Data from: Idiosyncratic responses to climate-driven forest fragmentation and marine incursions in reed frogs from Central Africa and the Gulf of Guinea Islands

Organismal traits interact with environmental variation to mediate how species respond to shared landscapes. Thus, differences in traits related to dispersal ability or physiological tolerance may result in phylogeographic discordance among co-distributed taxa, even when they are responding to common barriers. We quantified climatic suitability and stability, and phylogeographic divergence within three reed frog species complexes across the Guineo-Congolian forests and Gulf of Guinea archipelago of Central Africa to investigate how they responded to a shared climatic and geological history. Our species-specific estimates of climatic suitability through time are consistent with temporal and spatial heterogeneity in diversification among the species complexes, indicating that differences in ecological breadth may partly explain these idiosyncratic patterns. Likewise, we demonstrated that fluctuating sea levels periodically exposed a land bridge connecting Bioko Island with the mainland Guineo-Congolian forest and that habitats across the exposed land bridge likely enabled dispersal in some species, but not in others. We did not find evidence that rivers are biogeographic barriers across any of the species complexes. Despite marked differences in the geographic extent of stable climates and temporal estimates of divergence among the species complexes, we recovered a shared pattern of intermittent climatic suitability with recent population connectivity and demographic expansion across the Congo Basin. This pattern supports the hypothesis that genetic exchange across the Congo Basin during humid periods, followed by vicariance during arid periods, has shaped regional diversity. Finally, we identified many distinct lineages among our focal taxa, some of which may reflect incipient or unrecognized species.

生物性状（organismal traits）与环境变异（environmental variation）相互作用，共同介导物种对共享景观的响应路径。即便同分布类群（co-distributed taxa）面临共同障碍（common barriers），与扩散能力或生理耐受性相关的性状差异，仍可能导致其出现系统地理不一致性（phylogeographic discordance）。我们针对分布于中非几内亚-刚果森林区与几内亚湾群岛的3个苇蛙物种复合群（reed frog species complexes），量化了其气候适宜性（climatic suitability）与气候稳定性，并分析了系统地理分化（phylogeographic divergence）情况，以探究这些类群如何响应共享的气候与地质历史。我们针对各物种的历史气候适宜性估算结果，与各物种复合群演化过程中展现出的时空异质性分化模式相符，表明生态幅（ecological breadth）差异或可部分解释这些独特的分化格局（idiosyncratic patterns）。与此同时，我们证实海平面波动（fluctuating sea levels）曾周期性露出连接比奥科岛（Bioko Island）与大陆几内亚-刚果森林区的陆桥（land bridge），该露出陆桥的生境或支持部分类群完成扩散，但并非所有类群均可借此实现扩散。我们未发现证据表明河流对任意一个苇蛙物种复合群构成生物地理屏障（biogeographic barriers）。尽管各物种复合群的稳定气候区地理范围（geographic extent）与分化时间估算（temporal estimates of divergence）均存在显著差异，但我们仍在刚果盆地（Congo Basin）范围内发现了一致的模式：间歇性气候适宜性（intermittent climatic suitability）伴随近期种群连通性（recent population connectivity）与种群扩张（demographic expansion）。该模式支持如下假说：湿润时期刚果盆地内的基因交流，与干旱时期发生的隔离分化（vicariance）共同塑造了该区域的生物多样性格局。最终，我们在研究类群中发现了多个独特支系，其中部分支系或代表雏形物种（incipient species）或尚未被认知的新物种（unrecognized species）。