Paul Sidwell (2009) However,
Ilia Peiros (2011) criticized Sidwell's 2009 riverine dispersal hypothesis heavily and claimed many contradictions. He showed with his analysis that the homeland of Austroasiatic is somewhere near the
Yangtze. He suggests the
Sichuan Basin as likely homeland of proto-Austroasiatic before they migrated to other parts of central and southern China and then into Southeast Asia. He further suggests that the family must be as old as proto-Austronesian and proto-Sino-Tibetan or even older.
George van Driem (2011) proposed that the homeland of Austroasiatic was in the
Brahmaputra basin. He further suggested, based on genetic studies, that the migration of
Kra–Dai people from Taiwan replaced the original Austroasiatic language but the effect on the people was only minor. Local Austroasiatic speakers adopted Kra-Dai languages and partially their culture.
Laurent Sagart (2011) and
Peter Bellwood (2013) supported the theory of an origin of Austroasiatic along the
Yangtze river in southern China. Genetic and linguistic research in 2015 about ancient people in East Asia suggest an origin and homeland of Austroasiatic in today
southern China or even further north. Integrating computational phylogenetic linguistics with recent archaeological findings, Paul Sidwell (2015) further expanded his Mekong riverine hypothesis by proposing that Austroasiatic had ultimately expanded into
Indochina from the
Lingnan area of
southern China, with the subsequent Mekong riverine dispersal taking place after the initial arrival of Neolithic farmers from southern China. He tentatively suggests that Austroasiatic may have begun to split up 5,000 years B.P. during the
Neolithic transition era of
mainland Southeast Asia, with all the major branches of Austroasiatic formed by 4,000 B.P. Austroasiatic would have had two possible dispersal routes from the western periphery of the
Pearl River watershed of
Lingnan, which would have been either a coastal route down the coast of Vietnam, or downstream through the
Mekong River via
Yunnan. considers the Austroasiatic language family to have rapidly diversified around 4,000 years B.P. during the arrival of rice agriculture in Indochina, but notes that the origin of Proto-Austroasiatic itself is older than that date. The lexicon of Proto-Austroasiatic can be divided into an early and late stratum. The early stratum consists of basic lexicon including body parts, animal names, natural features, and pronouns, while the names of cultural items (agriculture terms and words for cultural artifacts, which are reconstructable in Proto-Austroasiatic) form part of the later stratum.
Roger Blench (2018) suggests that vocabulary related to aquatic subsistence strategies (such as boats, waterways, river fauna, and fish capture techniques) can be reconstructed for Proto-Austroasiatic. Blench (2018) finds widespread Austroasiatic roots for 'river, valley', 'boat', 'fish', 'catfish sp.', 'eel', 'prawn', 'shrimp' (Central Austroasiatic), 'crab', 'tortoise', 'turtle', 'otter', 'crocodile', 'heron, fishing bird', and '
fish trap'. Archaeological evidence for the presence of agriculture in northern
Indochina (northern Vietnam, Laos, and other nearby areas) dates back to only about 4,000 years B.P. (2,000 B.C.), with agriculture ultimately being introduced from further up to the north in the Yangtze valley where it has been dated to 6,000 B.P. proposes that the locus of Proto-Austroasiatic was in the
Red River Delta area about 4,000-4,500 years before present. Austroasiatic dispersed coastal maritime routes and also upstream through river valleys. Khmuic, Palaungic, and Khasic resulted from a westward dispersal that ultimately came from the
Red River valley. Based on their current distributions, about half of all Austroasiatic branches (including Nicobaric and Munda) can be traced to coastal maritime dispersals. ==References==