Sachdeva Himani, Barton Nicholas H
Institute of Science and Technology Austria (IST Austria), Am Campus 1, Klosterneuburg A-3400, Austria.
Evolution. 2017 Jun;71(6):1478-1493. doi: 10.1111/evo.13252. Epub 2017 May 16.
Assortative mating is an important driver of speciation in populations with gene flow and is predicted to evolve under certain conditions in few-locus models. However, the evolution of assortment is less understood for mating based on quantitative traits, which are often characterized by high genetic variability and extensive linkage disequilibrium between trait loci. We explore this scenario for a two-deme model with migration, by considering a single polygenic trait subject to divergent viability selection across demes, as well as assortative mating and sexual selection within demes, and investigate how trait divergence is shaped by various evolutionary forces. Our analysis reveals the existence of sharp thresholds of assortment strength, at which divergence increases dramatically. We also study the evolution of assortment via invasion of modifiers of mate discrimination and show that the ES assortment strength has an intermediate value under a range of migration-selection parameters, even in diverged populations, due to subtle effects which depend sensitively on the extent of phenotypic variation within these populations. The evolutionary dynamics of the polygenic trait is studied using the hypergeometric and infinitesimal models. We further investigate the sensitivity of our results to the assumptions of the hypergeometric model, using individual-based simulations.
选型交配是具有基因流的种群中物种形成的重要驱动力，并且预计在少数基因座模型的某些条件下会发生进化。然而，基于数量性状的交配中选型的进化却鲜为人知，数量性状通常具有高遗传变异性以及性状基因座之间广泛的连锁不平衡。我们通过考虑一个受不同种群间生存力选择影响的单一多基因性状、种群内的选型交配和性选择，来探索一个具有迁移的两种群模型的这种情况，并研究性状分化是如何由各种进化力量塑造的。我们的分析揭示了选型强度存在急剧的阈值，在该阈值处分化会急剧增加。我们还通过配偶识别修饰因子的入侵来研究选型的进化，并表明在一系列迁移 - 选择参数下，即使在分化的种群中，由于对这些种群内表型变异程度敏感依赖的微妙效应，平衡态选型强度也具有中间值。使用超几何模型和无穷小模型研究了多基因性状的进化动态。我们使用基于个体的模拟进一步研究了我们的结果对超几何模型假设的敏感性。
