9421643 Futuyma This project will use a group of closely related, specialized leaf beetles to study genetic constraints on the capacity to adapt to new host plants. Research combining genetic analyses of the relationship among insect populations will be combined with selection experiments where leaf beetles are "forced" to adapt to new hosts. These experiments will determine if genetic change occurs that reduces the adaptation of the experimental beetles to their normal host. The experiments will test the leading hypothesis of host specialization - that trade-offs occur in adaptation to different resources. This hypothesis is an important component of explanations concerning species divergence and the origins of biological diversity. Agricultural insect pests frequently adapt to crops that are related to their wild plant hosts, and to pest-resistant cultivars that are developed at considerable expense. This research will aid in understanding what kinds of plants an insect species can or can not adapt to. Answers will aid in the development of pest-control strategies such as determining the kinds of genes that can be engineered from wild into cultivated plants or the use of economically unimportant "trap" crops to prevent potential pests from adapting to valuable crops.
