School of Biological Sciences and Australian Centre for Biodiversity, Monash University, Clayton, Victoria, Australia.
PLoS One. 2009 Nov 24;4(11):e7950. doi: 10.1371/journal.pone.0007950.
Knowledge of historical changes in species range distribution provides context for investigating adaptive potential and dispersal ability. This is valuable for predicting the potential impact of environmental change on species of interest. Butterflies are one of the most important taxa for studying such impacts, and Heteronympha merope has the potential to provide a particularly valuable model, in part due to the existence of historical data on morphological traits and glycolytic enzyme variation. This study investigates the population genetic structure and phylogeography of H. merope, comparing the relative resolution achieved through partial DNA sequences of two mitochondrial loci, COI and ND5. These data are used to define the relationship between subspecies, showing that the subspecies are reciprocally monophyletic. On this basis, the Western Australian subspecies H. m. duboulayi is genetically distinct from the two eastern subspecies. Throughout the eastern part of the range, levels of migration and the timing of key population splits of potential relevance to climatic adaptation are estimated and indicate Late Pleistocene divergence both of the Tasmanian subspecies and of an isolated northern population from the eastern mainland subspecies H. m. merope. This information is then used to revisit historical data and provides support for the importance of clinal variation in wing characters, as well as evidence for selective pressure acting on allozyme loci phosphoglucose isomerase and phosphoglucomutase in H. merope. The study has thus confirmed the value of H. merope as a model organism for measuring responses to environmental change, offering the opportunity to focus on isolated populations, as well as a latitudinal gradient, and to use historical changes to test the accuracy of predictions for the future.
物种分布范围历史变化的知识为研究适应潜力和扩散能力提供了背景。这对于预测环境变化对感兴趣物种的潜在影响非常有价值。蝴蝶是研究此类影响的最重要类群之一，而 Heteronympha merope 有可能提供一个特别有价值的模型，部分原因是存在关于形态特征和糖酵解酶变异的历史数据。本研究调查了 H. merope 的种群遗传结构和系统地理学，比较了两个线粒体基因座 COI 和 ND5 的部分 DNA 序列获得的相对分辨率。这些数据用于定义亚种之间的关系，表明亚种是相互单系的。在此基础上，西澳大利亚亚种 H. m. duboulayi 与两个东部亚种在遗传上是不同的。在东部范围的整个地区，估计了迁移水平和关键种群分裂的时间，这些分裂与气候适应有关，并表明塔斯马尼亚亚种和东部大陆亚种 H. m. merope 的一个孤立北部种群在更新世晚期发生了分歧。然后，将这些信息用于重新审视历史数据，并为翅膀特征的渐变在其中的重要性提供了支持，同时也为选择压力作用于 allozyme 基因座磷酸葡萄糖异构酶和磷酸葡萄糖变位酶的证据提供了支持。因此，该研究证实了 H. merope 作为衡量对环境变化反应的模型生物的价值，为关注孤立种群以及纬度梯度提供了机会，并利用历史变化来检验对未来的预测的准确性。
