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, especially 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以揭示山地生物群的起源：阿拉伯爬行动物流行热点案例


基因组学的进步极大地增强了我们对山地生物多样性的理解，为驱动山地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种群动态和对这些环境的适应。然而，在整合大规模和精细的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，尤其是在历史上研究不足的干旱地区，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群（19 个已描述的物种和 600 多个标本测序）组装了一个从头的全基因组 SNP 数据集，并在种群、物种和群落水平上整合了最先进的生物地理学分析。因此，我们提供了整个地方性爬行动物群落如何通过山地系统起源、多样化和分散的整体整合。我们的结果表明，爬行动物独立定居在阿拉伯东南部的哈吉尔山脉 11 次。定植后，物种划界方法表明山内多样化程度很高，支持多达 49 个深谱系。这种多样性是遵循当地地形的强烈结构，最高峰是整个群落之间基因流动的广泛障碍。有趣的是，造山事件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群落组合中发挥了重要作用。 我们观察到从上新世晚期开始，vicariantic 事件有所增加，这与超干旱和半干旱条件之间快速变化的不稳定气候时期相吻合，导致阿拉伯持续的荒漠化。我们得出结论，古气候，尤其是极端干旱化，是干旱山区系统多样化的主要驱动力，这与高度适应的地方性流行病的产生纠缠在一起。总的来说，我们的研究不仅为理解山地生物多样性的演变做出了宝贵的贡献，而且还提供了一种灵活且可扩展的方法，可以在任何分类组和任何离散环境中复制。