Flycatcher song in allopatry and sympatry - convergence, divergence and reinforcement
Flycatcher song in allopatry and sympatry - convergence, divergence and reinforcement
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DOI：
10.1111/j.1420-9101.2003.00682.x
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发表时间：
2004-03-01
影响因子：
2.1
通讯作者：
Sætre, GP
中科院分区：
文献类型：
--
作者：
Haavie, J;Borge, T;Sætre, GP
强化理论预测，针对不适宜杂交品种的自然选择有利于增加选型交配的性状。文化遗传特征（例如鸟鸣）是否可以通过强化来增加选型交配，目前尚不清楚。我们将来自两个不同年龄的混合区的花斑鹟（Ficedula hyperleuca）和领鹟（F. albicollis）的鸣叫声与异域种群的鸣叫声进行了比较。此前，雄性羽毛特征的差异已被证明会加强同域鹟的交配前隔离。相比之下，我们发现花斑鹟的歌声已经趋向于领鹟的歌声（混合歌唱）。然而，颈鹟的相应分化表明鸣叫特征的物种差异在同源性中得以维持。遗传分析表明，混合鸣叫不是由领鹟基因渗入引起的，而是由于异种复制所致。间接证据表明，混合鸣叫可能会增加适应不良杂交的发生率。在最古老的杂交区，羽毛性状强化最为明显，混合鸣叫和杂交的频率也最低。因此，我们认为强化降低了花斑鹟混合歌唱的频率，并导致了领鹟的歌声出现了分歧。文化遗传特征是否促进或反对同源物种形成可能取决于其可塑性。可塑性程度可以由基因决定，并相应地通过强化进行选择。
The theory of reinforcement predicts that natural selection against the production of unfit hybrids favours traits that increase assortative mating. Whether culturally inherited traits, such as bird song, can increase assortative mating by reinforcement is largely unknown. We compared songs of pied (Ficedula hypoleuca) and collared flycatchers (F. albicollis) from two hybrid zones of different ages with songs from allopatric populations. Previously, a character divergence in male plumage traits has been shown to reinforce premating isolation in sympatric flycatchers. In contrast, we find that the song of the pied flycatcher has converged towards that of the collared flycatcher (mixed singing). However, a corresponding divergence in the collared flycatcher shows that the species differences in song characters are maintained in sympatry. Genetic analyses suggest that mixed song is not caused by introgression from the collared flycatcher, but rather due to heterospecific copying. Circumstantial evidence suggests that mixed song may increase the rate of maladaptive hybridization. In the oldest hybrid zone where reinforcement on plumage traits is most pronounced, the frequency of mixed singing and hybridization is also lowest. Thus, we suggest that reinforcement has reduced the frequency of mixed singing in the pied flycatcher and caused a divergence in the song of the collared flycatcher. Whether a culturally inherited trait promotes or opposes speciation in sympatry may depend on its plasticity. The degree of plasticity may be genetically determined and accordingly under selection by reinforcement.