Suppose you are studying a population of herbivores. The traditional food source for these herbivores is a small native plant species. In the last 200 years, the traditional food source of these herbivores was replaced by an invasive grass. The herbivores gained 5 calories of food from every 1 minute of grazing on the native plant, but gain only 3 calories of food from every 1 minute of grazing on the invasive grass. If you compared the current population of herbivores to the historical populations 200 years ago, which change would you be least likely to observe?
A) An increase in coprophagy
B) A decrease in the overall length of the digestive tract
C) An increase in bacterial symbionts associated with digestion
D) An increased ability to acclimatize to different food sources

Question

Quizplus · Accepted Answer

A decrease in the overall length of the digestive tract would be least likely because the herbivores would need to adapt to a less calorically dense food source, which typically requires a longer digestive tract to extract sufficient nutrients.

Suppose You Are Studying a Population of Herbivores