User blog comment:D. Cello/Assassinews 10/11 -- Desmond's Ancestry Revealed/@comment-91.182.19.112-20111013185115/@comment-4043223-20111013190355

it is done through the technology of Those Who Came Before. They didn't need to be related for it to work. Also remember that the animus was an offshoot of this original technology and not nearly as advanced as the original.