 Bavuga ko ibi bishyigikira igitekerezo cyuko, ku bantu bamwe, kugira urubavu ruto biterwa ahanini no kuba baragize amahirwe yo kugira ingirabuzima-fatizo genes bakuye ku bo bakomokaho, kurusha kuba byaterwa nindyo iboneye yabo cyangwa se imibereho yabo. 