5. Bronze Age migrations

Around 4,200 BP, the rapidly changing global climate caused massive flooding and crop failures in southern China. Austroasiatic speakers migrated:

1. westward up into Yunnan and beyond into Myanmar and Northeast India (Northern Austroasiatic linkage)

2. southwest through the Annamite Range and around the Mekong River drainage basin (Eastern Austroasiatic linkage)

3. down the coast of Vietnam and into western Island Southeast Asia (Southern Austroasiatic linkage)

Hence, Proto-Austroasiatic itself did not originate in the Mekong River drainage basin, although later branches did use the Mekong River to disperse (see McColl 2018, et al.).