The Origins of Agriculture in the Lowland Neotropics (review)

In the last 20 years, archeologists have undertaken considerable research into the paleoecology of the American tropics. New methods have not only provided new answers to old questions but also raised new questions. This book attempts to synthesize the information and inferences flowing from that research, focusing on the emergence of agriculture in the lands between southern Mexico and southern Amazonia below 1,200 meters elevation. It surveys the period from the first human occupation until about two thousand years ago, by which time the authors believe the basic patterns of slash-and-burn agriculture in the tropics had been set.

Their approach is deeply informed by evolutionary biology and behavioral ecology. They discard hypotheses about the origins of agriculture in the Americas based on population pressure (wisely) and on social change, believing that climate change—the end of the last glaciation—played a larger role than any other physical factor. In the end they explain the emergence of agriculture as "driven by changing selection pressures on hunter-gatherer resource procurement and, ultimately, their search for successful adaptations in changing environments" (p. 18).

After a most useful introduction, the book is arranged into four main chapters. The first covers the ecology and paleoecology of the American tropics, focusing on the potential to support human life. Next comes a detailed treatment of dozens of tropical food crops and their wild ancestors. They then offer a careful consideration of the first human settlement of these regions, the environmental modifications that resulted, and the transition (or perhaps transitions) to food production before seven thousand years ago. A long chapter reviews the spread and evolution of agriculture over the next five millennia, and the brief conclusion compares the American case to the emergence of agriculture in other parts of the world, mainly southwest Asia (where the scholarly literature is most sophisticated and abundant).

Their principal conclusion is that agriculture in the Americas originated gradually as small-scale horticulture between ten and eight thousand years ago, and that by seven thousand years ago slash-and-burn cultivation had emerged. This makes the American origins of agriculture every bit as ancient as in southwest Asia. Further, the authors are convinced that American agriculture began in the lowland tropical forests, not in highland Mexico or Peru. This latter argument supports the inferences made 30 years ago (without much evidence) by anthropologist Donald Lathrop. Piperno and Pearsall, for their part, have plenty of evidence.

The book is handsomely illustrated and features a complete scholarly apparatus. The language is that of botany, biology, and environmental archeology, which at times proved rough sledding for a humble historian. The level of detail exceeds greatly that which most readers of the HAHR will want, but the conclusions are important for anyone interested in the origins of agriculture in the Americas.