, 0 0 0 ▁years ▁ago , ▁so ▁that ▁by ▁the ▁beginning ▁of ▁the ▁M IS ▁ 5 ▁" m eg adr ought ", ▁ 1 3 0 , 0 0 0 ▁years ▁ago , ▁there ▁were ▁two ▁ancest ral ▁population ▁clusters ▁in ▁Africa , ▁bear ers ▁of ▁m t - D NA ▁ha p lo group ▁L 0 ▁in ▁southern ▁Africa , ▁ancest ral ▁to ▁the ▁K ho i - San , ▁and ▁bear ers ▁of ▁ha p lo group ▁L 1 - 6 ▁in ▁central / e astern ▁Africa , ▁ancest ral ▁to ▁everyone ▁else . ▁There ▁was ▁a ▁significant ▁back - m igration ▁of ▁bear ers ▁of ▁L 0 ▁towards ▁eastern ▁Africa ▁between ▁ 1 2 0 ▁and ▁ 7 5 ▁k ya . ▁ ▁Exp ansion ▁to ▁Central ▁Africa ▁by ▁the ▁ancest ors ▁of ▁the ▁Central ▁African ▁for ager ▁populations ▁( A fr ican ▁P yg m ies ) ▁most ▁likely ▁took ▁place ▁before ▁ 1 3 0 , 0 0 0 ▁years ▁ago , ▁and ▁certainly ▁before ▁ 6 0 , 0 0 0 ▁years ▁ago . ▁ ▁The ▁situation ▁in ▁West ▁Africa ▁is ▁difficult ▁to ▁interpret ▁due ▁to ▁a ▁sp ars ity ▁of ▁foss il ▁evidence . ▁H omo ▁s api ens ▁seems ▁to ▁have ▁reached ▁the ▁western ▁Sah elian ▁zone ▁by ▁ 1 3 0 ▁k ya , ▁while ▁tropical ▁West ▁African ▁sites ▁associated ▁with ▁H . ▁s api ens ▁are ▁known ▁only ▁from ▁after ▁ 1 3 0 ▁k ya . ▁Un like ▁elsewhere ▁in