highly significantP < 0.001
In particular, the general additive model (GAM) analyses show a highly significant temporal variation in rate (χ 2 = 40.15, df = 9, P < 0.001, adjusted R 2 = 45.8%, deviance explained = 12.8%) with a model in which the diversification rates trends receiving more support than one in which it steps suddenly (evidence weights = 0.9931 and 0.0069, respectively).