Molecular Clock of DENV-1 Colombian Isolates. Divergence time of DENV-1 Colombian isolates was estimated using year of isolation (scale used in the tree) as calibration points under the strict molecular clock model using GTR+Γ+I parameters. Posterior Probability (PP) values are indicated for each node, and the extent of the 95% highest posterior density (HPD) intervals for each divergence time is represented by the blue bars. Root of the tree was previously calculated by TRACE statistic interface of BEAST, and is placed in 1945 as the most recent ancestor. Taxa from the putative lineages 1 and 2 are shown in blue and red, respectively.