The phylogenetic relationships of the 40 genomes and sequence AF457102 using the BEAST program.

<p>The phylogeny of 40 recently sequenced HPIV-1 genomes and one sequence from GenBank (AF457102) was estimated using a Bayesian Markov Chain Monte Carlo (MCMC) method with a strict molecular clock. Strain HPIV-1/c-35/1957 showed the greatest distance from the 39 1997–2010 Milwaukee viruses which is consistent with its isolation time. Colored rectangles (labeled clade 1–3) represent the three clades of the 39 1997–2010 Milwaukee viruses. The sequence from strain HPIV-1/WI/629-007/1997 is a singleton. The scale bar shows the unit for branch age. The numbers following the underscore in each name represent the collection date in number of years since collection date of the oldest HPIV-1 strain. To make the figure more legible identical sequences were removed from the table.