Forensic Science Department, Trent University, Peterborough, Ontario, Canada.
J Hered. 2011 Sep-Oct;102(5):584-92. doi: 10.1093/jhered/esr055. Epub 2011 Jun 24.
We examined the mitochondrial genetic structure of American white pelicans (Pelecanus erythrorhynchos) to: 1) verify or refute whether American white pelicans are panmictic and 2) understand if any lack of genetic structure is the result of contemporary processes or historical phenomena. Sequence analysis of mitochondrial DNA control region haplotypes of 367 individuals from 19 colonies located across their North American range revealed a lack of population genetic or phylogeographic structure. This lack of structure was unexpected because: 1) Major geographic barriers such as the North American Continental Divide are thought to limit dispersal; 2) Differences in migratory behavior are expected to promote population differentiation; and 3) Many widespread North American migratory bird species show historic patterns of differentiation resulting from having inhabited multiple glacial refugia. Further, high haplotype diversity and many rare haplotypes are maintained across the species' distribution, despite frequent local extinctions and recolonizations that are expected to decrease diversity. Our findings suggest that American white pelicans have a high effective population size and low natal philopatry. We suggest that the rangewide panmixia we observed in American white pelicans is due to high historical and contemporary gene flow, enabled by high mobility and a lack of effective physical or behavioral barriers.
我们研究了美洲白鹈鹕（Pelecanus erythrorhynchos）的线粒体遗传结构，以：1）验证或反驳美洲白鹈鹕是否是泛化的，以及 2）了解任何遗传结构的缺乏是否是当代过程或历史现象的结果。对来自北美范围内 19 个栖息地的 367 只个体的线粒体 DNA 控制区序列分析显示，其没有种群遗传或系统地理结构。这种结构的缺乏是出乎意料的，因为：1）北美大陆分水岭等主要地理屏障被认为限制了扩散；2）迁徙行为的差异预计会促进种群分化；3）许多广泛分布的北美的候鸟物种由于曾经居住在多个冰川避难所而显示出历史上的分化模式。此外，尽管频繁发生局部灭绝和再定居，预计会降低多样性，但在物种分布范围内仍维持着高的单倍型多样性和许多罕见的单倍型。我们的研究结果表明，美洲白鹈鹕具有较高的有效种群大小和较低的出生地亲代遗传。我们认为，我们在美洲白鹈鹕中观察到的全谱系泛化是由于高历史和当代基因流动，这得益于高度的流动性和缺乏有效的物理或行为障碍。
