Data from: Influence of ecological and geological features on rangewide patterns of genetic structure in a widespread passerine.

AbstractGeological and ecological features restrict dispersal and gene flow, leading to isolated populations. Dispersal barriers can be obvious physical structures in the landscape; however microgeographic differences can also lead to genetic isolation. Our study examined dispersal barriers at both macro- and micro-geographical scales in the black-capped chickadee, a resident North American songbird. Although birds have high dispersal potential, evidence suggests dispersal is restricted by barriers. The chickadee’s range encompasses a number of physiological features which may impede movement and lead to divergence. Analyses of 913 individuals from 34 sampling sites across the entire range using 11 microsatellite loci revealed as many as 13 genetic clusters. Populations in the east were largely panmictic whereas populations in the western portion of the range showed significant genetic structure, which often coincided with large mountain ranges, such as the Cascade and Rocky Mountains, as well as areas of unsuitable habitat. Unlike populations in the central and southern Rockies, populations on either side of the northern Rockies were not genetically distinct. Furthermore, Northeast Oregon represents a forested island within the Great Basin; genetically isolated from all other populations. Substructuring at the microgeographical scale was also evident within the Fraser Plateau of central British Columbia, and in the southeast Rockies where no obvious physical barriers are present, suggesting additional factors may be impeding dispersal and gene flow. Dispersal barriers are therefore not restricted to large physical structures, although mountain ranges and large water bodies do play a large role in structuring populations in this study.
Usage notesGenotypeData_DRYAD_Adams&Burg2014Genotype data for 913 individuals screened for 11 microsatellite loci.

摘要：地质与生态特征会限制扩散与基因流，进而导致种群隔离。景观中的明显物理结构可构成扩散障碍，而微地理差异同样可能引发遗传隔离。本研究以北美留居鸣禽黑顶山雀（black-capped chickadee）为对象，探究了宏观与微观地理尺度下的扩散障碍。尽管鸟类具备较强的扩散潜力，但已有证据表明其扩散仍会受到障碍的限制。黑顶山雀的分布范围涵盖多种可能阻碍个体移动、进而引发种群分化的特征。本研究对分布范围内34个采样点的913个个体开展分析，利用11个微卫星位点（microsatellite loci），结果揭示了多达13个遗传聚类群。东部种群基本呈现随机交配模式，而分布范围西部的种群则表现出显著的遗传结构，且这些结构通常与喀斯喀特山脉、落基山脉等大型山系以及不适宜栖息生境的区域相吻合。与落基山脉中部和南部的种群不同，落基山脉北部两侧的种群并未出现遗传分化。此外，俄勒冈州东北部是大盆地（Great Basin）内一处森林覆盖的孤岛，与其他所有种群均存在遗传隔离。在不列颠哥伦比亚省中部的弗雷泽高原（Fraser Plateau）以及无明显物理障碍的落基山脉东南部区域，同样存在微观地理尺度下的种群亚结构，这表明可能存在其他因素阻碍了扩散与基因流。因此，扩散障碍并不局限于大型物理结构，尽管在本研究中，山系与大型水体对种群结构的形成发挥了重要作用。

使用说明：GenotypeData_DRYAD_Adams&Burg2014——涵盖913个经11个微卫星位点检测分型的个体的基因型数据。