Molecular clock estimates of separation times among B. anthracis sub-lineages.

a Sub-lineages according to Fig. 1, bTotal Syn Sites = The total sites for synonymous substitutions were determined separately for each pair-wise comparison. c The model for sSNP substitution rate is particularly sensitive to number of death cycles per year. Therefore, two possible scenarios (1 and 0.5 deaths per year) were modelled (see supporting methods on the PNAS website for more details). STD = The standard deviation for observed sSNPs, calculated as the square root of the time estimate. Thus, 2 STD represents ��95% confidence interval based upon fluctuation in this parameter of the model. d Sequence from the Vollum strain, The Institute for Genome Research (TIGR). e Sequence from the ��Ames Ancestor�� strain, GenBank Reference Sequence NC 007530. f Sequence from the Western North America USA 6153, TIGR.g Sequence from the CNEVA-9066, TIGR. h Sequence from the Kruger B strain, TIGR. I Sequence from A1055, TIGR