趋同的解决方案来应对共同的生物物理问题。
