Data from: Evaluating mechanisms of diversification in a Guineo-Congolian tropical forest frog using demographic model selection

The accumulation of biodiversity in tropical forests can occur through multiple allopatric and parapatric models of diversification, including forest refugia, riverine barriers and ecological gradients. Considerable debate surrounds the major diversification process, particularly in the West African Lower Guinea forests, which contain a complex geographic arrangement of topographic features and historical refugia. We used genomic data to investigate alternative mechanisms of diversification in the Gaboon forest frog, Scotobleps gabonicus, by first identifying population structure and then performing demographic model selection and spatially explicit analyses. We found that a majority of population divergences are best explained by allopatric models consistent with the forest refugia hypothesis and involve divergence in isolation with subsequent expansion and gene flow. These population divergences occurred simultaneously and conform to predictions based on climatically stable regions inferred through ecological niche modelling. Although forest refugia played a prominent role in the intraspecific diversification of S. gabonicus, we also find evidence for potential interactions between landscape features and historical refugia, including major rivers and elevational barriers such as the Cameroonian Volcanic Line. We outline the advantages of using genomewide variation in a model-testing framework to distinguish between alternative allopatric hypotheses, and the pitfalls of limited geographic and molecular sampling. Although phylogeographic patterns are often species-specific and related to life-history traits, additional comparative studies incorporating genomic data are necessary for separating shared historical processes from idiosyncratic responses to environmental, climatic and geological influences on diversification.热带森林的生物多样性积累可通过多种异域分化（allopatric）与邻域分化（parapatric）模型实现，涵盖森林避难所、河流屏障与生态梯度等分化机制。目前学界对主导性物种分化机制仍存在较大争议，西非下几内亚森林尤为典型——该区域的地形特征与历史避难所的地理排布极为复杂。本研究以加蓬森林蛙（*Scotobleps gabonicus*）为研究对象，利用基因组数据探究其潜在的分化机制：首先明确其种群结构，随后开展种群历史模型选择与空间显式分析。研究结果表明，多数种群分化事件均可通过契合森林避难所假说的异域分化模型得到最优解释，即经历隔离分化后伴随种群扩张与基因流。这些种群分化事件同步发生，与通过生态位模型推断的气候稳定区域的相关预测相符。尽管森林避难所在加蓬森林蛙的种内分化中发挥了关键作用，本研究仍发现景观特征与历史避难所存在潜在互作的证据，例如大型河流及喀麦隆火山带等海拔屏障。本研究阐述了在模型检验框架中使用全基因组变异以区分不同异域分化假说的优势，同时指出了有限地理采样与分子采样的潜在局限。尽管系统地理格局通常具有物种特异性，并与其生活史特征相关，但要区分共享的历史演化过程与物种对环境、气候及地质因素的特异响应，仍需开展更多结合基因组数据的比较研究。