Klaus Kristina V, Schulz Christian, Bauer Dennise S, Stützel Thomas
Department of Evolution and Biodiversity of Plants, Ruhr-Universität Bochum, Universitätsstraße 150, Bochum, 44801, Germany.
Cladistics. 2017 Oct;33(5):469-480. doi: 10.1111/cla.12184. Epub 2016 Dec 17.
The ancient and cosmopolitan lycophyte genus Selaginella has living representatives around the world, but their historical biogeography has not been assessed with modern methods. We estimated a time-calibrated phylogeny using DNA marker regions rbcL and ITS1-5.8S-ITS2 from 200 species. Node density analyses revealed that Selaginellaceae has significantly older median and mean node ages than other putative "ancient" families. We used statistical model comparison to assess different biogeographical models on our dated tree, and to estimate ancestral ranges. These revealed that Selaginella originated on Euramerica around 383 Ma in the Devonian period, while its peak diversification began with the formation of Pangea. The divergence of the two main species-rich Selaginella lineages occurred approximately 318 Ma on the supercontinent. The major divergences within these main lineages of Selaginella took place in the Late Permian and Early Triassic, along with lineages highly adapted for xeric habitats on Pangea.
古老且分布广泛的石松类植物卷柏属在世界各地都有现存代表，但它们的历史生物地理学尚未用现代方法进行评估。我们使用来自200个物种的DNA标记区域rbcL和ITS1-5.8S-ITS2估计了一个时间校准的系统发育树。节点密度分析表明，卷柏科的中位数和平均节点年龄比其他假定的“古老”科要老得多。我们使用统计模型比较来评估我们的定年树上不同的生物地理模型，并估计祖先分布范围。这些结果表明，卷柏起源于泥盆纪约3.83亿年前的欧美地区，而其多样化高峰始于泛大陆的形成。卷柏两个主要的物种丰富谱系的分歧大约发生在3.18亿年前的超级大陆上。卷柏这些主要谱系内的主要分歧发生在二叠纪晚期和三叠纪早期，同时还有在泛大陆上高度适应干旱生境的谱系。
