Advances in genomics have greatly enhanced our understanding of mountain biodiversity, providing new insights into the complex and dynamic mechanisms that drive the formation of mountain biotas. These span from broad biogeographic patterns to population dynamics and adaptations to these environments. However, significant challenges remain in integrating large-scale and fine-scale findings to develop a comprehensive understanding of mountain biodiversity. One significant challenge is the lack of genomic data, particularly in historically understudied arid regions where reptiles are a particularly diverse vertebrate group. In the present study, we assembled a de novo genome-wide SNP dataset for the complete endemic reptile fauna of a mountain range (19 described species with more than 600 specimens sequenced), and integrated state-of-the-art biogeographic analyses at the population, species, and community level. Thus, we provide a holistic integration of how a whole endemic reptile community has originated, diversified and dispersed through a mountain system. Our results show that reptiles independently colonized the Hajar Mountains of southeastern Arabia 11 times. After colonization, species delimitation methods suggest high levels of within-mountain diversification, supporting up to 49 deep lineages. This diversity is strongly structured following local topography, with the highest peaks acting as a broad barrier to gene flow among the entire community. Interestingly, orogenic events do not seem key drivers of the biogeographic history of reptiles in this system. Instead, past climatic events seem to have had a major role in this community assemblage. We observe an increase of vicariant events from Late Pliocene onwards, coinciding with an unstable climatic period of rapid shifts between hyper-arid and semiarid conditions that led to the ongoing desertification of Arabia. We conclude that paleoclimate, and particularly extreme aridification, acted as a main driver of diversification in arid mountain systems which is tangled with the generation of highly adapted endemicity. Overall, our study does not only provide a valuable contribution to understanding the evolution of mountain biodiversity, but also offers a flexible and scalable approach that can be reproduced into any taxonomic group and at any discrete environment.

中文翻译：

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整合基因组学和生物地理学来解开山区生物群的起源：阿拉伯爬行动物流行热点的案例


基因组学的进步极大地增强了我们对山区生物多样性的理解，为推动山区生物群形成的复杂和动态机制提供了新的见解。这些范围从广泛的生物地理模式到人口动态和对这些环境的适应。然而，在整合大规模和精细调查结果以全面了解山区生物多样性方面仍然存在重大挑战。一个重大挑战是缺乏基因组数据，特别是在历史上研究不足的干旱地区，那里的爬行动物是一个特别多样化的脊椎动物群体。在本研究中，我们为山脉的完整特有爬行动物动物群（描述了 19 种物种，对 600 多个标本进行了测序）构建了从头全基因组 SNP 数据集，并综合了最先进的生物地理学分析。人口、物种和群落水平。因此，我们提供了整个特有爬行动物群落如何通过山区系统起源、多样化和分散的整体整合。我们的研究结果表明，爬行动物曾独立在阿拉伯半岛东南部的哈吉尔山脉定居 11 次。殖民化后，物种界定方法表明山内存在高度多样化，支持多达 49 个深层谱系。这种多样性是按照当地地形强烈构建的，最高的山峰成为整个群落之间基因流动的广泛障碍。有趣的是，造山运动似乎并不是该系统中爬行动物生物地理历史的关键驱动因素。相反，过去的气候事件似乎在这个社区聚集中发挥了重要作用。 我们观察到从上新世晚期开始，替代事件有所增加，恰逢极端干旱和半干旱条件之间快速转变的不稳定气候时期，导致阿拉伯半岛持续荒漠化。我们得出的结论是，古气候，特别是极端干旱，是干旱山区系统多样化的主要驱动力，而干旱山区系统与高度适应的地方性流行病的产生密切相关。总的来说，我们的研究不仅为了解山区生物多样性的演变提供了宝贵的贡献，而且还提供了一种灵活且可扩展的方法，可以复制到任何分类群和任何离散环境中。