SARS-CoV-2(62) Evolution(32) COVID-19(30) pandemic(28) sequence(22) analysis(21) virus(21) Phylogenetic(20) molecular(18) Evidence(18) Mutation(18) Analysis(18) Spread(17) Genome(16) Viral(15) analyzed(14) molecular clock(14) driven by(14) mutations(14) Host(13) Rate(13) Influenza(13) variants(12) Genetic(12) variant(12) virus(12) provide(11) identify(11) Affect(11) pathogen(11)