Matrilocality during the Prehistoric Transition to Agriculture in Thailand?
Bentley, R. Alexander, Pietrusewsky, Michael, Douglas, Michele T., Atkinson, Tim C., Antiquity
During separate Holocene events in Europe, Asia and the Americas, language, human genes and material culture seem to have spread with the practice of agriculture (e.g. Bellwood 2001; Diamond & Bellwood 2003; Renfrew 2000). In many areas of the world, agriculture appears to have spread through 'demic diffusion', that is, increases in population, and densities of population, that agriculture itself made possible (Ammerman & Cavalli-Sforza 1984), and languages and genetic similarity could also have spread through a similar demic process (Diamond & Bellwood 2003; Higham 1996; Renfrew 1987, 2000). But while demic diffusion may have predominated, it is equally important to assess the involvement, different for each place and time, of indigenous hunter-gatherers who adopted farming through contact with colonising farmers. For example in Neolithic Europe, indigenous adoption has been shown to have been substantial (e.g. Gronenborn 1999; Renfrew 2000; Price 2000; Zvelebil & Lillie 2000). The foragers and farmers may have exchanged raw materials and foods, but also marriage partners; the immigration of forager women into farming communities seems particularly likely (e.g. Bentley et al. 2003b; Cronk 1989; Spielmann & Eder 1994; Zvelebil & Lillie 2000). Intermarriage between indigenous and colonising groups, explicitly considered by Ammerman and Cavalli-Sforza in their 'wave of advance' model (1984: 82-84) has been subsequently somewhat under-emphasised in discussions of demic diffusion.
Although there is a good case for demic diffusion as a mechanism by which agriculture spread from southern China into Southeast Asia, c. 6500 BC to 1000 BC (Bellwood 2001; Higham 2002), it also appears likely that contact with indigenous groups took place and was significant. As Higham (2002: 110-11) points out, 'In reality, ... the situation between 2500-1500 BC was probably much more complex than the [demic diffusion] model might suggest at first sight. Any intrusive group entering Southeast Asia would have encountered long-established hunters and gatherers.' In contrast to the rapid transition from hunting and gathering to farming in Central Europe, many communities in prehistoric Southeast Asia appear to have had the knowledge of cultivation for centuries without practising it intensively. In Thailand, the transition, having begun at least by the late third millennium BC, from hunter-gathering to small, sedentary communities with animal husbandry and knowledge of domestic crops, did not lead to intensive rice agriculture until much later, c. 1000 BC. During this prolonged transition, local foraging groups may have influenced the development of farming (Bellwood 1996).
A productive area of research into the prehistoric spread of agriculture is human population genetics. Currently, most genetic samples come from modern living people, so the ancestries of the haplotypes (groups of genetic similarity) must be extrapolated backward through probabilistic means that, although mathematically sophisticated, are necessarily inexact. Nonetheless, a surprising amount of information about the past is extracted from modern gene distributions. One example is the characterisation of marital residence patterns by comparing geographic patterns of human mitochondrial (mt) DNA, which is passed through the female line, with those of male-transmitted Y-chromosomes (e.g. Seielstad et al. 1998). In Thailand, the geographic distribution of Y-chromosome haplotypes from modern populations suggests that the earliest farmers of Thailand were migrants from China (Tajima et al. 2002), whereas evidence from human mitochondrial (mt) DNA suggests that some Thai ethnic groups share ancient maternal ancestors (Fucharoen et al. 2001). Although these indications may seem contradictory, a possible explanation is that indigenous, pre-agricultural communities in Thailand had been matrilocal, such that male migrants married into their brides' indigenous communities. …