Ellis Allan G, Weis Arthur E, Gaut Brandon S
Department of Ecology and Evolutionary Biology, 321 Steinhaus Hall, University of California, Irvine, CA 92697, USA.
Leslie Hill Institute for Plant Conservation, Botany Department, University of Cape Town, Rondebosch 7701, South Africa.
New Phytol. 2007;174(4):904-914. doi: 10.1111/j.1469-8137.2007.02043.x.
Explicit understanding of the spatial scale of evolutionary processes is required in order to set targets for their effective conservation. Here, we explore the spatial context of neutral and adaptive divergence in the species-rich Knersvlakte region of South Africa. Specifically, we aimed to assess the importance of erosional drainage basins as spatial units of evolutionary process. We used amplified fragment length polymorphism (AFLP) and reciprocal transplants to investigate genetic differentiation in Argyroderma pearsonii, sampled from sparse and dense quartz habitats within each of three drainage basins. This design allowed assessment of differentiation at two distinct spatial scales; between habitats within basins, and between basins. We found near-perfect concordance between genetic clusters and basin occupancy, suggesting restricted interbasin gene flow. In addition, transplants reveal adaptive divergence between basins on the dense quartz habitat. We have shown that neutral and adaptive differentiation occurs between basins, but not between habitats within basins, suggesting that conservation plans aimed at conserving multiple interconnected drainage basins will capture an important axis of evolutionary process on the Knersvlakte.
为了为有效保护进化过程设定目标，需要对进化过程的空间尺度有明确的认识。在这里，我们探索了南非物种丰富的克内斯维勒特地区中性和适应性分化的空间背景。具体来说，我们旨在评估侵蚀性流域作为进化过程空间单元的重要性。我们使用扩增片段长度多态性（AFLP）和相互移植实验，对从三个流域中每个流域的稀疏和密集石英栖息地采集的皮尔逊银叶花进行遗传分化研究。这种设计允许在两个不同的空间尺度上评估分化；流域内栖息地之间，以及流域之间。我们发现遗传簇与流域占据情况几乎完全一致，这表明流域间基因流受到限制。此外，移植实验揭示了密集石英栖息地流域之间的适应性分化。我们已经表明，中性和适应性分化发生在流域之间，而不是流域内的栖息地之间，这表明旨在保护多个相互连接的流域的保护计划将捕捉到克内斯维勒特地区进化过程的一个重要轴。
