Under the threat of climate change populations can disperse, acclimatise or evolve in order to avoid fitness loss. In light of this, it is important to understand neutral gene flow patterns as a measure of dispersal potential, but also adaptive genetic variation as a measure of evolutionary potential. In order to assess genetic variation and how this relates to environment in the honeycomb worm (Sabellaria alveolata (L.)), a reef-building polychaete that supports high biodiversity, we carried out RAD sequencing using individuals from along its complete latitudinal range. Patterns of neutral population genetic structure were compared to larval dispersal as predicted by ocean circulation modelling, and outlier analyses and genotype-environment association tests were used to attempt to identify loci under selection in relation to local temperature data. We genotyped 482 filtered SNPs, from 68 individuals across nine sites, 27 of which were identified as outliers using BAYESCAN and ARLEQUIN. All outlier loci were potentially under balancing selection, despite previous evidence of local adaptation in the system. Limited gene flow was observed among reef-sites (FST = 0.28 ± 0.10), in line with the low dispersal potential identified by the larval dispersal models. The North Atlantic reef emerged as a distinct population and this was linked to high local larval retention and the effect of the North Atlantic Current on dispersal. As an isolated population, with limited potential for natural genetic or demographic augmentation from other reefs, the North Atlantic site warrants conservation attention in order to preserve not only this species, but above all the crucial functional ecological roles that are associated with their bioconstructions. Our study highlights the utility of using seascape genomics to identify populations of conservation concern.

中文翻译：

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海景基因组学揭示了造礁蜂窝虫 Sabellaria alveolata (L.) 中的种群隔离。


在气候变化的威胁下，种群可能会分散、适应或进化，以避免健康损失。有鉴于此，重要的是了解中性基因流动模式作为分散潜力的衡量标准，同时也了解适应性遗传变异作为进化潜力的衡量标准。为了评估蜂窝虫（Sabellaria alveolata (L.)）（一种支持高度生物多样性的造礁多毛动物）的遗传变异及其与环境的关系，我们使用来自其整个纬度范围的个体进行了 RAD 测序。将中性种群遗传结构的模式与海洋环流模型预测的幼虫扩散进行比较，并使用离群值分析和基因型-环境关联测试来尝试识别与当地温度数据相关的选择基因座。我们对来自 9 个地点的 68 个人的 482 个过滤的 SNP 进行了基因分型，其中 27 个使用 BAYESCAN 和 ARLEQUIN 被识别为异常值。尽管之前有证据表明系统存在局部适应，但所有离群基因座都可能处于平衡选择之下。在珊瑚礁地点之间观察到有限的基因流（FST = 0.28 ± 0.10），这与幼虫扩散模型确定的低扩散潜力一致。北大西洋珊瑚礁成为一个独特的种群，这与当地幼虫的高保留率和北大西洋洋流对扩散的影响有关。作为一个孤立的种群，来自其他珊瑚礁的自然遗传或人口增长的潜力有限，北大西洋遗址值得保护，不仅要保护该物种，而且首先要保护与其生物结构相关的关键功能生态作用。 我们的研究强调了使用海景基因组学来识别受保护群体的实用性。