Table 1. Host-virus phylogeny congruence test for retroviruses.

Test1	Event costs2	Total cost	Cospeciation3	Duplication3	Duplication & host switching3	Loss3	Failure to diverge3	P-value4
I	-1,0,0,0,0	-13	13–13	9–9	14–14	12–15	0	>0.05
	0,1,1,2,0	29	7–7	8–8	21–21	0	0	>0.05
	0,1,2,1,1	47	8–9	12–13	15–15	4–5	0	>0.05
II	-1,0,0,0,0	-25	25–25	9–14	25–30	69–104	2–2	>0.05
	0,1,1,2,0	98	14–14	9–9	41–41	24–24	2–2	>0.05
	0,1,2,1,1	114	14–17	9–12	36–38	24–28	2–2	>0.05
III	-1,0,0,0,0	-13	13–13	9–9	14–14	12–15	0	>0.05
	0,1,1,2,0	29	7–7	8–8	21–21	0	0	>0.05
	0,1,2,1,1	47	8–9	12–13	15–15	4–5	0	>0.05
IV	-1,0,0,0,0	-9	9–9	0	1–1	0	0	<0.01
	0,1,1,2,0	1	9–9	0	1–1	0	0	<0.01
	0,1,2,1,1	2	9–9	0	1–1	0	0	<0.01

¹Tests I-IV correspond to asterisks I-IV in Fig 1.

²Event cost schemes used in this study are for cospeciation, duplication, duplication & host switching, loss, failure to diverge, respectively.

³Numbers of events with the same total cost are expressed as ranges.

⁴P-value represents statistical test results by using random parasite tree algorithm with sample size of 500.