Rejecting strictly allopatric speciation on a continental island: prolonged postdivergence gene flow between Taiwan (Leucodioptron taewanus, Passeriformes Timaliidae) and Chinese (L. canorum canorum) hwameis
Rejecting strictly allopatric speciation on a continental island: prolonged postdivergence gene flow between Taiwan (Leucodioptron taewanus, Passeriformes Timaliidae) and Chinese (L. canorum canorum) hwameis
复制标题
DOI：
10.1111/j.1365-294x.2009.04494.x
复制
发表时间：
2010-02
影响因子：
4.9
通讯作者：
Jing-Wen Li;C. Yeung;Pi-Wen Tsai;Rong-Chien Lin;C. Yeh;Cheng‐te Yao;Lianxian Han;Le Manh Hung-
中科院分区：
文献类型：
--
作者：
Jing-Wen Li;C. Yeung;Pi-Wen Tsai;Rong-Chien Lin;C. Yeh;Cheng‐te Yao;Lianxian Han;Le Manh Hung-
异域分布通常被认为是大陆岛屿生物物种形成的地理模式。然而，严格的异域物种形成模型，假设缺乏postdivergence基因流似乎过于简化的复发陆桥在冰期以来的上新世晚期。为了评估大陆岛屿特有种台湾画眉（Leucodioptron taewanus，Passeriformes Timaliidae）是否具有严格的异地分布，我们使用基于加权回归的近似贝叶斯计算（ABC）分析了台湾画眉及其大陆姊妹种中国画眉（L. canorum canorum）。nonallopatry模型被认为是更适合观察到的遗传多态性的两个画眉物种（后验概率= 0.82）。我们还恢复了明确的信号，非平凡的双向postdivergence基因流（Nem » 1）之间的中国和台湾花梅，直到0.5 Ma。分歧时间估计为350万至200万年前比线粒体细胞色素B序列估计。最后，使用推断的nonallopatry模型来模拟遗传变异在24个核基因检查表明，脂联素受体1基因可能是在趋异适应。我们的研究结果意味着，地理障碍的作用可能是大陆岛屿特有种的物种形成不太突出，并建议物种形成研究从简单地关联地理障碍和遗传分化，以检查因素，促进和维持分歧，如差异选择和性选择，特别是在面对种群间的基因流。
Allopatry is conventionally considered the geographical mode of speciation for continental island organisms. However, strictly allopatric speciation models that assume the lack of postdivergence gene flow seem oversimplified given the recurrence of land bridges during glacial periods since the late Pliocene. Here, to evaluate whether a continental island endemic, the Taiwan hwamei (Leucodioptron taewanus, Passeriformes Timaliidae) speciated in strict allopatry, we used weighted‐regression‐based approximate Bayesian computation (ABC) to analyse the genetic polymorphism of 18 neutral nuclear loci (total length: 8500 bp) in Taiwan hwamei and its continental sister species, the Chinese hwamei (L. canorum canorum). The nonallopatry model was found to fit better with observed genetic polymorphism of the two hwamei species (posterior possibility = 0.82). We also recovered unambiguous signals of nontrivial bidirectional postdivergence gene flow (Nem » 1) between Chinese hwamei and Taiwan hwamei until 0.5 Ma. Divergence time was estimated to be 3.5 to 2 million years earlier than that estimated from mitochondrial cytochrome b sequences. Finally, using the inferred nonallopatry model to simulate genetic variation at 24 nuclear genes examined showed that the adiponectin receptor 1 gene may be under divergent adaptation. Our findings imply that the role of geographical barrier may be less prominent for the speciation of continental island endemics, and suggest a shift in speciation studies from simply correlating geographical barrier and genetic divergence to examining factors that facilitate and maintain divergence, e.g. differential selection and sexual selection, especially in the face of interpopulation gene flow.