Summary
The role whole genome duplication (WGD) plays in the history of lineages is actively debated. WGDs have been associated with advantages including superior colonization, adaptations, and increased effective population size. However, the lack of a comprehensive mapping of WGDs within a major plant clade has led to questions regarding the potential association of WGDs and higher diversification rates.
Using seven chloroplast and nuclear ribosomal genes, we constructed a phylogeny of 5,036 species of Caryophyllales, representing nearly half of the extant species. We phylogenetically mapped putative WGDs as identified from analyses on transcriptomic and genomic data and analyzed these in conjunction with shifts in climatic niche and lineage diversification rate.
Thirteen putative WGDs and twenty-seven diversification shifts could be mapped onto the phylogeny. Of these, four WGDs were concurrent with diversification shifts, with other diversification shifts occurring at shallower nodes than WGDs. Five WGDs were associated with shifts to colder climatic niches.
While we find that many diversification shifts occurred after WGDs it is difficult to directly associate these and consider diversification and duplication to be tightly correlated. Our findings suggest that duplications may often along with shifts in either diversification rate, climatic niche, or rate of evolution.