Barton Nicholas
Institute of Science and Technology Austria, Klosterneuburg, Austria.
J Evol Biol. 2024 Jun 28;37(6):605-615. doi: 10.1093/jeb/voae052.
We know that heritable variation is abundant, and that selection causes all but the smallest populations to rapidly shift beyond their original trait distribution. So then, what limits the range of a species? There are physical constraints and also population genetic limits to the effectiveness of selection, ultimately set by population size. Global adaptation, where the same genotype is favoured over the whole range, is most efficient when based on a multitude of weakly selected alleles and is effective even when local demes are small, provided that there is some gene flow. In contrast, local adaptation is sensitive to gene flow and may require alleles with substantial effect. How can populations combine the advantages of large effective size with the ability to specialise into local niches? To what extent does reproductive isolation help resolve this tension? I address these questions using eco-evolutionary models of polygenic adaptation, contrasting discrete demes with continuousspace.
我们知道可遗传变异十分丰富，而且自然选择会使除最小种群之外的所有种群迅速偏离其原有的性状分布。那么，是什么限制了一个物种的分布范围呢？存在物理限制，同时自然选择的有效性也存在种群遗传学限制，最终由种群大小决定。全局适应是指在整个分布范围内相同基因型受到青睐，当基于大量弱选择等位基因时最为高效，并且即使当地种群规模较小也有效，前提是存在一些基因流。相比之下，局部适应对基因流敏感，可能需要具有显著效应的等位基因。种群如何将有效规模大的优势与适应当地生态位的能力相结合？生殖隔离在多大程度上有助于解决这种矛盾？我使用多基因适应的生态进化模型来探讨这些问题，对比离散种群和连续空间。
