Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, OX1 3PS, United Kingdom.
Evolution. 2013 Dec;67(12):3488-500. doi: 10.1111/evo.12121. Epub 2013 Apr 29.
Individuals are typically not randomly distributed in space; consequently ecological and evolutionary theory depends heavily on understanding the spatial structure of populations. The central challenge of landscape genetics is therefore to link spatial heterogeneity of environments to population genetic structure. Here, we employ multivariate spatial analyses to identify environmentally induced genetic structures in a single breeding population of 1174 great tits Parus major genotyped at 4701 single-nucleotide polymorphism (SNP) loci. Despite the small spatial scale of the study relative to natal dispersal, we found multiple axes of genetic structure. We built distance-based Moran's eigenvector maps to identify axes of pure spatial variation, which we used for spatial correction of regressions between SNPs and various external traits known to be related to fitness components (avian malaria infection risk, local density of conspecifics, oak tree density, and altitude). We found clear evidence of fine-scale genetic structure, with 21, seven, and nine significant SNPs, respectively, associated with infection risk by two species of avian malaria (Plasmodium circumflexum and P. relictum) and local conspecific density. Such fine-scale genetic structure relative to dispersal capabilities suggests ecological and evolutionary mechanisms maintain within-population genetic diversity in this population with the potential to drive microevolutionary change.
个体通常不会随机分布在空间中；因此，生态和进化理论在很大程度上依赖于对种群空间结构的理解。因此，景观遗传学的核心挑战是将环境的空间异质性与种群遗传结构联系起来。在这里，我们采用多元空间分析来确定在一个 1174 只大山雀 Parus major 的单一繁殖种群中，由环境引起的遗传结构，这些大山雀在 4701 个单核苷酸多态性 (SNP) 位点上进行了基因型分析。尽管相对于扩散而言，研究的空间尺度较小，但我们发现了多个遗传结构轴。我们构建了基于距离的 Moran 特征向量图来识别纯空间变异的轴，我们将这些轴用于 SNP 与各种已知与适应度成分（鸟类疟疾感染风险、同种个体的局部密度、橡树密度和海拔）相关的外部特征之间的回归的空间校正。我们发现了明显的精细遗传结构证据，分别有 21、7 和 9 个显著的 SNP 与两种鸟类疟疾（Plasmodium circumflexum 和 P. relictum）的感染风险以及当地同种密度有关。与扩散能力相比，这种精细的遗传结构表明，生态和进化机制在这个种群中维持了种群内的遗传多样性，具有驱动微观进化变化的潜力。
