Barbosa S, Paupério J, Herman J S, Ferreira C M, Pita R, Vale-Gonçalves H M, Cabral J A, Garrido-García J A, Soriguer R C, Beja P, Mira A, Alves P C, Searle J B
CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, 4485-661, Vairão, Portugal.
Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal.
Mol Ecol. 2017 Feb;26(3):951-967. doi: 10.1111/mec.13994. Epub 2017 Jan 27.
Glacial refugia protected and promoted biodiversity during the Pleistocene, not only at a broader scale, but also for many endemics that contracted and expanded their ranges within refugial areas. Understanding the evolutionary history of refugial endemics is especially important in the case of endangered species to recognize the origins of their genetic structure and thus produce better informed conservation practices. The Iberian Peninsula is an important European glacial refugium, rich in endemics of conservation concern, including small mammals, such as the Cabrera vole (Microtus cabrerae). This near-threatened rodent is characterized by an unusual suite of genetic, life history and ecological traits, being restricted to isolated geographic nuclei in fast-disappearing Mediterranean subhumid herbaceous habitats. To reconstruct the evolutionary history of the Cabrera vole, we studied sequence variation at mitochondrial, autosomal and sex-linked loci, using invasive and noninvasive samples. Despite low overall mitochondrial and nuclear nucleotide diversities, we observed two main well-supported mitochondrial lineages, west and east. Phylogeographic modelling in the context of the Cabrera vole's detailed fossil record supports a demographic scenario of isolation of two populations during the Last Glacial Maximum from a single focus in the southern part of the Iberian Peninsula. In addition, our data suggest subsequent divergence within the east, and secondary contact and introgression of the expanding western population, during the late Holocene. This work emphasizes that refugial endemics may have a phylogeographic history as rich as that of more widespread species, and conservation of such endemics includes the preservation of that genetic legacy.
在更新世期间，冰川避难所不仅在更广泛的范围内保护和促进了生物多样性，对于许多在避难区域内收缩和扩张分布范围的特有物种也是如此。了解避难所特有物种的进化历史对于濒危物种而言尤为重要，有助于认识其遗传结构的起源，从而制定更明智的保护措施。伊比利亚半岛是欧洲一个重要的冰川避难所，拥有许多受保护关注的特有物种，包括小型哺乳动物，如卡布雷拉田鼠（Microtus cabrerae）。这种近危啮齿动物具有一系列独特的遗传、生活史和生态特征，仅分布于快速消失的地中海亚湿润草本栖息地中的孤立地理核心区域。为了重建卡布雷拉田鼠的进化历史，我们利用侵入性和非侵入性样本，研究了线粒体、常染色体和性连锁基因座的序列变异。尽管线粒体和核基因的总体核苷酸多样性较低，但我们观察到两个主要且得到有力支持的线粒体谱系，即西部谱系和东部谱系。结合卡布雷拉田鼠详细的化石记录进行系统地理学建模，支持了末次盛冰期期间两个种群从伊比利亚半岛南部的一个单一焦点隔离的人口统计学情景。此外，我们的数据表明，在全新世晚期，东部谱系内部随后发生了分化，扩张的西部种群出现了二次接触和基因渗入。这项工作强调，避难所特有物种可能具有与分布更广泛的物种一样丰富的系统地理学历史，对这些特有物种的保护包括保护其遗传遗产。
