Table 2.

Mk model fits for the four-state system. Ordered by AIC weight. Transition rates provided in electronic supplementary material, A.

model rank	model name	AIC weight	ΔAIC	log-likelihood
1	NR ALL	0.4306	0	−82.94
2	NR ER	0.3698	0.3045	−85.09
3	ER	0.1386	2.2668	−86.07
4	NR SYM	0.0430	4.6069	−82.24
5	SYM	0.0153	6.6719	−83.27
6	NR ARD	0.0025	10.2296	−82.05
7	ARD	0.0001	16.2296	−82.05