Data from: Role of recent and old riverine barriers in fine scale population genetic structure of Geoffroy's Tamarin (Saguinus geoffroyi) in the Panama Canal Watershed

The role of physical barriers in promoting population divergence and genetic structuring is well known. While it is well established that animals can show genetic structuring at small spatial scales, less well resolved is how the timing of the appearance of barriers affects population structure. This study uses the Panama Canal watershed as a test of the effects of old and novel riverine barriers in creating population structure in Saguinus geoffroyi, a small cooperatively breeding Neotropical primate. Mitochondrial sequences and microsatellite genotypes from three sampling localities revealed genetic structure across the Chagres River and the Panama Canal, suggesting that both waterways act as barriers to gene flow. F-statistics and exact tests of population differentiation suggest population structure on either side of both riverine barriers. Genetic differentiation across the Canal, however, was less than observed across the Chagres. Accordingly, Bayesian clustering algorithms detected between two and three populations, with localities across the older Chagres river always assigned as distinct populations. While conclusions represent a preliminary assessment of genetic structure of S. geoffroyi, this study adds to the evidence indicating that riverine barriers create genetic structure across a wide variety of taxa in the Panama Canal watershed and highlights the potential of this study area for discerning modern from historical influences on observed patterns of population genetic structure.

物理屏障在促进种群分化与遗传结构形成中的作用已得到广泛证实。尽管学界已明确动物可在小空间尺度下呈现遗传结构，但对于屏障出现的时序如何影响种群结构这一问题，目前仍未得到充分解析。本研究以巴拿马运河流域为研究系统，探究新旧河流屏障对戈氏柽柳猴（Saguinus geoffroyi）种群结构形成的影响，该物种是一种小型协作繁殖的新热带灵长类。对三个采样位点的线粒体序列与微卫星基因型进行分析后发现，查格雷斯河与巴拿马运河沿线存在遗传结构，表明这两条水道均可作为基因流的屏障。F统计量与种群分化精确检验结果显示，两条河流屏障的两侧均存在种群结构。然而，巴拿马运河沿线的遗传分化程度低于查格雷斯河。贝叶斯聚类算法检测到2至3个种群，其中位于更古老的查格雷斯河两侧的采样位点始终被划分为独立种群。尽管本研究仅为戈氏柽柳猴遗传结构的初步评估，但该研究进一步补充了证据，表明河流屏障可在巴拿马运河流域的诸多类群中塑造遗传结构，同时也凸显了本研究区域在区分种群遗传结构观测模式的现代与历史影响方面的研究潜力。