Endemism in recently diverged angiosperms is associated with polyploidy

Abstract Endemic (range restricted or precinctive) plant species are frequently observed to exhibit polyploidy (chromosome set duplication), which can drive shifts in ecology for angiosperms, but whether endemism is generally associated with throughout the flowering plants has not been determined. We tested hypothesis that more frequent and pronounced (higher evident ploidy levels) recently evolved endemic angiosperms. Chromosome count data, molecular dating distribution 4210 (representing all major clades of angiosperms including largest families) were mined from literature-based databases. Upper boundary regression was used investigate relationship between maximum number chromosomes time since taxon divergence, across separately families, comparing non-endemic species. A significant negative exponential age ( R 2 adj = 0.48 species, 0.49 endemics; 0.44 non-endemics; p always < 0.0001), recent endemics demonstrating greater chromosome numbers y intercept 164 cf. 111) declining rapidly (decay constant 0.12, 0.04) respect non-endemics. The majority families exhibited this relationship, a steeper slope Campanulaceae, Asteraceae, Fabaceae, Poaceae, Caryophyllaceae Rosaceae, duplication extensive particularly young endemics, supporting as key explanation range restriction. However, may also be diploid, an exclusive driver endemism.