Polyploids increase overall diversity despite higher turnover than diploids in the Brassicaceae

Although polyploidy is widespread across the plant Tree of Life, its long-term evolutionary significance is still poorly understood. Here we examine the effects of polyploidy in explaining the large-scale evolutionary patterns within angiosperms by focusing on a single family exhibiting extensive inter-specific variation in chromosome numbers. We inferred ploidy from haploid chromosome numbers for 80% of species in the most comprehensive species-level chronogram for the Brassicaceae. After evaluating a total of 94 phylogenetic models of diversification, we found that ploidy influences diversification rates across the Brassicaceae. We also found that despite diversifying at a similar rate to diploids, polyploids have played a significant role in driving present-day differences in species richness among clades. Overall, in addition to highlighting the complexity in the evolutionary consequences of polyploidy, our results suggest that rare successful polyploids persist while significantly ...

尽管多倍体（polyploidy）在整个植物生命之树中广泛分布，但其长期演化意义仍不甚明晰。本研究聚焦于一个染色体数目存在广泛种间变异的单科类群，探讨多倍体对被子植物（angiosperms）内大型演化格局的影响。我们基于十字花科（Brassicaceae）目前最全面的物种水平年代校准树，对其中80%的物种的单倍染色体数目进行了倍性推断。在总计评估了94个分化演化的系统发育模型后，我们发现多倍体对十字花科的分化速率存在显著影响。我们还发现，尽管多倍体的分化速率与二倍体相近，但多倍体在驱动当前各演化支（clades）间物种丰富度差异方面发挥了重要作用。总体而言，本研究不仅凸显了多倍体演化后果的复杂性，研究结果还表明，极少数成功的多倍体得以存续，且其作用显著……