摘要
Optimization models developed within evolutionary ecology provide a useful framework for analyzing patterns of acceptance and utilization of new crops by food-producing populations. The deterministic version of the diet choice model predicts that new crops of relatively low profitability are likely to enter the diet if highly ranked resources are in short supply, but will be ignored if such items are abundant. A stochastic version of the same model (the “zscore” model) predicts adoption when the chance of energetic shortfall is very low and addition of new foods (even if they are of poor quality) may minimize risk by reducing variance in yields. Similar environments may consequently elicit strikingly different responses to new resources depending on which goal (e.g., risk minimization or efficiency maximization) guides decision-making. A case study, the introduction of the peach to eastern North America, illustrates how these models might be enlisted to develop and evaluate adaptation-based explanations of crop adoption. The opportunity cost model is used to predict optimal time allocation to different tasks as a function of the relationship between rising opportunity costs and diminishing returns. Manipulation of the model suggests that high opportunity costs may have limited investment in maize production following the initial introduction of this crop to eastern North America. Both increased productivity of maize and improvement in labor efficiency are likely causes of its eventual establishment as an economic staple. These findings illustrate the heuristic value of evolutionary ecology models as tools for investigating the origins and development of agricultural systems, including the diffusion of specific crops.