Department of Evolution and Ecology, and Center for Population Biology, University of California, Davis, CA 95616-8755, USA.
Mol Ecol. 2010 Aug;19(16):3301-14. doi: 10.1111/j.1365-294X.2010.04718.x.
Quantifying the influence of the landscape on the genetic structure of natural populations remains an important empirical challenge, particularly for poorly studied, ecologically cryptic species. We conducted an extensive microsatellite analysis to examine the population genetics of the southern long-toed salamander (Ambystoma macrodactylum sigillatum) in a naturally complex landscape. Using spatially explicit modelling, we investigated the influence of the Sierra Nevada topography on potential dispersal corridors between sampled populations. Our results indicate very high-genetic divergence among populations, high within-deme relatedness, and little evidence of recent migration or population admixture. We also discovered unexpectedly high between-year genetic differentiation (F(ST)) for breeding sites, suggesting that breeding groups vary over localized space and time. While environmental factors associated with high-elevation montane habitats apparently play an important role in shaping population differentiation, additional, species-specific biological processes must also be operating to account for observed deviations from temporal, among-year panmixia. Our study emphasizes the population-level insights that can be gained from high-density sampling in space and time, and the highly substructured population biology that may characterize amphibians in extreme montane habitats.
量化景观对自然种群遗传结构的影响仍然是一个重要的经验挑战，特别是对于研究较少、生态上隐蔽的物种。我们进行了广泛的微卫星分析，以研究南部长趾蟾（Ambystoma macrodactylum sigillatum）在自然复杂景观中的种群遗传学。我们利用空间显式模型研究了内华达山脉地形对抽样种群之间潜在扩散走廊的影响。我们的结果表明，种群之间存在非常高的遗传分歧、高的同系相关度，并且几乎没有最近迁移或种群混合的证据。我们还发现了出乎意料的高的繁殖地点间年度遗传分化（F（ST）），这表明繁殖群体在局部空间和时间上存在差异。虽然与高海拔山地生境相关的环境因素显然在塑造种群分化方面起着重要作用，但还必须存在其他特定于物种的生物学过程，以解释观察到的偏离年度间泛群的情况。我们的研究强调了在空间和时间上进行高密度采样可以获得的群体水平的见解，以及在极端山地生境中可能存在的高度亚结构种群生物学。
