Data from: The interplay of dispersal limitation, rivers, and historical events shapes the genetic structure of an Amazonian frog

Disentangling the impact of landscape features such as rivers and historical events on dispersal is a challenging but necessary task to gain a comprehensive picture of the evolution of diverse biota such as that found in Amazonia. Adenomera andreae, a small, territorial, terrestrial frog species of the Amazonian forest represents a good model for such studies. We combined Cytochrome b sequences with 12 microsatellites to investigate the genetic structure at two contrasted spatial scales in French Guiana: along a ~6 km transect to evaluate dispersal ability and between paired bank populations along a ~65 km stretch of the Approuague river to test the effect of rivers as barriers to dispersal. We observed significant spatial genetic structure between individuals at a remarkably small geographical scale and conclude that the species has a restricted dispersal ability likely tied to its life history traits. Mitochondrial and microsatellite data also indicate a high level of differentiation among populations on opposite banks of the river and, in some cases, among populations on the same riverbank. These results suggest that the observed population structure in A. andreae is due to restricted dispersal abilities combined with the action of rivers and Quaternary population isolation. Given that Amazonia hosts a great portion of anurans, as well as other small vertebrates, that display life history traits comparable to Adenomera andreae, we argue that our analyses provide new insights into the complex interactions among evolutionary processes shaping Amazonian biodiversity.

厘清河流等景观特征与历史事件对生物扩散的影响，是全面解析亚马逊流域多样生物类群演化历程的一项兼具挑战性与必要性的工作。安第列斯腺蛙（Adenomera andreae）是亚马逊森林中一种小型、具领地性的陆栖蛙类，是此类研究的理想模型物种。我们结合细胞色素b（Cytochrome b）基因序列与12个微卫星（microsatellite）标记，在法属圭亚那开展了两类差异化空间尺度下的种群遗传结构研究：一是沿约6公里的样带以评估该物种的扩散能力，二是沿阿普鲁阿克河（Approuague river）约65公里河段的两岸配对种群，以检验河流作为扩散屏障的效应。我们在极小的地理尺度内便观测到个体间存在显著的空间遗传结构，由此推断该物种的扩散能力受限，这大概率与其生活史特征相关。线粒体与微卫星数据同样显示，河流两岸种群间存在高度遗传分化，部分情况下同岸种群间也存在分化。上述结果表明，安第列斯腺蛙观测到的种群结构，是扩散能力受限、河流阻隔作用与第四纪种群隔离共同作用的结果。鉴于亚马逊流域孕育了大量与安第列斯腺蛙具有相似生活史特征的无尾两栖类与其他小型脊椎类群，我们认为本研究为解析塑造亚马逊生物多样性的各类演化过程间的复杂互作关系提供了全新视角。