Department of Ecology and Evolutionary Biology, Biological Sciences Building, University of Michigan, Ann Arbor, Michigan, 48109.
Present Address: Department of Botany, National Museum of Natural History, MRC166, Smithsonian Institution, Washington, DC, 20013.
Evolution. 2021 Feb;75(2):349-364. doi: 10.1111/evo.14159. Epub 2021 Jan 12.
Co-distributed species may exhibit similar phylogeographic patterns due to shared environmental factors or discordant patterns attributed to the influence of species-specific traits. Although either concordant or discordant patterns could occur due to chance, stark differences in key traits (e.g., dispersal ability) may readily explain differences between species. Multiple species' attributes may affect genetic patterns, and it is difficult to isolate the contribution of each. Here we compare the relative importance of two attributes, range size, and niche breadth, in shaping the spatial structure of genetic variation in four sedge species (genus Carex) from the Rocky Mountains. Within two pairs of co-distributed species, one species exhibits narrow niche breadth, while the other species has broad niche breadth. Furthermore, one pair of co-distributed species has a large geographical distribution, while the other has a small distribution. The four species represent a natural experiment to tease apart how these attributes (i.e., range size and niche breadth) affect phylogeographic patterns. Investigations of genetic variation and structure revealed that range size, but not niche breadth, is related to spatial genetic covariation across species of montane sedges. Our study highlights how isolating key attributes across multiple species can inform their impact on processes driving intraspecific differentiation.
共分布的物种可能由于共享的环境因素表现出相似的系统地理格局，或者由于物种特有性状的影响而出现不一致的模式。尽管由于偶然因素，可能会出现一致或不一致的模式，但关键特征（例如扩散能力）的明显差异可能很容易解释物种之间的差异。多个物种的属性可能会影响遗传模式，而且很难隔离每个属性的贡献。在这里，我们比较了两个属性（范围大小和生态位宽度）在塑造落矶山脉四种苔草属（Carex 属）植物遗传变异空间结构中的相对重要性。在两对共分布的物种中，一种物种具有较窄的生态位宽度，而另一种物种具有较宽的生态位宽度。此外，一对共分布的物种具有较大的地理分布范围，而另一种则分布范围较小。这四种物种构成了一个自然实验，可以分离这些属性（即范围大小和生态位宽度）如何影响系统地理格局。对遗传变异和结构的研究表明，范围大小而不是生态位宽度与高山苔草物种之间的空间遗传协变有关。我们的研究强调了如何在多个物种中隔离关键属性，从而了解它们对驱动种内分化过程的影响。
