Table 2. Fit of the observed distribution of deleterious mutational effects to several models for random and preobserved mutations.

		Random		Preobserved
Model	Parameters	R2	AIC	R2	AIC
Exponential	1	0.958	105.047	0.964	106.746
γ	2	0.961	106.866	0.974	110.546
β	2	0.955	109.071	0.977	109.470
Weibull	2	0.962	106.618	0.973	110.527
Log-normal	2	0.974	102.217	0.956	113.200
Exponential + uniform	3	0.968	104.775	0.989	101.083
γ + uniform	4	0.992	92.615	0.996	97.630
β + uniform	4	0.992	94.775	0.996	97.610
Weibull + uniform	4	0.991	92.523	0.993	97.776
Log-normal + uniform	4	0.993	92.382	0.995	98.138

See text for details.