your text discusses paul ewald's studies of how evolutionary trade-offs might have influenced the evolution of virulence in human pathogens. one thing your text did not mention is disease caused by food-borne pathogens such as salmonella, campylobacter, and escherichia coli o157:h7. in industrialized nations, fresh food is often shipped in bulk quantities for thousands of miles from where it is grown. this means that food-borne outbreaks can sicken large numbers of people, and also may force the costly recall of large amounts of contaminated food, over wide regions. this is a relatively recent development; for almost all of human history, fresh food had to be eaten close to where it was produced. apply ewald's ideas to food-borne diseases. can we make any predictions of future trends in virulence? are there steps we can take, specifically based on evolutionary biology, to decrease the incidence and severity of food-borne disease?