The evolution of eyes
The evolution of eyes
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DOI：
10.1159/000113339
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发表时间：
1997-10-01
影响因子：
1.7
通讯作者：
Fernald, RD
中科院分区：
文献类型：
--
作者：
Fernald, RD
在大多数物种中，眼睛是大脑感官信息的主要来源，眼睛的许多特征反映了对特定选择压力的进化解决方案，这些压力来自非生物环境和其他动物。因此，在所有感觉器官中，眼睛的进化引起了科学家的极大关注。在脊椎动物、节肢动物和软体动物这三大门中，成对的眼睛一直被认为是进化趋同的经典例子。在宏观层面上，这一定是真的，因为它们来自不同的组织，并且已经进化出完全不同的解决方案来解决收集和聚焦光的共同问题。然而，视蛋白，光吸收受体蛋白，具有显着量的共享DNA序列同源性的门，最近已经发现，在不同的门的眼睛发育的一些部分是由同源基因，Pax-6协调。因此，尽管不同门的眼睛显然不是同源的，但它们也不能被视为仅仅是趋同的结果。相反，这表明在组织的分子水平上的同源性并不能预测在器官或组织水平上的同源性。在非同源结构中存在同源组成分子提醒我们，分子不是眼睛。
Eyes are the preeminent source of sensory information for the brain in most species, and many features of eyes reflect evolutionary solutions to particular selective pressures, both from the nonbiological environment and from other animals. As a result, the evolution of eyes, among all the sense organs, has attracted considerable attention from scientists. Paired eyes in the three major phyla, vertebrates, arthropods and mollusks, have long been considered to be classic examples of evolutionary convergence. At the macroscopic level, this must be true since they arise from different tissues and have evolved radically different solutions to the common problem of collecting and focusing light. However, opsin, the light-absorbing receptor protein, has a significant amount of shared DNA sequence homology across the phyla, and recently it has been discovered that some part of ocular development in different phyla is coordinated by a homologous gene, Pax-6. So, although eyes from diverse phyla are clearly not homologous, neither can they be viewed as resulting solely from convergence. Instead, this shows that homology at the molecular level of organization does not predict homology at the organ or organismic level. The presence of homologous constituent molecules in nonhomologous structures reminds us that molecules are not eyes.