Canje-canje a cikin yawan allele a cikin yawan jama'a suna rinjayar zabin halitta, inda wani allele ya ba da zaɓi ko amfani da kwayoyin halitta ga kwayoyin halitta, da kuma wasu dalilai kamar maye gurbi, jigilar kwayoyin halitta, jigilar kwayoyin halitta, zabin artificial da ƙaura. A cikin tsararraki da yawa, kwayoyin halittu na iya canzawa sosai, wanda ke haifar da juyin halitta. A cikin tsarin da ake kira daidaitawa, zaɓi don maye gurbi mai amfani na iya haifar da nau'in halitta zuwa nau'ikan da suka fi dacewa su tsira a muhallinsu. Sabbin nau'ikan suna samuwa ta hanyar tsari na nau'ikan, sau da yawa ta hanyar rabuwa na ƙasa wanda ke hana yawan jama'a daga musayar kwayoyin halitta tare da wasu. Ta hanyar kwatanta homology tsakanin nau'ikan daban-daban, yana yiwuwa a ƙididdige zaɓi ko fa'idar haifuwa ga kwayoyin halitta tsakanin kwayoyin halitta, kazalika da wasu dalilai kamar maye gurbi, janyewar kwayoyin halitta tsakanin nau'ikan da aka saba da itace da itacen da kuma ba a sani ba.
daidaitawa