Agricultural origins from the ground up: archaeological approaches to plant domestication.

The timing, geographical locations, causes, and consequences of crop domestication have long been major concerns of archaeologists, and agricultural origins and dispersals are currently more relevant than ever to scientists seeking solutions to elusive problems involving food insecurity and global health disparities. Perennial research issues that archaeologists continue to tackle include (1) thinking outside centers of origin that were based on limited and insufficient past knowledge; (2) distinguishing between single and multiple domestications of specific crops; (3) measuring the pace of domestication; and (4) decoupling domestication from agricultural economies. Paleoethnobotanists have expanded their toolkits to include analysis of ancient and modern DNA and have added increasingly sophisticated techniques in the field and the laboratory to derive precise chronological sequences to assess morphological changes in ancient and often fragmentary archaeobotanical remains and to correctly interpret taphonomy and context. Multiple lines of archaeological evidence are ideally brought together, and whenever possible, these are integrated with information from complementary sources. We discuss current perspectives and anthropological approaches to research that have as their goals the fuller and broader understanding of ancient farming societies, the plants that were domesticated, the landscapes that were created, and the culinary legacies that were passed on.

The diffusion of maize to the southwestern United States and its impact.

Our understanding of the initial period of agriculture in the southwestern United States has been transformed by recent discoveries that establish the presence of maize there by 2100 cal. B.C. (calibrated calendrical years before the Christian era) and document the processes by which it was integrated into local foraging economies. Here we review archaeological, paleoecological, linguistic, and genetic data to evaluate the hypothesis that Proto-Uto-Aztecan (PUA) farmers migrating from a homeland in Mesoamerica introduced maize agriculture to the region. We conclude that this hypothesis is untenable and that the available data indicate instead a Great Basin homeland for the PUA, the breakup of this speech community into northern and southern divisions approximately 6900 cal. B.C. and the dispersal of maize agriculture from Mesoamerica to the US Southwest via group-to-group diffusion across a Southern Uto-Aztecan linguistic continuum.

Growing the lost crops of eastern North America's original agricultural system.

Thousands of years before the maize-based agriculture practiced by many Native American societies in eastern North America at the time of contact with Europeans, there existed a unique crop system only known through archaeological evidence. There are no written or oral records of how these lost crops were cultivated, but several domesticated subspecies have been identified in the archaeological record. Growth experiments and observations of living progenitors of these crops can provide insights into the ancient agricultural system of eastern North America, the role of developmental plasticity in the process of domestication, and the creation and maintenance of diverse landraces under cultivation. In addition, experimental gardens are potent tools for public education, and can also be used to conserve remaining populations of lost crop progenitors and explore the possibility of re-domesticating these species.