Komarova Valeria A, Kostin Danila S, Bryja Josef, Mikula Ondřej, Bryjová Anna, Čížková Dagmar, Šumbera Radim, Meheretu Yonas, Lavrenchenko Leonid A
A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
Institute of Vertebrate Biology, Czech Academy of Sciences, Brno, Czech Republic.
Mol Ecol. 2021 May;30(10):2349-2365. doi: 10.1111/mec.15891. Epub 2021 Apr 2.
The Ethiopian highlands represent a remarkable biodiversity 'hot spot' with a very high number of endemic species, even among vertebrates. Ethiopian representatives of a species complex of speckled brush-furred rats (Lophuromys flavopunctatus sensu lato) inhabit highland habitats ranging from low-elevation forests to Afroalpine grasslands. These may serve as a suitable model for understanding evolutionary processes leading to high genetic and ecological diversity in montane biodiversity hot spots. Here, we analyse the most comprehensive genetic data set of this group, comprising 315 specimens (all nine putative Ethiopian Lophuromys taxa sampled across most of their distribution ranges) genotyped at one mitochondrial and four nuclear markers, and thousands of SNPs from ddRAD sequencing. We performed phylogenetic analyses, delimited species and mapped their distribution and estimated divergence time between species (under the species-tree framework) and mitochondrial lineages. We found significant incongruence between mitochondrial and nuclear phylogenies, most probably caused by multiple interspecific introgression events. We discuss alternative scenarios of Ethiopian Lophuromys evolution, from retention of ancestral polymorphism to hybridization upon secondary contact of partially reproductively isolated lineages leading to reticulate evolution. Finally, we use the diversity of the speckled brush-furred rats for the description of the main biogeographic patterns in the fauna of the Ethiopian highlands.
埃塞俄比亚高地是一个显著的生物多样性“热点地区”，拥有大量的特有物种，即使在脊椎动物中也是如此。斑点刷毛鼠（Lophuromys flavopunctatus sensu lato）物种复合体的埃塞俄比亚代表栖息在从低海拔森林到非洲高山草原的高地栖息地。这些可能是理解导致山地生物多样性热点地区高遗传和生态多样性的进化过程的合适模型。在这里，我们分析了该群体最全面的遗传数据集，包括315个标本（所有九个假定的埃塞俄比亚刷毛鼠分类群，在其大部分分布范围内采样），在一个线粒体和四个核标记以及来自ddRAD测序的数千个单核苷酸多态性（SNP）上进行了基因分型。我们进行了系统发育分析，划定了物种界限并绘制了它们的分布，并估计了物种（在物种树框架下）和线粒体谱系之间的分化时间。我们发现线粒体和核系统发育之间存在显著不一致，很可能是由多次种间基因渗入事件引起的。我们讨论了埃塞俄比亚刷毛鼠进化的替代情景，从祖先多态性的保留到部分生殖隔离谱系在二次接触时杂交导致网状进化。最后，我们利用斑点刷毛鼠的多样性来描述埃塞俄比亚高地动物群的主要生物地理模式。
