Chiefdoms developed along the southern Mexican Gulf Coast during the Early, Middle, Late, and Terminal Formative periods (1400-1000 BC, 1000-400 BC, 400 BC-AD 100, and AD 100-300). Scholars interested in regional political economy for this area have long relied on archaeological data from three large sites: San Lorenzo, La Venta, and Tres Zapotes. This focus on large centers to the exclusion of smaller, outlying villages and hamlets has limited our understanding of regional political development. Scholars have also relied heavily on assumptions about regional subsistence economy, for example, that agricultural tribute was used to fund labor projects and feed the elite. Such assumptions, however, are based on little actual subsistence data. We can begin to elucidate the nature and development of Formative agriculture by shifting our attention to rural villages and hamlets and to issues of basic subsistence reconstruction.

Here I consider agricultural intensification and risk in the tropical lowlands of the Olmec hinterland during a period of political formation. To address the relationship between the development of agriculture and the emergence of complex political formations (e.g., chiefdoms and states), I consider subsistence data from two sites spanning the Formative period: La Joya and Bezuapan, located in the Sierra de los Tuxtlas approximately 100 km from the lowland Olmec centers.

The Tuxtla region is well suited for exploring this relationship. Settlement data from the region indicate that Early Formative groups were egalitarian and semi-sedentary (Arnold 2000; McCormack 2002; Santley et al. 1997). By the Middle Formative period, people had settled into more permanent villages, maintaining a relatively egalitarian social organization (Arnold 2000; McCormack 2002; Santley et al. 1997). The subsequent Late and Terminal Formative periods were marked by the emergence of a regional site hierarchy and increasing social differentiation, though the manifestation of social inequality in the Tuxtlas was not as pronounced as among lowland Olmec groups (Santley et al. 1997; Stark and Arnold 1997a). Thus, analysis of the available subsistence data makes it possible to consider farming strategies as they developed alongside sedentism and chiefdom formation.

In order to understand an agricultural system, we need to understand the subsistence system as a whole. This requires that we answer basic questions regarding local and regional subsistence practices. What foods were people eating? To what extent did people rely on domesticated versus wild foods and how did this vary through time? Did people narrow or diversify their resource base through time? How varied were subsistence practices through time and across space? How predictable were plant and animal resources throughout the region? How did volcanic eruptions affect the distribution and predictability of these resources? Once these basic questions are answered, we can begin to address more complex questions linking subsistence to regional politics. What is the nature of the Formative subsistence system along the southern Gulf Coast of Mexico? Did Formative villagers intensify their agricultural systems? If so, what was the timing of the agricultural intensification relative to political development in the region? What strategies of intensification did they choose and what were the consequences of these strategies for subsistence economy, household organization, and local and regional political development? How did regional environmental catastrophe in the form of volcanic eruptions and ashfall affect the way Formative people made a living?

Addressing these questions requires multiple lines of evidence that are directly relevant to the reconstruction of subsistence economy. I consider archaeobotanical, zooarchaeological, and stable carbon and nitrogen isotopic data from La Joya and Bezuapan. Although these types of subsistence data are rarely considered together in the general literature, they bear directly on the research questions, as they represent the direct residues of past subsistence economies. The integration of these three kinds of subsistence data allows for a fuller understanding of Formative subsistence than would otherwise be possible.

Before I consider these data, it is important to provide the background necessary for understanding and interpreting them. Chapter 2 presents some theoretical background on the origins of agriculture. In covering this monumental topic, I focus on four major issues: the process of early plant domestication, the connection between incipient agriculture and early social complexity, the process of agricultural intensification, and strategies of risk management. Although my case study does not directly address domestication, many of the arguments put forth to explain the process of agricultural intensification have their roots in discussions of the initial process of plant domestication.

Chapter 3 presents an overview of Olmec research as it pertains to farming and political complexity. The history of the Olmec problem is particularly relevant because previous studies have set the stage for the research questions pursued here. Few subsistence studies have been conducted in the region, which has long hampered our understanding of Gulf Formative agricultural systems—this is one reason why the data presented here are so crucial. Chapter 3 also provides the environmental and archaeological background for the Tuxtlas, the region in which the study sites are located. This chapter constructs a foundation for understanding subsistence adaptations in the Tuxtlas, a foundation that is necessary for proper interpretation of the archaeological data.

The second part of the book involves the presentation and analysis of the data. These are the chapters in which I discuss specific archaeological correlates for answering the larger questions posed above. Chapters 4 and 5 consider the archaeobotanical and zooarchaeological assemblages, respectively. Both chapters consider temporal trends in these data, in addition to dealing with preservation and recovery biases, field recovery techniques, field and laboratory sampling, laboratory procedures and identification, and quantification for the subsistence data. Chapter 6 presents stable carbon and nitrogen isotopes for human, domestic dog, and white-tailed deer skeletal specimens. Indeed, it is only through the analysis of multiple kinds of subsistence data that we can begin to truly understand prehistoric systems of agriculture. Finally, in Chapter 7 I tie the analyses together and relate them to the larger research questions stated above.