Recently Formed Polyploid Plants Diversify at Lower Rates

摘要

Polyploidy (or whole-genome duplication) is a widespread feature of plant genomes, but its importance to evolution has long been debated. Polyploids have been postulated to be evolutionary dead ends because of the inefficiency of selection when genes are masked by multiple copies (7). However, most plant species have experienced at least one genome doubling early in their history (2), suggesting that rather than being an evolutionary dead end, polyploidy is a route to evolutionary success. A recent study (3) confirmed the ubiquity of polyploidy, with about 35% of vascular plant species being recent polyploids ("neopoly-ploids," having formed since their genus arose), representing 15% of speciation events in flowering plants and 31% in ferns. It remains unknown, however, whether the abundance of polyploids is a consequence of higher diversification rates following polyploidy or of frequent polyploid formation.