▁County ): ▁controvers ial ly ▁dated ▁at ▁ 1 3 9 , 0 0 0 – 1 1 1 , 0 0 0 ▁years ▁ago ▁). ▁D ating ▁results ▁of ▁the ▁L un ad ong ▁( B ub ing ▁Bas in , ▁Gu ang xi , ▁southern ▁China ) ▁teeth , ▁which ▁include ▁a ▁right ▁upper ▁second ▁mol ar ▁and ▁a ▁left ▁lower ▁second ▁mol ar , ▁indicate ▁that ▁the ▁mol ars ▁may ▁be ▁as ▁old ▁as ▁ 1 2 6 , 0 0 0 ▁years . ▁Since ▁these ▁previous ▁ex its ▁from ▁Africa ▁did ▁not ▁leave ▁traces ▁in ▁the ▁results ▁of ▁gen etic ▁anal ys es ▁based ▁on ▁the ▁Y ▁chrom os ome ▁and ▁on ▁M t D NA ▁( which ▁represent ▁only ▁a ▁small ▁part ▁of ▁the ▁human ▁gen etic ▁material ), ▁it ▁seems ▁that ▁those ▁modern ▁humans ▁did ▁not ▁surv ive ▁in ▁large ▁numbers ▁and ▁were ▁assim il ated ▁by ▁our ▁major ▁ante cess ors . ▁An ▁explanation ▁for ▁their ▁ext inction ▁( or ▁small ▁gen etic ▁im print ) ▁may ▁be ▁the ▁T oba ▁er u ption ▁( 7 4 , 0 0 0 ▁years ▁ago ), ▁though ▁some ▁argue ▁it ▁scarcely ▁impact ed ▁human ▁population . ▁ ▁An ▁Asia ▁center ▁of ▁origin ▁and ▁dispers al ▁for ▁the ▁m t D NA ▁ha p lo group ▁L 3 ▁has ▁also ▁been ▁hypoth es ized ▁based ▁on ▁the ▁foss il ▁record , ▁the ▁similar ▁co ales c ence ▁dates ▁of ▁L 3 ▁and ▁its ▁E uras ian - dist ributed