wˌaɪl ˌæntɪdʒˈɛnɪk dɹˈɪft ðə ɡɹˈædʒuːəl tʃˈeɪndʒ ʌv sˈɜːfɪs ˈæntɪdʒˌɛnz ɪz kənsˈɪdɚd ðə tɹɐdˈɪʃənəl mˈɑːdəl fɔːɹ tʃˈeɪndʒᵻz ɪnðə vˈaɪɚɹəl dʒˈɛnətˌaɪp, ɹˈiːsənt ˈɛvɪdəns sədʒˈɛsts ðæt sᵻlˈɛktɪv swˈiːps plˈeɪ ɐn ɪmpˈoːɹtənt ɹˈoʊl æz wˈɛl.
While antigenic drift (the gradual change of surface antigens) is considered the traditional model for changes in the viral genotype, recent evidence suggests that selective sweeps play an important role as well.