sˈʌtʃ ɐ mjuːtˈeɪʃən mˈeɪ biː pɹˈɛzənt ˌɔn sˈɛvɹəl dʒɛnˈɑːmɪk bˈækɡɹaʊndz sˌoʊ ðæt wɛn ɪt ɹˈæpɪdli ˈɪŋkɹiːsᵻz ɪn fɹˈiːkwənsi, ɪt dˈʌzənt ᵻɹˈeɪs ˈɔːl dʒɪnˈɛɾɪk vˌɛɹɪˈeɪʃən ɪnðə pˌɑːpjʊlˈeɪʃən.
Such a mutation may be present on several genomic backgrounds so that when it rapidly increases in frequency, it doesn't erase all genetic variation in the population.