Abstract
Despite the fact that small seeds are often inefficient to exploit, they are consumed and sometimes cultivated in many parts of the world, including eastern North America. Foraging models predict that seeds are likely to be utilized only if preferred resources become scarce, or if their own profitability is increased through processes such as domestication or technological innovation. Ethnographic, experimental, and nutritional studies of the small grains used prehistorically in eastern North America suggest that they offered low rates of return (measured as energy per unit time spent) compared to many alternative resources. These estimates rely on the assumption that some degree of post-harvest processing was required to make seed foods palatable and nutritious. That this assumption is reasonable is supported by archaeological and archaeobotanical evidence from rockshelters in eastern Kentucky. Resource stress and technological innovation are unlikely explanations for the adoption of such low-ranking resources in this region around 3500 B.P. However, estimation of return rates does not take account of the lowered significance of time costs in the winter season, when seed processing could take place with little competition from other productive tasks. The timing of the adoption of small seeds also reflects historical factors such as spatial distribution of plant populations and habitats.