The role of agriculture in the evolution of Southeast Asian language phyla

The emergence of mainland Southeast Asian (MSEA) nations from decades of war and the gradual opening up of individual countries has created a new focus on the region. Southeast Asia presents an intriguing mix, combining highly diverse ethnolinguistic groups with generally small populations, and more numerous peoples, such as the Thai, Burmese, Lao, Vietnamese and Khmer, who cover significant swathes of territory and are politically dominant. Historically the vast majority of languages of Southeast Asia were unwritten and remain poorly described, but the existence of scripts has created something of a focus on texts. Recent years have seen the emergence of much new data, often quite difficult to access; nonetheless, the linguistic map is gradually becoming clearer, although many questions remain. There are five major language phyla in mainland Southeast Asia, Austroasiatic, Austronesian, Daic, Sino-Tibetan and Hmong-Mien and no true isolates, except on offshore islands. Despite a considerable expansion of research in recent years, models for the dates, homelands and engines of expansion of these phyla are markedly absent from the literature, as are convincing correlations with archaeological and genetic research. A claim that has generated considerable discussion in recent years is the importance of agriculture and thus demographic expansion in accounting for ethnolinguistic geography. The chapter considers whether the reconstruction of agricultural terminology in individual language phyla supports this claim, and if so, what can be said about the dating of individual phyla. Since Austroasiatic is discussed at greater length elsewhere in this volume (for example, Diffloth, Sidwell and Blench) its treatment will be abbreviated here.