An evolutionary perspective on middle ears
An evolutionary perspective on middle ears
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DOI：
10.1016/j.heares.2009.09.004
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发表时间：
2010-05-01
期刊：
影响因子：
2.8
通讯作者：
Manley, Geoffrey A.
中科院分区：
文献类型：
--
作者：
Manley, Geoffrey A.
传统的观点认为，鼓膜中耳只发育了一次，当脊椎动物从水中的鱼类过渡到陆地动物时，已经被证明是不正确的。中耳有一个由一个或多个听小骨连接到耳蜗的鼓室，在进化史上发展得很晚，在许多脊椎动物谱系中独立存在-大多数现在已经灭绝。哺乳动物的中耳是独一无二的，但它不仅仅是一个“改进”的单小骨中耳。这是一个激进和偶然的新发展，其起源更多地归功于喂养模式的变化，而不是听力。它碰巧比单小骨中耳更好地传输高频声音，并使大多数哺乳动物的高频听力极限得以进化。与兽目哺乳动物的鼓膜中耳的发育相平行，大脑的大小增加，并发展出第二腭，导致祖先的压力梯度中耳被纯粹的压力系统所取代。声音定位几乎完全依赖于神经计算，这是提高早期哺乳动物频率上限的最重要因素。本文对这些非常简单但非常有效的结构进行了历史透视。(C)2009 Elsevier B. V.保留所有权利。
The traditional view that a tympanic middle ear developed only once, when vertebrates made the transition from fish in water to land-living animals, has been shown to be incorrect. Middle ears with a tympanum connected by one or more ossicles to the cochlea developed very much later in evolutionary history and independently in many amniote vertebrate lineages - most now extinct. The mammalian middle ear is unique but it is not simply an "improved" single-ossicle middle ear. It is a radical and fortuitous new development that owes its origin more to changes in feeding patterns than to hearing. It happened to transmit higher-frequency sounds better than single-ossicle middle ears and enabled the evolution of the high upper-frequency hearing limits of most mammals. Parallel to the development of a tympanic middle ear in therian mammals, the brain increased in size and a secondary palate developed, resulting in the ancestral pressure-gradient middle ear being replaced by a purely pressure system. Sound localization then became almost completely dependent on neural computation and this was the most important factor driving up the upper frequency limits of early mammals. This paper presents an historical perspective on these remarkably simple and yet highly effective structures. (C) 2009 Elsevier B.V. All rights reserved.