Also after multiple generations on the low-starch plants, female moths preferred to lay their eggs on these same plants. This, Behmer said, is one of the first instances of a moth showing egg-laying behavior that is tied to a plant's nutritional chemistry.
Moths from low-starch plants might avoid the high-starch plants because these plants might make their offspring obese, he explained. Female moths reared on the high-starch mutant for multiple generations showed no preference for either mutant.plant.
Inferences can be made to humans from this work, he said. Looking back over human history, even as recently as 100 years ago, the diets of western cultures have undergone some radical changes.
Like insects, humans require carbohydrates and proteins. But, Behmer said, humans are not well adapted to diets containing extremely high levels of carbohydrates.
"Historically we haven't always had a lot of access to carbohydrates," he said, "and one of the biggest sources of carbohydrate in our current food is refined sugar. Our bodies tend to convert most of this excess carbohydrate to fat."
However, Behmer said other factors, such as a lack of exercise, might also be to blame.