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.

人类活动通过引发环境变化，影响微进化动态（microevolutionary dynamics）。具体而言，土地覆被转换与原生栖息地丧失会降低种群的遗传多样性，损害种群的适应能力。尽管如此，新形成的人为栖息地也可助力标志性先锋物种成功定殖。我们通过分析法国北部黄条蟾蜍（natterjack toad，Bufo [Epidalea] calamita）的种群遗传特征与进化历史，对该议题展开了调查；该区域内的黄条蟾蜍种群既栖息于原生沿海生境，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其他欧洲种群作为补充样本。我们曾预测会出现差异化的遗传结构模式，即新定殖的煤田种群偏离迁移-漂变平衡。正如预期，煤田种群呈现出遗传分化种群的镶嵌分布格局，且基因流仅局限于短距离范围内；而原生沿海种群则处于平衡状态，其距离隔离模式暗示了冰期后的种群范围扩张。不过，煤田种群展现出三方面独特的遗传特征：(i) 高水平的遗传多样性，(ii) 未检测到局部近交或有效种群规模缩减的迹象，(iii) 存在多个母系线粒体谱系——这一遗传印记反映了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，其进化轨迹存在多种可能性：源自更新世冰期避难所的古老隔离事件，而近期扩张的生物地理特征可能因人类介导的不同谱系混合而被混淆。从进化生物学与保护生物学的视角来看，本研究强调了工业区域的生态价值——前提是需确保现有谱系边界内的持续区域基因流得以维持。