Diversification of Phlyctinus in the Cape region

<strong>This item contains:</strong> - Fasta alignment of concatenated dataset. - Seven treefiles from ML analyses on 2 mitochondrial and 4 nuclear genes as well as on the concatenated dataset. - Four xml files used to run BEAST analyses. - Excel table containg the calculation of match ratios. <br> <strong>Abstract of the study related: </strong> The Cape Floristic Region in the Republic of South Africa is a well-recognized hotspot of biodiversity. Although this region is mostly known for its high level of plant diversity and endemicity, it also hosts an understudied and likely diverse arthropod fauna. Here we investigate the evolutionary history and timing of diversification of the apterous weevil genus <em>Phlyctinus</em> (Curculionidae: Entiminae), which is endemic to the coastal area and adjacent mountain ranges of the Cape floristic region and generally associated with sunflower plants (Asteraceae). We use a diverse array of molecular analyses (phylogenetic inference, molecular species delimitation and dating analyses) to analyse a novel molecular dataset of 202 weevil specimens (including 170 <em>Phlyctinus</em> sampled in 60 sites), and sequenced for two mitochondrial and four nuclear gene fragments. Phylogenetic and dating analyses indicate that the genus started diversifying in the late Miocene, with contrasting diversification dynamics for the three inferred clades, which present disjunct distributions. Host plant records and the lack of relatedness of species living in sympatry indicate that the diversification of <em>Phlyctinus</em> was predominantly driven by allopatric (geographic) speciation. We hypothesize that the interplay between topography and recurring cycles of coastline-habitat fragmentation resulting from sea level oscillations spurred the diversification of the most speciose clade, whereas in the two remaining clades populations likely remained connected thus hampering allopatric speciation. Interestingly, this pattern echoes with the role of sea level oscillations as an important driver of the radiation of several lineages in the coastline ecosystems of the Cape Floristic Region.

本数据集包含：
- 串联数据集的FASTA格式比对文件（Fasta alignment）
- 基于2个线粒体基因、4个核基因以及串联数据集的最大似然（Maximum Likelihood，ML）系统发育分析得到的7份系统发育树文件
- 用于运行BEAST分析（Bayesian Evolutionary Analysis Sampling Trees）的4份XML格式文件
- 包含匹配比率计算结果的Excel表格

相关研究摘要：
南非共和国的开普植物区（Cape Floristic Region）是全球公认的生物多样性热点区域。该区域虽以极高的植物多样性和特有性闻名，但其节肢动物区系却长期鲜被研究，且极有可能蕴藏着丰富的物种多样性。本研究针对仅分布于开普植物区沿海区域及邻近山地的无翅象鼻虫属 *Phlyctinus*（象鼻虫科：Entiminae）展开，该属昆虫常与菊科（Asteraceae）向日葵类植物共生。我们采用多种分子分析手段（系统发育推断、分子物种界定及分化时间估算分析），对包含202份象鼻虫标本的全新分子数据集开展分析：其中包括采自60个采样点的170份 *Phlyctinus* 标本，测序覆盖2个线粒体基因片段与4个核基因片段。系统发育与分化时间分析结果显示，该属的物种分化始于中新世（Miocene）晚期，且三个推断出的演化支呈现出截然不同的分化动态，各支分布均呈间断格局。寄主植物记录以及同域分布物种间缺乏近缘关系的现象表明，*Phlyctinus* 属的物种分化主要由异域（地理）成种作用驱动。我们提出假说：地形变化与海平面波动引发的海岸生境反复碎片化过程共同作用，推动了物种最丰富的演化支的分化；而其余两个演化支的种群间始终存在基因交流，从而阻碍了异域成种作用的发生。值得注意的是，这一模式与海平面波动作为开普植物区沿海生态系统中多个类群辐射演化的重要驱动因素这一结论相呼应。