Data from: Spatial heterogeneity in genetic relatedness among house sparrows along an urban-rural gradient as revealed by individual-based analysis

Understanding factors that shape patterns of kinship in sedentary species is important for evolutionary ecologists as well as conservation biologists. Yet, how patterns of relatedness are hierarchically structured in space remains poorly known, even in common species. Here we use information from 16 polymorphic microsatellite DNA markers to study how small-scale kinship structure varies among house sparrows (Passer domesticus) along an urban-rural gradient. Average levels of relatedness were higher among urban individuals than among individuals from rural areas, suggesting lower rates of dispersal in more built up habitats. Comparison of observed levels of relatedness with simulated distributions of known kinship values showed that central urban individuals had the highest proportion of closely-related conspecifics in their immediate neighbourhood. Spatial auto-correlograms supported this small-scale genetic structure and further indicated stronger effects of genetic drift and/or limited dispersal in urban populations. Results of this study underscore the importance of individual-level analyses as a complementary approach to traditional population-level analyses when studying genetic population structure over small spatial scales.

阐明定居物种种群亲缘关系格局的形成机制，对于进化生态学家与保护生物学家而言均具有重要意义。然而，即便在常见物种中，亲缘关系模式如何在空间上呈层级结构分布，目前仍鲜为人知。本研究利用16个多态性微卫星DNA标记（microsatellite DNA markers），探究家麻雀（Passer domesticus）的小型亲缘结构沿城乡梯度的变化规律。城市个体间的平均亲缘关系水平高于农村种群个体，这表明在建筑更为密集的生境中，个体扩散速率更低。将观测到的亲缘关系水平与已知亲缘值的模拟分布进行对比后发现，城市核心区域的个体在其邻近邻域内拥有最高比例的近亲同物种个体。空间自相关图（spatial auto-correlograms）验证了这一小型空间遗传结构，并进一步揭示城市种群中遗传漂变和/或有限扩散的作用更强。本研究结果强调，在探究小型空间尺度下的种群遗传结构时，以个体水平分析作为传统种群水平分析的补充方法具有重要价值。