CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization &Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland.
Sci Rep. 2016 Sep 7;6:32624. doi: 10.1038/srep32624.
The role of ecological niche in lineage diversification has been the subject of long-standing interest of ecologists and evolutionary biologists. Gynandropaa frogs diversified into three independent clades endemic to the southeastern Qinghai-Tibetan Plateau. Here, we address the question whether these clades kept the same niche after separation, and what it tells us about possible diversification processes. We applied predictions in geographical (G)-space and tests of niche conservatism in environmental (E)-space. Niche models in G-space indicate separate regions with high suitability for the different clades, with some potential areas of sympatry. While the pair of central and eastern clades displayed the largest niche overlap for most variables, and strict niche equivalency was rejected for all clade-pairs, we found no strong evidence for niche divergence, but rather the signature of niche conservatism compared to null models in E-space. These results suggest a common ancestral ecological niche, and as such give good support to divergence through allopatric speciation, but alternative explanations are also possible. Our findings illustrate how testing for niche conservatism in lineage diversification can provide insights into underlying speciation processes, and how this information may guide further research and conservation practices, as illustrated here for amphibians on the Qinghai-Tibetan Plateau.
生态位在谱系多样化中的作用一直是生态学家和进化生物学家长期关注的主题。冈氏齿蟾分化为三个独立的分支，分布于青藏高原东南部。在这里，我们探讨了这些分支在分离后是否保持相同的生态位，以及这对可能的多样化过程有何启示。我们应用了地理（G）空间中的预测，并在环境（E）空间中检验了生态位保守性。G 空间中的生态位模型表明，不同分支有各自适宜的高地区域，存在一些潜在的同域分布区。虽然中部和东部的两个分支在大多数变量上显示出最大的生态位重叠，并且严格的生态位等价性被拒绝，但我们没有发现强烈的证据表明生态位分化，而是在 E 空间的零模型中表现出生态位保守性的特征。这些结果表明存在一个共同的祖先生态位，因此很好地支持了通过异域物种形成的分化，但也存在其他可能的解释。我们的研究结果说明了在谱系多样化中检验生态位保守性如何为潜在的物种形成过程提供见解，以及如何为进一步的研究和保护实践提供信息，如本文所述，针对青藏高原的两栖动物。
