Summarize Argument: Phenomenon-Hypothesis
The author concludes that tent caterpillars engage in communal foraging. This is because tent caterpillars mark their routes to food with pheromones, and moreover mark routes to food more heavily than roots that don’t lead to food.
Notable Assumptions
The author assumes that tent caterpillars are attempting to convey information to one another by marking their trails, and that other caterpillars can pick up on such markings. If tent caterpillars don’t sense pheromones, then these trails would be useless.
A
A hungry tent caterpillar is more likely to follow heavily marked routes than lightly marked routes.
Hungry tent caterpillars know which routes to follow to food. This means tent caterpillars can indeed pick up on pheromones, and moreover know what heavily marked trails signify.
B
Tent caterpillars can detect the presence but not the concentration of pheromones.
If tent caterpillars can’t detect the concentration of pheromones, then the author’s claim about heavily marked paths is useless. This weakens the argument.
C
Sometimes individual tent caterpillars will not return to the nest until a food source is located.
This is irrelevant. The paths these tent caterpillars make would nevertheless lead to food.
D
The pheromones left by tent caterpillars are different from the pheromones left by other animals.
We don’t even know if tent caterpillars can sense pheromones.
E
The pheromones that tent caterpillars leave behind are detectable by certain other species of caterpillars.
We need to know if tent caterpillars can detect pheromones themselves. We don’t care what other caterpillars can do.