First Farmers: The Origins of Agricultural Societies
(2005) is a multidisciplinary historical study by British academic Peter Bellwood, Emeritus Professor of Archaeology at the Australian National University. Drawing on research in archaeology, anthropology, linguistics, genetics, and the science of farming, Bellwood examines the earliest origins of agriculture in human societies. He argues that the spread of agriculture correlates with the spread of languages and material cultures, a position known as the “farming/language dispersal hypothesis.” Bellwood concludes that agriculture spread primarily through “demic diffusion,” that is, the migration of people, in most cases probably displacing hunter-gatherers.
Agriculture developed at several different “points of origin” around the globe, starting as early as the year 10,000 B.C. As it spread, farming revolutionized human societies, generating surplus food that could support larger, sedentary populations. The spread of agriculture ultimately led to the development of the first civilizations. A key question remains to be answered about this pre-historical revolution: How did agriculture spread?
Bellwood outlines two competing explanations. The first is “demic diffusion,” which argues that early agricultural societies expanded as they grew, displacing or absorbing their hunter-gatherer neighbors. The second is the “social interaction” model, which posits that hunter-gatherers acquired agricultural knowledge and skills through interaction with neighboring farmers. Bellwood proposes that these two alternatives should be seen as the two ends of a spectrum. The question then becomes: Where on the spectrum does the truth lie?
Bellwood argues that the best hope of answering this question lies in a comparative approach. He argues that by examining archaeological, linguistic, and genetic evidence, it is possible to identify a correlation between the spread of agriculture and the spread of both languages and material cultures. If this correlation holds, Bellwood argues, then it constitutes evidence for the “demic diffusion” model, because if something closer to the “social interaction” model were correct, we would expect to see a less direct correlation between the spread of farming and the spread of languages, cultures, and genes.
Before turning to the evidence for this theory, Bellwood outlines his “Operational Considerations,” including his comparative methodology, a working definition of agriculture, and some theories about the reasons for agriculture’s initial development.
First, Bellwood turns to anthropology, suggesting that modern encounters between hunter-gatherers and farmers may indicate how pre-historic hunter-gatherers might have responded to the appearance of agriculture among neighboring peoples. After a review of ethnographic studies, Bellwood concludes that hunter-gatherers rarely choose to adopt agriculture. While early encounters between the two types of society are usually mutually beneficial, any “interactive network” between them can only remain stable until the farmers’ numbers increase. At that point, the farmers require more land, and the hunter-gatherers must either migrate (displacing other hunter-gatherers), join the farmers as an “underclass,” or adopt agriculture themselves. The evidence suggests that hunter-gatherers typically become an underclass of indentured laborers. Nevertheless, the ethnographic record offers very few examples of “eager and successful” agricultural adoption by hunter-gatherers.
From here, Bellwood examines the archaeological evidence for the development and spread of agriculture in each region. He begins with the earliest evidence for agriculture, in Southwest Asia, before turning to its spread through Europe and Asia. Next, he considers the independent development of agriculture in East Asia and its spread into Oceania. He considers several different theories about the origins of agriculture in the Americas before turning to Africa and New Guinea.
In each area, Bellwood discusses evidence for the exact location of the first agricultural communities, and the possible reasons why farming developed in those places. He draws on scientific evidence relating to the domestication of plants and animals, and to climatic change. In each location, he then considers the spread of agriculture from its proposed origin.
Turning to linguistics, Bellwood provides an overview of the key linguistic concepts that enable linguistic evidence to serve as evidence for the history of agriculture. In particular, he discusses the evidence that demic diffusion and social interaction create different patterns of language development.
He proceeds to compare the spread of the major language families with the archaeological evidence for the spread of agriculture. He argues that the spread of each language family can be plausibly mapped onto the spread of agriculture through the relevant region. He goes on to argue for a similar correlation between the spread of languages and of material cultures.
Bellwood’s final set of data comes from genetics. He surveys the academic debate about genetic evidence from Southwest Asia and Europe, and from East Asia and Oceania. He concludes that the genetic evidence suggests a “middle-of-the-road” model in which demic diffusion is combined with the constant mixing of populations, as well as different migratory patterns for each sex.
In conclusion, Bellwood draws together the different strands of evidence he has examined. He argues that the correlation between cultural, linguistic, and genetic evidence at each location where agriculture originated suggests that agriculture spread primarily through demic diffusion. However, he suggests that this diffusion probably took place at “intervals,” with “often extremely long periods” in between. During these periods, some cultural interaction and population mixing took place.