as ian ▁gen etic ▁markers ▁in ▁Ama z onia ▁supports ▁the ▁coast al ▁route ▁hypothesis . ▁ ▁Hol oc ene ▁migr ations ▁ ▁The ▁Hol oc ene ▁is ▁taken ▁to ▁begin ▁ 1 2 , 0 0 0 ▁years ▁ago , ▁after ▁the ▁end ▁of ▁the ▁Last ▁Gla cial ▁Max imum . ▁During ▁the ▁Hol oc ene ▁clim atic ▁optim um , ▁beginning ▁about ▁ 9 , 0 0 0 ▁years ▁ago , ▁human ▁populations ▁which ▁had ▁been ▁ge ograph ically ▁conf ined ▁to ▁ref ug ia ▁began ▁to ▁migr ate . ▁By ▁this ▁time , ▁most ▁parts ▁of ▁the ▁glo be ▁had ▁been ▁settled ▁by ▁H . ▁s api ens ; ▁however , ▁large ▁areas ▁that ▁had ▁been ▁covered ▁by ▁gla ci ers ▁were ▁now ▁re - pop ulated . ▁ ▁This ▁period ▁sees ▁the ▁transition ▁from ▁the ▁Mes ol ith ic ▁to ▁the ▁Ne ol ith ic ▁stage ▁throughout ▁the ▁temper ate ▁zone . ▁The ▁Ne ol ith ic ▁subsequently ▁gives ▁way ▁to ▁the ▁Bron ze ▁Age ▁in ▁Old ▁World ▁cult ures ▁and ▁the ▁grad ual ▁emer gence ▁of ▁the ▁historical ▁record ▁in ▁the ▁Near ▁East ▁and ▁China ▁beginning ▁around ▁ 4 , 0 0 0 ▁years ▁ago . ▁ ▁Lar ge - scale ▁migr ations ▁of ▁the ▁Mes ol ith ic ▁to ▁Ne ol ith ic ▁era ▁are ▁thought ▁to ▁have ▁given ▁rise ▁to ▁the ▁pre - mod ern ▁distribution ▁of ▁the ▁world ' s ▁major ▁language ▁families ▁such ▁as ▁the ▁Niger - C ongo , ▁N ilo - S