Sympatry affects the evolution of genetic versus cultural determination of song
Sympatry affects the evolution of genetic versus cultural determination of song
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DOI：
10.1093/beheco/arn002
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发表时间：
2008-05-01
影响因子：
2.4
通讯作者：
Servedio, Maria R.
中科院分区：
文献类型：
--
作者：
Olofsson, Helen;Servedio, Maria R.
一种解释鸣禽种类丰富的假设是基于这样一个事实，即这些物种通常是通过社交而不是遗传来获得鸣叫的。在这里，我们考虑鸟类之间的二次接触的结果，已经发展出不同的歌曲方言在异域。我们问了两个问题：1)给定一个固定的学习概率，这些歌曲是如何在同情中进化的？ 2)在这种情况下，进化是倾向于增加还是减少基因，而不是文化，对歌曲的决定？我们假设这两种地方方言都可以通过遗传决定，并通过歌曲复制来学习，而第三种歌曲，混合歌曲，只能学习。我们对这两个问题进行了评估，假设除了通过复制学习之外，还有三种不同的方法可以生成混合歌曲。我们发现，当学习的概率是固定的，即使绝大多数雄性都学过歌曲，当地方言通常也能保持下去。然而，如果歌曲学习本身能够进化，那么歌曲的差异性就会消失。这在一定程度上是积极反馈机制的结果；混合的歌曲很容易被所有的雌性接受，导致选择倾向于一个等位基因，这增加了雄性产生这些歌曲的可能性。这反过来又增加了混合歌曲的频率，使方言更难维持。由于人类干扰改变了物种范围，部分分化的种群可能越来越多地接触；这项工作预测，在这些条件的很大一部分下，歌曲的分化可能确实倾向于消失。
One hypothesis explaining the species richness of the songbirds is based on the fact that these species generally acquire their songs socially rather than genetically. Here we consider the outcome of secondary contact between birds that have developed distinct song dialects in allopatry. We ask 2 questions: 1) given a fixed probability of learning, how do the songs evolve in sympatry and 2) would evolution tend to increase or decrease the genetic, versus cultural, determination of song in this situation? We assume that the 2 local dialects can be both genetically determined and learned via song copying, whereas a third category of song, mixed song, is only learned. We evaluate both questions assuming 3 different ways that mixed song can be generated in addition to learning via copying. We find that when the probability of learning is fixed, local dialects can generally be maintained even when a substantial majority of males produce learned songs. Song differentiation will, however, be lost if song learning itself can evolve. This is partly a result of a positive feedback mechanism; mixed songs are readily accepted by all females, leading to selection favoring an allele which increases the probability that males will produce those songs. This in turn increases the frequency of mixed songs, making it harder for dialects to be maintained. As human disturbance alters species ranges, partially differentiated populations may increasingly come into contact; this work predicts that song differentiation may indeed tend to be lost under a significant proportion of these conditions.