Table 2.

Ages of Syzran isolates and their hypothetical common precursor.

Isolate Genome	Number of Mutations Per Genome	Approximated Age, Months *
“Common ancestor”	61	7.7
P-1	75	9.5
P-2	78	9.8
C-1	70	8.8
C-2	84	10.6
C-3	77	9.7

* The age was estimated according to Sabin-3 by the approximate rate of 1.28·10² substitutions per site per year [33].