Fig 2. Rates of chromosome number evolution.

Each curve represents the posterior distribution of the ΔR_x statistic, where x is either fission, fusion, or polyploidy which is indicated by the color of the fill. Positive values of this statistic indicate that holocentric clades evolve more quickly than monocentric clades while negative values indicate that monocentric clades evolve more quickly than holocentric clades. Below the curves the lines indicate the 95% credible interval of each statistic. A) Results from fitting a model with all three possible transitions (fissions, fusions, and polyploidy). B) Results from fitting a model where chromosome number can change only through fissions and fusions. Under both models the credible interval of each parameter spans zero indicating no significant difference in rates of chromosome number evolution in clades with holocentric and monocentric chromosomes.