TABLE 1.

Nucleotide substitution rates and times to most recent common ancestor (TMRCAs) of H2N2 segments analyzed

Origin and gene	Lineage	Nucleotide substitution rate (subs/site/yr)			TMRCA (yr)
		Mean	95% HPD		Mean	95% HPD
			Lower	Upper		Lower	Upper
Avian
HA	Human H2N2	3.59E−03	3.00E−03	4.22E−03	1955.39	1956.25	1954.47
	Avian H2N2	3.50E−03	3.00E−03	4.06E−03	1949.03	1956.77	1940.95
NA	Human H2N2	0.91E−03	0.68E−03	1.15E−03	1951.47	1954.11	1948.73
	Avian H2N2	2.57E−03	2.24E−03	2.89E−03	1954.89	1961.33	1948.16
PB1	Human H2N2	1.13E−03	0.89E−03	1.38E−03	1954.24	1955.66	1952.66
	Avian H2N2	1.76E−03	1.55E−03	1.98E−03	1973.03	1975.40	1970.58
Human
PB2	H1N1, H2N2	1.46E−03	1.25E−03	1.67E−03	1923.83	1928.70	1918.34
PA	H1N1, H2N2	1.30E−03	1.09E−03	1.51E−03	1923.01	1928.30	1917.38
NP	H1N1, H2N2	1.46E−03	1.20E−03	1.73E−03	1926.06	1929.83	1922.18
MP	H1N1, H2N2	1.08E−03	8.69E−04	1.29E−03	1923.58	1928.46	1918.52
NS	H1N1, H2N2	1.73E−03	1.27E−03	2.19E−03	1925.06	1929.20	1920.55