Who were the early farmers?
Many traditional textbooks propose that the CurrentJapanese population can be divided into Jomon' type and ‘Yayoi' type people, and much physical anthropological research has gone into identifying these different populations and relating them to other peoples across Asia and the Pacific, work now supported by genetic evidence.[792] Temple and Larsen identify a number of impacts that agriculture has on the biology of many of the inhabitants of the archipelago, based on study of the skeletal remains of 400 Jomon and 521 Yayoi individuals.[793] The increasingly starchy diet, reflecting the consumption of carbohydrates such as sticky rice and yams and tubers, results in higher incidences of dental caries, notably during the late and final Jomon and into the Yayoi.
Evidence for nutritional stress, affecting for example the formation of dental enamel, decreases with the arrival of rice farming, probably related to the increasing predictability and stability of food supply afforded by rice farming, as against the seasonal availability of foods for much of the Jomon. As discussed above, episodes of natural disaster, including flooding, must have caused stress in different ways. Work in the field of ‘toilet archaeology' indicates that Jomon and Yayoi communities were equally affected by parasites, which must have thrived in the relatively densely packed settlements.[794] Infectious diseases may have affected Jomon and Yayoi populations differently. Temple and Larsen argue that while the frequency of infectious diseases may have fallen during the Yayoi period, the diversity of such diseases likely increased as a result of migration, with new illnesses such as tuberculosis being introduced from the continent.[795] While instances of such diseases fell during the first stages of farming in the Yayoi, chronic infection then increased once certain population thresholds were reached, and as agricultural practices intensified and political authority became more centralized. It will be interesting to see how such studies relate to the rise and fall of large communities such as Hie-Naka, and the population movements associated with port-of-trade types of settlement such as Nishijinmachi.Hudson defines agriculture on social criteria ‘as a socioeconomic system which is expansionary, exploitative, and is based on principles of social exclusion, and argues that the biological evidence for an influx of migrants at the start of the Yayoi period ‘is some of the best from anywhere in the prehistoric world'.[796] Estimates of population growth in the period from the end of the Jomon through to the first centuries of the first millennium ce suggest a possible increase from 75,000 to 5.4 million people, and an average annual population increase of over ι per cent.
Comparable approaches have been adopted in the study of the early development of the Japanese language.[797] It is thought that the mountainous topography of the archipelago fostered great linguistic diversity during the Jomon period, perhaps reflected in the diversity of Jomon pottery styles, although some Japanese archaeologists argue that Jomon peoples must have been able to communicate with each other. But this diversity did not survive the advent of farming. This is argued to have resulted from population movement associated with the expansion of farming - the farming peoples speaking Japonic, the prototype for modern Japanese - rather than the adoption of the new language by existing Jomon peoples.