#13 - Tent caterpillars' routes between their nests and

[Administrator]

Complete Question Explanation

Strengthen. The correct answer choice is (A)

Here the author tells us that caterpillars mark their routes, most heavily when they lead to food
sources. From this information the author concludes that tent caterpillars engage in communal
foraging, i.e. that they help each other find food. The argument assumes, however, that routes
between food sources and the nest would be marked more heavily for the purpose of conveying that
information to other caterpillars.

This is a questionable assumption. What if tent caterpillars have a different purpose for marking the
helpful routes more heavily (a “reminder to self” perhaps)? Alternatively, what if a hungry caterpillar
is unable to differentiate between heavily marked and lightly marked routes, or is less likely to
follow the heavily marked routes? For the conclusion to be strengthened, the correct answer choice
must establish a stronger connection between the likelihood of following a heavily marked route and
the purpose of communal foraging.

Answer choice (A): This is the correct answer choice. If a hungry caterpillar is more likely to
follow heavily marked routes than lightly marked routes, this would support the observation that the
purpose of marking certain routes more heavily is to help other members of the colony find food.
Because answer choice (A) lends support to the author’s argument that the caterpillars’ helpful trails
reflect communal foraging, it is the correct answer choice.

Answer choice (B): This is the Opposite answer. If tent caterpillars cannot detect the concentration
of pheromones, then it is unlikely that they would be able to differentiate between a heavily marked
route and a mere exploratory route. This answer choice suggests that marking some routes more
heavily than others would not help other caterpillars find food, weakening the argument that tent
caterpillars engage in communal foraging.

Answer choice (C): This answer choice does not help explain why some routes are marked more
heavily than others, and therefore cannot strengthen the causal relationship in the conclusion.

Answer choice (D): If tent caterpillars leave pheromones that are unique, this may explain why they
can differentiate between their own routes and the routes marked by other animals. The issue we
need to address, however, is whether tent caterpillars can differentiate between heavily marked routes
and lightly marked routes for the purposes of finding food.

Answer choice (E): Whether the pheromones left by tent caterpillars can be detected by certain
other species of caterpillars has no bearing on the question of whether tent caterpillars engage in
communal foraging. This observation might even weaken the argument, if we presume that the
detection of pheromones by other species would increase competition for food and decrease the tent
caterpillars’ ability to find food.

[afinelli]

Any info on why A is the right answer to this question? I didn't like any of the answer choices...and went for D.
Thanks!

[Steve Stein]

Here the author tells us that caterpillars mark their routes, most heavily when they lead to food sources. From this information the author concludes that caterpillars are doing this for the good of the other caterpillars.

So, which answer choice strengthens this argument? Correct answer choice A tells us that hungry caterpillars are more likely to follow these heavily marked routes, lending support to the author's argument that the caterpillars' helpful trails reflect communal foraging.

[afinelli]

Thanks!

[MBG13]

Choice A still does not make sense to me. I don't see how this strengthens the stimulus even a little bit.

[Nikki Siclunov]

Hi MBG13,

Thanks for your question. Let's unpack this argument a bit more carefully:

The author tells us that caterpillars mark their routes, most heavily when they lead to food sources. From this information the author concludes that tent caterpillars engage in communal foraging, i.e. that they help each other find food. Because the conclusion explains a certain phenomenon, it can be said to provide a cause for that phenomenon. In other words, the argument assumes that routes between food sources and the nest would be marked more heavily for the purpose of conveying that information to other caterpillars:

• Cause Effect
  
  Communal foraging Marked routes

This is a questionable assumption. What if tent caterpillars have a different purpose for marking the helpful routes more heavily (a “reminder to self” perhaps)? Alternatively, what if a hungry caterpillar is unable to differentiate between heavily marked and lightly marked routes, or is less likely to follow the heavily marked routes? For the conclusion to be strengthened, the correct answer choice must establish a stronger causal connection between the likelihood of following a heavily marked route and the purpose of communal foraging.

Answer choice (A): This is the correct answer choice. If a hungry caterpillar is more likely to follow heavily marked routes than lightly marked routes, this would support the observation that the purpose of marking certain routes more heavily is to help other members of the colony find food. Because answer choice (A) lends support to the author’s argument that the caterpillars’ helpful trails reflect communal foraging, it is the correct answer choice.

Answer choice (B): This is the Opposite answer. If tent caterpillars cannot detect the concentration of pheromones, then it is unlikely that they would be able to differentiate between a heavily marked route and a mere exploratory route. This answer choice suggests that marking some routes more heavily than others would not help other caterpillars find food, weakening the argument that tent caterpillars engage in communal foraging.

Answer choice (C): This answer choice does not help explain why some routes are marked more heavily than others, and therefore cannot strengthen the causal relationship in the conclusion.

Answer choice (D): If tent caterpillars leave pheromones that are unique, this may explain why they can differentiate between their own routes and the routes marked by other animals. The issue we need to address, however, is whether tent caterpillars can differentiate between heavily marked routes and lightly marked routes for the purposes of finding food.

Answer choice (E): Whether the pheromones left by tent caterpillars can be detected by certain other species of caterpillars has no bearing on the question of whether tent caterpillars engage in communal foraging. This observation might even weaken the argument, if we presume that the detection of pheromones by other species would increase competition for food and decrease the tent caterpillars’ ability to find food.

Hope this helps! Let me know if you have any follow-up questions.

Thanks,

[MBG13]

Wow! Yes I totally see that now! Thanks!

[Lsat_student2019]

Hi, I was a bit confused by this. I see now why A is correct, but in selecting D i thought it strengthened the argument. This is because if the pheromones left by caterpillars were not different than the pheromones left by other animals, then maybe the heavily marked routes were the result of other animals doing, or that the paths were popular to the food source for other animals as well. In stating that it is unique to caterpillars, i thought this strengthened the argument by proving that the increased amount of pheromones observed were from the caterpillars. Could you explain please? Thank you!!

[James Finch]

Hi LSAT student,

The stimulus deals with a portion of this in the first sentence where it notes that the caterpillars leave behind pheromones. Moreover, the scope of the second sentence tells us that the we're specifically talking about routes used and marked by the caterpillars. So we can infer from these two sentences that the caterpillars are in fact the animals leaving the pheromones behind.

The real key in a Strengthen question is to notice where the logical gap is, especially when there isn't clear causal reasoning. In this question, we need to tie the purported cause (communal foraging) to the effect of leaving the pheromones behind. (A) helps to connect the premises by making it more likely that the pheromones are leading other caterpillars to food, which is essentially communal foraging.

Hope this helps!

[PresidentLSAT]

D is still a struggle for me to rule out. Is it because the answer choice doesn't go far enough to explain how this difference impacts the behaviors of the caterpillars?

With A, am I to assume the heavily marked route is how they communicate which signals there is food?