ON THE POSSIBLE ROLE OF EGG MIMICS IN SPECIATION
ON THE POSSIBLE ROLE OF EGG MIMICS IN SPECIATION
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DOI：
10.1007/bf00047549
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发表时间：
1990-06-01
影响因子：
1.3
通讯作者：
DEVISSER, J
中科院分区：
文献类型：
--
作者：
GOLDSCHMIDT, T;DEVISSER, J
性生活活跃的雄鱼在肛鳍上有明显的黄色卵形斑点，模仿雌鱼的卵，因此被称为卵假人(Wickler，1962b)。据认为，卵子假人特征的差异会极大地减少基因流动，从而可能引发生殖隔离。描述了卵子虚发散发展的两种方式。这两种机制可能在同一时间、在同一地区、在不同物种中运行，甚至可能在单一物种中运行。首先，如果在暂时隔离的DEME中，鸡蛋特征(大小、形状)的选择压力不同，那么在具有准确模仿的鸡蛋假人的物种中可能会产生鸡蛋假人的分歧。一旦鸡蛋的特征出现分歧，鸡蛋的假特征就会随之而来。这种类型的卵子假人分化导致了通过模仿来进行生殖隔离。拟态隔离是用来描述这种机制的概念。其次，如果在两个暂时隔离的Deme中，鸡蛋伪特征的选择压力不同，则可能会产生鸡蛋伪差异。在二次接触时，这种分化可能是一种性隔离机制，因为雌性伴侣的选择在单色胺中是重要的。卵子的假分化可能会迅速发展，如果这种情况反复发生，可能会导致爆炸性的物种形成。显然，单色胺中已经发生了爆炸性的物种形成。这两种模式都没有经过适当的测试。一些初步证据表明，第二个模型是有效的，但到目前为止还没有证据支持第一个模型。
Sexually active male haplochromine cichlid fishes possess pronounced yellow ovoid spots on the anal fin, which mimic eggs of the female and have therefore been called egg dummies (Wickler, 1962b). It is thought that divergence in egg dummy characteristics can considerably reduce gene flow and in this way may trigger off reproductive isolation. Two ways in which egg dummy divergence can develop are described. Both mechanisms may have been operating, at the same time and in the same area, in different species, or possibly even in a single species. Firstly, egg dummy divergence can develop in species with accurately mimetic egg dummies if selection pressures on egg characteristics (size, shape) differ in temporarily isolated demes. As soon as egg characteristics diverge, egg dummy characteristics follow. This type of egg dummy divergence leads to reproductive isolation by mimicry. Mimetic isolation is proposed as a term to describe the mechanism. Secondly, egg dummy divergence can develop if selection pressures on the egg dummy characteristics are different in two temporarily isolated demes. Upon secondary contact, this divergence may work as a sexual isolation mechanism, since female mate choic is important in haplochromines. Egg dummy divergence is likely to develop rapidly and, if this happen repeatedly, explosive speciation may result. Apparently, explosive speciation has occurred in haplochromines. Neither of the two models has been properly tested. Some preliminary evidence was found that the second model is valid, but so far there is no evidence in favour of the first model.