When selective forces are absent or relatively weak, allele frequencies are equally likely to drift upward or downward at each successive generation because the alleles are subject to sampling error.
Alwăq wa ǝd assăhăt tan nefrăn war t-ǝlla meɣ tăbrur, ǝddǝkud n allele tan ogdăhăn tiw-at d afanaz  daɣ ǝkǝ tan n ǝššaɣǝb azzămăn ǝyyăn fuk hărwa daɣ wăr t- ǝjješăn mărsălăn