Burridge Christopher P, Peucker Amanda J, Valautham Sureen K, Styan Craig A, Dann Peter
From the School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia (Burridge and Valautham); the School of Life and Environmental Sciences, Deakin University, Warrnambool, Victoria 3280, Australia (Peucker and Styan); the School of Energy and Resources, UCL Australia, Adelaide, South Australia 5000, Australia (Styan); and the Research Department, Phillip Island Nature Parks, Cowes, Victoria 3922, Australia (Dann).
J Hered. 2015 May-Jun;106(3):228-37. doi: 10.1093/jhered/esv009. Epub 2015 Apr 1.
Factors responsible for spatial structuring of population genetic variation are varied, and in many instances there may be no obvious explanations for genetic structuring observed, or those invoked may reflect spurious correlations. A study of little penguins (Eudyptula minor) in southeast Australia documented low spatial structuring of genetic variation with the exception of colonies at the western limit of sampling, and this distinction was attributed to an intervening oceanographic feature (Bonney Upwelling), differences in breeding phenology, or sea level change. Here, we conducted sampling across the entire Australian range, employing additional markers (12 microsatellites and mitochondrial DNA, 697 individuals, 17 colonies). The zone of elevated genetic structuring previously observed actually represents the eastern half of a genetic cline, within which structuring exists over much shorter spatial scales than elsewhere. Colonies separated by as little as 27 km in the zone are genetically distinguishable, while outside the zone, homogeneity cannot be rejected at scales of up to 1400 km. Given a lack of additional physical or environmental barriers to gene flow, the zone of elevated genetic structuring may reflect secondary contact of lineages (with or without selection against interbreeding), or recent colonization and expansion from this region. This study highlights the importance of sampling scale to reveal the cause of genetic structuring.
导致种群遗传变异空间结构形成的因素多种多样，在许多情况下，对于所观察到的遗传结构可能没有明显的解释，或者所提出的解释可能反映的是虚假相关性。一项对澳大利亚东南部小企鹅（Eudyptula minor）的研究记录了遗传变异的低空间结构，采样西部边界的殖民地除外，这种差异归因于一个中间海洋学特征（邦尼上升流）、繁殖物候的差异或海平面变化。在这里，我们在澳大利亚的整个分布范围内进行了采样，使用了额外的标记（12个微卫星和线粒体DNA，697个个体，17个殖民地）。先前观察到的遗传结构升高区域实际上代表了一个遗传渐变群的东半部，在该区域内，结构存在的空间尺度比其他地方短得多。在该区域内相距仅27公里的殖民地在基因上是可区分的，而在该区域外，在长达1400公里的尺度上不能拒绝同质性。鉴于缺乏基因流动的额外物理或环境障碍，遗传结构升高区域可能反映了谱系的二次接触（有或没有对杂交的选择），或者是从该区域最近的殖民和扩张。这项研究强调了采样尺度对于揭示遗传结构成因的重要性。
