Institute of Entomology, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China.
College of Life Sciences, Zaozhuang University, 1 Beian Road, Shandong 277000, China.
Mol Biol Evol. 2022 May 3;39(5). doi: 10.1093/molbev/msac089.
Holocene climate warming has dramatically altered biological diversity and distributions. Recent human-induced emissions of greenhouse gases will exacerbate global warming and thus induce threats to cold-adapted taxa. However, the impacts of this major climate change on transcontinental temperate species are still poorly understood. Here, we generated extensive genomic datasets for a water strider, Aquarius paludum, which was sampled across its entire distribution in Eurasia and used these datasets in combination with ecological niche modeling (ENM) to elucidate the influence of the Holocene and future climate warming on its population structure and demographic history. We found that A. paludum consisted of two phylogeographic lineages that diverged in the middle Pleistocene, which resulted in a "west-east component" genetic pattern that was probably triggered by Central Asia-Mongoxin aridification and Pleistocene glaciations. The diverged western and eastern lineages had a second contact in the Holocene, which shaped a temporary hybrid zone located at the boundary of the arid-semiarid regions of China. Future predictions detected a potentially novel northern corridor to connect the western and eastern populations, indicating west-east gene flow would possibly continue to intensify under future warming climate conditions. Further integrating phylogeographic and ENM analyses of multiple Eurasian temperate taxa based on published studies reinforced our findings on the "west-east component" genetic pattern and the predicted future northern corridor for A. paludum. Our study provided a detailed paradigm from a phylogeographic perspective of how transcontinental temperate species differ from cold-adapted taxa in their response to climate warming.
全新世气候变暖极大地改变了生物多样性和分布。最近人为温室气体排放将加剧全球变暖，从而对适应寒冷的分类群造成威胁。然而，这种主要气候变化对跨大陆温带物种的影响仍知之甚少。在这里，我们为一种水黾 Aquarius paludum 生成了广泛的基因组数据集，该水黾在欧亚大陆的整个分布范围内进行了采样，并将这些数据集与生态位模型 (ENM) 结合使用，以阐明全新世和未来气候变暖对其种群结构和种群历史的影响。我们发现，A. paludum 由两个在更新世中期分化的谱系组成，这导致了一种“西-东成分”的遗传模式，可能是由中亚-蒙古干旱化和更新世冰川作用引发的。分化的西部和东部谱系在全新世再次接触，形成了一个位于中国干旱半干旱地区边界的临时杂交区。未来的预测检测到了一个潜在的连接西部和东部种群的新的北部走廊，表明在未来变暖的气候条件下，东西向的基因流可能会继续加剧。进一步整合基于已发表研究的欧亚大陆多个温带分类群的系统地理学和 ENM 分析，加强了我们对“西-东成分”遗传模式和未来 A. paludum 北部走廊的预测的发现。我们的研究从系统地理学的角度提供了一个详细的范例，说明了跨大陆温带物种如何与适应寒冷的分类群在对气候变暖的反应上有所不同。
