Data from: When new human-modified habitats favor the expansion of an amphibian pioneer species: evolutionary history of the natterjack toad (Bufo calamita) in a coal basin

Human activities affect microevolutionary dynamics by inducing environmental changes. In particular, land cover conversion and loss of native habitats decrease genetic diversity and jeopardize the adaptive ability of populations. Nonetheless, new anthropogenic habitats can also promote the successful establishment of emblematic pioneer species. We investigated this issue by examining the population genetic features and evolutionary history of the natterjack toad (Bufo [Epidalea] calamita) in northern France, where populations can be found in native coastal habitats and coalfield habitats shaped by European industrial history, along with an additional set of European populations located outside this focal area. We predicted contrasting patterns of genetic structure, with newly settled coalfield populations departing from migration–drift equilibrium. As expected, coalfield populations showed a mosaic of genetically divergent populations with short-range patterns of gene flow, and native coastal populations indicated an equilibrium state with an isolation-by-distance pattern suggestive of postglacial range expansion. However, coalfield populations exhibited (i) high levels of genetic diversity, (ii) no evidence of local inbreeding or reduced effective population size and (iii) multiple maternal mitochondrial lineages, a genetic footprint depicting independent colonization events. Furthermore, approximate Bayesian computations suggested several evolutionary trajectories from ancient isolation in glacial refugia during the Pleistocene, with biogeographical signatures of recent expansion probably confounded by human-mediated mixing of different lineages. From an evolutionary and conservation perspective, this study highlights the ecological value of industrial areas, provided that ongoing regional gene flow is ensured within the existing lineage boundaries.人类活动通过诱发环境变化，进而影响微观演化动力学（microevolutionary dynamics）。具体而言，土地覆被转化与原生栖息地丧失会降低种群遗传多样性，损害种群的适应能力。不过，新形成的人为生境也可助力标志性先锋物种成功定殖。本研究以法国北部的黄条背蟾蜍（Bufo [Epidalea] calamita）为研究对象，探究了该科学问题：该区域的蟾蜍种群既栖息于原生海岸生境，也存活于受欧洲工业历史塑造的煤田生境，同时本研究还纳入了该焦点区域之外的一批欧洲种群作为补充样本。我们预测种群遗传结构将呈现差异化模式，即新定殖的煤田种群会偏离迁移-漂变平衡（migration–drift equilibrium）。实验结果与预期一致：煤田种群呈现出遗传分化的镶嵌格局，且基因流仅局限于短距离范围；而原生海岸种群则处于平衡状态，呈现距离隔离（isolation-by-distance）模式，暗示其经历了冰期后的范围扩张。不过，煤田种群同时具备三项特征：(i) 高水平的遗传多样性；(ii) 未检测到局部近交或有效种群大小（effective population size）降低的迹象；(iii) 多重母系线粒体谱系（mitochondrial lineages），这一遗传印记表明存在多次独立的定殖事件。此外，近似贝叶斯计算（approximate Bayesian computations）结果显示，该物种的演化轨迹大概率源自更新世（Pleistocene）冰期避难所（glacial refugia）的古老隔离事件，而近期扩张的生物地理信号可能受到人类介导的不同谱系混合作用的干扰。从演化与保护生物学视角来看，本研究凸显了工业区域的生态价值——前提是需确保在现有谱系边界内维持持续的区域基因流。