Parallel Miocene dispersal events explain the cosmopolitan distribution of the Hypogymnioid lichens
Parallel Miocene dispersal events explain the cosmopolitan distribution of the Hypogymnioid lichens
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平行的中新世扩散事件解释了下裸类地衣的世界性分布
DOI：
10.1111/jbi.13554
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发表时间：
2019-05-01
影响因子：
3.9
通讯作者：
Lumbsch, H. Thorsten
中科院分区：
文献类型：
--
作者：
Divakar, Pradeep K.;Wei, Xin-Li;Lumbsch, H. Thorsten
目的：当代物种的分布受到地理和历史事件的双重影响，如灭绝、特定地区的多样化和远距离扩散。在最多样化的地衣形成真菌家族中，Parmeliaceae，即拟地衣分支，是由两个半球温带至亚极地地区的物种组成的进化谱系的一个例子。在此，我们阐明了多样化事件的时间和历史事件对该谱系物种分布的影响。地点:全球。分类群：白桦属、白桦属、白桦属、白桦属（白桦科）。方法：我们的采样集中在分支中最多样化的属，Hypogymnia，包括约70%的描述物种。我们利用多位点数据集、估计的分化时间和推断的祖先分布重建了系统发育关系。结果：我们的分析表明，下体操类分支的祖先出现在全北极地区。在这四个属中，每一个属都是单系的，在中新世和上新世期间发生了很大程度的多样化。许多目前被接受的物种并没有形成单系群，特别是在标本来自不同地理区域的情况下，有多个不同的分支对应于起源的地理区域。我们的研究结果表明，只有极少数的亚种具有世界性分布，所有的物种都使用包括共生伴侣在内的营养繁殖体进行繁殖。主要结论：中新世的物种多样化主要发生在北半球，但从北半球到南半球的长距离扩散事件导致了一个主要局限于南半球的物种分支的多样化。与这一多样化家族中的其他类群类似，我们的研究强调了重新评估下gymnioid分支成员之间物种界限的必要性。
Aim: Contemporary species' distributions are shaped by both geography and historical events, such as extinction, diversification in specific areas and long-distance dispersals. In the most diverse family of lichen-forming fungi, Parmeliaceae, the Hypogymnioid clade, is an example of an evolutionary lineage comprised of species occurring in temperate to subpolar regions in both hemispheres. Here, we elucidate the timing of diversification events and the impact of historical events on the species distribution in this lineage.Location: Worldwide.Taxon: Genera Arctoparmelia, Brodoa, Hypogymnia and Pseudevernia (Parmeliaceae).Methods: Our sampling focused on the most diverse genus of the clade, Hypogymnia, including c. 70% of the described species. We reconstructed phylogenetic relationships using a multi-locus data set, estimated divergence times, and inferred ancestral distributions.Results: Our analyses suggest that the ancestor of the Hypogymnioid clade occurred in the Holarctic. In each of the four genera, all recovered as monophyletic here, diversification have occurred largely during the Miocene and Pliocene. A number of currently accepted species did not form monophyletic groups, especially in cases where specimens were collected from distinct geographic areas, with multiple, distinct clades corresponding to the geographic region of origin. Our results suggest that only a very few species in the Hypogymnioid clade have cosmopolitan distributions, all of which reproduces using vegetative propagules including both symbiotic partners.Main conclusions: While the diversification occurred predominantly in the Northern Hemisphere during the Miocene, a long-distance dispersal event from the Northern to the Southern Hemisphere, resulted in diversification of a clade of species largely restricted to the Southern Hemisphere. Similar to other groups in this diverse family, our study highlights the need for re-evaluation of species boundaries among members of the Hypogymnioid clade.