Molecular Evolution of Viruses of the Family Filoviridae Based on 97 Whole-Genome Sequences

Viruses in the Ebolavirus andMarburgvirus genera (family Filoviridae) have been associated with large outbreaks of hemor-rhagic fever in human and nonhuman primates. The first documented cases occurred in primates over 45 years ago, but the amount of virus genetic diversity detected within bat populations, which have recently been identified as potential reservoir hosts, suggests that the filoviruses are much older. Here, detailed Bayesian coalescent phylogenetic analyses are performed on 97 whole-genome sequences, 55 of which are newly reported, to comprehensively examine molecular evolutionary rates and esti-mate dates of common ancestry for viruses within the family Filoviridae. Molecular evolutionary rates for viruses belonging to different species range from 0.46 104 nucleotide substitutions/site/year for Sudan ebolavirus to 8.21 104 nucleotide sub-stitutions/site/year for Reston ebolavirus. Most recent common ancestry can be traced back only within the last 50 years for Res-ton ebolavirus and Zaire ebolavirus species and suggests that viruses within these species may have undergone recent genetic bottlenecks. Viruses withinMarburg marburgvirus and Sudan ebolavirus species can be traced back further and share most re-cent common ancestors approximately 700 and 850 years before the present, respectively. Examination of the whole family sug-gests that members of the Filoviridae, including the recently described Lloviu virus, shared a most recent common ancestor ap-proximately 10,000 years ago. These data will be valuable for understanding the evolution of filoviruses in the context of natural history as new reservoir hosts are identified and, further, for determining mechanisms of emergence, pathogenicity, and the on-going threat to public health