Newman R A, Squire T
Starcher Hall/Department of Biology, University of North Dakota, Grand Forks, ND 58202-9019, USA.
Mol Ecol. 2001 May;10(5):1087-100. doi: 10.1046/j.1365-294x.2001.01255.x.
We investigated genetic population structure in wood frogs (Rana sylvatica) from a series of Prairie Pothole wetlands in the northern Great Plains. Amphibians are often thought to exist in demographic metapopulations, which require some movement between populations, yet genetic studies have revealed strong subdivision among populations, even at relatively fine scales (several km). Wood frogs are highly philopatric and studies of dispersal suggest that they may exhibit subdivision on a scale of approximately 1-2 km. We used microsatellites to examine population structure among 11 breeding assemblages separated by as little as 50 m up to approximately 5.5 km, plus one population separated from the others by 20 km. We found evidence for differentiation at the largest distances we examined and among a few neighbouring ponds, but most populations were strikingly similar in allele frequencies, suggesting high gene flow among all but the most distant populations. We hypothesize that the few significant differences among neighbouring populations at the finest scale may be a transient effect of extinction-recolonization founder events, driven by periodic drying of wetlands in this hydrologically dynamic landscape.
我们研究了来自大平原北部一系列草原坑洼湿地的林蛙（Rana sylvatica）的遗传种群结构。两栖动物通常被认为存在于集合种群中，这需要种群之间有一定的迁移，然而遗传研究表明，即使在相对精细的尺度（几公里）上，种群之间也存在强烈的细分。林蛙具有高度的恋巢性，对其扩散的研究表明它们可能在大约1 - 2公里的尺度上表现出细分。我们使用微卫星来检查11个繁殖群体之间的种群结构，这些群体之间的距离最短为50米，最长约为5.5公里，另外还有一个与其他群体相隔20公里的种群。我们发现在我们研究的最大距离以及一些相邻池塘之间存在分化的证据，但大多数种群的等位基因频率惊人地相似，这表明除了距离最远的种群外，所有种群之间都有很高的基因流。我们推测，在最精细尺度上相邻种群之间的少数显著差异可能是由这种水文动态景观中湿地的周期性干涸所驱动的灭绝 - 再定殖奠基者事件的短暂效应。
