 The adage that your enemies know your weaknesses best is especially true in the case of plants and predators that have CO- EVOLVED: As the predators evolve new strategies for attack, plants counter with their own unique defenses. Milkweed is the latest example of this response,research suggests that plant may be shifting away from elaborate defenses against specialized caterpillars,instead  putting more effort into repairing themselves faster than caterpillars can eat them.
“An important question with co-evolution is where does it end?” said Anurag Agrawal, Cornell associate professor of ecology and evolutionary biology and lead author of a paper in the current issue of the Proceedings of the National Academy of Sciences. “One answer is when it becomes too costly. Some plants seem to have shifted away from resisting herbivory [plant eating] and have taken that same energy and used it to repair themselves.”The paper is important because it sheds light on key theories of co-evolution,