Ecology and Evolution in Microbial Model Systems, EEMiS, Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden.
National Institute of Aquatic Resources, Technical University of Denmark, Silkeborg, Denmark.
Mol Ecol. 2022 Feb;31(4):1093-1110. doi: 10.1111/mec.16315. Epub 2021 Dec 15.
Understanding how eco-evolutionary processes and environmental factors drive population differentiation and adaptation are key challenges in evolutionary biology of relevance for biodiversity protection. Differentiation requires at least partial reproductive separation, which may result from different modes of isolation such as geographic isolation (allopatry) or isolation by distance (IBD), resistance (IBR), and environment (IBE). Despite that multiple modes might jointly influence differentiation, studies that compare the relative contributions are scarce. Using RADseq, we analyse neutral and adaptive genetic diversity and structure in 11 pike (Esox lucius) populations from contrasting environments along a latitudinal gradient (54.9-63.6°N), to investigate the relative effects of IBD, IBE and IBR, and to assess whether the effects differ between neutral and adaptive variation, or across structural levels. Patterns of neutral and adaptive variation differed, probably reflecting that they have been differently affected by stochastic and deterministic processes. The importance of the different modes of isolation differed between neutral and adaptive diversity, yet were consistent across structural levels. Neutral variation was influenced by interactions among all three modes of isolation, with IBR (seascape features) playing a central role, wheares adaptive variation was mainly influenced by IBE (environmental conditions). Taken together, this and previous studies suggest that it is common that multiple modes of isolation interactively shape patterns of genetic variation, and that their relative contributions differ among systems. To enable identification of general patterns and understand how various factors influence the relative contributions, it is important that several modes are simultaneously investigated in additional populations, species and environmental settings.
理解生态进化过程和环境因素如何驱动种群分化和适应，是进化生物学中与生物多样性保护相关的关键挑战。分化至少需要部分生殖隔离，这可能是由于不同的隔离模式造成的，如地理隔离（异域分布）或距离隔离（IBD）、抗性（IBR）和环境（IBE）。尽管多种模式可能共同影响分化，但比较相对贡献的研究很少。我们使用 RADseq 分析了 11 个来自不同环境的梭鲈（Esox lucius）种群的中性和适应性遗传多样性和结构，这些种群分布在一个纬度梯度上（54.9-63.6°N），以研究 IBD、IBE 和 IBR 的相对影响，并评估它们在中性和适应性变异之间或在结构水平上是否存在差异。中性和适应性变异的模式不同，这可能反映了它们受到随机和确定性过程的不同影响。不同隔离模式的重要性在中性和适应性多样性之间存在差异，但在结构水平上是一致的。中性变异受到三种隔离模式相互作用的影响，IBR（景观特征）起着核心作用，而适应性变异主要受到 IBE（环境条件）的影响。综上所述，本研究和以前的研究表明，多种隔离模式相互作用塑造遗传变异模式是很常见的，它们的相对贡献在不同的系统中存在差异。为了能够识别一般模式并了解各种因素如何影响相对贡献，在其他种群、物种和环境设置中同时研究几种模式是很重要的。
