Data from: Polyploid formation shapes flowering plant diversity

Polyploidy, or whole genome duplication, has been an important feature of
eukaryotic evolution. This is especially true in flowering plants, where
all extant angiosperms have descended from polyploid species. Here we
present a broad comparative analysis of the effect of polyploidy on
flowering plant diversity. We examine the widely held hypothesis that
polyploid flowering plants generate more diversity than their diploid
counterparts, by fitting stochastic birth/death models to observed ploidal
frequency data from 60 extant angiosperm genera. Our results suggest the
opposite, that diploids speciate at higher rates than polyploids, through
a combination of simple diploid speciation and tetraploidy. Importantly,
the estimated diploid advantage stemmed primarily from a higher rate of
polyploidization in diploids than polyploids. Our model is also able to
account for the empirically observed correlation between polyploidy and
species richness without assuming that polyploids have a speciation
advantage over diploids.