3 , 5 0 0 ▁years ▁ago . ▁They ▁occur ▁at ▁very ▁high ▁frequencies ▁among ▁East ▁Asian ▁populations ▁in ▁contrast ▁to ▁other ▁E uras ian ▁populations ▁( e . g . ▁European ▁and ▁South ▁Asian ▁populations ). ▁The ▁find ings ▁also ▁suggests ▁that ▁this ▁Ne ander th al ▁intro gression ▁occurred ▁within ▁the ▁ancest ral ▁population ▁shared ▁by ▁East ▁A si ans ▁and ▁Native ▁Americans . ▁ ▁A ▁ 2 0 1 6 ▁study ▁presented ▁an ▁analysis ▁of ▁the ▁population ▁gen et ics ▁of ▁the ▁A inu ▁people ▁of ▁northern ▁Japan ▁as ▁key ▁to ▁the ▁reconst ruction ▁of ▁the ▁early ▁pe op ling ▁of ▁East ▁Asia . ▁The ▁A inu ▁were ▁found ▁to ▁represent ▁a ▁more ▁bas al ▁branch ▁than ▁the ▁modern ▁far ming ▁populations ▁of ▁East ▁Asia , ▁suggesting ▁an ▁ancient ▁( pre - Ne ol ith ic ) ▁connection ▁with ▁n ortheast ▁Si ber ians . ▁A ▁ 2 0 1 3 ▁study ▁associated ▁several ▁phen ot yp ical ▁tra its ▁associated ▁with ▁Mong ol oid s ▁with ▁a ▁single ▁mut ation ▁of ▁the ▁ED AR ▁gene , ▁dated ▁to ▁c . ▁ 3 5 , 0 0 0 ▁years ▁ago . ▁ ▁M ito ch ond rial ▁ha p lo groups ▁A , ▁B ▁and ▁G ▁origin ated ▁about ▁ 5 0 , 0 0 0 ▁years ▁ago , ▁and ▁bear ers ▁subsequently ▁colon ized ▁Si ber ia , ▁Korea ▁and ▁Japan , ▁by ▁about ▁ 3 5 , 0 0 0 ▁years ▁ago . ▁Part s ▁of ▁these ▁populations