Table 2.

Bayesian estimates of evolutionary parameters for WNV in suburban Chicago over time^a.

year	number of samples	range of dates of sample collection	substitution rateb (95% HPD)	TMRCAc (95% HPD)
2005	128	21 July–4 October	6.87 × 10−6 (1.11 × 10−6–1.50 × 10−5)	532 (143–1243)
2006	80	13 June–7 September	13.11 × 10−6 (4.82 × 10−7–2.74 × 10−5)	408 (92–1253)
2007	46	5 July–9 September	4.48 × 10−6 (6.73 × 10−8–1.38 × 10−5)	2057 (122–7584)
all years	254	21 July 2005–9 September 2007	4.17 × 10−6 (3.34 × 10−6–5.04 × 10−6)	1206 (984–1531)

^aAll evolutionary parameters were estimated under the Bayesian skyline plot uncorrelated exponential relaxed clock model.

^bMean number of nucleotide substitutions per site per day. HPD: high posterior density.

^cMean time to the most recent common ancestor (TMRCA), in days.